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Evidence of lifestyle interventions in a pregnant population with chronic hypertension and/or pre-existing diabetes: A systematic review and narrative synthesis.
Goddard, L, Patel, R, Astbury, NM, Tucker, K, McManus, RJ
Pregnancy hypertension. 2023;31:60-72
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Chronic hypertension complicates ≤5 % of pregnancies, and those entering pregnancy with a pre-existing diagnosis of diabetes has a global prevalence of between 0.5 % and 2.6 %. The aim of this study was to collate the evidence around lifestyle interventions during pregnancy for women with chronic hypertension and/or pre-existing diabetes (type 1 and type 2). This study is a systematic review and meta-analysis of nine randomised controlled trials. Results show lack of clarity and data on the effect of lifestyle interventions in pregnant women with chronic hypertension and/or pre-existing diabetes, thereby exposing key gaps in the literature. Authors conclude that there is a shortage of primary interventional studies examining the effect of lifestyle interventions in high-risk pregnant populations who enter pregnancy with chronic conditions.
Abstract
BACKGROUND Pregnant people with chronic hypertension, pre-existing diabetes or both are at high risk of developing cardiovascular disease. Lifestyle interventions play an important role in disease management in non-pregnant populations. AIM: To review the existing evidence of randomised controlled trials (RCTs) that examine lifestyle interventions in pregnant people with chronic hypertension and/or pre-existing diabetes. METHODS A systematic review and narrative synthesis was conducted. Five electronic databases were searched from inception to April 2021 for RCTs evaluating antenatal lifestyle interventions in people with chronic hypertension and/or pre-existing diabetes with outcomes to include weight or blood pressure change. RESULTS Nine randomised controlled trials including 7438 pregnant women were eligible. Eight studies were mixed pregnant populations that included women with chronic hypertension and/or pre-existing diabetes. One study included only pregnant women with pre-existing diabetes. Intervention characteristics and procedures varied and targeted diet, physical activity and/or gestational weight. All studies reported weight and one study reported blood pressure change. Outcome data were frequently unavailable for the subset of women of interest, including subgroup data on important pregnancy and birth complications. Eligibility criteria were often ambiguous and baseline data on chronic hypertension was often omitted. CONCLUSION A lack of primary interventional trials examining the effect of lifestyle interventions on weight and blood pressure outcomes in pregnant populations with chronic hypertension and/or pre-existing diabetes was evident. Lifestyle modification has the potential to alter disease progression. Future trials should address the ambiguity and frequent exclusion of these important populations.
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Impact of energy density on energy intake in children and adults: a systematic review and meta-analysis of randomized controlled trials.
Klos, B, Cook, J, Crepaz, L, Weiland, A, Zipfel, S, Mack, I
European journal of nutrition. 2023;62(3):1059-1076
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Consumption of energy-dense food (ED) is a significant contributor to obesity and overweight. To manage weight, reducing portion size and ED of food is a critical strategy. This study conducted a systematic review and meta-analysis of thirty-eight randomised controlled trials to determine the effect of ED manipulation on energy intake. The results indicated that lower ED interventions were more effective than higher ED interventions in reducing energy intake. A positive linear relationship was observed between ED and energy intake, regardless of age, meal type, or intervention duration. The study findings can be used by healthcare professionals to understand the benefits of ED manipulation in weight management. However, further rigorous studies are necessary to validate these results.
Abstract
PURPOSE The energy density (ED) of a diet can be leveraged to prevent weight gain or treat overweight and obesity. By lowering the ED of the diet, energy intake can be reduced while maintaining portion size. However, a reliable meta-analysis of data from randomized controlled trials (RCTs) is missing. Therefore, this meta-analysis synthesized the evidence of ED manipulation on energy intake in RCTs. METHODS The systematic literature search of multiple databases according to PRISMA criteria considered RCTs investigating the objectively measured energy intake from meals with different ED (lower ED (median 1.1 kcal/g) versus higher ED (median 1.5 kcal/g)) under controlled conditions. Subgroup analyses for age (children versus adults), meal type (preload versus entrée design), and intervention length (1 meal versus > 1 meal) were performed to achieve the most homogeneous result. RESULTS The meta-analysis of 38 included studies demonstrated that lowering ED considerably reduced energy intake - 223 kcal (95% CI: - 259.7, - 186.0) in comparison to the higher ED interventions. As heterogeneity was high among studies, subgroup analyses were conducted. Heterogeneity decreased in subgroup analyses for age and meal type combined, strengthening the results. An extended analysis showed a positive linear relationship between ED and energy intake. Dietary ED did not affect the amount of food intake. CONCLUSION Manipulating ED substantially affects energy intake whereas food intake remains constant. Thus, this approach can be regarded as a powerful tool for weight management through nutrition therapy. Registration on 08/08/2021: CRD42021266653.
