Racial differences in abdominal depot-specific adiposity in white and African American adults

Evaluation of visceral adipose tissue thresholds for elevated metabolic syndrome risk across diverse populations: A systematic review

Beyond obesity, excess levels of visceral adipose tissue (VAT) significantly contribute to the risk of developing metabolic syndrome (MetS), although thresholds for increased risk vary based on population, regions of interest, and units of measure employed. We sought to determine whether a common threshold exists that is indicative of heightened MetS risk across all populations, accounting for sex, age, BMI, and race/ethnicity. A systematic literature review was conducted in September 2023, presenting threshold values for elevated MetS risk. Standardization equations harmonized the results from DXA, CT, and MRI systems to facilitate a comparison of threshold variations across studies. A total of 52 papers were identified. No single threshold could accurately indicate elevated risk for both males and females across varying BMI, race/ethnicity, and age groups. Thresholds fluctuated from 70 to 165.9 cm2, with reported values consistently lower in females. Generally, premenopausal females and younger adults manifested elevated risks at lower VAT compared to their older counterparts. Notably, Asian populations exhibited elevated risks at lower VAT areas (70-136 cm2) compared to Caucasian populations (85.6-165.9 cm2). All considered studies reported associations of VAT without accommodating covariates. No single VAT area threshold for elevated MetS risk was discernible post-harmonization by technology, units of measure, and region of interest. This review summarizes available evidence for MetS risk assessment in clinical practice. Further exploration of demographic-specific interactions between VAT area and other risk factors is imperative to comprehensively delineate overarching MetS risk.

Computed Tomography and Dual-Energy X-Ray Asorptiometry body composition parameter harmonisation to universalise adipose tissue measurements in a population-based cross-sectional study

To harmonise computed tomography (CT) and dual-energy x-ray absorptiometry (DXA) body composition measurements allowing easy conversion in longitudinal assessments and across cohorts to assess cardiometabolic risk and disease. Retrospective cross-sectional observational study from 1996 to 2008 included participants in the Pennington Center Longitudinal Study (PCLS) (N = 1967; 571 African American/1396 White). Anthropometrics, whole-body DXA and abdominal CT images were obtained. Multi-layer segmentation techniques (Analyze; Rochester, MN) quantified visceral adipose tissue (VAT). Clinical biomarkers were obtained from routine blood samples. Linear models were used to predict CT-VAT from DXA-VAT and examine the effects of traditional biomarkers on cross-sectional-VAT. Predicted CT-VAT was highly associated with measured CT-VAT using ordinary least square linear regression analysis and random forest models (R2 = 0.84; 0.94, respectively, p < .0001). Model stratification effects showed low variability between races and sexes. Overall, associations between measured CT-VAT and DXA-predicted CT-VAT were good (R2 > 0.7) or excellent (R2 > 0.8) and improved for all stratification groups except African American men using random forest models. The clinical effects on measured CT-VAT and DXA-VAT showed no significant clinical difference in the measured adipose tissue areas (mean difference = 0.22 cm2). Random forest modelling seamlessly predicts CT-VAT from measured DXA-VAT to a degree of accuracy that falls within the bounds of universally accepted standard error.

Near-infrared reactance spectroscopy-derived visceral adipose tissue for the assessment of metabolic syndrome in a multi-ethnic sample of young adults

OBJECTIVES

Visceral adipose tissue (VAT) is highly associated with metabolic syndrome (MetS), which is rapidly increasing in young adults. However, accessible VAT measurement methods are limited, restricting the use of VAT in early detection. This cross-sectional study sought to determine if near-infrared reactance spectroscopy (NIRS)-derived VAT (VATNIRS) was associated with MetS in a multi-ethnic sample of young adults.

METHODS

A total of 107 male and female (F:62, M:45) participants (age: 23.0 ± 4.3y; BMI: 27.1 ± 6.6 kg/m2) completed measurements of fasting blood pressure, blood glucose (FBG), blood lipids, and anthropometric assessments including waist circumference and VATNIRS. MetS severity (MetSindex) was calculated from the aforementioned risk factors using sex and race-specific equations.

RESULTS

VATNIRS was higher in participants with, and at risk for, MetS compared to those with lower risks (all p < .001). VATNIRS was positively associated with MetSindex for all groups (all p < .001). VATNIRS showed positive associations with systolic (SBP), diastolic (DBP), and mean arterial pressure (MAP), LDL-C and LDL-C-related biomarkers, and FBG; and negative associations with HDL-C and HDL-C-to-total cholesterol ratio (all p < .050). Associations between VATNIRS and blood pressure for females, and LDL-C and LDL-C-related biomarkers for males, were nonsignificant (all p > .050). VATNIRS was positively associated with DBP in African-American participants, and SBP in White participants, resulting in positive associations with MAP for both groups (all p < .050).

CONCLUSIONS

VATNIRS is associated with MetS and individual MetS risks factors in a multi-ethnic sample of young adults; providing a noninvasive, cost-effective, portable, and accessible method that may assist in the early detection of MetS and other cardiometabolic abnormalities.

Faster rehabilitation weight gain during childhood is associated with risk of non-communicable disease in adult survivors of severe acute malnutrition

Nutritional rehabilitation during severe acute malnutrition (SAM) aims to quickly restore body size and minimize poor short-term outcomes. We hypothesized that faster weight gain during treatment is associated with greater cardiometabolic risk in adult life. Anthropometry, body composition (DEXA), blood pressure, blood glucose, insulin and lipids were measured in a cohort of adults who were hospitalized as children for SAM between 1963 and 1993. Weight and height measured during hospitalization and at one year post-recovery were abstracted from hospital records. Childhood weight gain during nutritional rehabilitation and weight and height gain one year post-recovery were analysed as continuous variables, quintiles and latent classes in age, sex and minimum weight-for-age z-scores-adjusted regression models against adult measurements. Data for 278 adult SAM survivors who had childhood admission records were analysed. Of these adults, 85 also had data collected 1 year post-hospitalisation. Sixty percent of participants were male, mean (SD) age was 28.2 (7.7) years, mean (SD) BMI was 23.6 (5.2) kg/m2. Mean admission age for SAM was 10.9 months (range 0.3-36.3 months), 77% were wasted (weight-for-height z-scores<-2). Mean rehabilitation weight gain (SD) was 10.1 (3.8) g/kg/day and 61.6 (25.3) g/day. Rehabilitation weight gain > 12.9 g/kg/day was associated with higher adult BMI (difference = 0.5 kg/m2, 95% CI: 0.1-0.9, p = 0.02), waist circumference (difference = 1.4 cm, 95% CI: 0.4-2.4, p = 0.005), fat mass (difference = 1.1 kg, 95% CI: 0.2-2, p = 0.02), fat mass index (difference = 0.32kg/m2, 95% CI: -0.0001-0.6, p = 0.05), and android fat mass (difference = 0.09 kg, 95% CI: 0.01-0.2, p = 0.03). Post-recovery weight gain (g/kg/month) was associated with lean mass (difference = 1.3 kg, 95% CI: 0.3-2.4, p = 0.015) and inversely associated with android-gynoid fat ratio (difference = -0.03, 95% CI: -0.07to-0.001 p = 0.045). Rehabilitation weight gain exceeding 13g/kg/day was associated with adult adiposity in young, normal-weight adult SAM survivors. This challenges existing guidelines for treating malnutrition and warrants further studies aiming at optimising these targets.

Measuring Racial Differences in Obesity Risk Factors in Non-Hispanic Black and White Men Aged 20 Years or Older

Obesity prevalence in the United States has increased drastically in the last two decades. Racial differences in obesity have emerged with the increase in obesity, with temporal trends because of individual, socioeconomic, and environmental factors, eating behaviors, lack of exercise, etc., raising questions about understanding the mechanisms driving these racial differences in the prevalence of obesity among non-Hispanic Black (NHB) and non-Hispanic White (NHW) men. Although many studies have measured obesity using body mass index (BMI), little is known about waist circumference (WC). This study examines variations in obesity among NHW and NHB using BMI and WC. We used National Health and Nutrition Examination Surveys (1999-2016) with a sample of 9,000 NHW and 3,913 NHB men aged 20 years or older. To estimate the association between the prevalence of obesity (BMI ≥30) and race, we applied modified Poisson regression; to explore and decompose racial differences, we used Oaxaca-Blinder decomposition (OBD). We found that NHW had higher abdominal obesity (WC ≥102) than NHB, but NHB were more likely to be obese (BMI ≥30) during most years, with some fluctuations. Modified Poisson regression showed that NHB had a higher prevalence of obesity (prevalence ratio [PR]: 1.11, 95% confidence interval [CI] = [1.04, 1.18]) but lower abdominal obesity (PR: 0.845; 95% CI = [0.801, 0.892]) than NHW. OBD showed that age, access to health care, smoking, and drinking contributed to the differences in abdominal obesity. The study identifies a significant increase in obesity among men over the last two decades; generalized obesity (based on BMI) was more problematic for NHB men, but abdominal obesity was more problematic for NHW men.

