Central adiposity and the overweight risk paradox in aging: follow-up of 130,473 UK Biobank participants

Association Between Adiposity and Perceived Physical Fatigability in Mid- to Late Life

OBJECTIVE

This study aimed to compare and contrast the associations between measures of adiposity and fat distribution and perceived fatigability among well-functioning individuals in mid- to late life.

METHODS

In 1,054 adults (70.4 ± 12.4 years, 52% female), adiposity was measured as BMI, percent fat (dual-energy x-ray absorptiometry), waist and hip circumferences, and waist to height ratio. In a subset of 383 participants, visceral fat was measured. Perceived fatigability was evaluated after a 5-minute treadmill walk (1.5 mph) using the Borg rating of perceived exertion (range, 6-20). Associations between adiposity measures and perceived fatigability were assessed using regression models adjusting for age, sex, race, smoking, and comorbidities.

RESULTS

All adiposity measures, except subcutaneous fat, were positively associated with perceived fatigability after adjustment (P < 0.05 for all). Standardized coefficients indicated that BMI, hip circumference, and visceral fat had the strongest associations with fatigability. Associations between BMI and fatigability were present only among those above the threshold for overweight and strongest in those aged ≥ 65 years. Moreover, BMI was associated with fatigability only among participants with higher waist circumference.

CONCLUSIONS

Measures of adiposity, particularly central adiposity, are strongly associated with fatigability, suggesting that weight management may be an effective target for curbing fatigability and maintaining quality of life with aging.

Impact of Normal Weight Central Obesity on Clinical Outcomes in Male Patients With Premature Acute Coronary Syndrome

There is a lack of studies that evaluate the association between normal weight central obesity and subsequent outcomes in patients with premature acute coronary syndrome (ACS). We evaluated 338 consecutive male patients (aged ≤ 55 years) with premature ACS. The primary outcomes were all-cause mortality and major adverse cardiac and cerebrovascular events (MACCE). We compared the hazard ratios (HRs) in patients with and without normal weight central obesity using multivariable Cox proportional hazard models. All-cause mortality (16.8%) of patients with normal weight central obesity was much higher than those (7.1%) without normal weight central obesity (P = .008). The incidence of MACCE in patients with and without normal weight central obesity were 40.7 and 23.6% (P = .001), respectively. After multivariable adjustment, the risks of all-cause mortality and MACCE were significantly higher in patients with normal weight central obesity than those without normal weight central obesity (adjusted HR: 1.83; 95% confidence interval [CI]: 1.04-3.31; P = .004 and adjusted HR: 1.62; 95% CI: 1.18-2.27; P = .017, respectively). In conclusion, the risks of all-cause mortality and MACCE were significantly higher in male patients with premature ACS with normal weight central obesity than in those without normal weight central obesity.

Obesity and Atrial Fibrillation: Epidemiology, Pathophysiology and Novel Therapeutic Opportunities

Obesity is already a major global public health issue, implicated in a vast array of conditions affecting multiple body systems. It is now also firmly established as an independent risk factor in the incidence and progression of AF. The rapidly rising morbidity, mortality and healthcare costs associated with AF despite implementation of the three pillars of AF management — anticoagulation, rate control and rhythm control — suggest other strategies need to be considered. Compelling data has unveiled novel insights into adipose tissue biology and its effect on arrhythmogenesis while secondary prevention strategies targeting obesity as part of a comprehensive risk factor management programme have been demonstrated to be highly effective. Here, the authors review the epidemiological basis of the obesity—AF relationship, consider its underlying pathophysiology and discuss new therapeutic opportunities on the horizon.

Obesity Paradox in Caucasian Seniors: Results of the PolSenior Study

OBJECTIVES

To investigate the influence of overweight and obesity on general performance and mortality in seniors.

DESIGN

Cross-sectional multidisciplinary study on ageing of the Polish population.

SETTING

Community-dwelling individuals aged 65 years or older, selected using three-stage stratified, proportional draw.

PARTICIPANTS

4944 Polish Caucasian seniors, aged 65 years or older recruited between October 2007 and October 2010.

MEASUREMENTS

All study subjects underwent measurement of body mass index (BMI), waist circumference (WC), and arm circumference (AC). The physical and cognitive performance was evaluated using the Katz Activities of Daily Living (ADL) score and Mini-Mental State Examination (MMSE), respectively. Morbidity data were obtained from a medical questionnaire. Mortality data were obtained from the Population Register of Poland between October 2015 and October 2018.