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Distribution of energy intake across the day and weight loss: A systematic review and meta-analysis.
Young, IE, Poobalan, A, Steinbeck, K, O'Connor, HT, Parker, HM
Obesity reviews : an official journal of the International Association for the Study of Obesity. 2023;24(3):e13537
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Obesity increases an individual's risk of metabolic disease, such as diabetes and cardiovascular disease, musculoskeletal disorders such as osteoarthritis, and some cancers. “Chrononutrition” relates to the timing of meals and distribution of total energy intake across the day. Evidence is building chrononutrition as a potential target in both weight loss and metabolic disease interventions. The aim of this study was to examine the impact of earlier versus later distribution of total daily energy intake on weight loss, and to evaluate the potential for utilizing altered energy distribution as a tool in weight loss interventions. This study is a systematic review and meta-analysis of nine clinical studies. Total number of participants was 485 (earlier distributed total energy intakes: n = 244, later distributed total energy intakes; n = 241). Results show that energy intakes with a focus on earlier distribution resulted in significantly greater weight loss when compared with similarly energy-restricted diets with individuals consuming a larger proportion of their total energy intake later in the day and into the evening. Authors conclude that earlier energy intakes may be a promising tool to be used in conjunction with other weight loss strategies such as energy restriction to enhance weight loss. However, further research is required to elucidate the additional positive impacts that earlier distributed total energy intakes may have on weight and metabolic health.
Expert Review
Conflicts of interest:
None
Take Home Message:
Implementing a dietary strategy where a higher proportion of energy is consumed earlier in the day may offer additional benefits to an energy restricted diet for weight loss, blood glucose, improve markers of insulin resistance, increase satiety and improve hunger management. Based on the findings, earlier distribution of energy intake may serve as an effective component of a weight loss protocol.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Background
Chrononutrition refers to the timing and distribution of total daily energy intake across the day. It has been proposed that consuming a greater proportion of total daily energy intake earlier in the day as opposed to the evening may be beneficial for weight loss and metabolic health.
Aims
This systematic review and meta-analysis aimed to assess the impact of earlier versus later distribution of total daily energy intake on weight loss.
Results
A total of 9 randomised controlled trials involving 485 participants were included in this analysis. The study durations ranged from 5-16 weeks. All of the studies included in this analysis applied energy-restricted diets to both intervention arms. The mean percentages of energy intake in 8 of the 9 studies per meal were:
- Earlier distributed intakes: breakfast: 34% ± 16%, lunch: 38% ± 7%, dinner: 20% ± 6%.
- Later distributed intakes: breakfast: 19% ± 6%, lunch: 30% ± 10%, dinner; 40% ± 11%.
One of the studies advised percentage of energy intakes as either:
- Earlier: 70% for breakfast, morning tea and lunch and 30% for afternoon tea and dinner
- Late: 55% for breakfast, morning tea and lunch and 45% for afternoon tea and dinner.
The earlier distributed energy intake groups demonstrated significantly greater weight loss when compared with later distributed energy intake groups ( Mean Difference (MD) −1.23 kg; 95% CI −2.40, −0.06, p = 0.04;
I2 = 98%).
The earlier energy intake groups also displayed lower fasting and bedtime glucose levels (fasting: −0.83 vs. −0.27 mmol/L, p = 0.001; before sleep: −1.70 vs. −0.28 mmol/L, p = 0.009).
A random-effects model demonstrated that the earlier intake groups displayed greater reductions in LDL (MD: −0.11 mmol/L; 95% CI −0.14, −0.07, p < 0.01), fasting glucose (MD: 0.15 mmol/L, 95% CI −0.23, −0.06, p < 0.001) and HOMA-IR (MD: −0.38; 95% CI −0.64, −0.11, p = 0.005).
One study reported that earlier distribution energy intake also led to a greater reduction in medications following the intervention for type 2 diabetics (31% vs. 0%, P=0.002).
Two of the studies assessed both appetite and hunger and identified that earlier distribution of energy led to improvements in their urge to eat, preoccupation with food and cravings for sweets and fats.
Clinical practice applications:
Earlier distribution of energy intake may be beneficial for:
- Weight loss
- Improve fasting insulin, HOMA-IR, fasting glucose and HbA1c
- Reducing LDL
- Improving satiety and hunger management
- Supporting the reduction of medications for individuals with type 2 diabetes
- Improving regularity of sleep and waking times
Considerations for future research:
As the included studies only ranged from 5-16 weeks, longer duration studies would be useful to identify the effect of earlier distribution of energy intake on body weight, metabolic health and appetite over a longer period of time. There was a high degree of heterogeneity between the studies and a lack of uniformity in the distributions of energy intake across the day. Further studies with more uniformity of energy distribution would be needed to identify the optimal distribution of energy across the day to improve body weight and metabolic health.
