Abstract

The interest in intermittent energy restriction (IER) diets as a weight-loss approach is increasing. Different IER protocols exist, including time-restricted eating (TRE), alternate-day fasting (ADF), and the 5:2 diet. This meta-analysis compared the effects of these IER diets with continuous energy restriction (CER) on anthropometrics and cardiometabolic risk markers in healthy adults. Twenty-eight trials were identified that studied TRE (k = 7), ADF (k = 10), or the 5:2 diet (k = 11) for 2-52 wk. Energy intakes between intervention groups within a study were comparable (17 trials), lower in IER (5 trials), or not reported (6 trials). Weighted mean differences (WMDs) were calculated using fixed- or random-effects models. Changes in body weight [WMD: -0.42 kg; 95% confidence interval (CI): -0.96 to 0.13; P = 0.132] and fat mass (FM) (WMD: -0.31 kg; 95% CI: -0.98 to 0.36; P = 0.362) were comparable when results of the 3 IER diets were combined and compared with those of CER. All IER diets combined reduced fat-free mass (WMD: -0.20 kg; 95% CI: -0.39 to -0.01; P = 0.044) and waist circumference (WMD: -0.91 cm; 95% CI: -1.76 to -0.06; P = 0.036) more than CER. Effects on body mass index [BMI (kg/m2)], glucose, insulin, homeostatic model assessment for insulin resistance (HOMA-IR), serum lipid and lipoprotein concentrations, and blood pressure did not differ. Further, TRE reduced body weight, FM, and fat-free mass more than CER, whereas ADF improved HOMA-IR more. BMI was reduced less in the 5:2 diet compared with CER. In conclusion, the 3 IER diets combined did not lead to superior improvements in anthropometrics and cardiometabolic risk markers compared with CER diets. Slightly greater reductions were, however, observed in fat-free mass and waist circumference. To what extent differences in energy intakes between groups within studies may have influenced these outcomes should be addressed in future studies.

Abstract

Background: The potential positive interaction between intermittent fasting (IF) and brain-derived neurotrophic factor (BDNF) on cognitive function has been widely discussed. This systematic review tried to assess the efficacy of interventions with different IF regimens on BDNF levels and their association with cognitive functions in humans. Interventions with different forms of IF such as caloric restriction (CR), alternate-day fasting (ADF), time-restricted eating (TRE), and the Ramadan model of intermittent fasting (RIF) were targeted. Methods: A systematic review was conducted for experimental and observational studies on healthy people and patients with diseases published in EMBASE, Scopus, PubMed, and Google Scholar databases from January 2000 to December 2023. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statements (PRISMA) for writing this review. Results: Sixteen research works conducted on healthy people and patients with metabolic disorders met the inclusion criteria for this systematic review. Five studies showed a significant increase in BDNF after the intervention, while five studies reported a significant decrease in BDNF levels, and the other six studies showed no significant changes in BDNF levels due to IF regimens. Moreover, five studies examined the RIF protocol, of which, three studies showed a significant reduction, while two showed a significant increase in BDNF levels, along with an improvement in cognitive function after RIF. Conclusions: The current findings suggest that IF has varying effects on BDNF levels and cognitive functions in healthy, overweight/obese individuals and patients with metabolic conditions. However, few human studies have shown that IF increases BDNF levels, with controversial results. In humans, IF has yet to be fully investigated in terms of its long-term effect on BDNF and cognitive functions. Large-scale, well-controlled studies with high-quality data are warranted to elucidate the impact of the IF regimens on BDNF levels and cognitive functions.

