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The impact of diabetes mellitus type 1 on male fertility: Systematic review and meta-analysis.
Facondo, P, Di Lodovico, E, Delbarba, A, Anelli, V, Pezzaioli, LC, Filippini, E, Cappelli, C, Corona, G, Ferlin, A
Andrology. 2022;10(3):426-440
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The relationship between type 2 diabetes mellitus and male hypogonadism is well known, whereas the impact of type 1 diabetes mellitus (DM1) on male fertility and testis functions has been less studied. The aim of this study was to systematically review and discuss the available evidence evaluating paternity rate, male gonadal axis, and sperm parameters in men with DM1. This study is a systematic review and meta-analysis of fourteen studies. Results show: - reduced fertility potential in patients with DM1, as they have a lower number of children compared with unaffected population. In fact, the rate of children is statistically significantly lower among men who had been diagnosed with DM1 at an earlier age, according to a longer duration of the disease. - that men with DM1, compared with controls, have significantly lower normal sperm morphology, progressive motility and a trend toward a reduced semen volume, without difference in total sperm count and concentration. Authors conclude that DM1 might impair reproductive health at different levels, including functional sperm alterations definitively leading to reduced fertility rate in these patients.
Abstract
BACKGROUND Some evidence suggests that diabetes mellitus type 1 (DM1) could affect male fertility, gonadal axis, semen parameters, and spermatogenesis because of effects of hyperglycemia and insulin deficiency. Anyhow, the exact impact of DM1 on male fertility is unclear. OBJECTIVES To review the studies evaluating paternity rate, male gonadal axis, and semen parameters in men with DM1. MATERIALS AND METHODS A review of relevant literature from January 1980 to December 2020 was performed. Only studies published in English reporting data on fatherhood (rate of children by natural fertility), hormonal and seminal parameters were included. Out of 14 retrieved articles, the eight studies evaluating semen parameters were meta-analyzed. RESULTS The rate of children (four studies) was lower than controls among men affected by DM1, especially in men with a longer duration of disease. The data of gonadal hormonal profile in DM1 men (six studies) are very heterogeneous and a neutral effect of DM1 or a condition of subclinical hypogonadism could not be concluded. Meta-analysis showed that men with DM1 (n = 380), compared with controls (n = 434), have significantly lower normal sperm morphology [-0.36% (-0.66; -0.06), p < 0.05, six studies] and sperm progressive motility [33.62% (-39.13; -28.11), p < 0.001, two studies] and a trend toward a lower seminal volume [-0.51 (-1.03; 0.02), p = 0.06, eight studies], without difference in total sperm count and concentration. Data on scrotal ultrasound and sperm DNA fragmentation are too few. No study evaluated other factors of male infertility, such as transrectal ultrasound, semen infections, sperm auto-antibodies, and retrograde ejaculation. DISCUSSION DM1 might impair male fertility and testis functions (endocrine, spermatogenesis), but definition of its actual impact needs further studies. CONCLUSION Men with DM1 should be evaluated with a complete hormonal, seminal, and ultrasound workup to better define their fertility potential and need for follow up of testis functions.
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Cadmium exposure and risk of diabetes and prediabetes: A systematic review and dose-response meta-analysis.
Filippini, T, Wise, LA, Vinceti, M
Environment international. 2022;158:106920
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Cadmium is a toxic metal released in the environment after both natural and anthropogenic activities, particularly in contaminated and industrial areas devoted to smelting and refining of metals, and the manufacturing of batteries, coatings, or plastics. Exposure to cadmium may occur through occupational activities, smoking, food, and air pollution. The aim of this study was to provide updated literature on cadmium exposure and the risk of both type 2 diabetes and prediabetes, and to model the shape of these associations using a dose response approach. This study is a systematic review and meta-analysis of forty-two studies. Diabetes was investigated as an outcome in thirty-one studies, prediabetes in four studies, and both diabetes and prediabetes in seven studies. Results show that higher cadmium exposure was associated with increased risks of both diabetes and prediabetes. Diabetes risk increased linearly in studies using urinary cadmium concentrations, while disease risk increased only at the highest exposure levels when assessed using blood concentrations. The analysis for prediabetes also showed a linear increase in risk from low exposure, with a flattening effect at higher urinary cadmium concentrations. Authors conclude that their findings add to the available evidence on potential adverse health effects of environmental exposure to cadmium.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Cadmium exposure through diet, occupational exposure and smoking may increase the risk of type 2 diabetes in affected individuals.