RESULTS

Increasing age was associated with a decreased prevalence of obesity (all p<0.001). Higher BMI, WC and AC values were associated with higher ADL and MMSE scores (all p<0.001). On multivariate analysis, all three body measurements in women remained independent predictors of the ADL score (BMI p=0.002, WC p=0.005, AC p<0.001) and MMSE score (p<0.001, p=0.003, p<0.001). In men, physical functioning was associated with AC (p=0.003), and cognitive status was associated with AC (p<0.001) and BMI (p=0.013). There was no association between general obesity, abdominal obesity, or AC with several aging-related adverse conditions. Kaplan-Meier survival curves showed that overweight and obesity were associated with the lowest mortality. On multivariate analysis, BMI and AC values remained independent predictors of mortality. In successfully aging individuals, neither BMI, WC, nor AC remained such predictors.

CONCLUSIONS

Overweight and obesity in Caucasian seniors are not associated with deterioration of physical and cognitive function or with increased mortality.

Identification of chronic kidney disease risk in relatively lean Southern Chinese: the hypertriglyceridemic waist phenotype vs. anthropometric indexes

PURPOSE

Assessing and comparing the ability of the hypertriglyceridemic waist (HW) phenotype and anthropometric obesity indexes to identify subjects at high risk of chronic kidney disease (CKD) in a relatively lean population in South China.

METHODS

Using data from a community-based, cross-sectional study conducted in Zhuhai City, Southern China, we examined associations between the HW phenotype, anthropometric obesity indexes, and incident CKD risk in a relatively lean population. Multiple logistic regression analyses were used to evaluate the associations.

RESULTS

The HW phenotype associated with CKD significantly in the unadjusted analysis (OR 3.53, 95% CI 1.65-7.52, P = 0.001). Further adjustment for gender, age, and other potential confounding variables had an impact on the odd ratios (OR); the OR decreased but still existed (OR 2.91, 95% 1.23-6.87, P = 0.016). The association of the HW phenotype with CKD remained significant after further adjustment for hypertension and diabetes. No significant association between the anthropometric indexes and incident CKD was found.

CONCLUSION

The HW phenotype, but not the anthropometric indexes, is associated with an elevated risk of CKD in relatively lean subjects. The HW phenotype appears to be a better predictor of CKD than the anthropometric indexes.

LEVEL OF EVIDENCE

Level V, descriptive study.

Association between hyperuricemia and nontraditional adiposity indices

BACKGROUND

The association between several novel adiposity indices and hyperuricemia is inconclusive. Therefore, we aimed to investigate this association so as to provide theoretical support for the management of hyperuricemia in overweight/obese individuals.

METHODS

A cross-sectional study was carried out among 174,698 adults. The values of body adiposity index (BAI), conicity index (CI), a body shape index (ABSI), body roundness index (BRI), visceral adiposity index (VAI), lipid accumulation product (LAP) index, and cardiometabolic index (CMI) were divided into four quartiles, and multivariate logistic analysis was used to analyze the association between them and hyperuricemia. Receiver operating characteristic curve and area under curve (AUC) were used to evaluate the power of predictions for hyperuricemia.

RESULTS

After adjusting for confounding variables, LAP and CMI exhibited stronger association with hyperuricemia than other indices. The odd ratio (OR) for hyperuricemia in the highest quartile of the LAP and CMI was 2.049 (CI 95% = 1.824-2.302) and 4.332(CI 95% = 3.938-4.765). The AUC value of LAP was 0.632 (95% CI = 0.626-0.637), p < 0.001; and the AUC value of CMI was 0.687 (95% CI = 0.682-0.692), p < 0.001. The optimal cutoff values of LAP and CMI were 26.21 and 0.485, respectively.

CONCLUSIONS

LAP and CMI, combination of WC and lipid parameters and reliable visceral adiposity indices, were strongly associated with hyperuricemia than other indices. So they could be potential monitoring indicators for hyperuricemia management in overweight/obese individuals.

Obesity in Older Type 2 Diabetic Patients: Does Working Environment Add Vulnerability?

Little is known about how working adults with type 2 diabetes are managing their health. This study aims to analyze the associations between health, behavioral, and sociodemographic characteristics and obesity in older diabetic patients in Europe. Data from the Survey of Health, Ageing, and Retirement in Europe was used to compare 1447 participants that were identified as having type 2 diabetes with 28,047 participants without diabetes. Multilevel logistic models stratified by type 2 diabetes examined the relationships of health, behavioral, and sociodemographic characteristics with obesity. The proportion of physical inactivity was significantly higher among those with type 2 diabetes (15.0% vs. 6.1%). Individuals with diabetes had more chronic diseases, more limitations in activities, higher body mass index, more depression, lower quality of life and well-being, and lower employment rate. Among those with type 2 diabetes, those employed were more likely to be obese (OR = 1.377, 95% CI, 1.023 to 1.853) and women were 52% more likely to be obese than men. The surveillance of weight in working environments should be required within workers with type 2 diabetes. It is concluded that this and other adjustments could be beneficial in people with diabetes.

