Obesity, body fat distribution and eye diseases.

BACKGROUND: The prevalence of obesity, a chronic disease, is increasing, and obesity is now considered a global epidemic. Eye diseases are also increasing worldwide and have serious repercussions on quality of life as well as increasingly high costs for the community. The relationships between obesity and ocular pathologies are not yet well clarified and are not pathologically homogeneous: they seem to be somehow linked to excess body fat, especially to the distribution of adipose tissue and its ectopic deposits. PURPOSE: Our objective was to examine the associations between obesity and anthropometric indices, including body mass index (BMI), waist circumference (WC), and the waist/hip ratio (WHR), and the risk of most widespread eye diseases, with particular attention given to the most significant metabolic mechanisms. METHODS: This article provides a narrative overview of the effect of obesity and anthropometric measurements of body fat on prevalent eye diseases. We used the MEDLINE/PubMed, CINAHL, EMBASE, and Cochrane Library databases from 1984 to 2024. In addition, we hand-searched references from the retrieved articles and explored a number of related websites. A total of 153 publications were considered. RESULTS: There is significant evidence that obesity is associated with several eye diseases. Waist circumference (WC) and the waist/hip ratio (WHR) have been observed to have stronger positive associations with eye diseases than BMI. CONCLUSIONS: Obesity must be considered a significant risk factor for eye diseases; hence, a multidisciplinary and multidimensional approach to treating obesity, which also affects ocular health, is important. In the prevention and treatment of eye diseases related to obesity, lifestyle factors, especially diet and physical activity, as well as weight changes, both weight loss and weight gain, should not be overlooked. LEVEL OF EVIDENCE: Level V narrative review.

The Impact of a Nutritional Intervention on Glycemic Control and Cardiovascular Risk Markers in Type 2 Diabetes.

INTRODUCTION: Nutritional management plays a crucial role in treating patients with type 2 diabetes (T2D), working to prevent and control the progression of chronic non-communicable diseases. OBJECTIVES: To evaluate the effects of individualized nutritional interventions on weight, body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), fasting blood glucose (FBG), hemoglobin A1c (HbA1c), total cholesterol (TC), LDL cholesterol (LDL-C), HDL cholesterol (HDL-C), triglycerides (TGs), systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR)} over 12 months and subsequently at follow-up (15 months). METHODS: This longitudinal experimental study (without randomization and blinding) enrolled 84 sedentary participants with T2D (both sexes, aged 18-80 years). They were divided into a control group of 40 participants who received only medical consultations, and an intervention group of 44 participants who received the same medical care along with a nutritional assessment. Consultations occurred quarterly from August 2020 to November 2022 (first-twelfth month), with six to nine patients per session. Subsequently, a follow-up was conducted from December 2022 to November 2023, during which the intervention group had only medical care (during the 12th-15th months). Personalized dietary planning was inspired by the Mediterranean/DASH diets adapted to Brazilian foods and socioeconomic cultures. STATISTICAL ANALYSIS: Normal variables were compared between groups for each time point and also within each group across different time points using a two-way ANOVA (repeated measures for intragroup) followed by the Sídák post hoc test. Non-normal variables were compared between groups for each time point using Kruskal-Wallis followed by the Dunn post hoc test, and within each group across different time points using Friedman followed by the Dunn post hoc test. Data with a Gaussian distribution were presented as mean ± standard deviation (SD), and data with a non-Gaussian distribution were presented as median ± interquartile range (IQR). For all cases, α < 0.05 and p < 0.05 were adopted. RESULTS: In the intervention group, significant reductions were observed between the first and twelfth month for all parameters (p < 0.05), (except for TC), along with an increase in HDL-C (p = 0.0105). Conversely, in the control group, there was a significant increase in HbA1c, weight, BMI, FBG, and WHR (p < 0.05) between the first and twelfth months. Regarding the comparison between groups, there was a significant difference for all analyzed parameters (p < 0.05) from the first to the twelfth month. In the follow-up, differences were also observed (p < 0.05), except for BMI (p > 0.05). CONCLUSION: The individualized nutritional intervention improved eating habits, anthropometric, biochemical, and cardiovascular markers in T2D over 12 months, with sustained results during follow-up. The dietary plan inspired by the Mediterranean and DASH diets demonstrated good adaptation to the Brazilian food culture and the patients' socioeconomic contexts. Consistent monitoring and personalized nutritional management are essential for optimizing long-term outcomes. However, more clinical trials are necessary in order to optimize the level of evidence for longitudinal interventions.