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:
Background
Cadmium exposure might occur through occupational activities, food, air pollution, and smoking. Smokers, in particular, have higher blood cadmium concentrations than non-smokers. Food is the main transmission route for non-smokers, particularly cereals, vegetables, mollusks, and offal. Females and older adults are at a greater risk due to an increased risk of iron deficiency in these population groups, leading to increased absorption, as well as greater age-related bioaccumulation.
Furthermore, cadmium exposure has been associated with an increased risk of diabetes in a number of studies, as referenced in the present manuscript. However, the magnitude and shape of the correlation are uncertain.This systematic review and meta-analysis therefore investigates the relationship between exposure to cadmium and type 2 diabetes and prediabetes risk.
Methods
- The systematic review was conducted and reported in line with the PRISMA 2020 statement. Search strings related to the terms “cadmium” and “diabetes”, or “prediabetes state” in PubMed/MEDLINE, Web of Science and EMBASE databases were employed to search for relevant articles. Latest search date: 1 October 2021.
- Eligibility criteria included: studies evaluating cadmium exposure via biomarker levels with outcomes of interest being type 2 diabetes or prediabetes using WHO criteria and the American Diabetes Association; and reporting of relative risk estimates using the hazard ratio (HR), risk ratio (RR), or odds ratio (OR) with the corresponding 95% confidence interval (CIs). For inclusion in dose-response meta-analysis: reported effect estimates for all exposure categories along with dose in each category.
- Studies were assessed for risk of bias using theROBINS-E tool. Overall certainty of the evidence was assessed using the GRADE approach.
- The meta-analysis involved estimating RRs with corresponding 95% CIs from each study. Generalised least-squares regression with a random effects model and restricted maximum likelihood estimation were used. The highest versus lowest exposure categories were compared. The association between exposure and risk of diabetes or prediabetes was investigated using a one-stage dose-response meta-analysis. Sensitivity analyses were performed and heterogeneity between studies was assessed..
Results
- 42 eligible studies (case-control, cross-sectional, and cohort studies), ranging 65-34, 814 male and female adult participants, were identified investigating the association between cadmium exposure and risk of diabetes or prediabetes. Seven of the included studies were at overall high risk of bias; heterogeneity in the resulting meta-analyses was moderate to substantial. Sensitivity analyses indicated comparable results. Assessment with GRADE found no major inconsistency, indirectness or imprecision for either outcome.
- Comparing the highest versus lowest cadmium exposure concentrations associated with type 2 diabetes resulted in a RR of 1.24 (95% CI 0.96–1.59), RR 1.21 (CI 95% 1.00–1.45), and RR 1.47 (CI 95% 1.01–2.13) for blood, urinary, and toenail matrices, respectively. Concurrently, there was an elevated risk of prediabetes for cadmium levels in urine of RR 1.41 (95% CI: 1.15–1.73) and blood RR 1.38 (95% CI: 1.16–1.63), respectively.
- In the dose-response meta-analysis, a linear positive correlation between increasing urinary cadmium levels and diabetes risk was observed, with a RR 1.25 (95% CI 0.90–1.72) at concentration 2.0 µg/g of creatinine compared with no exposure. Conversely, for blood cadmium concentrations, the diabetes risk seemed to rise above 1 µg/L compared with no exposure. Moreover, prediabetes risk increased up to approximately 2 µg/g creatinine beyond which a plateau was reached with RR 1.40 (95% CI 1.12–1.76) at 2 µg/g creatinine.