Adiposity-Mortality Relationships in Type 2 Diabetes, Coronary Heart Disease, and Cancer Subgroups in the UK Biobank, and Their Modification by Smoking

OBJECTIVE

The obesity paradox in which overweight/obesity is associated with mortality benefits is believed to be explained by confounding and reverse causality rather than by a genuine clinical benefit of excess body weight. We aimed to gain deeper insights into the paradox through analyzing mortality relationships with several adiposity measures; assessing subgroups with type 2 diabetes, with coronary heart disease (CHD), with cancer, and by smoking status; and adjusting for several confounders.

RESEARCH DESIGN AND METHODS

We studied the general UK Biobank population (N = 502,631) along with three subgroups of people with type 2 diabetes (n = 23,842), CHD (n = 24,268), and cancer (n = 45,790) at baseline. A range of adiposity exposures were considered, including BMI (continuous and categorical), waist circumference, body fat percentage, and waist-to-hip ratio, and the outcome was all-cause mortality. We used Cox regression models adjusted for age, smoking status, deprivation index, education, and disease history.

RESULTS

For BMI, the obesity paradox was observed among people with type 2 diabetes (adjusted hazard ratio for obese vs. normal BMI 0.78 [95% CI 0.65, 0.95]) but not among those with CHD (1.00 [0.86, 1.17]). The obesity paradox was pronounced in current smokers, absent in never smokers, and more pronounced in men than in women. For other adiposity measures, there was less evidence for an obesity paradox, yet smoking status consistently modified the adiposity-mortality relationship.

CONCLUSIONS

The obesity paradox was observed in people with type 2 diabetes and is heavily modified by smoking status. The results of subgroup analyses and statistical adjustments are consistent with reverse causality and confounding.

Abdominal obesity in normal weight versus overweight and obese hemodialysis patients: Associations with nutrition, inflammation, muscle strength, and quality of life

OBJECTIVE

The biological basis of abdominal obesity leading to more severe outcomes in patients with normal body mass index (BMI) on maintenance hemodialysis (MHD) is unclear. The aim of this study was to compare the properties of abdominal obesity in different BMI categories of patients on MHD.

METHODS

We performed a cross-sectional study of 188 MHD patients (52.7% women; mean age, 69.4 ± 11.5 y) with abdominal obesity in different BMI groups using criteria from the World Health Organization. Appetite and dietary intake, body composition, handgrip strength, malnutrition inflammation score (MIS), inflammatory biomarkers, adipokines, and health-related quality-of-life (QoL) questionnaires were studied.

RESULTS

According to multivariable analyses, abdominally obese patients with normal BMIs consumed less protein per day (P = 0.04); had lower measurements of surrogates of lean (P < 0.001) and fat mass (P < 0.001); and had higher total cholesterol, tumor necrosis factor-α (P < 0.05), and ratios of adiponectin to leptin (P = 0.003) than overweight and obese patients with abdominal obesity. Multivariable analyses showed no differences in handgrip strength among the study groups.The abdominally obese study participants with normal weight had significantly lower scores in role physical (P = 0.003) and pain (P = 0.04) scales after multivariable adjustments.

CONCLUSIONS

Normal-weight MHD patients with abdominal obesity exhibited a more proatherogenic profile in terms of inflammatory markers and adipokine expression, lower body composition reserves, and lower physical ability than patients with abdominal obesity with overweight and obesity. This at least partially explains the abdominal obesity paradox in the MHD population in which worse clinical outcomes are seen in abdominally obese patients with normal BMIs, as opposed to overweight and obese patients who are also abdominally obese.

Obesity Paradox in Aging: From Prevalence to Pathophysiology

Recent advances in medical technology and health care have greatly improved the management for chronic diseases and prolonged human lifespan. Unfortunately, increased lifespan and the aging population impose a major challenge on the ever-rising prevalence of chronic diseases, in particular cardiometabolic stress associated with the pandemic obesity in our modern society. Although overweight and obesity are associated with incident cardiovascular diseases (CVD), including heart failure (HF), it paradoxically leads to a more favorable prognosis in patients with chronic HF, a phenomenon commonly defined as "obesity paradox". Numerous population-based and clinical studies have suggested possible explanations such as better metabolic reserve, smoking and disease-associated weight loss for obesity paradox. Recent evidence noticed a shift in obesity paradox with aging. While some studies have reported a more pronounced "obesity paradox" in the older patients, others have seen diminished cardiac benefits with overweight and obesity in the elderly patients with CVD. These findings suggested that a complex relationship among aging, metabolism, and HF severity/chronicity, which may explain the shift in obesity paradox in the elderly. Aging negatively affects body metabolism and cardiac function although its precise impact on obesity paradox remains elusive. To develop new strategies for cardiovascular health in the elderly, it is imperative to understand the precise role for aging on obesity-related CVD.