A pooled analysis of waist circumference and mortality in 650,000 adults

Increased central obesity correlates with physical activity and food processing in recently diagnosed multiple sclerosis

BACKGROUND

Environmental and lifestyle factors are associated with an increased risk of Multiple Sclerosis (MS). Metabolic syndrome (MetS) contributes to systemic inflammation, which is associated with poorer MS disease evolution. We compared persons with MS (PwMS) and controls to assess metabolic and lifestyle parameters associated with MS.

METHODS

We pooled data from two prospective observational studies with the same eligibility criteria, matching PwMS and controls (1:2 ratio) by sex, age, and body mass index (BMI). We compared anthropometric, biological and lifestyle parameters, including sleep and physical activity.

RESULTS

We included 53 PwMS and 106 controls with a median age of 35 years and 79% of women. PwMS had low Expanded Disability Status Scale (median 1.5). Compared to controls, PwMS had increased waist-to-hip (p<0.001) and waist-to-height (p=0.007) ratios, and practiced less physical activity (p=0.03). In regression models, lifestyle factors with the strongest factor loadings to predict central obesity were processed food consumption, and vigorous physical activity.

DISCUSSION

Although both groups were matched by age, sex, and BMI, we found increased central obesity in PwMS. Even with minimal neurological impairment, PwMS practiced less physical activity. This suggests that improvement of lifestyle and metabolic parameters should be targeted in MS.

[Sociodemographic and dietary factors and health conditions: determinants of malnutrition in the elderly in Colombia]

This study aimed to estimate the prevalence of malnutrition using clustered anthropometric indicators and to describe the sociodemographic and dietary factors and health conditions that determine malnutrition in elderly Colombians. This was a secondary analysis of the study Health, Well-being and Ageing (SABE) Colombia, 2015. The survey included 23,694 people aged ≥ 60 years. Malnutrition excess was defined by clustering two indicators: body mass index (BMI) and waist circumference; weight deficit was defined by clustering BMI and arm and calf circumferences. The chi-square test was used to associate malnutrition with sociodemographic variables, dietary and health conditions, and to determine the heterogeneity of malnutrition, a latent class analysis was performed. Overweight was 31.9%, whereas underweight, according to BMI and calf circumference, was 7.9%, and increased to 18.8% when arm circumference was also taken into account. Five latent classes of malnutrition were generated - class 1: no overweight and deteriorated health conditions; class 2: no weight deficit and deteriorated health conditions; class 3: no malnutrition and deteriorated health conditions; class 4: overweight and multimorbidity; and class 5: low protein food intake without being underweight or overweight. It is concluded that a high prevalence of malnutrition in older adults exists, with excess rather than deficit. Sociodemographic and dietary factors and health conditions are associated differently with overweight and underweight.

Strengths and Limitations of BMI in the Diagnosis of Obesity: What is the Path Forward?

PURPOSE OF REVIEW

This review aims to discuss strengths and limitations of body mass index (BMI) in diagnosing obesity, the use of alternative anthropometric measurements, and potential new technology that may change the future of obesity diagnosis and management.

RECENT FINDINGS

The diagnosis of obesity requires the anthropometric assessment of adiposity. In clinical settings, this should include BMI with confirmation that elevated BMI represents excess adiposity and a measure of fat distribution (i.e., waist circumference (WC), waist to height ratio (WHtR), or WC divided by height0.5 (WHR.5R). Digital anthropometry and bioelectric impedance (BIA) can estimate fat distribution and be feasibly employed in the clinic. In addition, the diagnosis should include a clinical component assessing the presence and severity of weight-related complications. As anthropometric measures used in the diagnosis of obesity, BMI is generally sufficient if confirmed to represent excess adiposity, and there are advantages to the use of WHtR over WC to assess fat distribution. BIA and digital anthropometry have the potential to provide accurate measures of fat mass and distribution in clinical settings. There should also be a clinical evaluation for the presence and severity of obesity complications that can be used to stage the disease.

Associations of fruit intake with adiposity and cardiometabolic biomarkers in UK Biobank

BACKGROUND

Fruit consumption has been associated with a lower cardiovascular disease (CVD) risk but the underlying mechanisms are unclear. We investigated the cross-sectional and prospective associations of fruit consumption with markers of adiposity, blood pressure, lipids, low-grade inflammation, glycaemia, and oxidative stress.

METHODS

The main analyses included 365 534 middle-aged adults from the UK Biobank at baseline, of whom 11 510, and 38 988 were included in the first and second follow-up respectively, free from CVD and cancer at baseline. Fruit consumption frequency at baseline was assessed using a questionnaire. We assessed the cross-sectional and prospective associations of fruit with adiposity (body mass index, waist circumference and %body fat), systolic and diastolic blood pressure, lipids (low-density and high-density lipoproteins, triglycerides and apolipoprotein B), glycaemia (haemoglobin A1c), low-grade inflammation (C-reactive protein) and oxidative stress (gamma-glutamyl-transferase) using linear regression models adjusted for socioeconomic and lifestyle factors. Analyses were repeated in a subset with two to five complete 24-h dietary assessments (n = 26 596) allowing for adjustment for total energy intake.

RESULTS

Fruit consumption at baseline generally showed weak inverse associations with adiposity and biomarkers at baseline. Most of these relationships did not persist through follow-up, except for inverse associations with diastolic blood pressure, C-reactive protein, gamma-glutamyl transferase and adiposity. However, for most mechanisms, mean levels varied by less than 0.1 standard deviations (SD) between high and low fruit consumption (> 3 vs < 1 servings/day) in further adjusted models (while the difference was < 0.2 SD for all of them). For example, waist circumference and diastolic blood pressure were 1 cm and 1 mmHg lower in high compared to low fruit intake at the first follow-up (95% confidence interval: -1.8, -0.1 and -1.8, -0.3, respectively). Analyses in the 24-h dietary assessment subset showed overall similar associations.

CONCLUSIONS

We observed very small differences in adiposity and cardiometabolic biomarkers between those who reported high fruit consumption vs low, most of which did not persist over follow-up. Future studies on other mechanisms and detailed assessment of confounding might further elucidate the relevance of fruit to cardiovascular disease.

Clinical characteristics of atrial fibrillation in nonagenarian population and relationship with mortality

BACKGROUND

There is a considerable amount of literature available on well-known risk factors for atrial fibrillation (AF); however, available data specifically focused on the ninth decade are scarce. The main objective of this study was to assess the demographic and clinical characteristics of AF and sinus rhythm in a nonagenarian population.

METHODS

All individuals aged >90 years who were admitted to the Cardiology outpatient clinic between April 2018 and January 2019 were enrolled in the study. The demographic and clinical characteristics of all patients were recorded. All deaths that occurred during the two-year follow-up period were recorded.

RESULTS

In total, 112 nonagenarian individuals were included in the study. Of these patients, 50 (44.6%) had AF. The groups showed similarities in demographic and clinical characteristics. During a mean follow-up period of 596±44 days, 39 patients (78%) in the AF group and 35 patients (56.5%) in the sinus group died. Patients with AF showed a lower overall survival distribution than those with sinus rhythm (P=0.005, log-rank test χ2=7.734). AF was associated with an increased risk of mortality (P=0.002, hazard ratio [HR] =2.104, 95% confidence interval [CI] = 1.326-3.339) in multivariate Cox regression analysis, while waist circumference and total cholesterol (P=0.003, HR=0.969, 95% CI=0.949-0.989 and P=0.046, HR=0.993, 95% CI=0.986-1.000, respectively) showed a decreased risk of mortality.

CONCLUSIONS

Atrial fibrillation is very common in individuals over the age of 90 years (44.6%). Well-known risk factors do not appear to be effective in this age group, and AF is associated with a 2.1-fold increase in the risk of mortality.

Risks and Benefits of Intermittent Fasting for the Aging Cardiovascular System

Population aging and the associated increase in cardiovascular disease rates pose serious threats to global public health. Different forms of fasting have become an increasingly attractive strategy to directly address aging and potentially limit or delay the onset of cardiovascular diseases. A growing number of experimental studies and clinical trials indicate that the amount and timing of food intake as well as the daily time window during which food is consumed, are crucial determinants of cardiovascular health. Indeed, intermittent fasting counteracts the molecular hallmarks of cardiovascular aging and promotes different aspects of cardiometabolic health, including blood pressure and glycemic control, as well as body weight reduction. In this report, we summarize current evidence from randomized clinical trials of intermittent fasting on body weight and composition as well as cardiovascular and metabolic risk factors. Moreover, we critically discuss the preventive and therapeutic potential of intermittent fasting, but also possible detrimental effects in the context of cardiovascular aging and related disease. We delve into the physiological mechanisms through which intermittent fasting might improve cardiovascular health, and raise important factors to consider in the design of clinical trials on the efficacy of intermittent fasting to reduce major adverse cardiovascular events among aged individuals at high risk of cardiovascular disease. We conclude that despite growing evidence and interest among the lay and scientific communities in the cardiovascular health-improving effects of intermittent fasting, further research efforts and appropriate caution are warranted before broadly implementing intermittent fasting regimens, especially in elderly persons.

A Precision Medicine Guided Approach to the Utilization of Biomarkers in MASLD

The new nomenclature of metabolic dysfunction-associated steatotic liver disease (MASLD) emphasizes a positive diagnosis based on cardiometabolic risk factors. This definition is not only less stigmatizing but also allows for subclassification and stratification, thereby addressing the heterogeneity of what was historically referred to as nonalcoholic fatty liver disease. The heterogeneity within this spectrum is influenced by several factors which include but are not limited to demographic/dietary factors, the amount of alcohol use and drinking patterns, metabolic status, gut microbiome, genetic predisposition together with epigenetic factors. The net effect of this dynamic and intricate system-level interaction is reflected in the phenotypic presentation of MASLD. Therefore, the application of precision medicine in this scenario aims at complex phenotyping with consequent individual risk prediction, development of individualized preventive strategies, and improvements in the clinical trial designs. In this review, we aim to highlight the importance of precision medicine approaches in MASLD, including the use of novel biomarkers of disease, and its subsequent utilization in future study designs.