Abstract

CONTEXT Consumers are increasingly encouraged to reduce meat and dairy consumption. However, few meta-analyses of randomized controlled trials (RCTs) on the effect of reducing meat and/or dairy on (absolute) protein intake, anthropometric values, and body composition are available. OBJECTIVE The aim of this systematic review and meta-analysis was to evaluate the effect of reducing meat and/or dairy consumption on (absolute) protein intake, anthropometric values, and body composition in adults aged ≥ 45 years. DATA SOURCES The MEDLINE, Cochrane CENTRAL, Embase, ClinicalTrials.gov, and International Clinical Trials Registry Platform databases were searched up to November 24, 2021. DATA EXTRACTION Randomized controlled trials reporting protein intake, anthropometric values, and body composition were included. DATA ANALYSIS Data were pooled using random-effects models and expressed as the mean difference (MD) with 95%CI. Heterogeneity was assessed and quantified using Cochran's Q and I2 statistics. In total, 19 RCTs with a median duration of 12 weeks (range, 4-24 weeks) and a total enrollment of 1475 participants were included. Participants who consumed meat- and/or dairy-reduced diets had a significantly lower protein intake than those who consumed control diets (9 RCTs; MD, -14 g/d; 95%CI, -20 to -8; I2 = 81%). Reducing meat and/or dairy consumption had no significant effect on body weight (14 RCTs; MD, -1.2 kg; 95%CI, -3 to 0.7; I2 = 12%), body mass index (13 RCTs; MD, -0.3 kg/m2; 95%CI, -1 to 0.4; I2 = 34%), waist circumference (9 RCTs; MD, -0.5 cm; 95%CI, -2.1 to 1.1; I2 = 26%), amount of body fat (8 RCTs; MD, -1.0 kg; 95%CI, -3.0 to 1.0; I2 = 48%), or lean body mass (9 RCTs; MD, -0.4 kg; 95%CI, -1.5 to 0.7; I2 = 0%). CONCLUSION Reduction of meat and/or dairy appears to reduce protein intake. There is no evidence of a significant impact on anthropometric values or body composition. More long-term intervention studies with defined amounts of meat and dairy are needed to investigate the long-term effects on nutrient intakes and health outcomes. SYSTEMATIC REVIEW REGISTRATION PROSPERO registration no. CRD42020207325.

Abstract

Individuals with chronic obstructive pulmonary disease (COPD) are prone to malnutrition and sarcopenia as a result of nutritional deficiencies and increased energy metabolism. However, the effects of nutrient supplements (NS) on treating sarcopenia in patients with COPD are not well established from systematic evidence. This meta-analysis examined the effect of NS on sarcopenia in patients with COPD. A systematic search of multiple databases was conducted, and 29 randomized controlled trials involving 1625 participants (age, mean [SD] = 67.9 [7.8] years) were analyzed. NS demonstrated significant improvements in body weight (MD,1.33 kg; 95% CI, 0.60, 2.05 kg; P = 0.0003; I2 = 87%), fat-free mass index (MD, 0.74 kg/m2; 95% CI, 0.21, 1.27 kg/m2; P = 0.007; I2 = 75%), and 6-min walk test (MD, 19.43 m; 95% CI, 4.91, 33.94 m; P = 0.009; I2 = 81%) compared with control. However, NS had nonsignificant effects on handgrip strength (SMD, 0.36; 95% CI, - 0.15, 0.88; P = 0.16; I2 = 87%) and quadriceps muscle strength (SMD, 0.11; 95% CI, -  0.06, 0.27; P = 0.20; I2 = 25%) compared with the control. In conclusion, NS may be an effective treatment for improving body composition and physical performance in COPD. Future studies should explore the effects of intervention durations, specific NS types, or combined training in patients with COPD and sarcopenia.

Abstract

OBJECTIVE As the number of adults aged over 40 with obesity increases dramatically, intermittent fasting interventions (IF) may help them to lose fat and weight. This systematic review investigated the most recent research on the effects of intermittent fasting and a regular diet on body composition and lipids in adults aged over 40 with obesity without the metabolic disease. DATA SOURCES Randomized controlled trials (RCTs) on IF on adults aged over 40 with obesity were retrieved from PubMed, Web of Science, EBSCO, China Knowledge Network (CNKI), VIP database, Wanfang database with the experimental group using IF and the control group using a regular diet. Revman was used for meta-analysis. Effect sizes are expressed as weighted mean differences (WMD) and 95% confidence intervals (CI). STUDY SELECTION A total of 9 articles of randomised controlled trials that met the requirements were screened for inclusion. Studies typically lasted 2-6 weeks. The experimental population was aged 42-66 years, with a BMI range of 25.7-35 kg/m2. SYNTHESIS A total of 9 RCTs were included. meta-analysis showed that body weight (MD: -2.05 kg; 95% CI (-3.84, -0.27); p = 0.02), BMI (MD: -0.73 kg/m2; 95% CI (-1.05, -0.41); p < 0.001), fat mass (MD: -2.14 kg; 95% CI (-3.81, 0.47); p = 0.01), and TG (MD = -0.32 mmol/L, 95% CI (-0.50, -0.15, p < 0.001) were significantly lower in the experimental group than in the control group. No significant reduction in lean body mass (MD: -0.31 kg; 95% CI (-0.96, 0.34); p = 0.35). CONCLUSION IF had a reduction in body weight, BMI, fat mass, and TG in adults aged over 40 with obesity without metabolic disease compared to RD, and IF did not cause a significant decrease in lean body mass, which suggests healthy and effective fat loss. However, more long-term and high-quality trials are needed to reach definitive conclusions.