Cutaneous changes in diabetic patients: Primed for aberrant healing?

Cutaneous manifestations affect most patients with diabetes mellitus, clinically presenting with numerous dermatologic diseases from xerosis to diabetic foot ulcers (DFUs). Skin conditions not only impose a significantly impaired quality of life on individuals with diabetes but also predispose patients to further complications. Knowledge of cutaneous biology and the wound healing process under diabetic conditions is largely limited to animal models, and studies focusing on biology of the human condition of DFUs remain limited. In this review, we discuss the critical molecular, cellular, and structural changes to the skin in the hyperglycaemic and insulin-resistant environment of diabetes with a focus specifically on human-derived data. Elucidating the breadth of the cutaneous manifestations coupled with effective diabetes management is important for improving patient quality of life and averting future complications including wound healing disorders.

Skeletal muscle adiposity is a novel risk factor for poor cognition in African Caribbean women

OBJECTIVE

Skeletal muscle adiposity (myosteatosis) is recognized as a major risk factor for cardiometabolic diseases, and it increases with aging. The relationship of myosteatosis with cognitive impairment is unknown.

METHODS

The association of calf myosteatosis (measured by computed tomography-derived skeletal muscle density; higher values indicate less myosteatosis) with cognitive function was examined among 626 African Caribbean women who were aged 40 to 84 years, a population highly vulnerable to increased myosteatosis. Cognition was assessed by the Digit Symbol Substitution Test (DSST), a test of information processing speed (higher scores indicate better performance). Linear regression was used to assess the association of muscle density with DSST.

RESULTS

Adjusting for age, education, muscle area, BMI, hypertension, diabetes, cardiovascular event history, lifestyle factors, lipid-lowering medication use, and menopausal status, a one-SD lower muscle density was associated with a 1.69-point lower DSST score (p = 0.002). BMI, diabetes, and hypertension interactions were not statistically significant, suggesting that the main association was not moderated by overall obesity or cardiometabolic diseases.

CONCLUSIONS

These findings suggest that greater myosteatosis is associated with slower information processing speed, an early indicator of cognitive impairment. Further studies are needed to establish this association in this and other populations using an expanded battery of cognitive tests with longitudinal follow-up and to identify the biological mechanisms underlying this relationship.

Adiposity, aldosterone and plasma renin activity among African Americans: The Jackson Heart Study

Objective

To analyze associations between adiposity and the renin-angiotensin-aldosterone system (RAAS) in a large African American (AA) cohort.

Methods

Cross-sectional associations of adiposity (body mass index [BMI], waist circumference [WC], waist:height ratio, waist:hip ratio, leptin, adiponectin, leptin:adiponectin ratio [LAR], subcutaneous [SAT] and visceral adipose tissue [VAT], and liver attenuation [LA]) with aldosterone, plasma renin activity (renin), and aldosterone:renin ratio (ARR) were assessed in the Jackson Heart Study using adjusted linear regression models.

Results

A 1-SD higher BMI was associated with a 4.8 % higher aldosterone, 9.4 % higher renin, and 5.0 % lower ARR (all p < 0.05). Log-leptin had the largest magnitude of association with renin (30.2 % higher) and ARR (9.6 % lower), while the strongest association of aldosterone existed for log-LAR (15.3 % higher) (all 1-SD, p < 0.05). SAT was only associated with renin. VAT was associated with higher aldosterone, renin, and ARR. Liver fat was associated with aldosterone and renin, but not ARR. Associations of WC, BMI, and SAT with aldosterone were greater in men while the association with VAT was greater in women (p-interactions < 0.05).

Conclusion

Multiple measures of adiposity are associated with the RAAS in AAs. Further studies should examine the role of RAAS in obesity-driven cardiometabolic diseases.

Quantitative analysis of adipose tissue for predicting Crohn's disease postoperative endoscopic recurrence and anastomotic ulcer

OBJECTIVE

Inflammation and ulcers at the anastomotic site are frequently observed after intestinal resection surgery for Crohn's disease (CD), which often signify postoperative recurrence. Crohn's disease causes abnormalities in whole-body fat metabolism, and alterations in subcutaneous and visceral fat are potential indicators of disease development. This study aimed to quantify the areas of subcutaneous (SFA) and visceral fat (VFA) and investigate the relationship between fat tissue and endoscopic recurrence and anastomotic ulceration after Crohn's disease surgery.

METHODS

We conducted a retrospective analysis of clinical data from 279 patients diagnosed with Crohn's disease. Using abdominal CT (Computed Tomography) scans at the level of the umbilicus, we measured the area of subcutaneous and visceral fat, and calculated the Mesenteric Fat Index (MFI), which is defined as the ratio of the area of visceral fat to subcutaneous fat. We compared the changes in fat tissue between surgical Crohn's disease patients and non-surgical patients in remission, as well as changes in fat tissue before and after surgery, and between patients with and without endoscopic recurrence after surgery.

RESULTS

The MFI value of the surgical group was higher than that of the non-surgical group(0.88(1.27 ± 1.26) VS 0.39(0.44 ± 0.21), P < 0.001), while the SFA value was lower(70.16(92.97 ± 78.23) VS 157.64(175.96 ± 101.58), P < 0.001). Of the 134 surgical patients who underwent abdominal CT examination after surgery, the SFA value was significantly higher after surgery(143.61 ± 81.86 VS 90.87 ± 71.93, P < 0.001), and the MFI value decreased accordingly(0.57 ± 0.36 VS 1.30 ± 1.35, P < 0.001). Multivariate Cox analysis indicated that high VFA and MFI values, smoking history, and preoperative biologic therapy were all risk factors for postoperative endoscopic recurrence(p < 0.05), while high MFI values and preoperative biologic therapy were also risk factors for anastomotic ulcers(p < 0.05). The Kaplan-Meier analysis showed that these factors increased the risk of reaching the endpoint with time(p < 0.05). The ROC curve results showed that MFI value had high diagnostic value for postoperative endoscopic recurrence [AUC:0.831, 95% CI: 0.75-0.91, p < 0.001] and anastomotic ulcers [AUC:0.801, 95% CI: 0.71-0.89, p < 0.001].

CONCLUSIONS

Surgical CD patients have significantly higher MFI values but the values decline after surgery. When the preoperative MFI value is > 0.82, the risk of postoperative endoscopic recurrence increases significantly, and when the MFI value is ≥ 1.10, the risk of anastomotic ulceration after surgery increases significantly. Meanwhile, biologic therapy preoperatively also is a high-risk factor for early postoperative endoscopic recurrence or anastomotic ulcers after intestinal resection surgery.

Sex and race/ethnicity specific reference predictive equations for abdominal adiposity indices using anthropometry in US adults

BACKGROUND AND AIMS

Abdominal adiposity indices have stronger associations with cardiometabolic risk factors compared to anthropometric measures but are rarely used in large scale studies due to the cost and efficiency. The aim of this study is to establish sex and race/ethnicity specific reference equations using anthropometric measures.

METHODS AND RESULTS

A secondary data analysis (n = 6589) of healthy adults was conducted using data from National Health and Nutrition Examination Survey 2011-2018. Variables included in the analyses were anthropometric measures (height; weight; waist circumference, WC) and abdominal adiposity indices (android percent fat; android to gynoid ratio, A/G ratio; visceral adipose tissue area, VATA; visceral to subcutaneous adipose area ratio, VSR). Multivariable prediction models were developed using quantile regression. Bland-Altman was used for external validation of prediction models. Reference equations to estimate android percent fat, A/G ratio, VATA and VSR from anthropometric measurements were developed using a randomly selected subsample of 4613. These reference equations for four abdominal adiposity indices were then cross-validated in the remaining subsample of 1976. The measured and predicted android percent fat, A/G ratio, VATA and VSR were not statistically different (p > 0.05) except for the A/G ratio in Asian males and VSR in White females. The results of Bland-Altman further revealed that ≥93% of predicted abdominal adiposity indices fell within the limits of agreement (±1.96 standard deviation).

CONCLUSION

The sex and race/ethnicity specific reference equations for abdominal adiposity indices established using anthropometrics in the present study have strong predictive ability in US healthy adults.

Cut points of the conicity index as an indicator of abdominal obesity in individuals undergoing hemodialysis: An analysis of latent classes

OBJECTIVES

Abdominal obesity favors the involvement of cardiometabolic complications in renal patients on hemodialysis. Thus, the aim of the study was to identify the cut-points of the conicity index in individuals undergoing hemodialysis.