Systems genetics analysis of human body fat distribution genes identifies adipocyte processes.

Excess abdominal fat is a sexually dimorphic risk factor for cardio-metabolic disease and is approximated by the waist-to-hip ratio adjusted for body mass index (WHRadjBMI). Whereas this trait is highly heritable, few causal genes are known. We aimed to identify novel drivers of WHRadjBMI using systems genetics. We used two independent cohorts of adipose tissue gene expression and constructed sex- and depot-specific Bayesian networks to model gene-gene interactions from 8,492 genes. Using key driver analysis, we identified genes that, in silico and putatively in vitro, regulate many others. 51-119 key drivers in each network were replicated in both cohorts. In other cell types, 23 of these genes are found in crucial adipocyte pathways: Wnt signaling or mitochondrial function. We overexpressed or down-regulated seven key driver genes in human subcutaneous pre-adipocytes. Key driver genes ANAPC2 and RSPO1 inhibited adipogenesis, whereas PSME3 increased adipogenesis. RSPO1 increased Wnt signaling activity. In differentiated adipocytes, MIGA1 and UBR1 down-regulation led to mitochondrial dysfunction. These five genes regulate adipocyte function, and we hypothesize that they regulate fat distribution.

Association of lipid profile and obesity in patients with polycystic ovary syndrome.

Objective. Abnormal lipid profile and obesity increase the risk of polycystic ovary syndrome (PCOS). PCOS patients may have a greater risk of infertility, metabolic syndrome (MetS) and cardiovascular disease (CVD) due to abnormal lipid profile and obesity. The aim of the study was to find the association between abnormal lipid profile and obesity in patients with PCOS. Methods. In this case-control study, a total of 102 female subjects (51 diagnosed PCOS and 51 age-matched healthy controls) were enrolled, aged between 20-40 years. Biochemical parameters such as total cholesterol (TC), triglycerides (TG), low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), very low-density lipoprotein-cholesterol (VLDL-C), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were estimated. Anthropometric parameters such as body mass index (BMI), waist circumference (WC), hip circumference (HC), and waist-to-hip ratio (WHR) were recorded. A p<0.05 was considered statistically significant. Results. Mean of BMI, WC, WHR, LH, FSH, TC, TG, LDL-C, and VLDL-C was found significantly elevated in patients with PCOS as compared to controls (p<0.01). However, the mean of HDL-C was found significantly reduced in patients with PCOS as compared to controls (p<0.01). BMI has shown a significant positive correlation with WC (r=0.562, p<0.01) and WHR (r=0.580, p<0.01) among PCOS patients. LH has shown a significant positive correlation with FSH (r=0.572, p<0.01) among PCOS patients. TC has shown a significant positive correlation with TG (r=0.687, p<0.01), LDL-C (r=0.917, p<0.01), and VLDL-C (r=0.726, p<0.01) among PCOS patients. Conclusion. The results showed that abnormal lipid profile and obesity have a significant association with PCOS patients. Regular monitoring and treatment of PCOS patients are required to reduce the risk of infertility, MetS, and CVD.

Prevalence of risk factors for development of cardiovascular diseases in urban and rural areas of Eastern Croatia: a cross-sectional study.

OBJECTIVE: Cardiovascular diseases are the leading global cause of death. Due to the disparities in cardiovascular risk factors between rural and urban populations, this study aims to assess the differences in the prevalence of risk factors in urban and rural areas of eastern Croatia. METHODS: The cross-sectional study included 280 participants (140 from urban and 140 from rural areas) registered at studied general practice offices. Methods included e-health records, questionnaire, physical examination methods, and blood sampling for laboratory tests. RESULTS: The most common risk factors among participants were elevated total cholesterol (83.6%), elevated LDL cholesterol (81.8%), increased body mass index (75.0%), increased waist-hip ratio (82.9%), increased waist circumference (63.2%), and arterial hypertension (70.1%). The rural participants had a significantly higher prevalence of arterial hypertension (p = 0.023), increased body mass index (p = 0.004), increased waist circumference (p = 0.004), increased waist-hip ratio (p < 0.001), and increased LDL cholesterol (p = 0.029), while the urban participants had a significantly higher prevalence of insufficient physical activity (p < 0.001). CONCLUSIONS: In the examined sample, the prevalence of cardiovascular risk factors is generally high. Participants from rural areas are significantly more susceptible to cardiovascular risk factors than participants from urban areas.

Physical activity alters the effect of genetic determinants of adiposity on hypertension among individuals of European ancestry in the UKB.