- The meta-regression showed a negligible correlation between blood cadmium levels and diabetes risk. However, a positive yet imprecise association was found with increasing urinary cadmium concentrations. Similarly, no association was observed between blood cadmium concentrations and risk of prediabetes, whereas a positive relationship with urinary cadmium levels was observed. However, these findings were based on a limited cohort of studies.
Conclusions
- A positive linear correlation between cadmium concentration (measured in multiple matrices) and risk of both type 2 diabetes and prediabetes with a dose-response relationship (moderate-certainty evidence) were observed in this systematic review and meta-analysis. Diabetes risk increased linearly in studies using urinary cadmium concentrations, whereas disease risk increased only at the highest exposure levels when assessed using blood levels. The analysis for prediabetes also demonstrated a linear increase in risk from low exposure, which plateaued at higher urinary cadmium concentrations.
Clinical practice applications:
- To inform practitioners and clients of the risks of cadmium exposure in the diet, through occupational exposure, and through smoking.
- To motivate practitioners to educate themselves and their clients regarding the foods which may pose a higher risk of cadmium exposure (not reviewed in the present article).
- To advise clients on prediabetes and type 2 diabetes risk from cadmium exposure through smoking.
Considerations for future research:
- As cited by the authors, future studies could incorporate stratified analysis in specific subgroups, e.g., non-smokers, or could be restricted to prospective cohort studies with more sufficient data,
- Large-scale observational studies could be conducted investigating cadmium exposure in smokers versus non-smokers.
- Clinical trials could be performed to evaluate the effect of reduction or cessation of tobacco smoking on total body cadmium concentrations .
- Continuous surveillance of dietary cadmium exposure and other heavy metals should be prioritised to inform public health.
- Dietary interventions could assess the possibility to attenuate the risk of cadmium exposure.
Abstract
BACKGROUND Cadmium exposure has been associated with increased diabetes risk in several studies, though there is still considerable debate about the magnitude and shape of the association. OBJECTIVE To perform a systematic review and meta-analysis of observational studies investigating the relation between cadmium exposure and risk of type 2 diabetes and prediabetes, and to summarize data on the magnitude and shape of the association. DATA SOURCE After conducting an online literature search through October 1, 2021, we identified 42 eligible studies investigating the association between cadmium exposure and risk of diabetes and prediabetes. STUDY ELIGIBILITY CRITERIA We included studies that assessed cadmium exposure through biomarker levels; examined type 2 diabetes or prediabetes among outcomes; and reported effect estimates for cadmium exposure for meta-analysis only. STUDY APPRAISAL AND SYNTHESIS METHODS Studies were evaluated using ROBINS-E risk of bias tool. We quantitively assessed the relation between exposure and study outcomes using one-stage dose-response meta-analysis with a random effects meta-analytical model. RESULTS In the meta-analysis, comparing highest-versus-lowest cadmium exposure levels, summary relative risks (RRs) for type 2 diabetes were 1.24 (95% confidence interval 0.96-1.59), 1.21 (1.00-1.45), and 1.47 (1.01-2.13) for blood, urinary, and toenail matrices, respectively. Similarly, there was an increased risk of prediabetes for cadmium concentrations in both urine (RR = 1.41, 95% CI: 1.15-1.73) and blood (RR = 1.38, 95% CI: 1.16-1.63). In the dose-response meta-analysis, we observed a consistent linear positive association between cadmium exposure and diabetes risk, with RRs of 1.25 (0.90-1.72) at 2.0 µg/g of creatinine. Conversely for blood cadmium, diabetes risk appeared to increase only above 1 µg/L. Prediabetes risk increased up to approximately 2 µg/g creatinine above which it reached a plateau with RR of 1.42 (1.12-1.76) at 2 µg/g creatinine. LIMITATIONS AND CONCLUSIONS This analysis provides moderate-certainty evidence for a positive association between cadmium exposure (measured in multiple matrices) and risk of both diabetes and prediabetes.