Association between waist circumference and chronic pain: insights from observational study and two-sample Mendelian randomization

Background

Current research offers limited clarity on the correlation between waist circumference and chronic pain prevalence.

Objective

This investigation seeks to elucidate the potential relationship between waist circumference and chronic pain and their causal association.

Methods

An observational study was conducted, leveraging data from the National Health and Nutrition Examination Survey (NHANES) collected between 2001 and 2004. The multivariable logistic regression was used to assess the relationship between waist circumference and chronic pain. Furthermore, a meta-analysis of Mendelian Randomization (MR) was applied to explore a causal relationship between waist circumference and pain.

Results

The observational study, post multivariable adjustment, indicated that an increase in waist circumference by 1 dm (decimeter) correlates with a 14% elevation in chronic pain risk (Odds Ratio [OR] = 1.14, 95% Confidence Interval [CI]: 1.04-1.24, p = 0.01). Moreover, the meta-analysis of MR demonstrated that an increased waist circumference was associated with a genetic predisposition to pain risk (OR = 1.14, 95%CI: 1.06-1.23, p = 0.0007).

Conclusion

Observational analysis confirmed a significant relationship between increased waist circumference and the incidence of chronic pain, and results based on MR Study identified increased waist circumference as potentially causal for pain.

Renal adaptation in pre-obesity patients with hypertension

BACKGROUND AND HYPOTHESIS

Obesity aggravates the risk to develop chronic kidney disease in hypertensive patients. Whether pre-obesity already impairs renal function, renal perfusion and intraglomerular hemodynamics in hypertensive patients is unknown.

METHODS

Renal hemodynamic profiles were measured using steady state input clearance (infusion of para-amino-hippuric acid and inulin) in 36 patients with primary arterial hypertension stage 1-2 without antihypertensive medication. Intraglomerular pressure (IGP) and resistances of the afferent (RA) and efferent (RE) arterioles were calculated. The study population was divided into two groups based on median of waist circumference (WC) (96 cm) (pre-obesity and non-obesity group1) and median of body mass index (BMI) (26.5 kg/m2) (pre-obesity and non-obesity group2), respectively.

RESULTS

All patients were males, non-smoking, aged 36 ± 10 years, with an office blood pressure of 145 ± 8.6/89 ± 11.8 mmHg. None of the patients had cardiovascular disease. Patients from the pre-obese group 1 showed lower glomerular filtration rate (GFR), lower renal plasma flow (RPF) and lower IGP compared to the non-obese group1. Renal vascular resistance (RVR) and RA were higher in the pre-obese group1 compared to the non-obese group1. Similar differences in the hemodynamic profile were found for patients in the pre-obesity group2 compared to the non-obesity group2.

CONCLUSION

The renal hemodynamic profile in hypertensive patients with pre-obesity, irrespective whether defined by WC or BMI, was characterized by a reduced GFR and RPF and by an increased RVR preferentially at the preglomerular site. Our results suggest that hypofiltration is the first phase of renal adaptation in pre-obesity hypertension.

CLINICAL TRIAL REGISTRATION

www.clinicaltrials.gov: NCT02783456.

Epigenetic and Molecular Alterations in Obesity: Linking CRP and DNA Methylation to Systemic Inflammation

Obesity is marked by excessive fat accumulation in the adipose tissue, which disrupts metabolic processes and causes chronic systemic inflammation. Commonly, body mass index (BMI) is used to assess obesity-related risks, predicting potential metabolic disorders. However, for a better clustering of obese patients, we must consider molecular and epigenetic changes which may be responsible for inflammation and metabolic changes. Our study involved two groups of patients, obese and healthy donors, on which routine analysis were performed, focused on BMI, leukocytes count, and C-reactive protein (CRP) and completed with global DNA methylation and gene expression analysis for genes involved in inflammation and adipogenesis. Our results indicate that obese patients exhibited elevated leukocytes levels, along with increased BMI and CRP. The obese group revealed a global hypomethylation and upregulation of proinflammatory genes, with adipogenesis genes following the same trend of being overexpressed. The study confirms that obesity is linked to systematic inflammation and metabolic dysfunction through epigenetic and molecular alterations. The CRP was correlated with the hypomethylation status in obese patients, and this fact may contribute to a better understanding of the roles of specific genes in adipogenesis and inflammation, leading to a better personalized therapy.

Pro-vegetarian dietary patterns and mortality by all-cause and specific causes in an older Mediterranean population

PURPOSE

Pro-vegetarian (PVG) dietary patterns have shown health benefits, although the evidence concerning their association with mortality is scarce, particularly in older populations. We investigated the effect of three defined PVG patterns on all-cause, cardiovascular disease (CVD) and cancer mortality risk in an older Mediterranean population.

METHODS

We analysed baseline data from 597 adults aged 65 and older who participated in a population-based cross-sectional study, and mortality during a 12-year period. We used a validated food frequency questionnaire to estimate the adherence in tertiles to three evidence-based PVG dietary patterns: a general PVG pattern (gPVG) and two specific variations (healthful -hPVG, and unhealthful -uPVG). The gPVG pattern incorporated data from 12 food groups, consisting of 7 plant-based and 5 animal-based. The hPVG and uPVG versions included information from 18 food groups (4 food groups added and the splitting of 2 food groups). We used Cox regression to estimate hazard ratios (HR) and 95% confidence intervals (CI) adjusting for relevant covariates.

RESULTS

After the 12-years follow-up period, moderate adherence to hPVG pattern was associated with lower all-cause and CVD mortality whereas greater adherence to uPVG pattern was associated with higher all-cause and CVD mortality. Compared with those in the lowest tertile, participants in the second tertile of adherence to the hPVG pattern showed a significant lower risk of all-cause mortality (HR = 0.59; 95%CI: 0.43, 0.82) and CVD mortality (HR = 0.47; 0.28, 0.78). Participants in the highest tertile of adherence to the uPVG showed an increased mortality risk of all-cause (HR = 1.53; 1.07, 2.19) and CVD (HR = 2.10; 1.19, 3.70). No significant associations were found between adherence to any of the PVG dietary patterns and cancer mortality.

CONCLUSION

Moderate adherence to a healthy PVG pattern reduced the long-term mortality risk for all-cause and CVD in an older Mediterranean population, while higher adherence to an unhealthy PVG pattern increased the risk of all-cause and CVD mortality.

Adiposity, type 2 diabetes and atherosclerotic cardiovascular disease risk: Use and abuse of the body mass index

The worldwide prevalence of individuals with an elevated body weight has increased steadily over the past five decades. Billions of research dollars have been invested to improve our understanding of the causes and consequences of having an elevated body weight. All this knowledge has, however, failed to influence populational body weight trajectories of most countries around the world. Research on the definition of "obesity" has also evolved. Body mass index (BMI), the most commonly used tool to make its diagnosis, has major limitations. In this review article, we will highlight evidence from observational studies, genetic association studies and randomized clinical trials that have shown the remarkable inter-individual differences in the way humans store energy as body fat. Increasing evidence also suggests that, as opposed to weight inclusive, lifestyle-based approaches, weight-centric approaches advising people to simply eat less and move more are not sustainable for most people for long-term weight loss and maintenance. It is time to recognize that this outdated approach may have produced more harm than good. On the basis of pathophysiological, genetic and clinical evidence presented in this review, we propose that it may be time to shift away from the traditional clinical approach, which is BMI-centric. Rather, emphasis should be placed on actionable lifestyle-related risk factors aiming at improving overall diet quality and increasing physical activity level in the general population.

Body mass index, waist circumference, and mortality in subjects older than 80 years: a Mendelian randomization study

BACKGROUND AND AIMS

Emerging evidence has raised an obesity paradox in observational studies of body mass index (BMI) and health among the oldest-old (aged ≥80 years), as an inverse relationship of BMI with mortality was reported. This study was to investigate the causal associations of BMI, waist circumference (WC), or both with mortality in the oldest-old people in China.

METHODS

A total of 5306 community-based oldest-old (mean age 90.6 years) were enrolled in the Chinese Longitudinal Healthy Longevity Survey (CLHLS) between 1998 and 2018. Genetic risk scores were constructed from 58 single-nucleotide polymorphisms (SNPs) associated with BMI and 49 SNPs associated with WC to subsequently derive causal estimates for Mendelian randomization (MR) models. One-sample linear MR along with non-linear MR analyses were performed to explore the associations of genetically predicted BMI, WC, and their joint effect with all-cause mortality, cardiovascular disease (CVD) mortality, and non-CVD mortality.

RESULTS

During 24 337 person-years of follow-up, 3766 deaths were documented. In observational analyses, higher BMI and WC were both associated with decreased mortality risk [hazard ratio (HR) 0.963, 95% confidence interval (CI) 0.955-0.971 for a 1-kg/m2 increment of BMI and HR 0.971 (95% CI 0.950-0.993) for each 5 cm increase of WC]. Linear MR models indicated that each 1 kg/m2 increase in genetically predicted BMI was monotonically associated with a 4.5% decrease in all-cause mortality risk [HR 0.955 (95% CI 0.928-0.983)]. Non-linear curves showed the lowest mortality risk at the BMI of around 28.0 kg/m2, suggesting that optimal BMI for the oldest-old may be around overweight or mild obesity. Positive monotonic causal associations were observed between WC and all-cause mortality [HR 1.108 (95% CI 1.036-1.185) per 5 cm increase], CVD mortality [HR 1.193 (95% CI 1.064-1.337)], and non-CVD mortality [HR 1.110 (95% CI 1.016-1.212)]. The joint effect analyses indicated that the lowest risk was observed among those with higher BMI and lower WC.

CONCLUSIONS

Among the oldest-old, opposite causal associations of BMI and WC with mortality were observed, and a body figure with higher BMI and lower WC could substantially decrease the mortality risk. Guidelines for the weight management should be cautiously designed and implemented among the oldest-old people, considering distinct roles of BMI and WC.