Hypertension is a leading risk factor for cardiovascular disease and is modulated by genetic variants. This study aimed to assess the effect of obesity genetic liability and physical activity on hypertension among European and African ancestry individuals within the UK Biobank (UKB). Participants were 230 115 individuals of European ancestry and 3239 individuals of African ancestry from UKB. Genetic liability for obesity were estimated using previously published data including genetic variants and effect sizes for body mass index (BMI), waist-hip ratio (WHR) and waist circumference (WC) using Plink software. The outcome was defined as stage 2 hypertension (systolic blood pressure ≥ 140 mmHg, diastolic blood pressure ≥90 mmHg, or the use of anti-hypertensive medications). The association between obesity genetic liability and the outcome was assessed across categories of self-reported physical activity using logistic regression. Among European ancestry participants, there was up to a 1.2 greater odds of hypertension in individuals with high genetic liability and low physical activity compared to individuals with low genetic liability and high physical activity (p < 0.001). In individuals engaging in low levels of physical activity compared with moderate/high physical activity, the effect of BMI genetic liability on hypertension was greater (p interaction = 0.04). There was no evidence of an association between obesity genetic liability and hypertension in individuals of African ancestry in the whole sample or within separate physical activity groups (p > 0.05). This study suggests that higher physical activity levels are associated with lower odds of stage 2 hypertension among European ancestry individuals who carry high genetic liability for obesity. This cannot be inferred for individuals of African ancestry, possibly due to the low African ancestry sample size within the UKB.

Association of anthropometric measures with all-cause and cause-specific mortality in US adults: revisiting the obesity paradox.

OBJECTIVE: Previous studies have shown that the obesity paradox exists in a variety of clinical settings, whereby obese individuals have lower mortality than their normal-weight counterparts. It remains unclear whether the association between obesity and mortality risk varies by anthropometric measures. The purpose of this study is to examine the association between various anthropometric measures and all-cause and cause-specific mortality in US adults. METHODS: This cohort study included data from the National Health and Nutrition Examination Survey between 2009 and 2018, with a sample size of 28,353 individuals weighted to represent 231 million US adults. Anthropometric measurements were obtained by trained technicians using standardized methods. Mortality data were collected from the date of enrollment through December 31, 2019. Weighted Cox proportional hazards models, restricted cubic spline curves, and cumulative incidence analyses were performed. RESULTS: A total of 2091 all-cause deaths, 606 cardiovascular deaths, 519 cancer deaths, and 966 other-cause deaths occurred during a median follow-up of 5.9 years. The association between body mass index (BMI) and mortality risk was inversely J-shaped, whereas the association between waist-to-height ratio (WHtR) and mortality risk was positively J-shaped. There was a progressive increase in the association between the WHtR category and mortality risk. Compared with the reference category of WHtR < 0.5, the estimated hazard ratio (HR) for all-cause mortality was 1.004 (95% confidence interval [CI] 1.001-1.006) for WHtR 0.50-0.59, 1.123 (95% CI 1.120-1.127) for WHtR 0.60-0.69, 1.591 (95% CI 1.584-1.598) for WHtR 0.70-0.79, and 2.214 (95% CI 2.200-2.228) for WHtR ≥ 0.8, respectively. Other anthropometric indices reflecting central obesity also showed that greater adiposity was associated with higher mortality. CONCLUSIONS: Anthropometric measures reflecting central obesity were independently and positively associated with mortality risk, eliminating the possibility of an obesity paradox.

Predictive Ability of Hypertriglyceridemic Waist, Hypertriglyceridemic Waist-to-Height Ratio, and Waist-to-Hip Ratio for Cardiometabolic Risk Factors Clustering Screening among Chinese Children and Adolescents.

Objective: Hypertriglyceridemic waist (HW), hypertriglyceridemic waist-to-height ratio (HWHtR), and waist-to-hip ratio (WHR) have been shown to be indicators of cardiometabolic risk factors. However, it is not clear which indicator is more suitable for children and adolescents. We aimed to investigate the relationship between HW, HWHtR, WHR, and cardiovascular risk factors clustering to determine the best screening tools for cardiometabolic risk in children and adolescents. Methods: This was a national cross-sectional study. Anthropometric and biochemical variables were assessed in approximately 70,000 participants aged 6-18 years from seven provinces in China. Demographics, physical activity, dietary intake, and family history of chronic diseases were obtained through questionnaires. ANOVA, χ 2 and logistic regression analysis was conducted. Results: A significant sex difference was observed for HWHtR and WHR, but not for HW phenotype. The risk of cardiometabolic health risk factor clustering with HW phenotype or the HWHtR phenotype was significantly higher than that with the non-HW or non-HWHtR phenotypes among children and adolescents (HW: OR = 12.22, 95% CI: 9.54-15.67; HWHtR: OR = 9.70, 95% CI: 6.93-13.58). Compared with the HW and HWHtR phenotypes, the association between risk of cardiometabolic health risk factors (CHRF) clustering and high WHR was much weaker and not significant (WHR: OR = 1.14, 95% CI: 0.97-1.34). Conclusion: Compared with HWHtR and WHR, the HW phenotype is a more convenient indicator withhigher applicability to screen children and adolescents for cardiovascular risk factors.