Abstract

Sarcopenia is a risk factor for adverse clinical outcomes in chronic kidney disease (CKD) patients, including mortality. Diagnosis depends on adopted consensus definition and cutoff values; thus, prevalence rates are generally heterogeneous. We conducted a systematic review and meta-analysis to investigate the global prevalence of sarcopenia and its traits across the wide spectrum of CKD. A systematic search was conducted using databases, including MEDLINE and EMBASE, for observational studies reporting the prevalence of sarcopenia. We considered sarcopenia according to the consensus definition of the European Working Group on Sarcopenia in Older People (EWGSOP), the Asian Working Group for Sarcopenia, the Foundation for the National Institutes of Health Sarcopenia Project, and the International Working Group on Sarcopenia (IWGS). Subgroup analyses by CKD stages, consensus, and gender were performed. Pooled prevalence was obtained from random-effect models. A total of 140 studies (42 041 patients) across 25 countries were included in this systematic review and meta-analyses. Global prevalence of sarcopenia was 24.5% [95% confidence interval (CI): 20.9-28.3) and did not differ among stages (P = 0.33). Prevalence varied according to the consensus definition from 11% to 30%, with no significant difference (P = 0.42). Prevalence of severe sarcopenia was 21.0% (95% CI: 11.7-32.0), with higher rates for patients on dialysis (26.2%, 95% CI: 16.6-37.1) compared to non-dialysis (3.0%, 95% CI: 0-11.1; P < 0.01). Sarcopenic obesity was observed in 10.8% (95% CI: 3.5-21.2). Regarding sarcopenia traits, low muscle strength was found in 43.4% (95%CI: 35.0-51.9), low muscle mass in 29.1% (95% CI: 23.9-34.5), and low physical performance in 38.6 (95% CI: 30.9-46.6) for overall CKD. Prevalence was only higher in patients on dialysis (50.0%, 95% CI: 41.7-57.4) compared to non-dialysis (19.6%, 95% CI: 12.8-27.3; P < 0.01) for low muscle strength. We found a high global prevalence of sarcopenia in the wide spectrum of CKD. Low muscle strength, the primary sarcopenia trait, was found in almost half of the overall population with CKD. Patients on dialysis were more prevalent to low muscle strength and severe sarcopenia. Nephrology professionals should be aware of regularly assessing sarcopenia and its traits in patients with CKD, especially those on dialysis.

Abstract

Agricultural workers constitute two-thirds of the population of Low- and Middle-Income Countries (LMIC) and are at increased risk of developing musculoskeletal disorders (MSD) due to high-risk activities. This systematic review and meta-analysis aim to synthesise the prevalence, predictors, and outcomes of musculoskeletal pain amongst agricultural workers to identify priority areas for prevention and development of early interventions. This systematic review and meta-analysis included Studies published from the inception of global electronic databases until 30 September 2022 were included. Prevalence estimates for MSDs among agricultural workers aged over 18 years in LMIC were extracted. Narrative synthesis summarized study findings and pooled estimates for 12-month pain prevalence were calculated. 7502 potential studies were identified. 64 studies (68,684 participants from 23 countries) were included in the systematic review; 33 studies were included in the meta-analysis. Low back pain was the most widely investigated symptom. The 12-month pooled prevalence of low back pain was highest in Africa [61.96% (45.69-76.22)] compared to Asia [54.16% (47.76-60.50)] and South/Central America [28.52%(10.91-50.33)]. Narrative synthesis found associations between MSDs, particular activities including heavy lifting and repetitive movements, and outcomes including reduced productivity. MSDs are common in agriculture workers in LMIC. Global prevalence of low back pain in farmers, particularly in Africa, is greater than in previously reported global prevalence in the general population. This may be attributed to environmental factors and high-risk activities which could be targeted for prevention and early intervention strategies to support individuals, prevent disability, and reduce loss of productivity.