Cardiometabolic risk stratification using a novel obesity phenotyping system based on body adiposity and waist circumference

BACKGROUND

The estimation of obesity-associated cardiometabolic risk does not usually take into account body composition or the distribution of adiposity. The aim of the present study was to assess the clinical usefulness of a novel obesity phenotyping system based on the combination of actual body fat percentage (BF%) and waist circumference (WC) according to the cardiometabolic risk estimation.

METHODS

A classification matrix combining BF% and WC as measures of both amount and distribution of adiposity establishing nine body phenotypes (3 BF% x 3 WC) was developed. Individuals were grouped in five different cardiometabolic risk phenotypes. We conducted a validation study in a large cohort of White subjects from both genders representing a wide range of ages and adiposity (n = 12,754; 65 % females, aged 18-88 years).

RESULTS

The five risk groups using the matrix combination of BF% and WC exhibited a robust linear distribution regarding cardiometabolic risk, estimated by the Metabolic Syndrome Severity Score, showing a continuous increase between groups with significant differences (P < 0.001) among them, as well as in other cardiometabolic risk factors. An additional 24 % of patients at very high risk was detected with the new classification system proposed (P < 0.001) as compared to an equivalent matrix using BMI and WC instead of BF% and WC.

CONCLUSIONS

A more detailed phenotyping should be a priority in the diagnosis and management of patients with obesity. Our classification system allows to gradually estimate the cardiometabolic risk according to BF% and WC, thus representing a novel and useful tool for both research and clinical practice.

The Relationship of Waist Circumference with the Morbidity of Cardiovascular Diseases and All-Cause Mortality in Metabolically Healthy Individuals: A Population-Based Cohort Study

Background

This study explores the relationship between waist circumference and morbidity of cardiovascular diseases (CVD) and all-cause mortality in metabolically healthy individuals.

Methods

A cohort of 5775 metabolically healthy participants from the 2001-2014 US National Health and Nutrition Examination Survey and National Death Index database was tracked over a median period of 81 months. These participants were divided into quartiles (Q1, Q2, Q3, Q4) based on increasing waist circumference. To compensate for missing covariates, multivariate multiple imputation methods were used. Adjusted logistic regression models were employed to examine the correlation between waist circumference and cardiovascular disease prevalence. Furthermore, Kaplan-Meier curves and multivariable Cox regression analysis were utilized to evaluate the association between waist circumference and all-cause mortality, both qualitatively and quantitatively.

Results

The adjusted logistic regression model indicated that a 10 cm increase in waist circumference was associated with a 1.45 times higher prevalence of CVD. As a categorical variable, there was a significant upward trend in CVD incidence across quartiles of waist circumference. The adjusted odds ratios (95% confidence intervals) were 2.41 (1.13-5.53) for Q2, 2.65 (1.18-6.39) for Q3, and 2.53 (0.9-7.44) for Q4, compared to Q1. Notably, individuals with high waist circumference showed significantly poorer survival compared to those with low waist circumference (p = 0.008). The Cox regression analysis revealed that each 10 cm increase in waist circumference contributed to an ~8% increase in all-cause mortality.

Conclusions

This study underscores a positive correlation between waist circumference and both CVD morbidity and all-cause mortality in metabolically healthy individuals. The findings highlight the significance of routinely monitoring waist circumference for effective CVD risk management, regardless of metabolic health status.

Association of waist circumference and BMI with premature death in young and middle-aged population

Introduction

Premature death is a global health indicator, significantly impacted by obesity, especially in young and middle-aged population. Both body mass index (BMI) and waist circumference (WC) assess obesity, with WC specifically indicating central obesity and showing a stronger relationship with mortality. However, despite known associations between BMI and premature death, as well as the well-recognized correlation between WC and adverse health outcomes, the specific relationship between WC and premature death remains unclear. Therefore, focusing on young and middle-aged individuals, this study aimed to reliably estimate independent and combined associations between WC, BMI and premature death, thereby providing causal evidence to support strategies for obesity management.

Methods

This study involved 49,217 subjects aged 18-50 years in the United States from 1999 to 2018 National Health and Nutrition Examination Survey (NHANES). Independent and combined associations between WC and BMI with premature death across sex and age stratum were examined by Cox regression. Survey weighting and inverse probability weighting (IPW) were further considered to control selection and confounding bias. Robustness assessment has been conducted on both NHANES and China Health and Retirement Longitudinal Study (CHARLS) data.

Results

A linear and positive relationship between WC and all-cause premature death was found in both males and females, with adjusted HRs of 1.019 (95%CI = 1.004-1.034) and 1.065 (95%CI = 1.039-1.091), respectively. Nonlinear relationships were found with respect to BMI and all-cause premature death. For females aged 36-50 with a BMI below 28.6 kg/m2, the risk of premature death decreased as BMI increased, indicated by adjusted HRs of 0.856 (95%CI = 0.790-0.927). Joint analysis showed among people living with obesity, a larger WC increased premature death risk (HR = 1.924, 95%CI = 1.444-2.564).

Discussion

WC and BMI exhibited prominent associations with premature death in young and middle-aged population. Maintaining an appropriate WC and BMI bears significant implications for preventing premature death.

The impact of lifestyle, measured with the HLPCQ questionnaire on the prevalence of metabolic syndrome in Poland: a multicenter study

Metabolic syndrome is one of the most common health problems for people around the world. The aim of our study was to assess the prevalence of metabolic syndrome among adults without prior diagnosis of cardiovascular disease, diabetes, and chronic kidney disease. We also plan to assess the influence of certain lifestyle components on prevalence of metabolic syndrome. The study involved cardiovascularly healthy patients undergoing lab tests, measurements, and the HLPCQ questionnaire (The Healthy Lifestyle and Personal Control Questionnaire). The data were used to diagnose metabolic syndrome. Out of 1044 patients from 10 primary care facilities, 23.3% met the metabolic syndrome criteria, showing a strong link with increased blood pressure, cholesterol, and fasting glucose. Lower scores in the Organized physical exercise subscale of the HLPCQ questionnaire were noted in those with metabolic syndrome. Comparing the subscale of HLPCQ questionnaire, the lower results in Organized physical exercise subscale were found among the participants with metabolic syndrome, both male and females. Metabolic syndrome, a significant risk factor for cardiovascular disease, should be screened for actively, even in apparently healthy populations. Results obtained in our study from analysis of HLPCQ show that screening for metabolic syndrome should be preceded by prevention based on regular physical activity and proper eating habits.

Plasma proteomic profile of abdominal obesity in older adults

OBJECTIVE

This study examines the plasma proteomic profile of abdominal obesity in older adults.

METHODS

The association of abdominal obesity (waist circumference [WC]) with 4265 plasma proteins identified using the SomaScan Assay was examined in 969 Ashkenazi Jewish participants (LonGenity cohort), aged 65 years and older (mean [SD] age 75.7 [6.7] years, 55.4% women), using regression models. Pathway analysis, as well as weighted correlation network analysis, was performed. WC was determined from the proteome using elastic net regression.

RESULTS

A total of 480 out of 4265 proteins were associated with WC in the linear regression model. Leptin (β [SE] = 12.363 [0.490]), inhibin β C chain (INHBC; β [SE] = 24.324 [1.448]), insulin-like growth factor-binding protein 2 (IGFBP-2; β [SE] = -12.782 [0.841]), heparan-sulfate 6-O-sulfotransferase 3 (H6ST3; β [SE] = -39.995 [2.729]), and matrix-remodeling-associated protein 8 (MXRA8; β [SE] = -27.101 [1.850]) were the top proteins associated with WC. Cell adhesion, extracellular matrix remodeling, and IGF transport pathways were the top enriched pathways associated with WC. WC signature determined from plasma proteins was highly correlated with measured WC (r = 0.80) and was associated with various metabolic and physical traits.

CONCLUSIONS

The study unveiled a multifaceted plasma proteomic profile of abdominal obesity in older adults, offering insights into its wide-ranging impact on the proteome. It also elucidated novel proteins, clusters of correlated proteins, and pathways that are intricately associated with abdominal obesity.

Associations of body mass index trajectory, waist circumference trajectory, or both with type 2 diabetes mellitus risk in Chinese adults: The China-PAR project

AIMS

To identify the trajectories of body mass index (BMI) and waist circumference (WC), and assess the associations of BMI trajectory, WC trajectory, or the two combined, with type 2 diabetes mellitus (T2DM) risk in Chinese adults.

MATERIALS AND METHODS

This study was based on a prospective project-the Prediction for Atherosclerotic Cardiovascular Disease Risk in China (China-PAR). A total of 54 434 participants (39.21% men) who were measured on at least two occasions were included. Three slowly increasing trajectory patterns were identified for BMI, and four for WC, by latent mixed modelling. A nine-category variable was derived by combining the WC trajectory (low, moderate, moderate-high/high) and the BMI trajectory (low, moderate, high). Logistic regression models were applied to estimate the odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

The risk of developing T2DM increased with elevated BMI or WC trajectory levels (all ptrend <0.001). The risks were 2.85 (2.59-3.14) for high BMI trajectory and 4.34 (3.78-4.99) for high WC trajectory versus low trajectory groups, respectively. The association was more pronounced among younger individuals (pinteraction <0.001). In the joint analysis, compared to participants with low WC and BMI trajectory, those with moderate-high/high WC combined with high BMI trajectory had the highest risk of T2DM (OR 3.96, 95% CI 3.48-4.50); even those who maintained moderate-high/high WC but low BMI trajectory showed a higher T2DM risk (OR 3.00, 95% CI 2.31-3.91).

CONCLUSIONS

This study suggests that simultaneous dynamic and continuous monitoring of BMI and WC may contribute more than single measurements to predicting T2DM risk and determining preventive strategies.