Fat tissue quantity, waist circumference or waist-to-hip ratio in patients with chronic kidney disease: A systematic review and meta-analysis.

The BMI predicts mortality and cardiovascular disease (CVD) in the general population, while in patients with end-stage chronic kidney disease (CKD) a high BMI is associated with improved survival, a phenomenon referred to as the "obesity paradox". While BMI is easy to determine and helps to categorize patients, it does not differentiate between fat tissue, lean tissue and bone mass. As the BMI may be altered in CKD, e.g. by muscle wasting, we determined in this meta-analysis (i) the association of mortality with fat tissue quantity in CKD and (ii) the association of mortality with abdominal obesity (as measured by waist circumference (WC) or waist-to-hip ratio (WHR)) in CKD. We systematically reviewed databases for prospective or retrospective cohort studies. In eleven studies with 23,523 patients the association between mortality and high fat tissue quantity in CKD was calculated. The pooled hazard ratio (HR) for this association in the CKD group in the dialysis group 0.91 (CI 0.84- 0.98, p = 0.01) which is comparable to the HR for the association with BMI. The HR in patients without dialysis was 0.7 (95% CI 0.53- 0.93, p = 0.01), suggesting a better risk prediction of high fat tissue content with mortality as compared to higher BMI with mortality in patients with CKD without dialysis. Importantly, both BMI and fat tissue quantity in CKD are described by the "obesity paradox": the higher the fat tissue content or BMI, the lower the mortality risk. In thirteen studies with 55,175 patients the association between mortality and high WC or WHR in CKD (with or without dialysis) was calculated. We observed, that the HR in the WHR group was 1.31 (CI 1.08-1.58, p = 0.007), whereas the overall hazard ratio of both groups was 1.09 (CI 1.01-1.18, p = 0.03), indicating that a higher abdominal obesity as measured by WHR is associated with higher mortality in CKD. Our analysis suggests gender-specific differences, which need larger study numbers for validation. This meta-analysis confirms the obesity paradox in CKD using fat tissue quantity as measure and further shows that using abdominal obesity measurements in the routine in obese CKD patients might allow better risk assessment than using BMI or fat tissue quantity. Comparable to the overall population, here, the higher the WHR, the higher the mortality risk.

Causal analysis of body composition measurements in osteoarthritis knee: a two-sample mendelian randomization study.

BACKGROUND: To analyse the causal associations of different physical measures with osteoarthritis knee (KOA). METHODS: Exposure factors (weight, body mass index (BMI), body fat percentage, waist circumference, hip circumference, waist-hip ratio (WHR), and basal metabolic rate (BMR)), and outcome factor KOA were analyzed by inverse-variance weighted (IVW) method, along with heterogeneity test, sensitivity and pleiotropy analyses. Meta-analysis was used to combine the effect values of IVW methods in different data sources. RESULTS: Weight, BMI, body fat percentage, waist circumference, hip circumference and BMR analyses showed causal association with increased KOA risk, while WHR analysis indicated a reduction of the incidence of KOA. P-value for all the results was less than 0.05 and F-value large than 20. All results were negative for heterogeneity tests and sensitivity analyses, and there was pleiotropy in weight and BMR. Meta-analysis results showed that the results of Odds Ratios (95% Confidence Intervals) for Weight (1.43(1.35-1.51)), BMI (1.40(1.10-1.78)), body fat percentage (1.56(1.44-1.68)), waist circumference (1.40(1.10-1.78)), hip circumference (1.37(1.30-1.44)), WHR (0.86(0.71-1.04)) and BMR (1.36(1.27-1.46) were consistent with the ones by Mendelian randomization analyses. CONCLUSIONS: Body fat percentage may be a better indicator of KOA than BMI. In addition, weight and BMR may have a causal effect in KOA, but WHR does not have a causal relationship. BMI, body fat percentage, waist circumference, and hip circumference has a causal effect on KOA.