Abstract

Osteosarcopenia is defined as the concurrent occurrence of osteopenia/osteoporosis and sarcopenia. The aim of the current study was to perform a systematic review with meta-analysis to determine the global prevalence, risk factors and clinical outcomes of osteosarcopenia. This review was registered in PROSPERO (CRD42022351229). PubMed, Cochrane, Medline and Embase were searched from inception to February 2023 to retrieve eligible observational population-based studies. Pooled osteosarcopenia prevalence was calculated with 95% confidence interval (CI), and subgroup analyses were performed. The risk factor of osteosarcopenia and its association with clinical outcomes were expressed as odds ratio (OR) and hazard ratio (HR), respectively. Heterogeneity was estimated using the I2 test. Study quality was assessed using validated instruments matched to study designs. The search identified 55 158 studies, and 66 studies (64 404 participants, mean age from 46.6 to 93 years) were analysed in the final analysis, including 48 cross-sectional studies, 17 cohort studies and 1 case-control study. Overall, the pooled prevalence of osteosarcopenia was 18.5% (95% CI: 16.7-20.3, I2  = 98.7%), including 15.3% (95% CI: 13.2-17.4, I2  = 97.6%) in men and 19.4% (95% CI: 16.9-21.9, I2  = 98.5%) in women. The prevalence of osteosarcopenia diagnosed using sarcopenia plus osteopenia/osteoporosis was 20.7% (95% CI: 17.1-24.4, I2  = 98.55%), and the prevalence of using sarcopenia plus osteoporosis was 16.1% (95% CI: 13.3-18.9, I2  = 98.0%). The global osteosarcopenia prevalence varied in different regions with 22.9% in Oceania, 21.6% in Asia, 20.8% in South America, 15.7% in North America and 10.9% in Europe. A statistically significant difference was found in the subgroups of the study population between the hospital (24.7%) and community (12.9%) (P = 0.001). Frailty (OR = 4.72, 95% CI: 2.71-8.23, I2  = 61.1%), malnutrition (OR = 2.35, 95% CI: 1.62-3.40, I2  = 50.0%), female sex (OR = 5.07, 95% CI: 2.96-8.69, I2  = 73.0%) and higher age (OR = 1.10, 95% CI: 1.06-1.15, I2 ==86.0%) were significantly associated with a higher risk for osteosarcopenia. Meta-analysis of cohort studies showed that osteosarcopenia significantly increased the risk of fall (HR = 1.54, 95% CI: 1.20-1.97; I2  = 1.0%, three studies), fracture (HR = 2.13, 95% CI: 1.61-2.81; I2  = 67.8%, seven studies) and mortality (HR = 1.75, 95% CI: 1.34-2.28; I2  = 0.0%, five studies). Despite the heterogeneity arising from varied definitions and criteria, our findings highlight a significant global prevalence of osteosarcopenia and its negative impact on clinical health. Standardizing diagnostic criteria for osteosarcopenia would be advantageous in the future, and early detection and management should be emphasized in this patient population.