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Effectiveness of Therapeutic Patient Education Interventions in Obesity and Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.
Correia, JC, Waqas, A, Huat, TS, Gariani, K, Jornayvaz, FR, Golay, A, Pataky, Z
Nutrients. 2022;14(18)
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Obesity and diabetes mellitus (DM) account for the highest burden of non-communicable diseases. Obesity is also highly comorbid with type 2 DM with a prevalence of 8.5% among adults around the globe. The aims of this study were to present (a) a critical synthesis of the theoretical basis and development of therapeutic patient education (TPE) interventions for obesity and diabetes, and (b) quantitative evidence for the efficacy of these interventions across a range of biomedical, psychosocial and psychological outcomes. This study is a systematic review and meta-analysis of fifty-four randomised controlled trials. Results show that: - TPE interventions bring about significant improvements in biomedical outcomes among patients with DM and obesity. - there weren’t significant differences in the quality of life of participants undergoing TPE interventions (inconclusive as only data from two studies were considered). - interventions delivered through different media and delivery formats may be equally effective. Authors conclude that the use of electronic media such as short messaging services, website-based educational programs and animation media can be used to deliver TPE effectively.
Abstract
Diabetes mellitus (DM) and obesity account for the highest burden of non-communicable diseases. There is increasing evidence showing therapeutic patient education (TPE) as a clinically and cost-effective solution to improve biomedical and psychosocial outcomes among people with DM and obesity. The present systematic review and meta-analysis present a critical synthesis of the development of TPE interventions for DM and obesity and the efficacy of these interventions across a range of biomedical, psychosocial and psychological outcomes. A total of 54 of these RCTs were identified among patients with obesity and diabetes and were thus qualitatively synthesized. Out of these, 47 were included in the quantitative synthesis. There was substantial heterogeneity in the reporting of these outcomes (I2 = 88.35%, Q = 317.64), with a significant improvement noted in serum HbA1c levels (standardized mean difference (SMD) = 0.272, 95% CI: 0.118 to 0.525, n = 7360) and body weight (SMD = 0.526, 95% CI: 0.205 to 0.846, n = 1082) in the intervention group. The effect sizes were comparable across interventions delivered by different modes and delivery agents. These interventions can be delivered by allied health staff, doctors or electronically as self-help programs, with similar effectiveness (p < 0.001). These interventions should be implemented in healthcare and community settings to improve the health outcomes in patients suffering from obesity and DM.
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Impact of Diabetes Mellitus on Lower Urinary Tract Symptoms in Benign Prostatic Hyperplasia Patients: A Meta-Analysis.
Xin, C, Fan, H, Xie, J, Hu, J, Sun, X, Liu, Q
Frontiers in endocrinology. 2021;12:741748
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Benign prostatic hyperplasia (BPH) is a disease that causes lower urinary tract symptoms (LUTS). Age, sex hormones, diet, diabetes, obesity, and genetic factors are closely related to the occurrence of BPH. The aim of this study was to investigate the impact of diabetes mellitus on LUTS in BPH patients. This study is a systematic review and meta-analysis of eighteen articles consisting of 1685 cases and 4653 controls. Results show that the International Prostate Symptom Score of the diabetic BPH group was significantly higher than that of the non-diabetic BPH group, indicating that diabetes mellitus may aggravate the LUTS of BPH patients. Authors conclude that LUTS in BPH patients is increased in patients with diabetes mellitus compared with controls.