Abstract
Consuming a greater proportion of total energy intake earlier in the day rather than in the evening is proposed to positively influence weight loss and health, potentially due to greater synchronization of human body circadian rhythms. This systematic review provides an update on existing evidence regarding earlier distributed eating patterns in weight loss interventions. Using a robust search strategy in five electronic databases, nine randomized controlled trials investigating the impact of energy intake distribution on weight loss were identified. Following critical appraisal, a random-effects meta-analyses found that, in the context of an energy-reduced diet, distributing energy intake with a focus on earlier intake resulted in significantly greater weight loss (-1.23 kg; 95% CI 2.40, -0.06, p = 0.04). Improvements in HOMA-IR, fasting glucose, and LDL cholesterol were also seen. The current study provides a timely update on the evidence linking distribution of total daily energy intake and health, showing that a focus on earlier intakes can result in greater short-term weight loss compared with later intakes. Future studies are needed to elucidate the impact that earlier intakes may have on weight management and metabolic health.
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Effect of Targeted vs. Standard Fortification of Breast Milk on Growth and Development of Preterm Infants (≤32 Weeks): Results from an Interrupted Randomized Controlled Trial.
Seliga-Siwecka, J, Fiałkowska, J, Chmielewska, A
Nutrients. 2023;15(3)
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Preterm birth results in a high risk of mortality and is a cause of several morbidities, including extrauterine growth restriction. Despite numerous proven benefits, the concentration of some nutrients in human milk may be too low to meet the high nutritional needs of premature infants. Thus, to ensure optimal growth and development, human milk fortification is recommended for all very low birth weight babies. The primary aim of this study was to determine whether tailored compared to the standard fortification of enteral nutrition improved weight gain velocity in preterm infants born at ≤32 weeks of gestation. This study is a randomised observer- and patient-blinded controlled multicentre superiority trial, with two parallel groups with a 1:1 allocation ratio. Due to shortage of staff, two out of three centres failed to randomise patients. Patients were assigned to standard or tailored enteral nutrition fortification groups. Results show that there is no statistically significant difference in the velocity of weight gain during the supplementation period in infants born before 32 weeks of gestation who received targeted fortification compared to those who received standard fortification. Changes in length and head circumference did not differ between the groups. Authors conclude that targeted milk modification is a strategy that may allow for the optimisation of growth in premature infants; however, feasibility and poor tolerance of feeds may be important obstacles in introducing this strategy to neonatal intensive care unit clinical practice.
Abstract
Human milk is recommended for very low birth weight infants. Their nutritional needs are high, and the fortification of human milk is a standard procedure to optimize growth. Targeted fortification accounts for the variability in human milk composition. It has been a promising alternative to standard fixed-dose fortification, potentially improving short-term growth. In this trial, preterm infants (≤32 weeks of gestation) were randomized to receive human milk after standard fortification (HMF, Nutricia) or tailored fortification with modular components of proteins (Bebilon Bialko, Nutricia), carbohydrates (Polycal, Nutricia), and lipids (Calogen, Nutricia). The intervention started when preterms reached 80 mL/kg/day enteral feeds. Of the target number of 220 newborns, 39 were randomized. The trial was interrupted due to serious intolerance in five cases. There was no significant difference in velocity of weight gain during the supplementation period (primary outcome) in the tailored vs. standard fortification group: 27.01 ± 10.19 g/d vs. 25.84 ± 13.45 g/d, p = 0.0776. Length and head circumference were not significantly different between the groups. We found the feasibility of targeted fortification to be limited in neonatal intensive care unit practice. The trial was registered at clinicaltrials.gov NCT:03775785.
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The effect of a preconception and antenatal nutritional supplement on children's BMI and weight gain over the first 2 years of life: findings from the NiPPeR randomised controlled trial.
Lyons-Reid, J, Derraik, JGB, Kenealy, T, Albert, BB, Nieves, JMR, Monnard, CR, Titcombe, P, Nield, H, Barton, SJ, El-Heis, S, et al
The Lancet. Global health. 2023;11 Suppl 1:S11-S12
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Rapid weight gain in infancy is associated with future adverse metabolic health. Nutrition intervention before and during pregnancy may promote healthy weight gain in infants, however evidence is lacking. The purpose of this study was to see whether preconception and antenatal supplementation effects the size and growth of children from birth until 2 years of age. 1729 women were recruited for the study and divided into two groups. The intervention group took myo-inositol, probiotics and additional micronutrients, the control group took a standard micronutrient supplement. Measurements of weight and length were obtained from 576 children at multiple intervals during the first 2 years of life. Differences in age and sex standardised BMI at age 2 years (WHO standards) and the change in weight from birth were examined. The results show that the infants where the mother took the intervention supplement before and throughout pregnancy had a lower risk of rapid weight gain and high BMI at age 2 years. Long-term follow-up is required to assess the longevity of these benefits.