METHODS

This was a cross-sectional study carried out with 953 individuals undergoing hemodialysis in clinics in a metropolitan region of southeastern Brazil. The conicity index was calculated using the following mathematical equation: waist circumference/0.109 × √weight/height. The receiver operating characteristic (ROC) curve was calculated from the analysis of latent classes by cross-validation through a latent variable of abdominal obesity. This latent variable was defined using the response pattern of the observed anthropometric variables considering the presence and absence of abdominal obesity: waist circumference, waist-to-height ratio, and body shape index. The cut-points identified were elucidated by the area under the curve (AUC), Youden index, sensitivity, and specificity.

RESULTS

The cut-points for the conicity index found for both sexes were similar, resulting in a cut-point for men of 1.275 (AUC, 0.921; Youden index, 0.666), with a sensitivity and specificity of 83% and 83.6%, and a cut-point for women of 1.285 (AUC, 0.921; Youden index, 0.679), with a sensitivity and specificity of 78.6% and 89.3%, respectively.

CONCLUSIONS

The conicity index showed high discriminatory power for the identification of abdominal obesity in hemodialysis patients, therefore it can be a simple and easily accessible tool to be incorporated into clinical practice in this population.

Resting energy expenditure of a diverse group of South African men and women

BACKGROUND

In South Africa, overweight/obesity is a public health concern, disproportionally affecting Black females. A contributory role of a lower resting energy expenditure (REE) is suggested for African Americans. The present study assessed the REE of Black and White South African adults aiming to better understand the underlying predictors to overweight/obesity and transform this into locally appropriate recommendations.

METHODS

In 328 (63% female; 39% Black) healthy South African adults, REE was measured with indirect calorimetry and body composition with multifrequency bioelectrical impedance analysis. The REE was estimated with 30 sets of published equations. Black-White differences in REE, as measured and adjusted (analysis of covariance), were determined with quantile regression. Reliability/agreement of estimated (against measured) REE was determined with intra-class correlations (ICCs) and Bland-Altman analysis. A new equation was developed by median regression followed by preliminary validation.

RESULTS

Measured REE (adjusted for age along with fat-free mass [FFM], FFM index, FFM plus fat mass, FFM index plus fat mass index) in White subjects was significantly higher (p < 0.001) than in Black subjects for men and women alike, regardless of obesity class. None of the sets of estimation equations had good agreement with measured REE for Black, White, male and female subjects simultaneously. A new estimation equation, based on whole-body variables, had good reliability (ICC = 0.79) and agreement (mean difference: 27 kJ) and presents practical opportunities for groups at the local grass-roots level.

CONCLUSIONS

The REE in Black South African adults is lower than in White adults. Tailored REE equations may improve REE estimation of racially/ethnically diverse South African groups and contribute to improved obesity management.

Racial differences in anthropometric measures as risk factors for triple-negative breast cancer

PURPOSE

The incidence of triple-negative breast cancer (TNBC) is higher in Black women compared to White women which is not explained by racial differences in body mass index (BMI). As BMI has limitations as an anthropometric measure, we used different anthropometric measures to examine associations with TNBC by race.

METHOD

Of 161,808 postmenopausal participants in Women's Health Initiative, eligible were a subsample of 121,744 White and Black postmenopausal women enrolled from 1993 to 1998, 50-79 years of age with anthropometric measures who were followed for breast cancer incidence until March 2019. At entry, BMI, waist circumference (WC), and waist-hip ratio (WHR) were measured using standardized methods. Breast cancers were verified by central medical record review. Associations between anthropometric measures and triple-negative breast cancer risk were examined using Cox proportional hazards regression models.

RESULTS

After 17.6 years (median) follow-up, there were 87 Black women and 529 White women with incident triple-negative breast cancer. Overall, there were no significant associations between anthropometric measures and risk of triple-negative breast cancer. However, compared to White women with normal BMI, White women with obesity (BMI ≥ 30) (HR 0.76, 95% CI 0.60, 0.96) were significantly associated with a lower risk of triple-negative breast cancer. And larger waist circumference (HR per centimeter 0.99, 95% CI 0.99, 1.00) was significantly associated with a lower risk of triple-negative breast cancer among White women.

CONCLUSION

Overall, among postmenopausal women, anthropometric measures were not associated with risk of TNBC. The association among White women with larger waist circumference and women with obesity with a lower risk of triple-negative breast cancer needs further confirmation.

Replacing sedentary time with light activity was associated with less adiposity across several depots in African ancestry men

OBJECTIVE

The aim of this study was to determine whether displacement of sedentary time with activity was cross-sectionally associated with less adiposity among Black Caribbean men in the Tobago Health Study.

METHODS

Objectively assessed activity was categorized as sedentary (< 1.5 metabolic equivalents; METs), light (≥ 1.5 to < 3.0 METs), or moderate-to-vigorous (≥ 3.0 METs) using the SenseWear Pro armband. Computed tomography scans of the chest, abdomen, liver, and thigh were used to assess subcutaneous and ectopic adipose tissue. The isotemporal substitution framework paired with linear regression was used to examine associations between activity and adiposity adjusting for age, height, total awake time, and multiple comparisons.

RESULTS

On average, participants (n = 271) were 63 years old with 11.2 h/d of sedentary behavior, 4.5 h/d of light activity, and 54 min/d of moderate-to-vigorous activity. Replacing sedentary time with light activity was cross-sectionally associated with lower volume and higher density of abdominal and thigh subcutaneous adiposity, visceral adiposity, abdominal and thigh intermuscular adiposity, and pericardial adiposity and higher liver attenuation (p values ≤ 0.0001).

CONCLUSIONS

Displacement of sedentary time with light activity was associated with less adiposity among this Black Caribbean cohort. Interventions focused on increasing light activity may be easier to maintain than higher intensity interventions and thus may be more successful at reducing adiposity.

Adiposity in the older population and the risk of dementia: The Rotterdam Study

INTRODUCTION

We determined associations of total and regional adiposity with incident dementia among older adults.

METHODS

Within the population-based Rotterdam Study, adiposity was measured as total, android, and gynoid fat mass using dual-energy X-ray absorptiometry in 3408 men and 4563 women, every 3 to 6 years between 2002 and 2016. Incident dementia was recorded until 2020.

RESULTS

Higher adiposity measures were associated with a decreased risk of dementia in both sexes. After excluding the first 5 years of follow-up, only the association of gynoid fat among women remained significant (hazard ratio 0.85 [95% confidence interval 0.75-0.97] per standard deviation increase). No major differences in trajectories of adiposity measures were observed between dementia cases and dementia-free controls.

DISCUSSION

Higher total and regional fat mass related to a decreased risk of dementia. These results may be explained by reverse causality, although a protective effect of adiposity cannot be excluded.

HIGHLIGHTS

Total and regional adiposity were assessed using dual-energy X-ray absorptiometry scans in 7971 older adults. All adiposity measures were associated with a decreased risk of dementia. The results suggest a beneficial effect of gynoid fat on the risk of dementia in women. Reverse causation and competing risk may explain these inverse associations.

Associations between visceral adipose tissue estimates produced by near-infrared spectroscopy, mobile anthropometrics, and traditional body composition assessments and estimates derived from dual-energy X-ray absorptiometry

Assessments of visceral adipose tissue (VAT) are critical in preventing metabolic disorders; however, there are limited measurement methods that are accurate and accessible for VAT. The purpose of this cross-sectional study was to evaluate the association between VAT estimates from consumer-grade devices and traditional anthropometrics and VAT and subcutaneous adipose tissue (SAT) from dual-energy X-ray absorptiometry (DXA). Data were collected from 182 participants (female = 114; White = 127; Black/African-American (BAA) = 48) which included anthropometrics and indices of VAT produced by near-infrared reactance spectroscopy (NIRS), visual body composition (VBC) and multifrequency BIA (MFBIA). VAT and SAT were collected using DXA. Bivariate and partial correlations were calculated between DXAVAT and DXASAT and other VAT estimates. All VAT indices had positive moderate–strong correlations with VAT (all P < 0·001) and SAT (all P < 0·001). Only waist:hip (r = 0·69), VATVBC (r = 0·84), and VATMFBIA (r = 0·86) had stronger associations with VAT than SAT (P < 0·001). Partial associations between VATVBC and VATMFBIA were only stronger for VAT than SAT in White participants (r = 0·67, P < 0·001) but not female, male, or BAA participants individually. Partial correlations for waist:hip were stronger for VAT than SAT, but only for male (r = 0·40, P < 0·010) or White participants (r = 0·48, P < 0·001). NIRS was amongst the weakest predictors of VAT which was highest in male participants (r = 0·39, P < 0·010) but non-existent in BAA participants (r = –0·02, P > 0·050) after adjusting for SAT. Both anthropometric and consumer-grade VAT indices are consistently better predictors of SAT than VAT. These data highlight the need for a standardised, but convenient, VAT estimation protocol that can account for the relationship between SAT and VAT that differs by sex/race.

