Time to Retire the BMI?: Evaluating Abdominal Adipose Tissue Imaging as Novel Cardiovascular Risk Biomarker

Quantitative analysis of the caloric restriction versus isocaloric diets models based on macronutrients composition: impacts on body weight regulation, anthropometric, and bioimpedance parameters in women with obesity

Introduction

Obesity is a growing public health issue, especially among young adults, with long-term management strategies still under debate. This prospective study compares the effects of caloric restriction and isocaloric diets with different macronutrient distributions on body composition and anthropometric parameters in obese women during a 12-week weight loss program, aiming to identify the most effective dietary strategies for managing obesity-related health outcomes.

Methods

A certified clinical nutritionist assigned specific diets over a 12-week period to 150 participants, distributed as follows: hypocaloric diets-low-energy diet (LED, 31 subjects) and very low-energy diet (VLED, 13 subjects); isocaloric diets with macronutrient distribution-low-carbohydrate diet (LCD, 48 subjects), ketogenic diet (KD, 23 subjects), and high-protein diet (HPD, 24 subjects); and isocaloric diet without macronutrient distribution-time-restricted eating (TRE, 11 subjects). Participants were dynamically monitored using anthropometric parameters: body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR) and bioelectrical impedance analysis (BIA) using the TANITA Body Composition Analyzer BC-418 MA III (T5896, Tokyo, Japan) at three key intervals-baseline, 6 weeks, and 12 weeks. The following parameters were evaluated: body weight, basal metabolic rate (BMR), percentage of total body fat, trunk fat, muscle mass, fat-free mass, and hydration status.

Results

All diets led to weight loss, but differences emerged over time. The TRE model resulted in significantly less weight loss compared to LED at the final follow-up (6.30 kg, p < 0.001), similar to the VLED (4.69 kg, p < 0.001). Isocaloric diets with varied macronutrient distributions showed significant weight loss compared to LED (p < 0.001). The KD reduced waist circumference at both 6 and 12 weeks (-4.08 cm, p < 0.001), while significant differences in waist-to-hip ratio reduction were observed across diet groups at 12 weeks (p = 0.01). Post-hoc analysis revealed significant fat mass differences at 12 weeks, with HPD outperforming IF (p = 0.01) and VLED (p = 0.003). LCD reduced trunk fat at 6 weeks (-2.36%, p = 0.001) and 12 weeks (-3.79%, p < 0.001). HPD increased muscle mass at 12 weeks (2.95%, p = 0.001), while VLED decreased it (-2.02%, p = 0.031). TRE showed a smaller BMR reduction at 12 weeks compared to LED.

Conclusion

This study highlights the superior long-term benefits of isocaloric diets with macronutrients distribution over calorie-restrictive diets in optimizing weight, BMI, body composition, and central adiposity.

Comparative Analysis of Dietary Habits and Obesity Prediction: Body Mass Index versus Body Fat Percentage Classification Using Bioelectrical Impedance Analysis

Background: Obesity remains a widely debated issue, often criticized for the limitations in its identification and classification. This study aims to compare two distinct systems for classifying obesity: body mass index (BMI) and body fat percentage (BFP) as assessed by bioelectrical impedance analysis (BIA). By examining these measures, the study seeks to clarify how different metrics of body composition influence the identification of obesity-related risk factors. Methods: The study enrolled 1255 adults, comprising 471 males and 784 females, with a mean age of 36 ± 12 years. Participants exhibited varying degrees of weight status, including optimal weight, overweight, and obesity. Body composition analysis was conducted using the TANITA Body Composition Analyzer BC-418 MA III device (T5896, Tokyo, Japan), evaluating the following parameters: current weight, basal metabolic rate (BMR), adipose tissue (%), muscle mass (%), and hydration status (%). Results: Age and psychological factors like cravings, fatigue, stress, and compulsive eating were significant predictors of obesity in the BMI model but not in the BFP model. Additionally, having a family history of diabetes was protective in the BMI model (OR: 0.33, 0.11-0.87) but increased risk in the BFP model (OR: 1.66, 1.01-2.76). The BMI model demonstrates exceptional predictive ability (AUC = 0.998). In contrast, the BFP model, while still performing well, exhibits a lower AUC (0.975), indicating slightly reduced discriminative power compared to the BMI model. Conclusions: BMI classification demonstrates superior predictive accuracy, specificity, and sensitivity. This suggests that BMI remains a more reliable measure for identifying obesity-related risk factors compared to the BFP model.