Abstract
BACKGROUND Nutritional intervention before and throughout pregnancy might promote healthy infant weight gain; however, clinical evidence is scarce. Therefore, we examined whether preconception and antenatal supplementation would affect the body size and growth of children in the first 2 years of life. METHODS Women were recruited from the community before conception in the UK, Singapore, and New Zealand, and randomly allocated to either the intervention (myo-inositol, probiotics, and additional micronutrients) or control group (standard micronutrient supplement) with stratification by site and ethnicity. Measurements of weight and length were obtained from 576 children at multiple timepoints in the first 2 years of life. Differences in age and sex standardised BMI at age 2 years (WHO standards) and the change in weight from birth were examined. Written informed consent was obtained from the mothers, and ethics approval was granted by local committees. The NiPPeR trial was registered with ClinicalTrials.gov (NCT02509988) on July 16, 2015 (Universal Trial Number U1111-1171-8056). FINDINGS 1729 women were recruited between Aug 3, 2015, and May 31, 2017. Of the women randomised, 586 had births at 24 weeks or more of gestation between April, 2016, and January, 2019. At age 2 years, adjusting for study site, infant sex, parity, maternal smoking, maternal prepregnancy BMI, and gestational age, fewer children of mothers who received the intervention had a BMI of more than the 95th percentile (22 [9%] of 239 vs 44 [18%] of 245, adjusted risk ratio 0·51, 95% CI 0·31-0·82, p=0·006). Longitudinal data revealed that the children of mothers who received the intervention had a 24% reduced risk of experiencing rapid weight gain of more than 0·67 SD in the first year of life (58 [21·9%] of 265 vs 80 [31·1%] of 257, adjusted risk ratio 0·76, 95% CI 0·58-1·00, p=0·047). Risk was likewise decreased for sustained weight gain of more than 1·34 SD in the first 2 years (19 [7·7%] of 246 vs 43 [17·1%] of 251, adjusted risk ratio 0·55, 95% CI 0·34-0·88, p=0·014). INTERPRETATION Rapid weight gain in infancy is associated with future adverse metabolic health. The intervention supplement taken before and throughout pregnancy was associated with lower risk of rapid weight gain and high BMI at age 2 years among children. Long-term follow-up is required to assess the longevity of these benefits. FUNDING National Institute for Health Research; New Zealand Ministry of Business, Innovation and Employment; Société Des Produits Nestlé; UK Medical Research Council; Singapore National Research Foundation; National University of Singapore and the Agency of Science, Technology and Research; and Gravida.
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Effectiveness of a minimally processed food-based nutritional counselling intervention on weight gain in overweight pregnant women: a randomized controlled trial.
Sartorelli, DS, Crivellenti, LC, Baroni, NF, de Andrade Miranda, DEG, da Silva Santos, I, Carvalho, MR, de Lima, MC, Carreira, NP, Chaves, AVL, Manochio-Pina, MG, et al
European journal of nutrition. 2023;62(1):443-454
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Excessive gestational weight gain exposes the woman and the child to a higher risk of harmful health outcomes in the short and long term. Dietary patterns based on the substitution of meals made with unprocessed or minimally processed foods for the consumption of ultra-processed items can be partly blamed for the exponential global growth in the incidence of obesity. The main aim of this study was to evaluate the effectiveness of a nutritional intervention based on encouraging the consumption of unprocessed and minimally processed foods rather than ultra-processed products. This study is a two-armed parallel randomised controlled trial conducted among overweight, pregnant women receiving prenatal care in seven primary health units. Participants (n=350) were randomly allocated into the intervention group (IG) or control group (CG). The women allocated into the IG, in addition to the usual prenatal care, were invited to participate in three individualised nutritional counselling sessions conducted by trained nutritionists. Results show that even though there were more women in the IG who had increased their daily intake of minimally processed foods and vegetables at lunch time when compared to the CG, this was not statistically significant. Additionally, there weren’t any differences between the groups in relation to physical activity. Authors conclude that their study was unprecedented in demonstrating that a nutritional counselling intervention based on the NOVA food classification system, together with the practice of physical activity, is effective in preventing excessive gestational weight gain in overweight pregnant women.