Abstract

BACKGROUND & AIMS Continuous glucose monitoring (CGM) provides data on short-term glycemic variability (GV). GV is associated with adverse outcomes in individuals with diabetes. Whether GV is associated with cardiometabolic risk in individuals without diabetes is unclear. We systematically reviewed the literature to assess whether GV is associated with cardiometabolic risk markers or outcomes in individuals without diabetes. METHODS Searches were performed in PubMed/Medline, Embase and Cochrane from inception through April 2022. Two researchers were involved in study selection, data extraction and quality assessment. Studies evaluating GV using CGM for ≥24 h were included. Studies in populations with acute and/or critical illness were excluded. Both narrative synthesis and meta-analyzes were performed, depending on outcome. RESULTS Seventy-one studies were included; the majority were cross-sectional. Multiple measures of GV are higher in individuals with compared to without prediabetes and GV appears to be inversely associated with beta cell function. In contrast, GV is not clearly associated with insulin sensitivity, fatty liver disease, adiposity, blood lipids, blood pressure or oxidative stress. However, GV may be positively associated with the degree of atherosclerosis and cardiovascular events in individuals with coronary disease. CONCLUSION GV is elevated in prediabetes, potentially related to beta cell dysfunction, but less clearly associated with obesity or traditional risk factors. GV is associated with coronary atherosclerosis development and may predict cardiovascular events and type 2 diabetes. Prospective studies are warranted, investigating the predictive power of GV in relation to incident disease. GV may be an important risk measure also in individuals without diabetes.

Abstract

AIMS/HYPOTHESIS Continuous glucose monitoring (CGM) is increasingly used in the treatment of type 2 diabetes, but the effects on glycaemic control are unclear. The aim of this systematic review and meta-analysis is to provide a comprehensive overview of the effect of CGM on glycaemic control in adults with type 2 diabetes. METHODS We performed a systematic review using Embase, MEDLINE, Web of Science, Scopus and ClinicalTrials.gov from inception until 2 May 2023. We included RCTs investigating real-time CGM (rtCGM) or intermittently scanned CGM (isCGM) compared with self-monitoring of blood glucose (SMBG) in adults with type 2 diabetes. Studies with an intervention duration <6 weeks or investigating professional CGM, a combination of CGM and additional glucose-lowering treatment strategies or GlucoWatch were not eligible. Change in HbA1c and the CGM metrics time in range (TIR), time below range (TBR), time above range (TAR) and glycaemic variability were extracted. We evaluated the risk of bias using the Cochrane risk-of-bias tool version 2. Data were synthesised by performing a meta-analysis. We also explored the effects of CGM on severe hypoglycaemia and micro- and macrovascular complications. RESULTS We found 12 RCTs comprising 1248 participants, with eight investigating rtCGM and four isCGM. Compared with SMBG, CGM use (rtCGM or isCGM) led to a mean difference (MD) in HbA1c of -3.43 mmol/mol (-0.31%; 95% CI -4.75, -2.11, p<0.00001, I2=15%; moderate certainty). This effect was comparable in studies that included individuals using insulin with or without oral agents (MD -3.27 mmol/mol [-0.30%]; 95% CI -6.22, -0.31, p=0.03, I2=55%), and individuals using oral agents only (MD -3.22 mmol/mol [-0.29%]; 95% CI -5.39, -1.05, p=0.004, I2=0%). Use of rtCGM showed a trend towards a larger effect (MD -3.95 mmol/mol [-0.36%]; 95% CI -5.46 to -2.44, p<0.00001, I2=0%) than use of isCGM (MD -1.79 mmol/mol [-0.16%]; 95% CI -5.28, 1.69, p=0.31, I2=64%). CGM was also associated with an increase in TIR (+6.36%; 95% CI +2.48, +10.24, p=0.001, I2=9%) and a decrease in TBR (-0.66%; 95% CI -1.21, -0.12, p=0.02, I2=45%), TAR (-5.86%; 95% CI -10.88, -0.84, p=0.02, I2=37%) and glycaemic variability (-1.47%; 95% CI -2.94, -0.01, p=0.05, I2=0%). Three studies reported one or more events of severe hypoglycaemia and macrovascular complications. In comparison with SMBG, CGM use led to a non-statistically significant difference in the incidence of severe hypoglycaemia (RR 0.66, 95% CI 0.15, 3.00, p=0.57, I2=0%) and macrovascular complications (RR 1.54, 95% CI 0.42, 5.72, p=0.52, I2=29%). No trials reported data on microvascular complications. CONCLUSIONS/INTERPRETATION CGM use compared with SMBG is associated with improvements in glycaemic control in adults with type 2 diabetes. However, all studies were open label. In addition, outcome data on incident severe hypoglycaemia and incident microvascular and macrovascular complications were scarce. REGISTRATION This systematic review was registered on PROSPERO (ID CRD42023418005).