Genetic variant rs9939609 in FTO is associated with body composition and obesity risk in Korean females

INTRODUCTION

The fat mass and obesity-associated (FTO) gene is a significant locus in obesity. However, the association between FTO genetic variants and body composition has not been fully elucidated.

RESEARCH DESIGN AND METHODS

This observational study examined the associations of FTO rs9939609 T>A with obesity and body composition markers in Koreans. A total of 6474 participants from the Korean Genome and Epidemiology Study were analyzed for their general characteristics, body composition and FTO genotype with a sex-stratified approach.

RESULTS

Females with the obesity risk A allele showed significantly greater body weight, hip circumference, and body mass index and were at a 1.28-fold higher risk of obesity (95% CI=1.088 to 1.507) than those with the TT genotype. Analyses of body composition also showed that females with the A allele had a greater body fat mass and percentage, abdominal fat percentage, and degree of obesity, and this association and FTO genetic variation and adiposity was observed in females, especially aged under 50 years. However, the effect of the variant allele on non-fat tissue markers was not evident in females and was not associated with any parameters examined in males.

CONCLUSIONS

The FTO rs9939609 variant is associated with body composition in Koreans, especially body fat markers in females. These results support that the FTO rs9939609 variant is a genetic risk factor in the etiology of obesity.

Which BMI for Diabetes Patients is Better? From the View of the Adipose Tissue Macrophage-Derived Exosome

PURPOSE

Diabetes, as a group of metabolic diseases, can elevate blood glucose, thus leading to the development of life-threatening complications. It is difficult to define the outcome for diabetics with different BMI. This review will illustrate the adipose tissue macrophage-derived exosome in the diabetics with different BMI.

PATIENTS AND METHODS

Insulin resistance in peripheral tissues can cause diabetes. The peripheral tissues include liver, muscle, or the adipose depots. Communication between these organs is fatal to the maintenance of glucose homeostasis. This review will illustrate this communication. Obesity is closely linked with diabetes. There are different changes in fat distribution in diabetic patients. Adipose tissue macrophages can secrete various hormones, including adiponectin, leptin, resistin and other classical cytokines, such as TNF-α and IL-6. Studies illustrated that exosomes from the adipose tissue, can modulate inter-organ cross-talk by regulating gene expression in other tissues.

RESULTS

Adipose tissue macrophages exosomes links thin and fat individuals in the development of diabetes.

CONCLUSION

The molecular pathways initiated by exosomes such as miRNA in the situations of metabolic stress could help us gain a deeper knowledge of the pathophysiology of diabetes.

Impact of Cardiovascular Risk Factors on the Occurrence of Cardiovascular Events in Antineutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitides

Despite improvement in the prognosis of ANCA-associated vasculitides (AAVs), increased mortality, mainly from a cardiovascular origin, persists. We aimed to determine the role of cardiovascular risk factors (CVRFs) on the occurrence of major cardiovascular events (MACEs) in AAVs. Patients with AAVs were successively included in a prospective cohort study, which assessed CVRFs (defined by age >50 years in men and >60 years in women, personal history of cardiovascular disease, smoking status, obesity, diabetes, dyslipidemia, hypertension, and sedentary lifestyle), the use of glucocorticoids and immunosuppressive agents at baseline and during follow-up, and the occurrence of MACEs. One hundred and three patients were included, with a median follow-up time of 3.5 years. In the glucocorticoids and cyclophosphamide adjusted multivariate analysis, the occurrence of MACEs was associated with older age (p = 0.001, OR = 14.71, 95% CI (confidence interval) = 2.98–72.68), cardiovascular history (p = 0.007, OR (odds ratio) = 6.54, 95% CI = 1.66–25.71), sedentary lifestyle (p = 0.011, OR = 4.50, 95% CI = 1.42–14.29), hypertension (p = 0.017, OR = 5.04, 95% CI = 1.33–19.12), and dyslipidemia (p = 0.03, OR = 3.86, 95% CI = 1.14–13.09). The occurrence of MACEs was associated with the number of CVRFs (p < 0.001), but not with the use of glucocorticoids or cyclophosphamide (p = 0.733 and p = 0.339, respectively). The implementation of a screening and management program for modifiable CVRFs, particularly hypertension, sedentary lifestyle, and dyslipidemia, may be beneficial for AAV patients in order to reduce their cardiovascular risk.