Obesity and Breast Cancer Metastasis across Genomic Subtypes

BACKGROUND

Obese women have higher risk of aggressive breast tumors and distant metastasis. However, obesity has rarely been assessed in association with metastasis in diverse populations.

METHODS

In the Carolina Breast Cancer Study Phase 3 (2008-2013), waist-to-hip ratio (WHR), body mass index (BMI), and molecular subtype [PAM50 risk-of-recurrence (ROR) score] were assessed. Obesity measures were evaluated in association with metastasis within five years of diagnosis, overall and stratified by race and ROR score. Absolute risk of metastasis and risk differences between strata were calculated using the Kaplan-Meier estimator, adjusted for age, grade, stage, race, and ER status. Relative frequency of metastatic site and multiplicity were estimated in association with obesity using generalized linear models.

RESULTS

High-WHR was associated with higher risk of metastasis (5-year risk difference, RD, 4.3%; 95% confidence interval, 2.2-6.5). It was also associated with multiple metastases and metastases at all sites except brain. The 5-year risk of metastasis differed by race (11.2% and 6.9% in Black and non-Black, respectively) and ROR score (19.5% vs. 6.6% in high vs. low-to-intermediate ROR-PT). Non-Black women and those with low-to-intermediate ROR scores had similar risk in high- and low-WHR strata. However, among Black women and those with high ROR, risk of metastasis was elevated among high-WHR (RDBlack/non-Black = 4.6%, RDHigh/Low-Int = 3.1%). Patterns of metastasis were similar by BMI.

CONCLUSIONS

WHR is associated with metastatic risk, particularly among Black women and those with high-risk tumors.

IMPACT

Understanding how risk factors for metastasis interact may help in tailoring care plans and surveillance among patients with breast cancer.

The Demographic Specific Abdominal Fat Composition and Distribution Trends in US Adults from 2011 to 2018

Despite the rising awareness of abdominal adiposity associated health problems and demographic health disparities, research is lacking about abdominal fat trends using a national representative sample of US adults. Our purpose was to examine national demographic specific abdominal fat composition and distribution trends from 2011 to 2018. This trend analysis was using National Health and Nutrition Examination Survey data (n = 13,163). Visceral adipose percent (VAT%), visceral adipose tissue area (VAA) and visceral to subcutaneous adipose area ratio (VSR) were utilized in data analyses. Multiple polynomial linear regression was utilized with adjustment for confounding variables. Our findings revealed that VAT%, VAA and VSR trends were concave among all demographic groups. The VAT%, VAA and/or VSR changes were observed in most demographic groups (p < 0.05) except younger, White and Black respondents. The pattern was consistent with biennial increases up to 2014 or 2016 followed by decreases in 2017-2018. There were demographic disparities, with middle-aged respondents and Hispanics having the most evident VAT%, VSR and/or VAA changes biennially when compared to their counterparts (p < 0.05). In conclusion, abdominal fat composition and distribution increased before 2014 or 2016 but decreased afterwards with variations by age and/or race/ethnicity. Further research is needed to explore the possible causes of abdominal fat changes overtime.

Association of Abdominal Visceral Adiposity and Total Fat Mass with Cancer Incidence and Mortality in White and Black Adults

BACKGROUND

Race modifies the association between anthropometric measures of obesity and cancer risk. However, the degree to which abdominal visceral adipose tissue (VAT) and total fat mass (FM) are associated with cancer risk is not known.

METHODS

The sample included 3,017 White and 1,347 Black adults who were assessed between 1995 and 2016 and followed for outcome assessment through 2017. Abdominal VAT and FM were measured using imaging techniques. The co-primary endpoints were diagnosis of histologically confirmed invasive cancer (excluding nonmelanoma skin cancer) or death from cancer. Multivariable Cox proportional hazards models quantified the HR of incident cancer and cancer mortality.

RESULTS

There were 353 incident cancer cases and 75 cancer deaths in an average of 12.9 years of follow-up. Both VAT [HR, 1.21; 95% confidence interval (CI), 1.09-1.36] and FM (HR, 1.25; 95% CI, 1.10-1.43) were significantly associated with incident cancer, while VAT (HR, 1.28; 95% CI, 1.01-1.61) was significantly associated with cancer mortality after adjustment for several covariates. VAT remained significantly associated with cancer incidence (HR, 1.22; 95% CI, 1.03-1.46) after additional inclusion of FM in the multivariable model, but not vice versa. There were no significant sex- or race-interactions.

CONCLUSIONS

VAT was associated with risk of cancer and cancer mortality in this cohort, and the associations did not differ by sex or race. The association between VAT and incident cancer was largely independent of total FM.

IMPACT

Our results suggest that utility of anthropometry in assessing obesity-related cancer risk may need to be further refined by including more direct measures of adiposity.

Ten-Year Changes in Television Viewing and Physical Activity Are Associated With Concurrent 10-Year Change in Pericardial Adiposity: The Coronary Artery Risk Development in Young Adults Study

BACKGROUND

Longitudinal association of television (TV) viewing and moderate- to vigorous-intensity physical activity (MVPA) with pericardial adipose tissue (PAT) is unclear.

METHODS

We studied Coronary Artery Risk Development in Young Adults Study participants transitioning from early to middle age at Coronary Artery Risk Development in Young Adults (CARDIA) exam years 15 (2000-2001; N = 1975, mean age = 40.4, 55.4% women, 45.3% Black) and 25 (2010-2011). TV viewing (in hours per day) and MVPA (in exercise units) were measured using a self-report questionnaire. PAT volume (in milliliters) was measured using computed tomography. Multivariable linear regression was used to examine the associations of tertiles of 10-year change (years 25-15) in TV viewing and MVPA with a concurrent change in PAT with adjustments for covariates.

RESULTS

Participants in the highest tertile of 10-year increase in TV viewing had a greater increase in PAT (β = 2.96 mL, P < .01). Participants in both middle (β = -3.93 mL, P < .01) and highest (β = -6.22 mL, P < .01) tertiles of 10-year changes in MVPA had smaller mean increases in PAT over 10 years when compared with the lowest tertile in fully adjusted models.

CONCLUSIONS

Reducing or maintaining early-midlife levels of TV viewing and increasing MVPA may be associated with less PAT accumulation with age.

Mitochondrial Phenotype as a Driver of the Racial Dichotomy in Obesity and Insulin Resistance

African Americans (AA) are disproportionately burdened by metabolic diseases. While largely unexplored between Caucasian (C) and AA, differences in mitochondrial bioenergetics may provide crucial insight to mechanisms for increased susceptibility to metabolic diseases. AA display lower total energy expenditure and resting metabolic rate compared to C, but paradoxically have a higher amount of skeletal muscle mass, suggestive of inherent energetic efficiency differences between these races. Such adaptations would increase the chances of overnutrition in AA; however, these disparities would not explain the racial difference in insulin resistance (IR) in healthy subjects. Hallmarks associated with insulin resistance (IR), such as reduced mitochondrial oxidative capacity and metabolic inflexibility are present even in healthy AA without a metabolic disease. These adaptations might be influential of mitochondrial “substrate preference” and could play a role in disproportionate IR rates among races. A higher glycolytic flux and provision of shuttles transferring electrons from cytosol to mitochondrial matrix could be a contributing factor in development of IR via heightened reactive oxygen species (ROS) production. This review highlights the above concepts and provides suggestions for future studies that could help delineate molecular premises behind potential impairments in insulin signaling and metabolic disease susceptibility in AA.

Cross-Sectional and Longitudinal Associations of Lifestyle Behaviors with Pericardial Adipose Tissue: The MESA Study

PURPOSE

We examined associations of sedentary behavior (SB), light-intensity physical activity (LPA), and moderate-to-vigorous intensity physical activity (MVPA) with pericardial adipose tissue (PAT).

METHODS

Adults from the Multi-Ethnic Study of Atherosclerosis were included from exam years 1 (2000-2002; N = 6057; mean age, 62.2 yr; 52.9% female, 38.0% White; 12.8% Chinese American, 26.7% African American, 22.5% Hispanic American), 2 (2002-2004), and 3 (2004-2005). Weekly volume of SB, LPA, and MVPA (in MET-hours per week) was reported using a questionnaire. PAT volume (in cubic centimeters) was quantified using computed tomography, analysis of covariance, and repeated-measures linear mixed models with adjustment for covariates (sociodemographics, cardiovascular disease risk factors, inflammation, waist circumference) tested cross-sectional and longitudinal associations, respectively.