The correlation of obesity status with serum 25-hydroxyvitamin D in US Asian adults: NHANES 2011-2018

BACKGROUND

There is a correlation between obesity and 25-hydroxyvitamin D (25OHD) that tends to be negative. However, this relationship varies among different races. In this study, Asian adults with and without obesity were compared in terms of their levels of 25OHD.

METHODS

We carried out a cross-sectional analysis on 2664 non-Hispanic Asian adults who participated in the National Health and Nutrition Examination Survey (NHANES) conducted between 2011 and 2018. To examine the connection between obese status, body mass index (BMI), waist circumference (WC) and weight, and 25OHD, we ran multivariate linear regression models and multivariate logistic regression models.

RESULTS

After adjusting for all confounding factors, obesity status shows a significant positive correlation with vitamin D deficiency (model 3: OR = 2.318, 95% CI:1.317, 4.082). This positive correlation remains significant in males (males: OR = 2.713, 95% CI: -13.398, 5.217). In all three models, a negative association was observed between obesity status and 25OHD (model 1: β = -4.535, 95% CI: -6.987, -2.083; model 2 β = -4.249, 95% CI: -6.549, -2.039; model 3 β = -1.734, 95% CI: -7.285, 3.816). After controlling for covariates, there was a significant negative correlation between WC and 25OHD when stratified by gender and obesity status in both males with and without obesity (males with obesity: β = -1.461, 95% CI: -2.485, -0.436; males without obesity: β = -0.855. 95% CI: -1.499, -0.210). In males with obesity, there was a very strong positive connection between body weight and 25OHD (β = 0.912, 95% CI: 0.227, 1.597). In addition, neither gender's obese individuals showed a significant link between BMI and 25OHD.

CONCLUSION

This study demonstrated a positive correlation between obesity and vitamin D deficiency and a negative correlation between obesity and 25OHD in Asian American adults. Additionally, among male obese individuals, there was a significant negative correlation between WC and 25OHD, an observation that needs to be validated in further prospective studies.

The predictive ability of ABSI compared to BMI for mortality and frailty among older adults

Introduction

To study the utility of A Body Shape Index (ABSI) alongside body mass index (BMI) to predict mortality and frailty in an aging community population.

Materials and methods

Participants (n = 1,580) were drawn from the first Israeli national health and nutrition survey of older adults ("Mabat Zahav") conducted from 2005 to 2006, constituting adults aged ≥65 years. Socio-demographic, clinical, behavioral, and psychosocial data were collected. Baseline weight, height, and waist circumference (WC) were measured and expressed as the allometric indices BMI (kg/m2) and ABSI, a BMI-independent measure of abdominal obesity [WC/(BMI2/3*m1/2)]. Mortality follow-up lasted through 2019. Frailty was assessed in 2017-2019 by the Fried Biological Phenotype in a sub-cohort of 554 survivors. Cox and logistic regression models assessed associations of BMI and ABSI with mortality and frailty.

Results

At baseline, mean [SD] age was 74.5 [6.1] years, and 52.4% were women. The correlation between BMI and WC Z scores was 0.71, reduced to -0.11 for BMI and ABSI. Over a median follow-up of 13 years, 757 deaths occurred. The multivariable-adjusted hazard ratios (95% CIs) for mortality per standard deviation increase in BMI and ABSI were 1.07 (0.99;1.17) and 1.13 (1.05;1.21), respectively. Among participants assessed for frailty, 77 (14%) met the frailty criteria. After multivariable adjustment, the odds ratios (95% CIs) for frailty were 0.83 (0.69-1.01) for BMI and 1.55 (1.34-1.79) for ABSI.

Discussion

In a nationwide cohort of older adults, ABSI was independently associated with mortality risk. Furthermore, ABSI, but not BMI, was a strong predictor of frailty.

Association of Waist Circumference and Body Mass Index Deciles Ratio with All-Cause Mortality: Findings from the National Health and Nutrition Examination Survey

Given the importance and continued interest in finding a simple, accessible, and universal measure which reflects both general and abdominal adiposity, this study tested for an association of the ratio of WC decile to BMI decile (WC-d/BMI-d) with all-cause mortality. Individuals aged 18-79 years who had participated in the National Health and Nutrition Examination Survey (NHANES) during the years 2007 to 2018 were included in the analysis. WC and BMI deciles were defined separately for males and females, while WC-d/BMI-d was calculated for each individual. The association of WC-d/BMI-d with mortality was assessed using logistic models for the total study population, and then again after stratification by sex, ethnicity, morbidity level, and BMI categories. Positive associations between WC-d/BMI-d and mortality were demonstrated for the total study population (adjusted OR = 1.545, 95%CI: 1.369-1.722) and within different sub-groups, including the population with a normal BMI level (adjusted OR = 1.32, 95%CI: 1.13-1.50). WC-d/BMI-d increased with age, with ~40 years representing a critical time point when WC-d surpasses BMI-d, with a sharper incline for males as compared to females. WC-d/BMI-d was significantly associated with all-cause mortality amongst NHANES American adults; thus, measurements of WC and its integration with BMI in this metric should be considered in clinical practice.

Relation between waist circumference and the renal hemodynamic in healthy individuals

BACKGROUND AND AIMS

Obesity has been shown to be an independent risk factor for the development of CKD. Little is known about pathways of interaction of visceral fat mass estimated by waist circumference (WC) and metabolic factors with the renal and intraglomerular hemodynamic profile in healthy, non-obese individuals.

METHODS AND RESULTS

The study population of this post-hoc analysis in 80 healthy individuals, who participated in a randomized, controlled clinical trial (www.

CLINICALTRIALS

gov: NCT02783456) was divided into two groups based on median of WC (high WC and low WC group). Renal hemodynamic profiles were analyzed using steady state input clearance (infusion of para-amino-hippuric acid and inulin). Intraglomerular pressure (IGP) and resistances of the afferent (RA) and efferent (RE) arterioles were calculated (Gomez equation). The analysis included healthy, non-smoking individuals, aged 27 ± 9 years with median WC of 84.75 ± 9 cm. Glomerular filtration rate (GFR) (110 ± 15 vs. 127 ± 16 ml/min/m2, p < 0.001), renal plasma flow (RPF) (620 ± 109 vs. 700 ± 104 ml/min, p = 0.001) and IGP (36.7 ± 2.3 vs. 38.5 ± 3.1 mmHg, p = 0.003) were lower in the high WC compared to the low WC group. Patients in the high WC group showed higher renal vascular resistance (RVR) (85 ± 19 vs. 70 ± 12 mmHg/(ml/min), p < 0.001), higher RA (4034 ± 1177 vs. 3069 ± 786 dyn∗s/cm5, p < 0.001) and higher RE (2283 ± 339 vs. 2118 ± 280 dyn∗s/cm5, p = 0.021) compared to the low WC group. Individuals in the high WC group showed higher leptin levels (p = 0.003) and higher HOMA-IR (p = 0.024) compared to the low WC group.

CONCLUSION

Increased WC in healthy young individuals was associated with reduced GFR and RPF likely mediated by increased RVR.

Relationship between abdominal circumference and the incidence of hyperuricemia in the general Japanese population

In this study, we aimed to separately evaluate the relationship between waist circumference and the incidence of hyperuricemia in men and women in the general Japanese population. We performed a population-based longitudinal study using data from the annual health examination of residents of Iki City, Japan. A total of 5567 participants without hyperuricemia at baseline were included in the analysis. The men and women were placed into groups according to the tertile of waist circumference. The outcome was incident hyperuricemia (uric acid > 416 µmol/L [7.0 mg/dL]). The relationship between waist circumference and the incidence of hyperuricemia was investigated using Cox proportional hazards models. During the follow-up period, hyperuricemia developed in 697 people (551 men and 146 women). The incidence (per 1000 person-years) of hyperuricemia increased with increasing waist circumference in the men (34.9 for tertile 1, 49.9 for tertile 2 and 63.3 for tertile 3; Ptrend < 0.001) and women (5.5 for tertile 1, 6.3 for tertile 2 and 11.9 for tertile 3; Ptrend < 0.001). Significant associations were identified after adjustment for potential confounders (men: Ptrend < 0.001; women: Ptrend = 0.014). In conclusion, both men and women with larger waist circumferences were at higher risks of subsequent hyperuricemia.

Exercise-induced Changes in Central Adiposity During an RCT: Effect of Exercise Dose and Associations With Compensation

CONTEXT

Exercise can decrease central adiposity, but the effect of exercise dose and the relationship between central adiposity and exercise-induced compensation is unclear.

OBJECTIVE

Test the effect of exercise dose on central adiposity change and the association between central adiposity and exercise-induced weight compensation.

METHODS

In this ancillary analysis of a 6-month randomized controlled trial, 170 participants with overweight or obesity (mean ± SD body mass index: 31.5 ± 4.7 kg/m2) were randomized to a control group or exercise groups that reflected exercise recommendations for health (8 kcal/kg/week [KKW]) or weight loss and weight maintenance (20 KKW). Waist circumference was measured, and dual-energy X-ray absorptiometry assessed central adiposity. Predicted weight change was estimated and weight compensation (weight change - predicted weight change) was calculated.

RESULTS

Between-group change in waist circumference (control: .0 cm [95% CI, -1.0 to 1.0], 8 KKW: -.7 cm [95% CI, -1.7 to .4], 20 KKW: -1.3 cm [95% CI, -2.4 to -.2]) and visceral adipose tissue (VAT; control: -.02 kg [95% CI, -.07 to .04], 8 KKW: -.01 kg [95% CI, -.07 to .04], 20 KKW: -.04 kg [95% CI, -.10 to .02]) was similar (P ≥ .23). Most exercisers (82.6%) compensated (weight loss less than expected). Exercisers who compensated exhibited a 2.5-cm (95% CI, .8 to 4.2) and .23-kg (95% CI, .14 to .31) increase in waist circumference and VAT, respectively, vs those who did not (P < .01). Desire to eat predicted VAT change during exercise (β = .21; P = .03).

CONCLUSION

In the presence of significant weight compensation, exercise at doses recommended for health and weight loss and weight maintenance leads to negligible changes in central adiposity.