Inconsistent social rhythms are associated with abdominal adiposity after involuntary job loss: An observational study

Objective

Unemployment is an established risk factor for obesity. However, few studies have examined obesity-related health behavior after involuntary job loss specifically. Job loss confers a disruption in daily time structure that could lead to negative metabolic and psychological outcomes through chronobiological mechanisms. This study examines whether individuals with unstable social rhythms after involuntary job loss present with higher abdominal adiposity than individuals with more consistent social rhythms and whether this relationship varies as a function of depressive symptoms.

Methods

Cross-sectional baseline data (n = 191) from the ongoing Assessing Daily Activity Patterns in occupational Transitions (ADAPT) study were analyzed using linear regression techniques. Participants completed the Social Rhythm Metric-17 (SRM) daily over 2 weeks. They also completed the Beck Depression Inventory II (BDI-II) and participated in standardized waist circumference measurements (cm).

Results

A significant interaction emerged between SRM and BDI-II demonstrating that less consistent social rhythms were associated with larger waist circumference at lower levels of depressive symptoms. Additional exploratory analyses demonstrated a positive association between the number of daily activities performed alone and waist circumference when controlling for symptoms of depression.

Conclusion

These findings are the first to demonstrate a relationship between social rhythm stability and abdominal adiposity in adults who have recently, involuntarily lost their jobs. Results highlight the moderating role of depressive symptoms on daily routine in studies of metabolic health. Future prospective analysis is necessary to examine causal pathways.

Linked Lives: Exploring Gender and Sedentary Behaviors in Older Adult Couples

Objectives: We explored associations between co-habiting partners for sedentary behavior (type and time, via accelerometry and self-report), gender, and a surrogate health measure (inflammatory biomarker: C-reactive protein, CRP). Methods: Participants completed activity questionnaires and the Timed Up and Go (mobility), wore an accelerometer for 7 days, and provided samples for high-sensitivity (hs) CRP. We used multilevel modeling (partners within couples) to investigate associations between independent variables and (a) sedentary behavior and (b) hsCRP. Results: 112 couples (50% women) provided sedentary data and hsCRP. Sedentary behavior was significantly correlated (r = .440, p < .001) between women and men, but there were significant differences in sedentary time (women < men) and light activity (women > men). Gender, moderate to vigorous physical activity (MVPA), and mobility estimated 37% of the modeled variance in sedentary time, while body mass index (BMI) and MVPA estimated 10% of the modeled variance in hsCRP. Discussion: Despite differences in how activity was accumulated, there were no significant differences between women's and men's health biomarker.

Circulating adipose stromal cells as a response biomarker in phase II energy balance trials of obese breast cancer survivors and high-risk women

PURPOSE

Circulating adipose stromal cells (CASC) are thought to be increased in obesity and facilitate angiogenesis, and tumor metastases.

METHODS

CASC were identified from buffy coat peripheral blood mononuclear cells (PBMCs) by flow cytometry as CD34^brightCD31^- CD45^- and CASC frequency was compared to adiposity measures in 33 women at increased risk for breast cancer. Feasibility of CASC as a response biomarker for a diet and exercise intervention in ten breast cancer survivors was then explored.

RESULTS

For 33 high-risk women, median CASC frequency was 9.7 per million PBMCs and trended positively with body mass index, fat mass index (FMI), and percent android fat. Correlation was significant when BMI was dichotomized at > versus < 35 kg/m² (p = 0.02). For ten breast cancer survivors with a median BMI of 37 kg/m², median CASC frequency was 16.4 per million PBMCs. In univariate analyses, change in BMI, total fat and visceral fat were significantly correlated with change in CASC frequency. On multivariate analysis, change in visceral adipose had the strongest association with change in CASC frequency (p < 0.00078).