RESULTS

In cross-sectional analysis, the highest tertile of SB (β = 2.71; 95% confidence interval (CI), 0.69 to 4.73; P < 0.01) and the middle tertile of MVPA (β = -1.97; 95% CI, -3.92 to -0.02; P < 0.05) were associated with PAT, whereas no association was observed for LPA in fully adjusted models. In longitudinal models, SB, LPA, and MVPA were not associated with PAT in the full study sample; however, LPA was inversely associated with PAT among Whites in stratified analysis (β = -0.54; 95% CI, -0.95 to -0.13; P < 0.05).

CONCLUSIONS

Lower SB and higher LPA (among Whites only) and MVPA may be associated with lower PAT, but additional longitudinal research is needed.

Visceral, subcutaneous, and total fat mass accumulation in a prospective cohort of adolescents

BACKGROUND

Race and sex differences in adolescents' body fat are demonstrated in cross-sectional cohorts, yet a longitudinal design would better identify patterns of fat distribution over time.

OBJECTIVES

The aim was to examine race and sex differences in adiposity between black and white adolescents over 2 y.

METHODS

A cohort of adolescents aged 10-16 y (38% black; 52% girls; 15% overweight, 34% with obesity) underwent body composition measurements at baseline (n = 309) and 2 y later (n = 236), using DXA to quantify whole-body fat mass (FM) and MRI for abdominal subcutaneous (SAT) and visceral adipose tissue (VAT) volumes. General linear models were used to examine race and sex differences in log-transformed FM, SAT, and VAT, adjusting for age, sexual maturation, extended BMI percentile, and race-by-sex interaction. SAT and VAT models in addition controlled for baseline FM and change in FM (for change models).

RESULTS

Mean (95% CI) baseline FM (kg) was higher among white [18.5 (17.9, 19.2) than among black adolescents [17.4 (16.6, 18.2), P = 0.03] and girls [19.5 (18.8, 20.3) than boys [16.5 (15.8, 17.2), P < 0.0001]. Mean (95% CI) baseline SAT (L) was higher among girls [4.4 (4.2, 4.6)] than among boys [3.9 (3.7, 4.1), P < 0.0001]. Mean (95% CI) baseline VAT (L) was higher among white [0.5 (0.5, 0.6)] than among black [0.3 (0.3, 0.4)] adolescents (P < 0.0001) and boys [0.5 (0.4, 0.5)] than girls [0.4 (0.4, 0.4), P = 0.04]. Over 2 y mean (95% CI) FM change (kg) was higher among white [3.7 (2.9, 4.5)] than among black adolescents [2.3 (1.3, 3.3), P = 0.04] and girls [4.0 (3.0, 4.9)] than boys [2.0 (1.1, 3.0), P = 0.007], but SAT change (L) did not differ by race or sex. VAT change (L) was higher among white [0.1 (0.1, 0.1)] than among black adolescents [0.0 (0.0, 0.1), P = 0.003] and boys [0.1 (0.1, 0.1)] than girls [0.0 (0.0, 0.1), P = 0.034].

CONCLUSIONS

Sex and race differences in the deposition and accumulation of excess fat are important considerations for understanding obesity prevalence and obesity-related disease risk among adolescents.This trial was registered at clinicaltrials.gov as NCT02784509.

Magnetic Resonance Imaging Assessment of Abdominal Ectopic Fat Deposition in Correlation With Cardiometabolic Risk Factors

PURPOSE

Ectopic fat accumulation and abdominal fat distribution may have different cardiometabolic risk profiles. This study aimed to assess the associations between various magnetic resonance imaging (MRI)-acquired fat depots and cardiometabolic risk factors.

METHODS

A total of 320 subjects with median age of 59 years, 148 men and 172 women, were enrolled in the study. Visceral adipose tissue (VAT) area and fat fraction (FF), subcutaneous adipose tissue (SAT) area and FF at the L1-L2 levels, preperitoneal adipose tissue (pPAT) area and FF, hepatic FF, pancreatic FF, and intramuscular FF were assessed by MRI FF maps. The associations of various MRI-acquired fat depots with blood pressure, glucose, and lipid were examined using sex-stratified linear regression. Logistic regression stratified by sex was used to analyze the association of various MRI-acquired fat depots with the risk of hypertension, T2DM, and dyslipidemia.

RESULTS

The intraclass correlation coefficient (ICC) values were >0.9, which suggested good interobserver and intraobserver agreement. VAT area, V/S, hepatic fat, pancreatic fat, and pPAT rather than SAT area were significantly associated with multiple cardiometabolic risk factors (all p < 0.05). However, the patterns of these correlations varied by sex and specific risk factors. Also, VAT and SAT FF were only significantly associated with multiple cardiometabolic risk factors in women (all p < 0.05).

CONCLUSIONS

VAT, hepatic fat, pancreatic fat, and pPAT were associated with cardiovascular metabolic risk factors independent of BMI. The patterns of these correlations were related to gender. These findings further the understanding of the association between ectopic fat deposition and cardiometabolic risk factors and help to better understand the obesity heterogeneity.

Association Between Indices of Body Composition and Metabolically Unhealthy Phenotype in China: A Cross-Sectional Study

INTRODUCTION

Body composition is closely related to metabolic health status. Visceral adipose tissue (VAT) dysfunction contributes to metabolic syndrome. However, results regarding subcutaneous adipose tissue (SAT) and skeletal muscle are controversial. We aimed to determine the association of indices of body composition with abnormal metabolic phenotype in China.

METHODS

A total of 3, 954 subjects (age 50.2 ± 11.7 years) with body mass index (BMI) more than 18.5 kg/m² from Pinggu Metabolic Disease Study were analyzed. Quantitative computed tomography (QCT) was performed to measure total adipose tissue (TAT), VAT, SAT area, and lumbar skeletal muscle area (SMA). Participants were divided into six groups on the basis of BMI category (normal weight/overweight/obesity) and metabolic status (healthy/unhealthy), as defined by the presence or absence of components of the metabolic syndrome by Chinese Diabetes Society criteria.

RESULTS

63.4%, 39.5%, and 23.3% participants were classified as metabolically healthy phenotype in individuals with normal weight, overweight and obese, respectively. Individuals in the highest TAT, VAT, and VAT/TAT ratio category had higher risk of being metabolically unhealthy than individuals in the lowest group (all p<0.01). While, risk for metabolically unhealthy was reduced significantly in the highest SMA/TAT ratio category when compared with the lowest category in individuals with normal wight and overweight (both p<0.05). Risk for metabolically unhealthy was reduced significantly in the highest SAT category when compared with the lowest category (OR=0.555, 95%CI: 0.360-0.856, p=0.008) in individuals with obese after adjustment for age, sex and BMI. However, skeletal muscle index (SMI) showed no significant association with the metabolically healthy status in different BMI categories (p>0.05). The VAT and VAT/TAT ratio were better diagnostic values of indicators to differentiate metabolically unhealthy subjects from controls compared with other indicators, such as TAT, SAT, SMI, SMA/TAT ratio.

CONCLUSIONS

Higher visceral adipose tissue was closely associated with metabolically unhealthy phenotype in Chinese adults. Subcutaneous adipose tissue might be a protective factor for metabolic health status only in obese individuals.

Genetic risk score prediction of leg fat and insulin sensitivity differs by race/ethnicity in early pubertal children

BACKGROUND

In the United States, the underlying reasons for racial/ethnic disparities in type 2 diabetes risk remain unclear. However, differences in genetic risk for insulin resistance and peripheral adipose tissue distribution may be contributing factors.

OBJECTIVE

To investigate racial/ethnic differences in associations of genetic risk for insulin resistance with leg fat and insulin sensitivity in a cohort of American children.

METHODS

Participants were healthy European-American (n = 83), African-American (n = 79) and Hispanic-American (n = 74) children aged 7-12 years. Genetic risk scores were derived from published variants associated with insulin resistance phenotypes in European adults. Body composition was assessed using dual-energy X-ray absorptiometry. Insulin sensitivity was determined from the frequently sampled intravenous glucose tolerance test and minimal modelling. Statistical models were adjusted for age, sex, pubertal stage and body composition.

RESULTS

In the combined cohort, risk score was inversely associated with insulin sensitivity (p = 0.033) but not leg fat (p = 0.170). Within Hispanic Americans, risk score was inversely associated with insulin sensitivity (p = 0.027) and leg fat (p = 0.005), while associations were non-significant in European and African Americans (p > 0.200).

CONCLUSIONS

The higher type 2 diabetes risk observed among Hispanic Americans may have a genetic basis related to an inability to store lipid in peripheral adipose tissue.

Relative associations of abdominal and thigh compositions with cardiometabolic diseases in African Caribbean men

BACKGROUND

Regional body compositions are differentially associated with cardiometabolic risk factors. Simultaneous inclusion of both upper and lower body composition predictors in models is not often done, and studies which do include both measures (1) tend to exclude some tissue(s) of potential metabolic relevance, and (2) have used study populations with underrepresentation of individuals with African ancestries. Further, most body composition analyses do not employ compositional data analytic approaches, which may result in spurious associations.