Temporal Dietary Pattern Cluster Membership Varies on Weekdays and Weekends but Both Link to Health

BACKGROUND

Energy and dietary quality are known to differ between weekdays and weekends. Data-driven approaches that incorporate time, amount, and duration of dietary intake have previously been used to partition participants' daily weekday dietary intake time series into clusters representing weekday temporal dietary patterns (TDPs) linked to health indicators in United States adults. Yet, neither the relationship of weekend day TDPs to health indicators nor how the TDP membership may change from weekday to weekend is known.

OBJECTIVES

This study was conducted to determine the association between TDPs on weekdays and weekend days and health indicators [diet quality, waist circumference (WC), body mass index (BMI), and obesity] and their overlap among participants.

METHODS

A weekday and weekend day 24-hour dietary recall of 9494 nonpregnant United States adults aged 20-65 years from the cross-sectional National Health and Nutrition Examination Survey 2007-2018 was used to determine the timing and amount of energy intake. Modified dynamic time warping and kernel k-means algorithm clustered participants into 4 TDPs on weekdays and weekend days. Multivariate regression models determined the associations between TDPs and health indicators, controlling for potential confounders and adjusting for the survey design and multiple comparisons. The percentages of overlap in cluster membership between TDPs on weekdays and weekend days were also determined.

RESULTS

United States adults with a TDP of evenly spaced, energy-balanced eating occasions, representing the TDP of more than one-third of all adults on weekdays and weekends, had significantly higher diet quality, lower BMI, WC, and odds of obesity when compared to those with other TDPs. Membership of most United States adults to TDPs varied from weekdays to weekends.

CONCLUSIONS

Both weekday and weekend TDPs were significantly associated with health indicators. TDP membership of most United States adults was not consistent on weekdays and weekends.

Comparative efficacy of exercise training modes on systemic metabolic health in adults with overweight and obesity: a network meta-analysis of randomized controlled trials

Objective

This network meta-analysis (NMA) was conducted to compare and rank the effects of training interventions including aerobic exercise (AE), resistance training (RT), combined aerobic and resistance training (CT), and high-intensity interval training (HIIT) on vital metabolic indicators in adults with overweight and obesity.

Methods

PubMed, Cochrane, Embase, and Web of Science were searched from 1990 to February 2023. Articles were included if they described randomized controlled trials (RCTs) examining the effects of exercise training on anthropometry parameters, lipid profiles, glucose metabolism, blood pressure, and cardiorespiratory fitness in adults with overweight and obesity. Weighted mean difference with 95% CI was calculated.

Results

A total of 28 studies with 1,620 patients were included. Results revealed that AE exerts best effects on weight loss (-2.35 [-4.05, -0.64]) and body mass index (-0.9 [-1.38, -0.42]), while HIIT is the most effective in reducing waist circumference (-5.93 [10.71, -1.15]), percentage body fat (-3.93 [-5.73, -2.12]), serum triglycerides (-20.55 [-37.20, -3.91]), and fasting blood glucose (-14.31 [-22.47, -6.16]) and improving VO2 max (7.41 [4.37, 10.45]). However, no significant benefit was observed in terms of total cholesterol and blood pressure.

Conclusions

AE is the optimal exercise type for reducing body weight and BMI, while HIIT exerts the most beneficial effects on improving body composition, cardiorespiratory fitness, and metabolic abnormalities in adults with overweight and obesity.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023444322, identifier CRD42023444322.

Ratio of waist circumference to body mass index: A novel predictor of clinical outcome in hypertension patients

We aim to investigate the influence of waist circumference and body mass index (BMI) on all-cause death and cardiovascular-specific death in patients with hypertension. This prospective cohort study, based on waist circumference and body mass index measurements in patients with hypertension, provided risk estimates of all-cause mortality and cardiovascular events. The waist circumference-to-BMI ratio (WtBR) is an anthropometric measure integrating waist circumference and BMI. We utilized multivariable Cox regression analysis, restricted cubic spline model, Kaplan-Meier plot, random forest analysis, and sensitivity analysis to assess the relationship of WtBR with all-cause mortality. Subsequently, Fine-Gray competing risk regression models were applied to precisely evaluate the probability of cardiovascular-specific death attributed to high WtBR. The results indicate that thea deceased group showed significantly higher WtBR and lower BMI compared with the alive groups (P < .05), while no significant difference was observed in waist circumference (P = .373). When analyzed as continuous, the risk of all-cause death elevated with increasing WtBR in the adjusted model with an HR of 2.42 (95% CI, 2.06-2.85). The restricted cubic spline illustrated an elevated risk of all-cause mortality as WtBR increased (J-shaped curve). Nevertheless, WtBR showed no significant association with cardiovascular-specific death and the prediction model exhibited a reliable performance in the testing set. This study supported that WtBR, an anthropometric measure, is independently associated with all-cause death in hypertensive patients. It's advisable to routinely assess waist circumference in hypertensive patients regardless of BMI, in order to more effectively manage the risk of obesity-related health.

Diagnostic Accuracy of Waist-to-Height Ratio, Waist Circumference, and Body Mass Index in Identifying Metabolic Syndrome and Its Components in Older Adults: A Systematic Review and Meta-Analysis

Background

Although numerous studies have indicated the utility of waist-to-height ratio (WHtR) in early screening for individuals with adverse cardiometabolic health, there is controversy on using WHtR as a one-size-fits-all approach, including in older adults.

Objectives

Our study aims to identify the pooled diagnostic accuracy of WHtR in screening for metabolic syndrome (MetS) and its components among older adults.

Methods

A systematic review of observational studies was performed using 4 databases. A diagnostic meta-analysis with a random effects model was conducted, and the pooled area under the summary receiver operating characteristic curve, sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratio (dOR) of each outcome compared with WHtR, body mass index (BMI), and waist circumference (WC) were calculated, with sex-stratified analysis.

Results

A total of 17 studies with 74,520 participants were included. As reflected by the dOR, WHtR (7.65; 95% CI: 6.00, 9.75) performed better than BMI (5.17; 95% CI: 4.75, 5.62) and WC (5.77; 95% CI: 4.60, 7.25) in screening for MetS among older adults and was potentially better among males. For hyperglycemia, hypertension, and dyslipidemia, the performances of WHtR, BMI, and WC were comparable.

Conclusion

More studies focusing on older adults are still needed to determine the cutoff values of WHtR to screen for MetS.The search strategy was registered in PROSPERO as CRD42022350379.

Revisiting Waist Circumference: A Hypertension Risk Factor that Requires a More In-depth Understanding

As a major cause of various cardiovascular diseases, the prevalence of hypertension has been increasing in the past 30 years, leading to significant socioeconomic and health burdens. Obesity is one of the major risk factors for hypertension. Body mass index (BMI) is the most used anthropometric index to measure obesity in clinical practice and to assess the risk of obesity-related diseases. However, obesity is a heterogeneous disease, and the accumulation of fat in different body regions leads to differences in cardiovascular and metabolic risks. BMI only reflects the overall obesity but does not consider the distribution of fat and muscle mass. The limitation of BMI makes it insufficient to assess the risk of hypertension attributed to obesity. In addition, waist circumference is an easily obtainable anthropometric index to evaluate abdominal fat distribution. High waist circumference is an independent risk factor for various cardiovascular diseases and all-cause mortality regardless of BMI. Preliminary data indicate that waist circumference is significantly associated with the risk of hypertension at different BMI levels. However, routine measurement of waist circumference is currently not required in current clinical guidelines or is only recommended for obese populations, indicating an insufficient understanding of waist circumference. In this review, we summarize the measurement methods and diagnostic thresholds of waist circumference for abdominal obesity, the trend of central obesity prevalence, the superiority of waist circumference over other anthropometric indices, and recent cross-sectional and longitudinal studies on the association between obesity and hypertension.

The Definition and Prevalence of Obesity and Metabolic Syndrome: Correlative Clinical Evaluation Based on Phenotypes

Increase in the prevalence of obesity has become a major worldwide health problem in adults as well as among children and adolescents. In the last four decades, studies have revealed that the significant increase in the prevalence of obesity has become a pandemic. Obesity is the result of complex interactions between biological, genetic, environmental, and behavioral factors. Indeed, almost all of the children suffering from obesity in early childhood face with being overweight or obese in adolescence. Different phenotypes have different risk factors in the clinical evaluation of obesity. Individuals suffering from metabolically unhealthy obesity (MUO) are at an excess risk of developing cardiovascular diseases (CVDs), several cancer types, and metabolic syndrome (MetS), whereas the metabolically healthy obesity (MHO) phenotype has a high risk of all-cause mortality and cardiometabolic events but not MetS. While most obese individuals have the MUO phenotype, the frequency of the MHO phenotype is at most 10-20%. Over time, approximately three-quarters of obese individuals transform from MHO to MUO. Total adiposity and truncal subcutaneous fat accumulation during adolescence are positively and independently associated with atherosclerosis in adulthood. Obesity, in general, causes a large reduction in life expectancy. However, the mortality rate of morbid obesity is greater among younger than older adults. Insulin resistance (IR) develops with the central accumulation of body fat. MHO patients are insulin-sensitive like healthy normal-weight individuals and have lower visceral fat content and cardiovascular consequences than do the majority of MUO patients. MetS includes clustering of abdominal obesity, dyslipidemia, hyperglycemia, and hypertension. The average incidence of MetS is 3%, with a 1.5-fold increase in the risk of death from all causes in these patients. If lifestyle modifications, dietary habits, and pharmacotherapy do not provide any benefit, then bariatric surgery is recommended to reduce weight and improve comorbid diseases. However, obesity treatment should be continuous in obese patients by monitoring the accompanying diseases and their consequences. In addition to sodium-glucose co-transporter-2 (SGLT2) inhibitors, the long-acting glucagon-like peptide-1 (GLP-1) receptor agonist reduces the mean body weight. However, caloric restriction provides more favorable improvement in body composition than does treatment with the GLP-1 receptor (GLP1R) agonist alone. Combination therapy with orlistat and phentermine are the US Food and Drug Administration (FDA)-approved anti-obesity drugs. Recombinant leptin and synthetic melanocortin-4-receptor agonists are used in rarely occurring, monogenic obesity, which is due to loss of function in the leptin-melanocortin pathway.