Abstract
PURPOSE This study aimed at evaluating the effectiveness of a nutritional counselling intervention based on encouraging the consumption of unprocessed and minimally processed foods, rather than ultra-processed products, and the practice of physical activities to prevent excessive gestational weight gain in overweight pregnant women. METHODS This was a two-armed, parallel, randomized controlled trial conducted in primary health units of a Brazilian municipality from 2018 to 2021. Overweight, adult pregnant women (n = 350) were randomly assigned to control (CG) or intervention groups (IG). The intervention consisted of three individualized nutritional counselling sessions based on encouraging the consumption of unprocessed and minimally processed foods rather than ultra-processed products, following the NOVA food classification system, and the practice of physical activities. The primary outcome was the proportion of women whose weekly gestational weight gain (GWG) exceeded the Institute of Medicine guidelines. Adjusted logistic regression models were employed. RESULTS Complete data on weight gain were available for 121 women of the IG and 139 of the CG. In modified intention-to-treat analysis, there was a lower chance of the IG women having excessive GWG [OR 0.56 (95% CI 0.32, 0.98), p = .04], when compared to the CG. No between-group differences were observed for the other maternal outcomes investigated. CONCLUSION The present study was unprecedented in demonstrating that nutritional counselling based on the NOVA food classification system, together with encouraging the practice of physical activity, is effective in preventing excessive weight gain in overweight pregnant women. TRIAL REGISTRATION Registered on July 30th 2018 at Brazilian Registry of Clinical Trials (RBR-2w9bhc).
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HOMEFOOD randomised trial - Six-month nutrition therapy improves quality of life, self-rated health, cognitive function, and depression in older adults after hospital discharge.
Blondal, BS, Geirsdottir, OG, Halldorsson, TI, Beck, AM, Jonsson, PV, Ramel, A
Clinical nutrition ESPEN. 2022;48:74-81
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It is well known that older people are at a higher risk for nutritional inadequacy which is accompanied by depression, impaired cognitive function, and poor overall health. In this secondary analysis of a randomised controlled assessor-blinded dietary intervention trial, the authors examined the effects of six months of nutritional therapy on quality of life, self-rated health, cognitive function, and depression in elderly patients aged 65 years and over. The participants in the intervention group received nutritional therapy (HOMEFOOD) education to overcome malnutrition, which included dietary recommendations to ensure an adequate nutritional intake of energy and protein through diet and additional supplemental protein and energy-rich foods. After six months of nutritional therapy, the intervention group showed improvement in cognitive function, self-rated health, depression score, and quality of life scores, as well as improvements in measures related to weight gain. Further studies need to be conducted in order to determine if nutritional therapy provides additional benefits to older people. However, healthcare professionals can use the results of this study to better understand how nutritional therapy can improve the quality of life and health of older people in comparison to standard care, so they can better advise their patients.
Abstract
BACKGROUND AND AIMS Malnutrition is common among older adults and is related to quality of life, cognitive function, and depression. To what extent nutrition interventions can improve these outcomes remains unclear. The aim of this study was to investigate the effect of nutrition therapy on health-related quality of life (EQ-5D), self-rated health, cognitive function, and depression in community dwelling older adults recently discharged from hospital. METHODS Participants (>65 years) were randomised into an intervention (n = 53) and a control group (n = 53). The intervention group received individualised nutrition therapy based on the nutrition care process including 5 home visits and 3 phone calls, in combination with freely delivered energy- and protein-rich foods and oral nutrition supplements for six months after hospital discharge. EQ-5D, self-rated health, Mini-Mental-State-Examination (MMSE), and the Centre for Epidemiologic Studies Depression - IOWA (CES-D) scale were measured at baseline and at endpoint. RESULTS Two subjects dropped out, one from each arm. The control group experienced an increase in depressive symptoms and a decrease in self-rated health during the study period, while the intervention group experienced increases in cognitive function, self-rated health, and EQ-5D resulting in significant endpoint differences between the groups: EQ-5D (0.102, P = 0.001); self-rated health: 15.876 (P < 0.001); MMSE 1.701 (P < 0.001); depressive symptoms: - 3.072 (P < 0.001); all in favour of the intervention group. Improvements during the intervention in MMSE, self-rated health, and CES-D were significantly related to body weight gain in a linear way. CONCLUSION Cognitive function and mental well-being worsen or stagnate in older adults who receive standard care after hospital discharge. However, a six-month nutrition therapy improves these outcomes leading to statistically and clinically significant endpoint differences between the groups. As improvements were related to body weight gain after hospital discharge, we conclude that the increase in dietary intake, with focus on energy and protein density, and changes in body weight might have contributed to better cognitive function and mental well-being in older adults after the intervention.
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Efficacy and safety of oral alpha-lipoic acid supplementation for type 2 diabetes management: a systematic review and dose-response meta-analysis of randomized trials.