Abstract
BACKGROUND Benign prostatic hyperplasia (BPH) is a disease that causes lower urinary tract symptoms (LUTS), which are the most common urological problem in approximately one-third of the male population aged over 50 years. Some studies have suggested that diabetes may be a risk factor for the development of BPH. However, whether diabetes aggravates the LUTS of BPH patients is still controversial. AIM: To investigate the impact of diabetes mellitus on LUTS in BPH patients. METHODS A literature search was conducted using Web of Science, Embase, PubMed, and China National Knowledge Infrastructure literature databases. This meta-analysis was registered in PROSPERO (registration number: CRD 42020200794). Fixed- or random-effects models were used for analysis according to heterogeneity. The results of the systematic analysis are presented as weighted mean difference (WMD) with the corresponding 95% confidence intervals (CI). RESULTS In total, 1308 studies were retrieved from databases and 18 articles comprising 1685 cases and 4653 controls were selected for meta-analysis. The results of the meta-analysis showed that the International Prostate Symptom Score (IPSS) value and prostate volume of BPH patients with diabetes was significantly higher than that of BPH patients without diabetes. CONCLUSIONS This systematic review is the first to evaluate the impact of diabetes mellitus on LUTS in BPH patients. The results of our meta-analysis support the hypothesis that LUTS in BPH patients is increased in patients with diabetes mellitus compared with controls, which suggests that physicians should pay more attention to BPH patients with diabetes mellitus. SYSTEMATIC REVIEW REGISTRATION PROSPERO [https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=200794], identifier CRD 42020200794.
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Relationship between Prenatal or Postnatal Exposure to Pesticides and Obesity: A Systematic Review.
Pinos, H, Carrillo, B, Merchán, A, Biosca-Brull, J, Pérez-Fernández, C, Colomina, MT, Sánchez-Santed, F, Martín-Sánchez, F, Collado, P, Arias, JL, et al
International journal of environmental research and public health. 2021;18(13)
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Obesity is a multifactorial disease with biological, psychosocial, and behavioural factors that include genetic, socioeconomic, and cultural influences. Exposure to pesticides can result in weight gain through different pathways. The aim of this study was to assess a possible association between prenatal and postnatal exposure to pesticides and obesity in offspring from human and animal studies. This study is a systematic review of 9 animal studies and 25 human studies (23 cohorts and 2 crossover experimental designs). Results show that there is still scarce evidence to support a clear relationship between exposure to pesticides and obesity in humans and experimental animals. In fact, the effects of pesticide exposure on body weight change are mostly inconclusive and report conflicting results. Authors conclude that further research is required to improve understanding of whether repeated exposures over time or just short-term exposures to pesticides during critical windows of development are related to obesity.
Abstract
In recent years, the worldwide prevalence of overweight and obesity among adults and children has dramatically increased. The conventional model regarding the onset of obesity is based on an imbalance between energy intake and expenditure. However, other possible environmental factors involved, such as the exposure to chemicals like pesticides, cannot be discarded. These compounds could act as endocrine-disrupting chemicals (EDC) that may interfere with hormone activity related to several mechanisms involved in body weight control. The main objective of this study was to systematically review the data provided in the scientific literature for a possible association between prenatal and postnatal exposure to pesticides and obesity in offspring. A total of 25 human and 9 animal studies were analyzed. The prenatal, perinatal, and postnatal exposure to organophosphate, organochlorine, pyrethroid, neonicotinoid, and carbamate, as well as a combined pesticide exposure was reviewed. This systematic review reveals that the effects of pesticide exposure on body weight are mostly inconclusive, finding conflicting results in both humans and experimental animals. The outcomes reviewed are dependent on many factors, including dosage and route of administration, species, sex, and treatment duration. More research is needed to effectively evaluate the impact of the combined effects of different pesticides on human health.
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The association between environmental exposures to chlordanes, adiposity and diabetes-related features: a systematic review and meta-analysis.