OBJECTIVE

The objective of this analysis was to assess associations of abdominal and thigh adipose (AT) and muscle tissues with hypertension and type 2 diabetes using compositional data analytic methods.

RESEARCH DESIGN AND METHODS

This cross-sectional analysis included 610 African Caribbean men (median age: 62 years; mean BMI: 27.8 kg/m2). Abdominal (three components: subcutaneous [ASAT] and visceral [VAT] AT, 'other' abdominal tissue) and mid-thigh (four components: subcutaneous and intermuscular AT, muscle, bone) compositions were measured by computed tomography; additive log ratio transformations were applied to each composition. Regression models were used to simultaneously assess associations of abdominal and thigh component ratios with continuous risk factors (blood pressures, fasting glucose and insulin, HOMA-IR) and disease categories.

RESULTS

A two-fold increase in ASAT:'Other' ratio was associated with higher continuous risk factors and with odds of being in a higher hypertension (OR: 1.77, 95%CI: 1.10-2.84) or diabetes (OR: 1.81, 95%CI: 1.06-3.10) category. A two-fold increased VAT ratio was only associated with higher log-insulin and log-HOMA-IR (β = 0.10, p < 0.05 for both), while a two-fold increased thigh muscle:bone ratio was associated with a lower diabetes category (OR: 0.37, 95%CI: 0.14-1.01).

CONCLUSIONS

These findings support ASAT as a significant driver of cardiometabolic disease in African Ancestry populations, independent of other abdominal and thigh tissues.

Prevalence of Underweight, Overweight and Obesity among Adults in Urban Bissau, Western Africa

Overweight and obesity affect a large proportion of the population and are important causes of death in both developed and low- and middle-income countries. In Guinea-Bissau, there are no previous population-based studies assessing this phenomenon. Therefore, we aimed to quantify the prevalence of underweight, overweight, and obesity among adults in Bissau. A stratified and cluster sample of 935 adults was assembled in 2021 and was evaluated using standardized questionnaires and anthropometric measurements, following the World Health Organization Stepwise Approach to Chronic Disease Risk Factor Surveillance. Underweight, obesity, and overweight were defined by body mass index based on the World Health Organization definitions. The prevalence of overweight and obesity was 48.7% among women and 25.0% among men. The proportion of women with abdominal obesity was 14 times higher than it was in men (35.3% vs. 2.5%). The prevalence of overweight and obesity increased with age and income. Underweight was more prevalent in the age group of 18 to 24 years (18.4% in women and 28.9% in men) and was less frequent among individuals with higher socioeconomic status. In conclusion, the prevalence of overweight and obesity is similar to the trends that are observed in many other urbanized populations in Africa and is already a major public health issue in urban Guinea-Bissau.

Association of Adiposity With Incident Diabetes Among Black Adults in the Jackson Heart Study

Background

The prognostic value of anthropometric, adipokine, and computed tomography measures of adiposity to predict diabetes in Black, specifically by normoglycemia versus prediabetes, remains incompletely understood.

Methods and Results

Among Black participants without diabetes in the JHS (Jackson Heart Study), waist circumference [WC], body mass index, adiponectin, leptin, and leptin:adiponectin ratio were standardized in sample 1 (2422 participants at baseline [2000–2004]) and WC, body mass index, visceral adipose tissue (VAT), subcutaneous adipose tissue, and liver attenuation in 1537 participants at examination 2 (2005–2008) (sample 2). Hazard ratios (HRs) for diabetes were estimated using interval‐censored Cox modeling adjusting for traditional risk factors and validated with the C index. Over 5 years, 300 and 122 incident diabetes cases occurred in sample 1 and sample 2, respectively. In sample 1 and sample 2, a 1‐SD higher log‐leptin:adiponectin ratio and VAT had the strongest associations (HR, 1.95 [95% CI, 1.67–2.27] and 1.76 [95% CI, 1.52–2.04]) and discriminatory power (C index 0.68 [95% CI, 0.64–0.71] and C index 0.67 [95% CI, 0.61–0.74]) with diabetes. The normoglycemic compared with the prediabetes group had a 1.3 to 1.9 times greater magnitude of associations with diabetes for WC, liver attenuation, and VAT (P interaction <0.10). In sample 2, C indices for WC (HR, 0.84; 95% CI, 0.73–0.95), VAT (HR, 0.91; 95% CI, 0.85–0.98), and liver attenuation (HR, 0.90; 95% CI, 0.77–1.00) were greater than HbA_1c (HR, 0.74; 95% CI, 0.57–0.90) in normoglycemia, whereas HbA_1c was best in prediabetes (HR, 0.72; 95% CI, 0.66–0.78).

Conclusions

Overall, among Black adults, multiple measures of adiposity were associated with incident diabetes with modest predictive ability. In Black patients with normoglycemia, WC, liver attenuation, and VAT may appropriately identify those at high risk for diabetes, whereas HbA_1c was the best predictor in individuals with prediabetes.

Genetic underpinnings of regional adiposity distribution in African Americans: Assessments from the Jackson Heart Study

BACKGROUND

African ancestry individuals with comparable overall anthropometric measures to Europeans have lower abdominal adiposity. To explore the genetic underpinning of different adiposity patterns, we investigated whether genetic risk scores for well-studied adiposity phenotypes like body mass index (BMI) and waist circumference (WC) also predict other, less commonly measured adiposity measures in 2420 African American individuals from the Jackson Heart Study.

METHODS

Polygenic risk scores (PRS) were calculated using GWAS-significant variants extracted from published studies mostly representing European ancestry populations for BMI, waist-hip ratio (WHR) adjusted for BMI (WHRBMIadj), waist circumference adjusted for BMI (WCBMIadj), and body fat percentage (BF%). Associations between each PRS and adiposity measures including BF%, subcutaneous adiposity tissue (SAT), visceral adiposity tissue (VAT) and VAT:SAT ratio (VSR) were examined using multivariable linear regression, with or without BMI adjustment.

RESULTS

In non-BMI adjusted models, all phenotype-PRS were found to be positive predictors of BF%, SAT and VAT. WHR-PRS was a positive predictor of VSR, but BF% and BMI-PRS were negative predictors of VSR. After adjusting for BMI, WHR-PRS remained a positive predictor of BF%, VAT and VSR but not SAT. WC-PRS was a positive predictor of SAT and VAT; BF%-PRS was a positive predictor of BF% and SAT only.

CONCLUSION

These analyses suggest that genetically driven increases in BF% strongly associate with subcutaneous rather than visceral adiposity and BF% is strongly associated with BMI but not central adiposity-associated genetic variants. How common genetic variants may contribute to observed differences in adiposity patterns between African and European ancestry individuals requires further study.

Irisin plays an important role in the outcomes of newly diagnosed prediabetes in adults in Guiyang, China

AIMS/INTRODUCTION

To explore the potential role of irisin in the outcomes of newly diagnosed prediabetes.

MATERIALS AND METHODS

Data were obtained from the Guiyang subcenter of the Risk Evaluation of cAncers in Chinese diabeTic Individuals: a lONgitudinal (REACTION) study. A total of 2,530 participants had newly diagnosed prediabetes at baseline and completed follow up. The nested 1:1 case-control study included 161 participants who developed diabetes mellitus at follow up, and 161 age- and sex-matched controls. The follow-up study included 86 matched case-control pairs. Fasting serum irisin levels were measured using enzyme-linked immunosorbent assay.

RESULTS

Baseline serum irisin levels were higher in the cases than in the controls (P = 0.002); high baseline serum irisin levels were an independent risk factor for the development of diabetes (odds ratio 1.235, 95% confidence interval 1.025-1.488). After adjustment for age, sex, body mass index, glycated hemoglobin (HbA1c), smoking, exercise, and family history of diabetes, subjects in the highest quartile of irisin levels had a higher risk of diabetes than those in the lowest quartile (odds ratio 3.065, 95% confidence interval 1.511-6.218). The extent of decrease in irisin levels during follow-up was greater in the cases than in the controls (P < 0.001). Baseline serum irisin levels were positively correlated with the extent of decrease in irisin during follow-up (r = 0.773, P < 0.001). After adjustment for confounding factors, subjects with a decrease of irisin above the median had much higher risk for diabetes (odds ratio 5.077, 95% confidence interval 2.112-12.206).

CONCLUSIONS

Irisin might play an important role in the outcomes of newly diagnosed prediabetes in adults in Guiyang, and can predict the risk for developing diabetes in these individuals.