The IBD-FITT study - moderate-intensity exercise for patients with inflammatory bowel disease with moderate disease activity: an open-label randomized controlled trial

BACKGROUND

Inflammatory bowel disease (IBD), Crohn's disease, and ulcerative colitis are chronic autoimmune lifelong diseases with fluctuating activity over time. The treatment includes medical therapy and surgery, however, there is no definite cure. Therefore, the quest for new and supplementary treatment options is imperative to improve patients' general health and quality of life. Physical activity and exercise have been suggested to be elements in both the prevention and supplementary treatment of IBD; however, this is based on limited underpowered trials. Thus, the role of exercise as a treatment option still has to be settled. We aim to investigate the effect of a 12-week exercise intervention in adult patients with moderately active IBD on three categories of outcomes (1) disease-specific health-related quality of life (IBDQ); (2) general health status of the patients, i.e., waist circumference, disease activity by clinical scorings systems (Harvey Bradshaw Index, Simple Clinical Colitis Activity Index), blood pressure, blood lipids, and non-disease specific quality of life (EQ5D) scores; and (3) explorative outcomes on biomarkers (C-reactive protein and fecal calprotectin) plus different biomarkers of immunology (cytokine panel).

METHODS

We will apply a superiority design in this open-label randomized clinical trial including 150 patients equally allocated to intervention and usual care. The intervention will be based on a 12-week aerobic exercise program and will include two supervised exercise sessions of 60 min per week, combined with one weekly home training session. We have defined a moderate exercise level as 60-80% of patients' maximum heart rate. The patients in the intervention group will also be offered an online video lesson of 15-25 min on lifestyle guidance, and the same online video lesson will be offered in the comparator group. Questionnaires on quality of life will be forwarded electronically both at inclusion and at the end of the study, and the patients will have blood samples, and fecal samples for calprotectin at baseline, weeks 4 and 8, as well as after 12 weeks (study end).

DISCUSSION

This will be a clinical trial investigating the effect of exercise on patients with Crohn's disease and ulcerative colitis. This trial will add to the evidence on the possible effect of exercise and might clarify whether exercise can benefit as a supplementary treatment addendum. Thus, the trial may provide a new patient-active disease management approach.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04816812. Date of first registration: March 23, 2021.

Predicting risk of obesity in overweight adults using interpretable machine learning algorithms

Objective

To screen for predictive obesity factors in overweight populations using an optimal and interpretable machine learning algorithm.

Methods

This cross-sectional study was conducted between June 2011 and January 2012. The participants were randomly selected using a simple random sampling technique. Seven commonly used machine learning methods were employed to construct obesity risk prediction models. A total of 5,236 Chinese participants from Ningde City, Fujian Province, Southeast China, participated in this study. The best model was selected through appropriate verification and validation and suitably explained. Subsequently, a minimal set of significant predictors was identified. The Shapley additive explanation force plot was used to illustrate the model at the individual level.

Results

Machine learning models for predicting obesity have demonstrated strong performance, with CatBoost emerging as the most effective in both model validity and net clinical benefit. Specifically, the CatBoost algorithm yielded the highest scores, registering 0.91 in the training set and an impressive 0.83 in the test set. This was further corroborated by the area under the curve (AUC) metrics, where CatBoost achieved 0.95 for the training set and 0.87 for the test set. In a rigorous five-fold cross-validation, the AUC for the CatBoost model ranged between 0.84 and 0.91, with an average AUC of ROC at 0.87 ± 0.022. Key predictors identified within these models included waist circumference, hip circumference, female gender, and systolic blood pressure.

Conclusion

CatBoost may be the best machine learning method for prediction. Combining Shapley's additive explanation and machine learning methods can be effective in identifying disease risk factors for prevention and control.

Normal-weight central obesity and risk of cardiovascular and microvascular events in adults with prediabetes or diabetes: Chinese and British cohorts

OBJECTIVE

To investigate the relationship between body fat distribution and risk of cardiometabolic and microvascular events among individuals with prediabetes or diabetes with normal body mass index (BMI).

METHODS

A total of 17,232 participants with prediabetes or diabetes from UK Biobank (UKB) with 12-year follow-up and 499 diabetic participants from China with 2-year follow-up with normal BMI were included. Anthropometric measurements of waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR), and body fat composition assessment of trunk-to-leg fat ratio (TLFR) were obtained. Outcomes included incident all-cause and cardiovascular mortality and macrovascular and microvascular diseases.

RESULTS

In British cohort, participants with central obesity defined by WHR had 27%-54% higher risk of incident all-cause mortality (hazard ratio (HR) 1.42, 95% confidence interval (CI): 1.23-1.64), cardiovascular mortality (HR 1.54 [1.15-2.07]), myocardial infarction (HR = 1.43 [1.15, 1.78]), stroke (HR 1.26 [0.90, 1.75]), heart failure (HR = 1.27 [1.00, 1.61]), diabetic nephropathy (HR 1.33 [1.07, 1.65]), and diabetic retinopathy (DR) (HR = 1.48 [1.12, 1.96]) than those without obesity. Central obesity defined by WC and WHtR was associated with 40%-44% and 23%-98% higher risks of developing diabetic events, respectively. In the Chinese cohort, individuals with abdominal obesity, defined by WC (HR 1.44) or WHtR (HR 1.43) but not by WHR, carried more than 40% higher risk of developing DR than those without it. Higher TLFR carried 1.30-2.85 times higher risk of CVD and microvascular diseases among the dysglycemic population.

CONCLUSIONS

Body fat distribution diseases among individuals with prediabetes or diabetes are associated with an increased risk of cardiometabolic and microvascular diseases independent of BMI.

Effects of a supervised exercise training on body composition after bariatric surgery: a randomized controlled trial

OBJECTIVE

This study aimed to determine the effects of a multicomponent exercise intervention during the first year post-bariatric surgery (BS) on body composition, weight loss (WL), energy expenditure, and nutrient intake.

METHODS

A total of 84 patients were included in this study and were randomly assigned to either an exercise group (n = 41) or a control group (n = 20). The exercise group participated in a multicomponent exercise program that began 1-month post-BS, whereas the control group received only standard medical care post-BS. Body composition was assessed by dual-energy x-ray absorptiometry, and physical activity energy expenditure was assessed by accelerometers. Nutritional intake was assessed through a 4-day food diary.

RESULTS

A total of 6-months post-BS, exercise was found to be effective in mitigating the loss of lower-limb and appendicular lean mass (LM), as well as favoring trunk fat mass (FM) loss. Moreover, it further decreased percent FM and promoted additional excess WL. After 12 months, exercise not only reduced waist circumference but also helped to lessen the loss of total, trunk, and appendicular LM.

CONCLUSIONS

Exercise further induced trunk fat mass, percent FM, excess WL, and waist circumference reductions. Moreover, exercise attenuated the loss of total and regional LM.

Waist circumference cut-off points to identify major cardiovascular events and incident diabetes in Latin America: findings from the prospective Urban rural epidemiology study Colombia

Background

Abdominal obesity (AO) indirectly represents visceral adiposity and can be assessed by waist circumference (WC) measurement. In Latin America, cut-off points for the diagnosis of AO are based on Asian population data. We aim to establish the WC cut-off points to predict major cardiovascular events (MACE) and incident diabetes.

Methods

We analyzed data from the cohort PURE study in Colombia. WC cut-off points were defined according to the maximum Youden index. Multivariate logistic regression was used to obtain associations between WC and MACE, diabetes, and cumulative incidence of outcomes visualized using Kaplan-Meier curves.

Results

After a mean follow-up of 12 years, 6,580 individuals with a mean age of 50.7 ± 9.7 years were included; 64.2% were women, and 53.5% were from rural areas. The mean WC was 85.2 ± 11.6 cm and 88.3 ± 11.1 cm in women and men, respectively. There were 635 cases of the MACE composite plus incident diabetes (5.25 events per 1,000 person-years). Using a cut-off value of 88.85 cm in men (sensitivity = 0.565) and 85.65 cm in women (sensitivity = 0.558) resulted in the highest value for the prediction of the main outcome. These values were associated with a 1.76 and 1.41-fold increased risk of presenting the composite outcome in men and women, respectively.

Conclusions

We defined WC cut-off points of 89 cm in men and 86 cm in women to identify the elevated risk of MACE and incident diabetes. Therefore, we suggest using these values in cardiovascular risk assessment in Latin America.

Abdominal obesity in Chinese patients undergoing hemodialysis and its association with all-cause mortality

Introduction

Obesity in patients undergoing hemodialysis is common. However, there is limited information on the relationship between obesity types defined by the combined body mass index (BMI) and waist circumference (WC) classification criteria and all-cause mortality in Chinese hemodialysis patients. Our objective was to determine the association between obesity types and all-cause mortality in hemodialysis patients.

Methods

We conducted a prospective cohort study including patients from 11 hemodialysis centers in Beijing. According to the World Health Organization's standards, patients were classified into 2 categories with WC and 4 categories with BMI and then followed up for 1 year. Kaplan-Meier survival analysis was used to compare the difference in the cumulative survival rate in different BMI and WC groups. A multivariate Cox regression analysis was used to determine the association between different types of obesity and all-cause mortality.