Alternative models to support weight loss in chronic musculoskeletal conditions: effectiveness of a physiotherapist-delivered intensive diet programme for knee osteoarthritis, the POWER randomised controlled trial.

OBJECTIVES: To determine if physiotherapists can deliver a clinically effective very low energy diet (VLED) supplementary to exercise in people with knee osteoarthritis (OA) and overweight or obesity. METHODS: 88 participants with knee OA and body mass index (BMI) >27 kg/m2 were randomised to either intervention (n=42: VLED including two daily meal replacement products supplementary to control) or control (n=46: exercise). Both interventions were delivered by unblinded physiotherapists via six videoconference sessions over 6 months. The primary outcome was the percentage change in body weight at 6 months, measured by a blinded assessor. Secondary outcomes included BMI, waist circumference, waist-to-hip ratio, self-reported measures of pain, function, satisfaction and perceived global change, and physical performance tests. RESULTS: The intervention group lost a mean (SD) of 8.1% (5.2) body weight compared with 1.0% (3.2) in the control group (mean (95% CI) between-group difference 7.2% (95% CI 5.1 to 9.3), p<0.001), with significantly lower BMI and waist circumference compared with control group at follow-up. 76% of participants in the intervention group achieved ≥5% body weight loss and 37% acheived ≥10%, compared with 12% and 0%, respectively, in the control group. More participants in the intervention group (27/38 (71.1%)) reported global knee improvement than in the control group (20/42 (47.6%)) (p=0.02). There were no between-group differences in any other secondary outcomes. No serious adverse events were reported. CONCLUSION: A VLED delivered by physiotherapists achieved clinically relevant weight loss and was safe for people with knee OA who were overweight or obese. The results have potential implications for future service models of care for OA and obesity. TRIAL REGISTRATION NUMBER: NIH, US National Library of Medicine, Clinicaltrials.gov NCT04733053 (1 February 2021).

Causal relationship of obesity and adiposity distribution on risk of ventral hernia.

PURPOSE: Ventral hernia (VH) is a common surgical disease. Previous studies suggested that obesity is an important risk factor for VH. However, the causal relationship between fat distribution and the risk of VH is still unclear. This study used Mendelian randomization (MR) to evaluate their causal relationship. METHODS: We used the body mass index (BMI), body fat percentage, and body fat mass to represent general obesity and utilized the volume of abdominal subcutaneous adiposity tissue, visceral adiposity tissue, waist circumference, hip circumference, and waist-to-hip ratio to represent abdominal adiposity. The data were extracted from the large-scale genome-wide association study of European ancestry. We used two-sample MR to infer causality, using multivariate MR to correct the effects of confounding factors. RESULTS: Increased BMI, body fat percentage, body fat mass, visceral adiposity tissue, waist circumference, and hip circumference rather than subcutaneous adiposity tissue or waist-to-hip ratio, were causally associated with a higher risk of VH. The results of multivariate MR suggested that body fat percentage was causally associated with a higher risk of VH after adjusting for body mass index, diabetes, and smoking. CONCLUSION: General obesity, increased visceral adiposity tissue, waist circumference, and hip circumference rather than subcutaneous adiposity tissue or the waist-to-hip ratio were causally associated with a higher risk of VH. These findings provided a deeper understanding of the role that the distribution of adiposity plays in the mechanism of VH.

Adiposity indices and their higher predictive value for new-onset hypertension in metabolically healthy young women: findings from a population-based prospective cohort study.

BACKGROUND AND AIMS: The present study aimed to investigate the predictive ability of selected adiposity indices, such as body mass index (BMI), waist-to-hip ratio (WHR), waist circumference (WC), and waist-to-height ratio (WHtR), for new-onset hypertension in metabolically healthy Taiwanese adults. The study also sought to establish sex-specific cutoff points for these indices and to analyze the risk of new-onset hypertension, taking into account sex and age. METHODS: This prospective cohort study utilized the Taiwan Biobank database to examine metabolically healthy participants aged between 20 and 65 at baseline. Four adiposity indices, namely BMI, WHR, WC, and WHtR, were calculated and used to predict new-onset hypertension over 4 years. Receiver operating characteristics (ROCs) and areas under the curve (AUCs) were used to evaluate the effectiveness of the parameters in predicting new-onset hypertension over 4 years. Sex-specific cutoff points were identified and used to assess the risk of new-onset hypertension. RESULTS: This study analyzed 13,375 participants over 4.28 years. The incidence of new-onset hypertension was 17.65%. The new-onset rate of hypertension was 34.39% in men and 65.61% in women. Adiposity indices effectively predict new-onset hypertension, with WHtR having the highest predictive value (i.e., AUC) for both sexes. The classification of participants into low and high categories for each adiposity index was based on sex-specific cutoff points, and the risk of new-onset hypertension was assessed according to sex and age. This study found that high adiposity indices predicted a significantly higher risk of new-onset hypertension in metabolically healthy adults. The risk was equal for both sexes. Young women had a higher risk of new-onset hypertension than middle-aged women when they were further categorized. All risk ratios of the indices in young women were over two-fold and significant. CONCLUSION: According to the sex-specific cutoff point, high adiposity indices had a higher predictive value for new-onset hypertension in metabolically healthy Taiwanese young women.