Contribution of Adipose Tissue Oxidative Stress to Obesity-Associated Diabetes Risk and Ethnic Differences: Focus on Women of African Ancestry

Adipose tissue (AT) storage capacity is central in the maintenance of whole-body homeostasis, especially in obesity states. However, sustained nutrients overflow may dysregulate this function resulting in adipocytes hypertrophy, AT hypoxia, inflammation and oxidative stress. Systemic inflammation may also contribute to the disruption of AT redox equilibrium. AT and systemic oxidative stress have been involved in the development of obesity-associated insulin resistance (IR) and type 2 diabetes (T2D) through several mechanisms. Interestingly, fat accumulation, body fat distribution and the degree of how adiposity translates into cardio-metabolic diseases differ between ethnicities. Populations of African ancestry have a higher prevalence of obesity and higher T2D risk than populations of European ancestry, mainly driven by higher rates among African women. Considering the reported ethnic-specific differences in AT distribution and function and higher levels of systemic oxidative stress markers, oxidative stress is a potential contributor to the higher susceptibility for metabolic diseases in African women. This review summarizes existing evidence supporting this hypothesis while acknowledging a lack of data on AT oxidative stress in relation to IR in Africans, and the potential influence of other ethnicity-related modulators (e.g., genetic-environment interplay, socioeconomic factors) for consideration in future studies with different ethnicities.

Seeing the fetus from a DOHaD perspective: discussion paper from the advanced imaging techniques of DOHaD applications workshop held at the 2019 DOHaD World Congress

Advanced imaging techniques are enhancing research capacity focussed on the developmental origins of adult health and disease (DOHaD) hypothesis, and consequently increasing awareness of future health risks across various subareas of DOHaD research themes. Understanding how these advanced imaging techniques in animal models and human population studies can be both additively and synergistically used alongside traditional techniques in DOHaD-focussed laboratories is therefore of great interest. Global experts in advanced imaging techniques congregated at the advanced imaging workshop at the 2019 DOHaD World Congress in Melbourne, Australia. This review summarizes the presentations of new imaging modalities and novel applications to DOHaD research and discussions had by DOHaD researchers that are currently utilizing advanced imaging techniques including MRI, hyperpolarized MRI, ultrasound, and synchrotron-based techniques to aid their DOHaD research focus.

Visceral adiposity index and its association with Dietary Approaches to Stop Hypertension (DASH) diet scores among older adults: National Health and Nutrition Examination Surveys 2011-2014

BACKGROUND & AIMS

The visceral adiposity index (VAI) has been shown to be a reliable estimate of visceral adiposity, but little is known about its association with specific dietary patterns such as the Dietary Approaches to Stop Hypertension (DASH) diet, particularly in older adults. Many studies have shown the DASH diet to be beneficial for cardiometabolic health. The purpose of this study was to investigate the relationship between DASH diet scores and the VAI in older adults using a nationally representative dataset.

METHODS

Using the National Health and Nutrition Examination Surveys (NHANES) from 2011 to 2014, data from 508 community-dwelling older adults were examined, and dietary intake was evaluated using the Dixon's DASH diet index. Using multiple linear regression analysis, the relationship between VAI and DASH diet score was assessed while controlling for demographic variables.

RESULTS

Participants' average DASH diet score was 2.41 (SE = 0.07), and the average VAI was 1.55 (SE = 0.08). The results suggest a significant inverse relationship between the DASH diet and VAI (β = -0.19, t = -2.73, p = 0.009).

CONCLUSIONS

Results of this study suggest that protective properties of the DASH diet pattern may be due in part to its inverse relationship with visceral adiposity. This information supports practitioners' use of the VAI with older adults in addition to providing nutrition counseling with the DASH diet to reduce patients' cardiometabolic risk.

Adiposity Measures and Morning Serum Cortisol in African Americans: Jackson Heart Study

OBJECTIVE

Altered hormonal regulation, including cortisol, is a proposed mechanism linking adiposity to obesity-related disorders. We examined the association of anthropometric, adipokine, and body fat distribution measures of adiposity with morning serum cortisol in an African American (AA) cohort.

METHODS

We investigated the cross-sectional associations of adiposity measures (BMI, waist circumference, leptin, adiponectin, leptin:adiponectin ratio, subcutaneous and visceral adipose tissue) and liver attenuation with cortisol in the Jackson Heart Study. Linear regression models were used to analyze the association between exposures and cortisol. Models were adjusted for multiple covariates.

RESULTS

Among 4,211 participants, a 1-SD higher BMI and waist circumference were associated with a 3.92% and 3.05% lower cortisol, respectively. A 1-SD higher leptin and leptin:adiponectin ratio were associated with a 6.48% and 4.97% lower morning serum cortisol, respectively. A 1-SD higher subcutaneous adipose tissue was associated with a 4.97% lower cortisol (all P < 0.001). There were no associations of liver attenuation or visceral adipose tissue with cortisol.

CONCLUSIONS

Several measures of adiposity are associated with lower morning serum cortisol among AAs, with leptin having the greatest magnitude. Future studies examining the role of morning serum cortisol in the pathway from adiposity to cardiometabolic disease in AAs are warranted.

Race, Body Mass Index, and the Risk of Atrial Fibrillation: The Multi-Ethnic Study of Atherosclerosis

Background

Higher body mass index (BMI) is associated with increased risk of incident atrial fibrillation (AF), but it is not known whether this relationship varies by race/ethnicity.

Methods and Results

Eligible participants (6739) from MESA (Multi‐Ethnic Study of Atherosclerosis) were surveilled for incident AF using MESA hospital surveillance, scheduled MESA study ECG, and Medicare claims data. After a median 13.8 years of follow‐up, 970 participants (14.4%) had incident AF. With BMI modeled categorically in a Cox proportional hazards model, only those with grade II and grade III obesity had increased risks of AF (hazard ratio [HR], 1.50; 95% CI, 1.14–1.98, P=0.004 for grade II obesity and HR, 2.13; 95% CI, 1.48–3.05, P<0.0001 for grade III obesity). The relationship between BMI and AF risk was J‐shaped. However, the risk of AF as a function of BMI varied substantially by race/ethnicity (P value for interaction=0.02), with Chinese‐American participants having a much higher risk of AF with higher BMI and Black participants having minimal increased risk of AF with higher BMI.

Conclusions

Obesity is associated with an increased risk of incident AF, but the relationship between BMI and the risk of AF is J‐shaped and this relationship differs by race/ethnicity, such that Chinese‐American participants have a more pronounced increased risk of AF with higher BMI, while Black participants have minimal increased risk. Further exploration of the differential effects of BMI by race/ethnicity on cardiovascular outcomes is needed.

Age, gender, and racial/ethnic differences in the association of triclocarban with adulthood obesity using NHANES 2013-2016

This study examined the association between triclocarban and obesity among US adults and compared the pattern of this association across age, gender, and racial/ethnic groups. Study found triclocarban to be associated with obesity (OR: OR:1.123 95% CI: 1.046, 1.205) and this association remained among women (OR:1.14 95% CI: 1.031, 1.261). Study participants aged 60 years and older were more likely to be overweight (OR:1.131 95% CI: 1.022 1.251) and obese (OR:1.192 95% CI: 1.079, 1.317) when compared to other age groups. Likewise, non-Hispanic whites (OR:1.126 95% CI: 1.003, 1.263) and "other race including multi-racial" (OR:1.431 95% CI: 1.219, 1.679) were more likely to be obese when compared to other racial/ethnic groups. In conclusion, triclocarban is associated with obesity among US adults and there is evidence of gender, age, and racial/ethnicity differences in the association.

Covid-19: Fat, Obesity, Inflammation, Ethnicity, and Sex Differences

Although obesity is known to be a risk factor for COVID-19 severity, there is an urgent need to distinguish between different kinds of fat—visceral and subcutaneous fat—and their inflammation status in COVID-19. These different fat types have partially diverging biochemical roles in the human body, and they are differentially associated with SARS-CoV-2, which targets the angiotensin-converting enzyme 2 (ACE2) for cell entry. ACE2 is highly expressed in adipose tissue, especially in visceral fat, suggesting an important role for this tissue in determining COVID-19 disease severity. In this perspective article, we discuss group differences in the amount of visceral fat levels and the extent of inflammation in adipocytes of visceral fat tissue, which may, in part, drive population, cross-national, ethnic, and sex differences in COVID-19 disease. It is vital to steer the scientific community’s attention to the effects of visceral fat in creating individual and population differences in COVID-19 severity. This can help researchers unravel the reasons for the reported population, ethnic, and sex differences in COVID-19 severity and mortality.