Mendes, V, Ribeiro, C, Delgado, I, Peleteiro, B, Aggerbeck, M, Distel, E, Annesi-Maesano, I, Sarigiannis, D, Ramos, E
Scientific reports. 2021;11(1):14546
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Chlordane is a synthetic organochlorine pesticide used for several decades in agriculture, but also in housing for pest control. Chlordane compounds are endocrine disrupting chemicals (EDCs), which means that they may affect the natural function of hormones by blocking, mimicking, displacing, or acting to subvert their roles. The aim of this study was to investigate whether exposure to chlordane compounds increases the risk of adiposity and diabetes in humans. This study is a systematic review and meta-analysis of 31 publications. Results demonstrate that there is no association between chlordane compounds and adiposity. However, there are higher odds of having diabetes-related features with increasing levels of all the chlordane compounds evaluated. Authors conclude that an international agreement on methods to measure both exposure and outcome variables and to conduct epidemiological studies could increase the knowledge on how adverse effects of exposure to various stressors (exposome) can influence human health.
Abstract
Chlordane compounds (CHLs) are components of technical chlordane listed in the Stockholm convention on persistent organic pollutants identified as endocrine disrupting chemicals (EDCs) and may interfere with hormone biosynthesis, metabolism or action resulting in an unbalanced hormonal function. There is increasing scientific evidence showing EDCs as risk factors in the pathogenesis and development of obesity and obesity-related metabolic syndromes such as type 2 diabetes, but there is no systematized information on the effect of CHLs in humans. Our aim is to identify the epidemiological data on the association between CHLs with adiposity and diabetes using a systematic approach to identify the available data and summarizing the results through meta-analysis. We searched PubMed and Web of Science from inception up to 15 February 2021, to retrieve original data on the association between chlordanes, and adiposity or diabetes. For adiposity, regression coefficients and Pearson or Spearman correlation coefficients were extracted and converted into standardized regression coefficients. Data were combined using fixed effects meta-analyses to compute summary regression coefficients and corresponding 95% confidence intervals (95% CI). For the association between chlordanes and diabetes, Odds ratios (ORs) were extracted and the DerSimonian and Laird method was used to compute summary estimates and respective 95% CI. For both, adjusted estimates were preferred, whenever available. Among 31 eligible studies, mostly using a cross-sectional approach, the meta-analysis for adiposity was possible only for oxychlordane and transchlordane, none of them were significantly associated with adiposity [(β = 0.04, 95% CI 0.00; 0.07, I2 = 89.7%)] and (β = 0.02, 95% CI - 0.01; 0.06), respectively. For diabetes, the estimates were positive for all compounds but statistically significant for oxychlordane [OR = 1.96 (95% CI 1.19; 3.23)]; for trans-nonachlor [OR = 2.43 (95% CI 1.64; 3.62)] and for heptachlor epoxide [OR = 1.88 (95% CI 1.42; 2.49)]. Our results support that among adults, the odds of having diabetes significantly increase with increasing levels of chlordanes. The data did not allow to reach a clear conclusion regarding the association with adiposity.
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A systematic review and meta-analysis of school-based interventions with health education to reduce body mass index in adolescents aged 10 to 19 years.
Jacob, CM, Hardy-Johnson, PL, Inskip, HM, Morris, T, Parsons, CM, Barrett, M, Hanson, M, Woods-Townsend, K, Baird, J
The international journal of behavioral nutrition and physical activity. 2021;18(1):1
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Obesity in childhood and adolescence is associated with an increased risk of non-communicable diseases such as Type 2 diabetes, cardiovascular disease, chronic obstructive lung disease and some forms of cancer. The aim of this study was to investigate the effectiveness of health education interventions delivered in school settings to prevent overweight and obesity and/ or reduce BMI in adolescents, and to explore the key features of effectiveness. This study is a systematic review and meta-analysis of 39 publications based on 33 studies. Six studies recruited adolescent girls only, one adolescent boys only and one study included parent-student dyad. Results show that: - Most of the effective interventions were delivered by teachers who were trained prior to the intervention. - School-based interventions are often delivered through school-staff, however, appropriate training/ CPD prior to the intervention could be a crucial component to support the provision and uptake of the intervention. - Many of the effective interventions included parental involvement and modifications to the school environment. - Interventions should target the biological, psychosocial, environmental, and behavioural influences on diet and physical activity. Authors conclude that school-based health education interventions could potentially help in improving BMI outcomes in the adolescent age group.