[Impact of Anthropometric Indices of Obesity on the Risk of Incident Hypertension in Adults with Prehypertension: A Secondary Analysis of a Cohort Study].

PURPOSE: This study aimed to investigate the impact of anthropometric indices of obesity (body mass index [BMI], waist circumference, waist hip ratio, and body fat percentage) on the incidence of hypertension in adults with prehypertension. METHODS: A longitudinal study design using secondary data form the Korean Genome and Epidemiology Study was employed. The study included 1,838 adults with prehypertension tracked every two years from 2001 to 2018. Statistical analyses, including frequency assessments, number of cases per 1,000 person-years, log-rank tests, Kaplan-Meier curves, and Cox's proportional hazards regression, were conducted using SPSS version 25. RESULTS: Over the observation period (15,783.6 person-years), 1,136 individuals developed hypertension. The incidence of hypertension was significantly higher in the obesity groups defined by BMI (hazard ratio [HR] = 1.33), waist circumference (HR = 1.34), waist hip ratio (HR = 1.29), and body fat percentage (HR = 1.31) compared to the non-obese group. These findings indicate an increased risk of hypertension associated with obesity as measured by these indices. CONCLUSION: The study underscores the importance of avoiding obesity to prevent hypertension in individuals with prehypertension. Specifically, BMI, waist circumference, waist hip circumference, and body fat percentage were identified as significant risk factors for hypertension. The results suggest the need for individualized weight control interventions, emphasizing the role of health professionals in addressing the heightened hypertension risk in this population.

Analyses of potential causal contributors to increased waist/hip ratio-associated cardiometabolic disease: A combined and sex-stratified Mendelian randomization study.

BACKGROUND: Increased waist/hip ratio (WHR) contributes to type 2 diabetes, fatty liver, dyslipidaemia, hypertension and coronary artery disease, with potential sex-differential effects. Postulated mediators include increased lipid flux, branched-chain amino acids, glycine and glycoprotein acetyl, but their relative contributions and sex-specific impact on WHR-associated cardiometabolic disease (CMD) are not established. METHODS: We therefore undertook combined and sex-stratified Mendelian randomization (MR) to assess the relative causal contributions of these mediators to WHR-associated CMD using summary statistics from the largest genome-wide association studies in European ancestries. RESULTS: In sex-combined MR analyses, increased WHR significantly reduces high-density lipoprotein (beta = -0.416, SE = 0.029, p = 2.87E-47), increases triglyceride (beta = 0.431, SE = 0.029, p = 1.87E-50), type 2 diabetes (odds ratio = 2.747, SE = 0.09, p = 26E-23), coronary artery disease (odds ratio = 1.478, SE = 0.045, p = 6.96E-18), alanine transaminase (beta = 0.062, SE = 0.004, p = 6.88E-67), and systolic (beta = 0.134, SE = 0.022, p = 7.81E-10) and diastolic blood pressure (beta = 0.162, SE = 0.026, p = 5.38E-10). Adjustment for the mediators attenuated WHR's effects, but the associations remained significant with concordant results in females. In males, a similar pattern was seen, except after adjusting for the effect of the ratio of monounsaturated fatty acid to total free fatty acid, the potential causal effect of WHR was no longer significant: high-density lipoprotein (beta = -0.117, SE = 0.069, p = .09) and triglyceride (beta = 0.051, SE = 0.068, p = .459). CONCLUSIONS: MR suggests WHR increases the risk of CMD independent of these mediators, with the exception of dyslipidaemia in males, which is largely driven by the monounsaturated fatty acid to total free fatty acid ratio.

Estimating causality between smoking and abdominal obesity by Mendelian randomization.