Jibril, AT, Jayedi, A, Shab-Bidar, S
Endocrine connections. 2022;11(10)
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Many studies have shown that type 2 diabetes is associated with increased formation of free radicals and decreased antioxidant potential, leading to oxidative damage of cell components. Increased formation of free radicals and decreased antioxidant potential, coupled with lipid abnormalities, are substantial risk factors for developing complications, especially microvascular ones. The aim of this study was to investigate the effect of oral supplementation of alpha-lipoic acid (ALA) on cardiometabolic risk factors in patients with type 2 diabetes. This study is a systematic review and dose–response meta-analysis of 16 randomised controlled trials with a total of 1035 patients with type 2 diabetes. Results show that: - each 500 mg/day oral ALA supplementation reduced haemoglobin A1c and body weight but did not affect low-density lipoprotein cholesterol concentration. - ALA supplementation reduced c-reactive protein, fasting plasma glucose, serum triglycerides, and diastolic blood pressure but it had no affect on serum total cholesterol and high-density lipoprotein cholesterol concentrations and systolic blood pressure. Authors conclude that their findings do not support ALA supplementation in clinical practice for patients with type 2 diabetes.
Abstract
OBJECTIVE To examine the dose-dependent influence of oral alpha-lipoic acid (ALA) supplementation on cardiometabolic risk factors in patients with type 2 diabetes (T2D). DESIGN We followed the instructions outlined in the Cochrane Handbook for Systematic Reviews of Interventions and the Grading of Recommendations, Assessment, Development, and Evaluation Handbook to conduct our systematic review. The protocol of the study was registered in PROSPERO (CRD42021260587). METHOD We searched PubMed, Scopus, and Web of Science to May 2021 for trials of oral ALA supplementation in adults with T2D. The primary outcomes were HbA1c, weight loss, and LDL cholesterol (LDL-C). Secondary outcomes included fasting plasma glucose (FPG), triglyceride (TG), C-reactive protein (CRP), and blood pressure. We conducted a random-effects dose-response meta-analysis to calculate the mean difference (MD) and 95% CI for each 500 mg/day oral ALA supplementation. We performed a nonlinear dose-response meta-analysis using a restricted cubic spline. RESULTS We included 16 trials with 1035 patients. Each 500 mg/day increase in oral ALA supplementation significantly reduced HbA1c, body weight, CRP, FPG, and TG. Dose-response meta-analyses indicated a linear decrement in body weight at ALA supplementation of more than 600 mg/day (MD600 mg/day: -0.30 kg, 95% CI: -0.04, -0.57). A relatively J-shaped effect was seen for HbA1c (MD: -0.32%, 95% CI: -0.45, -0.18). Levels of FPG and LDL-C decreased up to 600 mg/day ALA intake. The point estimates were below minimal clinically important difference thresholds for all outcomes. CONCLUSION Despite significant improvements, the effects of oral ALA supplementation on cardiometabolic risk factors in patients with T2D were not clinically important.
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Effects of a multicomponent resistance-based exercise program with protein, vitamin D and calcium supplementation on cognition in men with prostate cancer treated with ADT: secondary analysis of a 12-month randomised controlled trial.
Mundell, NL, Owen, PJ, Dalla Via, J, Macpherson, H, Daly, RM, Livingston, PM, Rantalainen, T, Foulkes, S, Millar, J, Murphy, DG, et al
BMJ open. 2022;12(6):e060189
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Androgen deprivation therapy (ADT) for local and advanced prostate cancer (PCa) is effective at reducing androgens, and thus inhibiting tumour progression. However, testosterone reduces the production of a highly neurotoxic protein (amyloid beta peptide 40), which is linked with the development of dementia and Alzheimer’s disease. The aim of this study was to investigate the effects of a multi-component resistance-based exercise programme with daily protein, vitamin D and calcium supplementation on cognitive function compared with usual care in PCa survivors treated with ADT. This study is a secondary analysis of a 12-month single-blinded, two-arm randomised controlled trial. Participants (n = 70) were randomised (1:1 ratio) to either: (a) multi-component exercise intervention including progressive resistance training, body-weight impact and balance exercises, as well as a daily nutritional supplement containing whey protein, calcium and vitamin D, or (b) usual care control receiving 1000 IU vitamin D only. Results show that a multicomponent exercise training and nutritional supplementation intervention did not improve cognitive function in men treated with ADT for PCa compared with usual care. Authors conclude that cognitive decline associated with ADT may mechanistically differ to that of general age-related cognitive declines, thus it is important that future studies also examine other intervention modalities.