Abstract
BACKGROUND Adolescents are increasingly susceptible to obesity, and thus at risk of later non-communicable diseases, due to changes in food choices, physical activity levels and exposure to an obesogenic environment. This review aimed to synthesize the literature investigating the effectiveness of health education interventions delivered in school settings to prevent overweight and obesity and/ or reduce BMI in adolescents, and to explore the key features of effectiveness. METHODS A systematic search of electronic databases including MEDLINE, CINAHL, PsychINFO and ERIC for papers published from Jan 2006 was carried out in 2020, following PRISMA guidelines. Studies that evaluated health education interventions in 10-19-year-olds delivered in schools in high-income countries, with a control group and reported BMI/BMI z-score were selected. Three researchers screened titles and abstracts, conducted data extraction and assessed quality of the full text publications. A third of the papers from each set were cross-checked by another reviewer. A meta-analysis of a sub-set of studies was conducted for BMI z-score. RESULTS Thirty-three interventions based on 39 publications were included in the review. Most studies evaluated multi-component interventions using health education to improve behaviours related to diet, physical activity and body composition measures. Fourteen interventions were associated with reduced BMI/BMI z-score. Most interventions (n = 22) were delivered by teachers in classroom settings, 19 of which trained teachers before the intervention. The multi-component interventions (n = 26) included strategies such as environment modifications (n = 10), digital interventions (n = 15) and parent involvement (n = 16). Fourteen studies had a low risk of bias, followed by 10 with medium and nine with a high risk of bias. Fourteen studies were included in a random-effects meta-analysis for BMI z-score. The pooled estimate of this meta-analysis showed a small difference between intervention and control in change in BMI z-score (- 0.06 [95% CI -0.10, - 0.03]). A funnel plot indicated that some degree of publication bias was operating, and hence the effect size might be inflated. CONCLUSIONS Findings from our review suggest that school-based health education interventions have the public health potential to lower BMI towards a healthier range in adolescents. Multi-component interventions involving key stakeholders such as teachers and parents and digital components are a promising strategy.
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Trends in incidence of total or type 2 diabetes: systematic review.
Magliano, DJ, Islam, RM, Barr, ELM, Gregg, EW, Pavkov, ME, Harding, JL, Tabesh, M, Koye, DN, Shaw, JE
BMJ (Clinical research ed.). 2019;366:l5003
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Incidence measures the proportion of people who develop diabetes over a period of time among the population at risk. The aim of this study is to systematically review literature which reports diabetes incidence trends. This study is a systemic review of 47 studies. A total of 62% (n=29) of the studies exclusively reported on type 2 diabetes, and 38% (n=18) reported on total diabetes. Findings show that the incidence of diagnosed diabetes increased in most populations from the 1960s to the early 2000s, after which a pattern emerged of levelling trends in 30% and declining trends in 36% of the reported populations. Preventive strategies could have contributed to the fall in diabetes incidence in recent years. Authors conclude that improvement of the collection, availability, and analysis of incidence data will be important to effectively monitor the epidemic and guide prevention efforts into the future.
Abstract
OBJECTIVE To assess what proportions of studies reported increasing, stable, or declining trends in the incidence of diagnosed diabetes. DESIGN Systematic review of studies reporting trends of diabetes incidence in adults from 1980 to 2017 according to PRISMA guidelines. DATA SOURCES Medline, Embase, CINAHL, and reference lists of relevant publications. ELIGIBILITY CRITERIA Studies of open population based cohorts, diabetes registries, and administrative and health insurance databases on secular trends in the incidence of total diabetes or type 2 diabetes in adults were included. Poisson regression was used to model data by age group and year. RESULTS Among the 22 833 screened abstracts, 47 studies were included, providing data on 121 separate sex specific or ethnicity specific populations; 42 (89%) of the included studies reported on diagnosed diabetes. In 1960-89, 36% (8/22) of the populations studied had increasing trends in incidence of diabetes, 55% (12/22) had stable trends, and 9% (2/22) had decreasing trends. In 1990-2005, diabetes incidence increased in 66% (33/50) of populations, was stable in 32% (16/50), and decreased in 2% (1/50). In 2006-14, increasing trends were reported in only 33% (11/33) of populations, whereas 30% (10/33) and 36% (12/33) had stable or declining incidence, respectively. CONCLUSIONS The incidence of clinically diagnosed diabetes has continued to rise in only a minority of populations studied since 2006, with over a third of populations having a fall in incidence in this time period. Preventive strategies could have contributed to the fall in diabetes incidence in recent years. Data are limited in low and middle income countries, where trends in diabetes incidence could be different. SYSTEMATIC REVIEW REGISTRATION Prospero CRD42018092287.