Results

A total of 613 patients were enrolled, the mean age was 63.8 ± 7.1 years old, and 42.1% were women. Based on the baseline BMI, there were 303 (49.4%) patients with normal weight, 227 (37.0%) with overweight, 37(6.0%) with obesity, and 46 (7.5%) with underweight. Based on the baseline WC, 346 (56.4%) patients had abdominal obesity. During a median follow-up of 52 weeks, 69 deaths occurred. Kaplan-Meier plots demonstrated a significant association of BMI categories (log-rank χ2 = 18.574, p<0.001) and WC categories (log-rank χ2 = 5.698, p=0.017) with all-cause death. With normal BMI and non-abdominal obesity as a reference, multivariate Cox regression analysis results showed that obesity (HR 5.36, 95% CI, 2.09-13.76, p<0.001), underweight (HR, 5.29, 95% CI, 2.32-12.07, p<0.001), normal weight combined with abdominal obesity (HR 2.61, 95% CI, 1.20-5.66, p=0.016), and overweight combined with abdominal obesity (HR 1.79, 95% CI, 1.03-3.73, p=0.031, respectively) were significantly associated with higher risks of all-cause mortality.

Conclusion

Our study indicated that abdominal obesity is common and associated with all-cause mortality among Chinese hemodialysis patients.

Preoperative Body Mass Index, Waist Circumference, and Mortality After Major Cancer Surgery: A Nationwide Cohort Study in Korea

BACKGROUND

Body mass index (BMI) and waist circumference (WC) were used to evaluate nutritional status and obesity. We aimed to examine whether preoperative BMI or WC was associated with mortality after cancer surgery.

METHODS

This population-based cohort study used data extracted from the National Health Insurance Service database of South Korea. We included adult patients who underwent major cancer surgery with curative intent between January 1, 2016, and December 31, 2020.

RESULTS

A total of 87,220 patients were included in the final analysis, and 1,374 (1.6%) died within 90 days after cancer surgery. In the multiple logistic regression model, the BMI < 18.5/kg/m² and > 35 kg/m² groups showed 1.98-fold (odds ratio [OR], 1.98; 95% confidence interval [CI], 1.58-2.49; P < 0.001) and 2.60-fold (OR, 2.60; 95% CI, 1.25-5.40; P < 0.001) higher 90-day mortality after cancer surgery than did the BMI 18.5-24.9 kg/m² group. The 25.0-29.9 kg/m² (P = 0.144) and 30.0-34.9 kg/m² (P = 0.105) BMI groups did not show significant differences compared to the BMI 18.5-24.9 kg/m² group. Compared with the normal WC group, the high (P = 0.052) and very high (P = 0.232) WC groups also did not show significant differences in terms of 90-day mortality.

CONCLUSIONS

Preoperative BMI < 18.5 kg/m² and > 35 kg/m² is associated with an elevated risk of 90-day mortality after major cancer surgery. However, preoperative WC was not significantly associated with 90-day mortality after cancer surgery.

Thigh-hip ratio is significantly associated with all-cause mortality among Japanese community-dwelling men

Anthropometric evaluation is a simple yet essential indicator of muscle and fat mass when studying life prognosis in aging. This study aimed to investigate the contributions of anthropometric measurements, independent of body mass index, to measures of all-cause mortality. We examined data for 1,704 participants from the 2014 Nomura Cohort Study who attended follow-ups for the subsequent eight years (follow-up rate: 93.0%). Of these, 765 were male (aged 69 ± 11 years) and 939 were female (aged 69 ± 9 years). The Japanese Basic Resident Registry provided data on adjusted relative hazards for all-cause mortality. The data were subjected to a Cox regression analysis, wherein the time variable was age and the risk factors were gender, age, anthropometric index, smoking habits, drinking habits, exercise habits, cardiovascular history, hypertension, lipid levels, diabetes, renal function, and serum uric acid. Of the total number of participants, 158 (9.3%) were confirmed to have died, and of these, 92 were male (12.0% of all male participants) and 66 were female (7.0% of all female participants). The multivariable Cox regression analysis revealed that a smaller thigh-hip ratio predicted eight-year all-cause mortality in male participants, but only baseline body mass index was associated with all-cause mortality in female participants. Thigh-hip ratio is a useful predictor of death in Japanese community-dwelling men.

Bridging public and private health services to best meet the cardiometabolic needs of people with severe mental illness: a retrospective cohort study

OBJECTIVE

Cardiovascular disease is the leading cause of premature mortality in people with severe mental illness (SMI). Despite this, there lacks consensus regarding the most appropriate platform to monitor and treat cardiometabolic risk factors in this cohort. The current study aims to evaluate the effectiveness of tailored cardiometabolic healthcare in a private, GP-led clinic for people with SMI.

METHOD

A total of 63 adults with SMI were referred to a private GP-led cardiometabolic clinic from a neighbouring inner-city mental health service, where they received individualised cardiometabolic healthcare free-of-charge between 2014 and 2020. Paired t test was used to measure change in cardiometabolic data over the course of treatment. Chi-squared and Fisher's Exact tests were used to examine differences in demographic data and client engagement.

RESULTS

Over a mean period of 9 months, there was a significant mean reduction of weight (2.1 kg), BMI (0.72 kg/m2) and waist circumference (6 cm). Engagement over a longer period was associated with stable accommodation and improved cardiometabolic outcomes.

CONCLUSIONS

Targeted referral for individualised cardiometabolic interventions can lead to clinically significant improvement in cardiometabolic outcomes, providing a cause for therapeutic optimism when approaching physical health in people with SMI.

Relevance of body composition in phenotyping the obesities

Obesity is the most extended metabolic alteration worldwide increasing the risk for the development of cardiometabolic alterations such as type 2 diabetes, hypertension, and dyslipidemia. Body mass index (BMI) remains the most frequently used tool for classifying patients with obesity, but it does not accurately reflect body adiposity. In this document we review classical and new classification systems for phenotyping the obesities. Greater accuracy of and accessibility to body composition techniques at the same time as increased knowledge and use of cardiometabolic risk factors is leading to a more refined phenotyping of patients with obesity. It is time to incorporate these advances into routine clinical practice to better diagnose overweight and obesity, and to optimize the treatment of patients living with obesity.

Sex-Specific Comparison Between Triglyceride Glucose Index and Modified Triglyceride Glucose Indices to Predict New-Onset Hypertension in Middle-Aged and Older Adults

Background Triglyceride and glucose (TyG) index and TyG-related indices combined with obesity-related markers are considered important markers of insulin resistance. We aimed to examine the association between the TyG index and modified TyG indices with new-onset hypertension and their predictive ability stratified by sex. Methods and Results We analyzed data from 5414 Korean Genome and Epidemiology Study participants aged 40 to 69 years. Multiple Cox proportional hazard regression analyses were conducted to estimate the hazard ratio (HR) and 95% CI for new-onset hypertension according to sex-specific tertile groups after confounder adjustments. To evaluate the predictive performance of these indices for new-onset hypertension, we calculated Harrell's C-index (95% CI). Over a 9.5-year follow-up period, 1014 men and 1012 women developed new-onset hypertension. Compared with the lowest tertile (T) group, the adjusted HR and 95% CI for new-onset hypertension in T3 for TyG, TyG-body mass index, TyG-waist circumference, and TyG-waist-to-height ratio were 1.16 (0.95-1.40), 1.11 (0.84-1.48), 1.77 (1.38-2.27), and 1.68 (1.33-2.13) in men and 1.37 (1.13-1.66), 1.55 (1.16-2.06), 1.43 (1.15-1.79), and 1.64 (1.30-2.07) in women, respectively. The C-indices of TyG-waist-to-height ratio for new-onset hypertension were significantly higher than those of TyG and TyG-body mass index in both men and women. Conclusions TyG and TyG-body mass index were significantly associated with new-onset hypertension only in women. TyG-waist circumference and TyG-waist-to-height ratio were significantly associated with new-onset hypertension in both men and women. A sex-specific approach is required when using TyG and modified TyG indices to identify individuals at risk of incident hypertension.

Assessment of correlation between conventional anthropometric and imaging-derived measures of body fat composition: a systematic literature review and meta-analysis of observational studies

BACKGROUND

In studies of the association of adiposity with disease risk, widely used anthropometric measures of adiposity (e.g. body-mass-index [BMI], waist circumference [WC], waist-hip ratio [WHR]) are simple and inexpensive to implement at scale. In contrast, imaging-based techniques (e.g. magnetic resonance imaging [MRI] and dual x-ray absorptiometry [DXA]) are expensive and labour intensive, but can provide more accurate quantification of body fat composition. There is, however, limited evidence about the relationship between conventional and imaging-derived measures of adiposity.

METHODS

We searched Scopus and Web of Science for published reports in English of conventional versus imaging-derived measurements of adiposity. We identified 42 articles (MRI = 22; DXA = 20) that met selection criteria, involving 42,556 (MRI = 15,130; DXA = 27,426) individuals recruited from community or hospital settings. Study-specific correlation coefficients (r) were transformed using Fisher's Z transformation, and meta-analysed to yield weighted average correlations, both overall and by ancestry, sex and age, where feasible. Publication bias was investigated using funnel plots and Egger's test.

RESULTS

Overall, 98% of participants were 18 + years old, 85% male and 95% White. BMI and WC were most strongly correlated with imaging-derived total abdominal (MRI-derived: r = 0.88-; DXA-derived: 0.50-0.86) and subcutaneous abdominal fat (MRI-derived: 0.83-0.85), but were less strongly correlated with visceral abdominal fat (MRI-derived: 0.76-0.79; DXA-derived: 0.80) and with DXA-derived %body fat (0.76). WHR was, at best, strongly correlated with imaging-derived total abdominal (MRI-derived: 0.60; DXA-derived: 0.13), and visceral abdominal fat (MRI-derived: 0.67; DXA-derived: 0.65), and moderately with subcutaneous abdominal (MRI-derived: 0.54), and with DXA-derived %body fat (0.58). All conventional adiposity measures were at best moderately correlated with hepatic fat (MRI-derived: 0.36-0.43). In general, correlations were stronger in women than in men, in Whites than in non-Whites, and in those aged 18 + years.