Abstract
OBJECTIVES The aim of this preplanned secondary analysis of a 12-month randomised controlled trial was to investigate the effects of a multicomponent exercise programme combined with daily whey protein, calcium and vitamin D supplementation on cognition in men with prostate cancer treated with androgen deprivation therapy (ADT). DESIGN 12-month, two-arm, randomised controlled trial. SETTING University clinical exercise centre. PARTICIPANTS 70 ADT-treated men were randomised to exercise-training plus supplementation (Ex+ Suppl, n=34) or usual care (control, n=36). INTERVENTION Men allocated to Ex + Suppl undertook thrice weekly resistance training with weight-bearing exercise training plus daily whey protein (25 g), calcium (1200 mg) and vitamin D (2000 IU) supplementation. PRIMARY AND SECONDARY OUTCOME MEASURES Cognition was assessed at baseline, 6 and 12 months via a computerised battery (CogState), Trail-making test, Rey auditory-verbal learning test and Digit span. Data were analysed with linear mixed models and an intention-to-treat and prespecified per-protocol approach (exercise-training: ≥66%, nutritional supplement: ≥80%). RESULTS Sixty (86%) men completed the trial (Ex + Suppl, n=31; control, n=29). Five (7.1%) men were classified as having mild cognitive impairment at baseline. Median (IQR) adherence to the exercise and supplement was 56% (37%-82%) and 91% (66%-97%), respectively. Ex + Suppl had no effect on cognition at any time. CONCLUSIONS A 12-month multicomponent exercise training and supplementation intervention had no significant effect on cognition in men treated with ADT for prostate cancer compared with usual care. Exercise training adherence below recommended guidelines does not support cognitive health in men treated with ADT for prostate cancer. TRIAL REGISTRATION NUMBER Australian and New Zealand Clinical Trial Registry (ACTRN12614000317695, registered 25/03/2014) and acknowledged under the Therapeutic Goods Administration Clinical Trial Notification Scheme (CT-2015-CTN-03372-1 v1).
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Low-carbohydrate diets and men's cortisol and testosterone: Systematic review and meta-analysis.
Whittaker, J, Harris, M
Nutrition and health. 2022;28(4):543-554
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Testosterone is the primary male sex hormone, and vital for reproductive development and function. Moreover, low endogenous testosterone is associated with an increased risk of chronic disease, including type 2 diabetes and cardiovascular disease. The aim of this study was to investigate the effects of low- versus high-carbohydrate diets on mens' testosterone and cortisol. This study is a systematic review and meta-analysis of twenty-seven studies with a total of 309 participants. Twelve of these studies were randomised trials whilst the rest were non-randomised. Results show an increase in resting and post-exercise cortisol on short-term low-carbohydrate diets (<3 weeks). In fact, resting cortisol levels return to baseline after <3 weeks on a LC diet, whilst post-exercise cortisol remains elevated. Furthermore, high-protein diets cause a large decrease in resting total testosterone. Authors conclude that further research is required in order to warrant their findings.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Short-term LC-diets diets cause a moderate increase in resting and post-exercise cortisol however this effect is not seen in LC-diets followed for great than 3 weeks
- HP-LC diets caused a statistically significant decrease in resting TT, suggesting caution in relation to endocrine effects of LC diets
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction:
A systematic review and network meta-analysis was conducted on the effects of low-carbohydrate (LC) versus high-carbohydrate (HC) diets on men’s testosterone and cortisol.
The review was registered with PROSPERO and reported using PRISMA 2020 checklists.
Methods:
A comprehensive search strategy was used to find intervention studies looking at healthy adult males and LC diets of <35% carbohydrate. Studies were assessed for quality using the Cochrane Risk of Bias tool. Sub-group analyses was conducted for diet duration, protein intake and exercise duration.
Results:
The literature search resulted in 27 studies with a total of 309 healthy adult male participants, age: 27.3 ± 4.7 (to minimise variation in steroid hormone metabolism), body mass: 78.6± 7.1kg and BMI: 24.8 ±1.6. 12 randomised and 15 non-randomised controlled trials were analysed. 21 studies were considered low risk bias, 5 medium and 1 high risk.
- Short-term (<3 weeks) LC diets moderately increased resting cortisol (0.41 [0.16, 0.66], p < 0.01) when compared to HC diets.
- Long-term (≥3 weeks) LC diets had no consistent effect on resting cortisol
- LC diets resulted in higher post-exercise cortisol, after long-duration exercise (≥20 min): 0 h (0.78 [0.47, 1.1], p < 0.01), 1 h (0.81 [0.31, 1.31], p < 0.01), and 2 h (0.82 [0.33, 1.3], p < 0.01).
- The overall results for resting total testosterone (TT) showed a significant decrease on LC versus HC diets (SMD = −0.48, p = 0.01. However, subgroup analyses revealed this effect to be limited to high-protein (HP) LC diets, which yielded a very large decrease in TT (SMD = −1.08, p < 0.01; ∼5.23 nmol/L), albeit in a small sample (n = 26).