CONCLUSIONS

The association between the reduction in visceral adipose tissue and the decrease in frequency of circulating adipose stromal cells suggests that the latter might be a useful biomarker in clinical trials of obese breast cancer survivors undergoing a weight loss intervention.

Dynamic Relation of Changes in Weight and Indices of Fat Distribution With Cardiac Structure and Function: The Dallas Heart Study

BACKGROUND

Obesity may increase heart failure risk through cardiac remodeling. Cross-sectional associations between adiposity and cardiac structure and function have been elucidated, but the impact of longitudinal changes in adiposity on cardiac remodeling is less well understood.

METHODS AND RESULTS

Participants in the Dallas Heart Study without cardiovascular disease or left ventricular dysfunction underwent assessment of body weight, anthropometrics, and cardiac magnetic resonance imaging at baseline and 7 years later. Associations between changes in indices of generalized and central adiposity with changes in left ventricular mass, volume, mass/volume ratio (concentricity), wall thickness, and ejection fraction were assessed using multivariable linear regression. The study cohort (n=1262) mean age was 44 years with 57% women, 44% black, and 36% obese participants. At follow-up, 41% had ≥5% weight gain, and 15% had ≥5% weight loss. Greater weight gain was associated with younger age, lower risk factor burden, and lower body mass index at baseline. In multivariable models adjusting for age, sex, race, comorbid conditions at baseline and follow-up, baseline adiposity, and cardiac measurement, increasing weight was associated with increases in left ventricular mass (β=0.10, P<0.0001), wall thickness (β=0.10, P<0.0001), and concentricity (β=0.06, P=0.002), with modest effects on end-diastolic volume (β=0.04, P=0.044) and ejection fraction (β=0.05, P=0.046). Similar results were seen with other adiposity indices.

CONCLUSIONS

Concentric left ventricular remodeling is the predominant phenotype linked to increasing adiposity in middle age. Our findings support the importance of weight management to prevent secular changes in adiposity, concentric remodeling, and eventual heart failure over time.

ADIPOSITY-BASED CHRONIC DISEASE AS A NEW DIAGNOSTIC TERM: THE AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS AND AMERICAN COLLEGE OF ENDOCRINOLOGY POSITION STATEMENT

The American Association of Clinical Endocrinologists (AACE) and American College of Endocrinology (ACE) have created a chronic care model, advanced diagnostic framework, clinical practice guidelines, and clinical practice algorithm for the comprehensive management of obesity. This coordinated effort is not solely based on body mass index as in previous models, but emphasizes a complications-centric approach that primarily determines therapeutic decisions and desired outcomes. Adiposity-Based Chronic Disease (ABCD) is a new diagnostic term for obesity that explicitly identifies a chronic disease, alludes to a precise pathophysiologic basis, and avoids the stigmata and confusion related to the differential use and multiple meanings of the term "obesity." Key elements to further the care of patients using this new ABCD term are: (1) positioning lifestyle medicine in the promotion of overall health, not only as the first algorithmic step, but as the central, pervasive action; (2) standardizing protocols that comprehensively and durably address weight loss and management of adiposity-based complications; (3) approaching patient care through contextualization (e.g., primordial prevention to decrease obesogenic environmental risk factors and transculturalization to adapt evidence-based recommendations for different ethnicities, cultures, and socio-economics); and lastly, (4) developing evidence-based strategies for successful implementation, monitoring, and optimization of patient care over time. This AACE/ACE blueprint extends current work and aspires to meaningfully improve both individual and population health by presenting a new ABCD term for medical diagnostic purposes, use in a complications-centric management and staging strategy, and precise reference to the obesity chronic disease state, divested from counterproductive stigmata and ambiguities found in the general public sphere.

ABBREVIATIONS

AACE = American Association of Clinical Endocrinologists ABCD = Adiposity-Based Chronic Disease ACE = American College of Endocrinology BMI = body mass index CPG = clinical practice guidelines HCP = health care professionals.