BACKGROUND AND AIMS: Smokers tend to have a lower body weight than non-smokers, but also more abdominal fat. It remains unclear whether or not the relationship between smoking and abdominal obesity is causal. Previous Mendelian randomization (MR) studies have investigated this relationship by relying upon a single genetic variant for smoking heaviness. This approach is sensitive to pleiotropic effects and may produce imprecise causal estimates. We aimed to estimate causality between smoking and abdominal obesity using multiple genetic instruments. DESIGN: MR study using causal analysis using summary effect estimates (CAUSE) and latent heritable confounder MR (LHC-MR) methods that instrument smoking using genome-wide data, and also two-sample MR (2SMR) methods. SETTING: Genome-wide association studies (GWAS) summary statistics from participants of European ancestry, obtained from the GWAS and Sequencing Consortium of Alcohol and Nicotine use (GSCAN), Genetic Investigation of Anthropometric Traits (GIANT) Consortium and the UK Biobank. PARTICIPANTS: We used GWAS results for smoking initiation (n = 1 232 091), life-time smoking (n = 462 690) and smoking heaviness (n = 337 334) as exposure traits, and waist-hip ratio (WHR) and waist and hip circumferences (WC and HC) (n up to 697 734), with and without adjustment for body mass index (adjBMI), as outcome traits. MEASUREMENTS: Smoking initiation, life-time smoking, smoking heaviness, WHR, WC, HC, WHRadjBMI, WCadjBMI and HCadjBMI. FINDINGS: Both CAUSE and LHC-MR indicated a positive causal effect of smoking initiation on WHR (0.13 [95% confidence interval (CI) = 0.10, 0.16 and 0.49 (0.41, 0.57), respectively] and WHRadjBMI (0.07 (0.03, 0.10) and 0.31 (0.26, 0.37). Similarly, they indicated a positive causal effect of life-time smoking on WHR [0.35 (0.29, 0.41) and 0.44 (0.38, 0.51)] and WHRadjBMI [0.18 (0.13, 0.24) and 0.26 (0.20, 0.31)]. In follow-up analyses, smoking particularly increased visceral fat. There was no evidence of a mediating role by cortisol or sex hormones. CONCLUSIONS: Smoking initiation and higher life-time smoking may lead to increased abdominal fat distribution. The increase in abdominal fat due to smoking is characterized by an increase in visceral fat. Thus, efforts to prevent and cease smoking can have the added benefit of reducing abdominal fat.

Associations of 50 modifiable risk factors with atrial fibrillation using Mendelian randomization analysis.

BACKGROUND: Substantial focus has been placed on atrial fibrillation (AF) treatment and associated stroke prevention rather than preventing AF itself. We employed Mendelian randomization (MR) approach to examine the causal relationships between 50 modifiable risk factors (RFs) and AF. METHODS: Instrumental variables for genetically predicted exposures were derived from corresponding genome-wide association studies (GWASs). Summary-level statistical data for AF were obtained from a GWAS meta-analysis (discovery dataset, N = 1,030,836) and FinnGen (validation dataset, N = 208,594). Univariable and multivariable MR analyses were performed, primarily using inverse variance weighted method with a series of robust sensitivity analyses. RESULTS: Genetic predisposition to insomnia, daytime naps, apnea, smoking initiation, moderate to vigorous physical activity and obesity traits, including body mass index, waist-hip ratio, central and peripheral fat/fat-free mass, exhibited significant associations with an increased risk of AF. Coffee consumption and ApoB had suggestive increased risks. Hypertension (odds ratio (OR) 95% confidence interval (CI): 5.26 (4.42, 6.24)), heart failure (HF) (OR 95% CI, 4.77 (2.43, 9.37)) and coronary artery disease (CAD) (OR 95% CI: 1.20 (1.16, 1.24)) were strongly associated with AF, while college degree, higher education attachment and HDL levels were associated with a decreased AF risk. Reverse MR found a bidirectional relationship between genetically predicted AF and CAD, HF and ischemic stroke. Multivariable analysis further indicated that obesity-related traits, systolic blood pressure and lower HDL levels independently contributed to the development of AF. CONCLUSIONS: This study identified several lifestyles and cardiometabolic factors that might be causally related to AF, underscoring the importance of a holistic approach to AF management and prevention.

Associations of obesity indices change with cardiovascular outcomes: a dose-response meta-analysis.