CONCLUSIONS

In this meta-analysis, BMI and WC, but not WHR, were very strongly correlated with imaging-derived total and subcutaneous abdominal fat. By comparison, all three measures were moderately or strongly correlated with imaging-based visceral abdominal fat, with WC showing the greatest correlation. No anthropometric measure was substantially correlated with hepatic fat. Further larger studies are needed to compare these measures within the same study population, and to assess their relevance for disease risks in diverse populations.

Development and validation of an accurate smartphone application for measuring waist-to-hip circumference ratio

Waist-to-hip circumference ratio (WHR) is now recognized as among the strongest shape biometrics linked with health outcomes, although use of this phenotypic marker remains limited due to the inaccuracies in and inconvenient nature of flexible tape measurements when made in clinical and home settings. Here we report that accurate and reliable WHR estimation in adults is possible with a smartphone application based on novel computer vision algorithms. The developed application runs a convolutional neural network model referred to as MeasureNet that predicts a person's body circumferences and WHR using front, side, and back color images. MeasureNet bridges the gap between measurements conducted by trained professionals in clinical environments, which can be inconvenient, and self-measurements performed by users at home, which can be unreliable. MeasureNet's accuracy and reliability is evaluated using 1200 participants, measured by a trained staff member. The developed smartphone application, which is a part of Amazon Halo, is a major advance in digital anthropometry, filling a long-existing gap in convenient, accurate WHR measurement capabilities.

Change in the food environment and measured adiposity in adulthood in the Christchurch Health and development birth cohort, Aotearoa, New Zealand: A birth cohort study

This study investigated associations between change in the food environment and change in measured body mass index (BMI) and waist circumference (WC) in the Christchurch Health and Development Study (CHDS) birth cohort. Our findings suggest that cohort members who experienced the greatest proportional change towards better access to fast food outlets had the slightly larger increases in BMI and WC. Contrastingly, cohort members who experienced the greatest proportional change towards shorter distance and better access to supermarkets had slightly smaller increases in BMI and WC. Our findings may help explain the changes in BMI and WC at a population level.

Overall and abdominal obesity and risks of all-cause and cause-specific mortality in Korean adults: a pooled analysis of three population-based prospective cohorts

BACKGROUND

Studies found a J-shaped association between body mass index (BMI) and mortality. However, it is unclear whether the association is driven by biases, particularly confounding by fat-free mass.

METHODS

We conducted an individual-level pooled analysis of three cohorts of Korean adults (aged ≥ 40 years; n = 153 248). Mortality was followed up through December 2019. Anthropometric data were directly measured at baseline. Fat and fat-free mass were predicted using validated prediction models. Using Cox proportional hazards models, we estimated the associations of BMI and waist circumference (WC) with all-cause and cause-specific mortality. To account for biases, we excluded participants aged ≥ 70 years, deaths that occurred within 5 years of follow-up and ever smokers, and adjusted for fat-free mass index (FFMI).

RESULTS

During the follow-up of up to 18 years, 6061 deaths were identified. We observed J-shaped association of BMI (nadir at 22-26) and monotonically positive association of WC with all-cause, cardiovascular, and cancer mortality among Korean adults without a history of cancer or cardiovascular disease. In the BMI analysis, excluding ever smokers and adjusting for FFMI attenuated the excess mortality in underweight participants and transformed the J-shaped association into a monotonically positive shape, suggesting an increased mortality at BMI > 22.0. Excluding participants aged ≥ 70 years and deaths that occurred within 5 years of follow-up did not change the results. In the WC analysis, the monotonic positive associations did not change after the control. Similar results were observed among participants with a history of cancer or cardiovascular disease.

CONCLUSIONS

Our data suggest that both overall and abdominal body fat are associated with increased mortality in Korean adults.

Obesity Paradox in Lung Diseases: What Explains It?

BACKGROUND

Obesity is a globally increasing health problem that impacts multiple organ systems and a potentially modifiable risk factor for many diseases. Obesity has a significant impact on lung function and is strongly linked to the pathophysiology that contributes to lung diseases. On the other hand, reports have emerged that obesity is associated with a better prognosis than for normal weight individuals in some lung diseases, including pneumonia, acute lung injury/acute respiratory distress syndrome, chronic obstructive pulmonary disease, and lung cancer. The lesser mortality and better prognosis in patients with obesity is known as obesity paradox. While obesity paradox is both recognized and disputed in epidemiological studies, recent research has suggested possible mechanisms.

SUMMARY

In this review, we attempted to explain and summarize these factors and mechanisms, including immune response, pulmonary fibrosis, lung function, microbiota, fat and muscle reserves, which are significantly altered by obesity and may contribute to the obesity paradox in lung diseases. We also discuss contrary literature that attributes the "obesity paradox" to confounding.

KEY MESSAGES

The review will illustrate the possible role of obesity in the prognosis or course of lung diseases, leading to a better understanding of the obesity paradox and provide hints for further basic and clinical research in lung diseases.

Added value of waist circumference to body mass index for predicting fracture risk in obesity: a prospective study from the CARTaGENE cohort

Larger waist circumference is significantly associated with an increased risk of distal lower limb fractures in individuals aged 40-70 years with a body mass index within the normal or overweight category. Therefore, waist circumference provides additive information to body mass index for the identification of individuals at risk of obesity-related fractures.

INTRODUCTION

Waist circumference (WC) is a stronger risk factor of metabolic disorders than body mass index (BMI), but whether it holds true for fracture risk prediction remains unclear. We aimed to evaluate relationships between WC and fracture incidence within BMI categories and evaluate whether BMI modifies these relationships.

METHODS

Men and women aged 40-70 years from the CARTaGENE cohort were divided by BMI category at baseline: normal weight, overweight, and obesity. Incident fractures were identified over 7 years via linkage with healthcare administrative databases. Cox proportional hazard models estimated the relationships between WC and incident fractures at any site and by skeletal site within each BMI category. Results are reported as adjusted hazard ratios (95% confidence intervals) per 10 cm increase in WC. Effect modification was evaluated qualitatively by comparing relationships between BMI categories.

RESULTS

Of the 18 236 individuals included, 754 sustained a fracture. Significant relationships were found between WC and distal lower limb fractures in the normal (1.25 [1.08, 1.45]) and overweight (1.28 [1.07, 1.52]) BMI categories, but not in the obesity category. In the overweight category, we found an increased risk of distal upper limb fractures with increasing WC (1.49 [1.04, 2.15]). No significant relationship was observed regarding WC and fracture risk at any site or major osteoporotic fractures. An effect modification of BMI on the relationships between WC and distal lower limb fractures was observed.

CONCLUSION

WC provides both independent and additive information to BMI for the identification of individuals at risk of obesity-related fractures.

Body mass index and all-cause mortality in a 21st century U.S. population: A National Health Interview Survey analysis

INTRODUCTION

Much of the data on BMI-mortality associations stem from 20th century U.S. cohorts. The purpose of this study was to determine the association between BMI and mortality in a contemporary, nationally representative, 21st century, U.S. adult population.

METHODS

This was a retrospective cohort study of U.S. adults from the 1999-2018 National Health Interview Study (NHIS), linked to the National Death Index (NDI) through December 31st, 2019. BMI was calculated using self-reported height & weight and categorized into 9 groups. We estimated risk of all-cause mortality using multivariable Cox proportional hazards regression, adjusting for covariates, accounting for the survey design, and performing subgroup analyses to reduce analytic bias.

RESULTS

The study sample included 554,332 adults (mean age 46 years [SD 15], 50% female, 69% non-Hispanic White). Over a median follow-up of 9 years (IQR 5-14) and maximum follow-up of 20 years, there were 75,807 deaths. The risk of all-cause mortality was similar across a wide range of BMI categories: compared to BMI of 22.5-24.9 kg/m2, the adjusted HR was 0.95 [95% CI 0.92, 0.98] for BMI of 25.0-27.4 and 0.93 [0.90, 0.96] for BMI of 27.5-29.9. These results persisted after restriction to healthy never-smokers and exclusion of subjects who died within the first two years of follow-up. A 21-108% increased mortality risk was seen for BMI ≥30. Older adults showed no significant increase in mortality between BMI of 22.5 and 34.9, while in younger adults this lack of increase was limited to the BMI range of 22.5 to 27.4.

CONCLUSION

The risk of all-cause mortality was elevated by 21-108% among participants with BMI ≥30. BMI may not necessarily increase mortality independently of other risk factors in adults, especially older adults, with overweight BMI. Further studies incorporating weight history, body composition, and morbidity outcomes are needed to fully characterize BMI-mortality associations.

BMI category-specific waist circumference thresholds based on cardiovascular disease outcomes and all-cause mortality: Tehran lipid and glucose study (TLGS)

BACKGROUND

Waist circumference (WC), a representative of abdominal visceral fat, is strongly associated with cardiovascular disease (CVD) and its outcomes. We aimed to define body mass index (BMI)-specific WC thresholds as predictors of CVD and all-cause mortality.

METHODS

In this prospective cohort study in the context of the Tehran Lipid and Glucose Study (TLGS), a total of 3344 men and 4068 women were followed up for 18 years. Based on BMI, the participants were categorized into three groups: BMI < 25, 25 < BMI < 30, and BMI > 30. In each BMI category, sex-specific WC thresholds were estimated by the maximum value of Youden's index to predict based on incident CVD events and all-cause mortality prediction.

RESULTS

Overall 667 and 463 CVD events (the incidence rate of 3.1 to 4.5 in men and 1.1 to 2.6 in women per 1,000 person-years within BMI categories) and 438 and 302 mortalities (the incidence rate of 2.1 to 2.7 in men and 1.2 to 1.4 in women per 1,000 person-years within BMI categories) were recorded in men and women, respectively. WC thresholds in the BMI categories of < 25, 25-30, and BMI > 30 kg/m² with regard to CVD events were 82, 95, and 103 cm in men and 82, 89, and 100 cm in women, and regarding all-cause mortality, the respective values were 88, 95, and 103 cm in men and 83, 90, and 99 cm among women.

CONCLUSION

BMI-specific WC thresholds observed here can help to better identify individuals at high risk of developing CVDs.