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Diet Behavior Change Techniques in Type 2 Diabetes: A Systematic Review and Meta-analysis.
Cradock, KA, ÓLaighin, G, Finucane, FM, McKay, R, Quinlan, LR, Martin Ginis, KA, Gainforth, HL
Diabetes care. 2017;40(12):1800-1810
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Dietary behaviour is intrinsically linked to type 2 diabetes. Dietary factors have been linked to the highest proportion of deaths in type 2 diabetes, stroke, and heart disease. Identifying effective ways to help suffers successfully change to more effective dietary behaviours may help condition management and reduce disease progression. The objective of the systemic review and meta-analysis was to identify dietary behaviour change techniques, intervention features, and specific diets associated with changes in blood glucose levels (HbA1c) and body weight in type 2 diabetes. It included 54 studies, all of whose participants have type 2 diabetes. High-protein diets and meal replacement programs produced the greatest reductions in blood glucose (measured by HbA1c). Behavioural change techniques including 'problem solving,' 'feedback on behaviour,' 'adding objects to the environment' and 'social comparison' as well as interventions that were build on behavioural change theory were associated with clinically significant reductions in blood glucose as measured by HbA1c (a reduction of ≥0.3% (3.3 mmol/mol). However, the findings show that changing or controlling (e.g. providing all food) dietary environmental factors may be more effective than strategies to change dietary behaviour to reduce blood glucose levels in adults with type 2 diabetes. The authors conclude that changing the dietary environment may be more important than focusing on dietary behaviour in type 2 diabetes treatment.
Abstract
OBJECTIVE Dietary behavior is closely connected to type 2 diabetes. The purpose of this meta-analysis was to identify behavior change techniques (BCTs) and specific components of dietary interventions for patients with type 2 diabetes associated with changes in HbA1c and body weight. RESEARCH DESIGN AND METHODS The Cochrane Library, CINAHL, Embase, PubMed, PsycINFO, and Scopus databases were searched. Reports of randomized controlled trials published during 1975-2017 that focused on changing dietary behavior were selected, and methodological rigor, use of BCTs, and fidelity and intervention features were evaluated. RESULTS In total, 54 studies were included, with 42 different BCTs applied and an average of 7 BCTs used per study. Four BCTs-"problem solving," "feedback on behavior," "adding objects to the environment," and "social comparison"-and the intervention feature "use of theory" were associated with >0.3% (3.3 mmol/mol) reduction in HbA1c. Meta-analysis revealed that studies that aimed to control or change the environment showed a greater reduction in HbA1c of 0.5% (5.5 mmol/mol) (95% CI -0.65, -0.34), compared with 0.32% (3.5 mmol/mol) (95% CI -0.40, -0.23) for studies that aimed to change behavior. Limitations of our study were the heterogeneity of dietary interventions and poor quality of reporting of BCTs. CONCLUSIONS This study provides evidence that changing the dietary environment may have more of an effect on HbA1c in adults with type 2 diabetes than changing dietary behavior. Diet interventions achieved clinically significant reductions in HbA1c, although initial reductions in body weight diminished over time. If appropriate BCTs and theory are applied, dietary interventions may result in better glucose control.