BACKGROUND: Little is known about the degrees and shapes of associations of changes in obesity indices with cardiovascular disease (CVD) and mortality risks. We aimed to conduct a dose-response meta-analysis for the associations of changes in weight, body mass index (BMI), waist circumference (WC), waist-to-hip ratio, and waist-to-height ratio with CVD events, CVD-specific deaths, and all-cause mortality. METHODS: We searched MEDLINE via OvidSP, Embase via OvidSP, Web of Science, CINAHL, and Scopus for articles published before January 8th, 2023. Dose-response relationships were modeled using the one-stage mixed-effects meta-analysis. Random-effects models were used to pool the relative risk (RR) and 95% confidence interval (CI). RESULTS: We included 122 articles. Weight change was negatively associated with deaths from CVD and any cause, while WC change elevated CVD-specific mortality. Non-linear relationships also confirmed the adverse effects of increased WC on CVD-specific mortality. Additionally, gains of 5 kg in weight and 1 kg/m2 in BMI or more were associated with elevated CVD events, especially among young adults and individuals without CVD. Conversely, reductions of 5 kg in weight and 1 kg/m2 in BMI or more were associated with higher CVD-specific and all-cause deaths than increased counterparts, particularly among old adults and individuals with CVD. Similar non-linear relationships between relative changes in weight and BMI and deaths from CVD and any cause were observed. CONCLUSIONS: The effects of changes in weight and BMI on CVD outcomes were affected by age and cardiovascular health. Tailored weight management and avoidance of increased WC should be recommended.

Sex-specific associations of childhood maltreatment with obesity-related traits - The Study of Health in Pomerania (SHIP).

BACKGROUND: Child maltreatment (CM) is linked to obesity in adulthood. However, sex-differences and direct measurements of body fat have previously been insufficiently considered in this context. OBJECTIVE: To assess sex-specific associations of CM with anthropometric markers of overweight/obesity and direct measures of body fat. PARTICIPANTS AND SETTING: Analyses were conducted in 4006 adults from a population-based cohort in Northeastern Germany (SHIP-TREND-0). METHODS: CM was assessed using the Childhood Trauma Questionnaire (CTQ). Obesity-related traits included anthropometric indicators (i.e., height, weight, body mass index [BMI], waist [WC] and hip circumference [HC], waist-to-hip ratio [WHR], waist-to-height ratio [WHtR]), fat mass (FM) and fat-free mass (FFM) derived from bioelectrical impedance analysis (BIA), and subcutaneous (SAT) and visceral adipose tissue (VAT) ascertained using magnetic resonance imaging (MRI). Sex-stratified linear regression models predicting obesity-related traits from total CTQ scores were adjusted for age and education. Exploratory analyses investigated effects of CTQ subscales on obesity-related traits. RESULTS: In men, CM was positively associated with WHtR (ß = 0.04; p = .030) and VAT (ß = 0.02; p = .031) and inversely with body height (ß = -0.05; p = .010). In women, CM-exposure was positively associated with body weight (ß = 0.07; p = .018), BMI (ß = 0.03; p = .013), WC (ß = 0.07; p = .005), HC (ß = 0.05; p = .046), WHR (ß = 0.03; p = .015), WHtR (ß = 0.04; p = .006), FM (ß = 0.04; p = .006), and SAT (ß = 0.06; p = .041). In both sexes, effects were mainly driven by exposure to emotional and physical abuse. CONCLUSIONS: Results suggest that associations between CM-exposure and obesity-related traits in adulthood are primarily present in women. This may have implications for sex-specific obesity-related cardiometabolic risk after CM.

Is There a Relationship between Anthropometric Indices and Muscular, Motor, and Cardiorespiratory Components of Health-Related Fitness in Active European Older Adults?

The aging process induces alterations in the body, resulting in changes in both health-related fitness and specific anthropometric measures. These changes often pose health risks for older adults. The aim of the present study was to investigate whether there is an association between anthropometric indices and muscular, motor, and cardiorespiratory components of health-related fitness in active European older adults. This study included 2687 European older adults, comprising 1999 women and 688 men, with an average age of 70.05 ± 5.5 years. The assessment included health-related fitness using the Senior Fitness Test and anthropometric indices, such as the body adiposity index, body mass index, conicity index, waist-to-hip ratio, and waist-to-height ratio, among others. The results indicated that gender significantly influences the values of physical performance and anthropometric parameters, making them incomparable. The degree of correlation between anthropometric indices and muscular, motor, and cardiorespiratory components of fitness depends on each anthropometric index analysed. The anthropometric index most correlated with physical fitness performance parameters is the waist-to-height ratio (WHR), followed by the body mass index (BMI). Cardiorespiratory endurance and balance are the two physical parameters most correlated with anthropometric indices.