- Moderate protein (MP) (<35%), low-carbohydrate diets had no consistent effect on resting total testosterone, however high-protein (≥35%), low-carbohydrate diets greatly decreased resting (−1.08 [−1.67, −0.48], p < 0.01) and post-exercise total testosterone (−1.01 [−2, −0.01] p = 0.05).
- There was no overall effect of LC versus HC diets on 0 h post-exercise TT (SMD = −0.03, p = 0.95). However, subgroup analysis showed 0 h post-exercise was non-significantly higher on long-term LC versus HC diets (SMD = 0.44, p = 0.18), and much lower on short-term LC versus HC diets (SMD = −1.01, p = 0.05)
Conclusion:
This systematic review and metanalysis found an increase in resting and post-exercise cortisol on short-term LC diets. Cortisol does return to baseline in the first 3 weeks of a low-carbohydrate (LC) diet. The same response is, however, not seen in post-exercise cortisol, which remains elevated. In addition, the review showed that compared to moderate-protein diets, HP diets were found to cause a large decrease in resting and post-exercise TT (∼5.23 nmol/L).
Clinical practice applications:
The results of this review suggest that exercising whilst following a LC diet can increase cortisol in the short term, but not long-term. This suggests a period of diet adaptation. The effects of long-term LC diets on cardiovascular disease risk is uncertain and healthcare practitioners should monitor client responses and keep up-to-date with new research in this area
Since HP-LC diets were found to significantly decrease resting testosterone it highlights the need to ensure that protein intake does not exceed the urea cycle’s capacity due to potential adverse endocrine effects.
For clients where there is a desire to increase strength, power and hypertrophy, a MP-LC diet could be of benefit, as it showed potential to signal an increased anabolic state post exercise..
NB: Since the review only included a low number of studies and saw within these some heterogeneity that could not be explained, more research is needed before the paper’s findings can be conclusive. The above potential practice applications should therefore be seen as something to be mindful of when working with clients where cortisol and testosterone levels are relevant to their protocol.
Considerations for future research:
Future research should consider:
- Since LC diets have been shown to have a positive effect on health – decreased triglycerides, increased high density lipoprotein cholesterol and weight loss - future studies would benefit from including these markers so any positive and negative impacts can be monitored directly.
- Despite extensive analysis including sensitivity analysis to reduce bias and heterogeneity of the results, the paper highlights a need for further research to ensure consistency in key parameters e.g., exercise duration and intensity, carbohydrate supplements inclusion and period of dietary intervention. Since it was identified that HP-LP diets impact post exercise and resting TT, follow up studies would benefit from consistency in participants diets. This would help to reduce any potential confounding results.
Abstract
Background: Low-carbohydrate diets may have endocrine effects, although individual studies are conflicting. Therefore, a review was conducted on the effects of low- versus high-carbohydrate diets on men's testosterone and cortisol. Methods: The review was registered on PROSPERO (CRD42021255957). The inclusion criteria were: intervention study, healthy adult males, and low-carbohydrate diet: ≤35% carbohydrate. Eight databases were searched from conception to May 2021. Cochrane's risk of bias tool was used for quality assessment. Random-effects, meta-analyses using standardized mean differences and 95% confidence intervals, were performed with Review Manager. Subgroup analyses were conducted for diet duration, protein intake, and exercise duration. Results: Twenty-seven studies were included, with a total of 309 participants. Short-term (<3 weeks), low- versus high-carbohydrate diets moderately increased resting cortisol (0.41 [0.16, 0.66], p < 0.01). Whereas, long-term (≥3 weeks), low-carbohydrate diets had no consistent effect on resting cortisol. Low- versus high-carbohydrate diets resulted in much higher post-exercise cortisol, after long-duration exercise (≥20 min): 0 h (0.78 [0.47, 1.1], p < 0.01), 1 h (0.81 [0.31, 1.31], p < 0.01), and 2 h (0.82 [0.33, 1.3], p < 0.01). Moderate-protein (<35%), low-carbohydrate diets had no consistent effect on resting total testosterone, however high-protein (≥35%), low-carbohydrate diets greatly decreased resting (-1.08 [-1.67, -0.48], p < 0.01) and post-exercise total testosterone (-1.01 [-2, -0.01] p = 0.05). Conclusions: Resting and post-exercise cortisol increase during the first 3 weeks of a low-carbohydrate diet. Afterwards, resting cortisol appears to return to baseline, whilst post-exercise cortisol remains elevated. High-protein diets cause a large decrease in resting total testosterone (∼5.23 nmol/L).