[Abdominal obesity in ELSA-Brasil (Brazil's Longitudinal Study of Adult Health): construction of a latent gold standard and evaluation of the accuracy of diagnostic indicators]

This study evaluated the accuracy of abdominal obesity (AO) indicators, defining a latent variable as the gold standard. The study included 12,232 participants of the ELSA-Brasil (Brazil's Longitudinal Study of Adult Health), between 35 and 74 years of age. Three AO indicators were evaluated: waist circumference (WC), waist hip ratio (WHR) and conicity index (C index). Analyses were stratified by sex and race/skin color. All groups had a high prevalence of AO, being greater among white men (~70%) and black women (~60%). A high incidence of WC was observed for men, WHR and C index between men and women for discriminating latent AO. The following cutoff points for AO indicators were identified among white, brown and black men, respectively: WC: 89.9cm; 90.2cm and 91.7cm; WHR: 0.92; 0.92 and 0.90; C index: 1.24; 1.24 and 1.24. The cutoff points identified among white, brown and black women were, respectively: WC: 80.4cm, 82.7cm and 85.4cm; WHR: 0.82; 0.83 and 0.84; C index: 1.20; 1.22 and 1.19 The WC among men and the WHR and C index among men and women presented high power to discriminate latent AO, the C index being the best indicator.

Exercise Training Alters Red Blood Cell Fatty Acid Desaturase Indices and Adipose Tissue Fatty Acid Profile in African Women with Obesity

OBJECTIVE

This study assessed the changes in red blood cell total phospholipid (RBC-TPL) and subcutaneous adipose tissue (SAT) fatty acid (FA) composition in response to 12 weeks of exercise training in South African women with obesity and the associations with changes in cardiometabolic risk factors.

METHODS

Previously sedentary women were randomized into control (n = 15) or exercise (n = 20) groups. RBC-TPL and SAT FA profiles, SAT gene expression, systemic inflammatory markers, liver fat, and insulin sensitivity (S_I ) were measured before and after the intervention.

RESULTS

Compared with control, exercise training induced decreases in RBC-TPL dihomo-γ-linolenic acid content and stearoyl-CoA desaturase-1 and increased delta-5 desaturase-estimated activity (P < 0.05). In the combined group, these changes correlated with changes in circulating leptin and TNFα (P < 0.05), as well as lower liver fat (P < 0.01). Exercise training decreased saturated FA (lauric and myristic acids) and increased polyunsaturated FA (eicosadienoic and adrenic acids) (P < 0.05) in abdominal SAT, whereas γ-linolenic acid decreased (P < 0.01) in gluteal SAT. These changes in RBC-TPL and SAT FA compositions were not associated with changes in SAT gene expression and S_I .

CONCLUSIONS

Exercise training alters RBC-TPL desaturase activities, which correlate with lower liver fat and systemic inflammation but not with the improvement of S_I .

Distinct abdominal and gluteal adipose tissue transcriptome signatures are altered by exercise training in African women with obesity

The differential associations of adipose depots with metabolic risk during obesity have been proposed to be controlled by environmental and genetic factors. We evaluated the regional differences in transcriptome signatures between abdominal (aSAT) and gluteal subcutaneous adipose tissue (gSAT) in obese black South African women and tested the hypothesis that 12-week exercise training alters gene expression patterns in a depot-specific manner. Twelve young women performed 12-weeks of supervised aerobic and resistance training. Pre- and post-intervention measurements included peak oxygen consumption (VO_2peak), whole-body composition and unbiased gene expression analysis of SAT depots. VO_2peak increased, body weight decreased, and body fat distribution improved with exercise training (p < 0.05). The expression of 15 genes, mainly associated with embryonic development, differed between SAT depots at baseline, whereas 318 genes were differentially expressed post-training (p < 0.05). Four developmental genes were differentially expressed between these depots at both time points (HOXA5, DMRT2, DMRT3 and CSN1S1). Exercise training induced changes in the expression of genes associated with immune and inflammatory responses, and lipid metabolism in gSAT, and muscle-associated processes in aSAT. This study showed differences in developmental processes regulating SAT distribution and expandability of distinct depots, and depot-specific adaptation to exercise training in black South African women with obesity.

Longitudinal Associations Between Body Mass Index During Young Adulthood, Subsequent Weight Change, and Incident Diabetes During Mid- and Older-Adulthood in Non-Hispanic White and African American Populations: The Atherosclerosis Risk in Communities Study

Background: Excess body mass index (BMI) and weight gain are well-known risk factors for diabetes. Nevertheless, the associations of BMI and weight gain in young adulthood with subsequent diabetes in African Americans, and the standardized effects of these weight variables have not been well studied. Methods: We studied 12,672 white and African American men and women 45-64 years of age (i.e., during mid-adulthood) who participated in the Atherosclerosis Risk in Communities Study visit 1 (1987-1989), and were reexamined at three follow-up examinations. Associations between recalled BMI at age 25 (i.e., during young adulthood) and subsequent weight change with incident diabetes at ages 45 and above (i.e., during mid-adulthood to older adulthood) were examined using Cox proportional hazard models. Results: Over the 9-year follow-up, we identified 1,501 cases of incident diabetes. The incidence rates were higher among African Americans (men: 24.5 and women: 26.3 per 1,000 person-years) compared to whites (men: 16.3 and women: 10.5 per 1,000 person years). Compared to normal-weight individuals at age 25, those who were overweight or obese and those who gained more weight after age 25 had a higher risk of developing diabetes later in all four race-sex groups with the highest risk in African Americans. In the race-sex groups combined, the mutually adjusted hazard ratio for BMI at age 25 and percent weight change were 1.97 (1.79-2.17) and 2.89 (2.59-3.11), respectively, comparing the 85th to the 15th percentiles of the exposures. Conclusions: African Americans were at higher risk of diabetes than whites. Both higher BMI at age 25 and subsequent weight gain were independently associated with higher risk for diabetes in all the race-sex groups; however, overall weight gain was more potent than BMI.

Comparison of abdominal visceral adipose tissue measurements in adolescents between magnetic resonance imaging and dual-energy X-ray absorptiometry

Excess abdominal visceral adipose tissue (VAT) is associated with cardiometabolic risk factors in adolescents. VAT is mainly measured using Magnetic Resonance Imaging (MRI), yet dual-energy x-ray absorptiometry (DXA) is more affordable and available. The purpose was to compare adolescent VAT values obtained by MRI and DXA. A sample of 330 adolescents 10-16 years of age were recruited (52.3% female, 58.5% White). Abdominal VAT was measured using a General Electric (GE) Discovery MRI scanner with imaging software. A whole-body DXA (GE iDXA) scan was performed, and software calculated VAT within the android region. Wilcoxon signed-rank t-tests were used to determine differences between VAT values, within sex, race (White, African American, and Other race), and BMI categories (normal weight, overweight, and obese). VAT values from MRI and DXA were significantly correlated (r = 0.78, p < 0.001). Average VAT from MRI (0.54 ± 0.43 kg) was significantly higher than VAT from DXA (0.33 ± 0.39 kg) in the overall sample (p < 0.001) and within all subgroups (p < 0.001). All standardized values between the two measurements fell within ±1.96 standard deviations, and differences between the methods were not associated with level of VAT. In this sample, DXA values were correlated with MRI values, but DXA consistently underestimated VAT compared with MRI.

Hepatic and Skeletal Muscle Adiposity Are Associated with Diabetes Independent of Visceral Adiposity in Nonobese African-Caribbean Men

Background: Adipose tissue (AT) around and within non-AT organs (i.e., ectopic adiposity) is emerging as a strong risk factor for type 2 diabetes (T2D). Not known is whether major ectopic adiposity depots, such as hepatic, skeletal muscle, and pericardial adiposity (PAT), are associated with T2D independent of visceral adiposity (VAT). More data are particularly needed among high-risk nonobese minority populations, as the race/ethnic gap in T2D risk is greatest among nonobese. Methods: Thus, we measured several ectopic adiposity depots by computed tomography in 718 (mean age = 64 years) African-Caribbean men on the Island of Tobago overall, and stratified by obesity (obese N = 187 and nonobese N = 532). Results: In age, lifestyle risk factors, health status, lipid-lowering medication intake, body mass index and all other adiposity-adjusted regression analyses, and hepatic and skeletal muscle adiposity were associated with T2D among nonobese men only (all P < 0.05), despite no association between VAT and PAT and T2D. Conclusions: Our results support the "ectopic fat syndrome" theory in the pathogenesis of T2D among nonobese African-Caribbean men. Longitudinal studies are needed to clarify the independent role of ectopic adiposity in T2D, and to identify possible biological mechanisms underlying this relationship, particularly in high-risk African ancestry and other nonwhite populations.

The association of maternal obesity and race with serum adipokines in pregnancy and postpartum: Implications for gestational weight gain and infant birth weight

Adiponectin and leptin are hormones known to play roles in maternal metabolism during pregnancy. Levels of these hormones have been demonstrated to vary based on adiposity and race. However, there is a lack of data concerning the relationship between race and the change of adiponectin and leptin throughout pregnancy. The purpose of this study was to examine serum levels of adiponectin, leptin, and leptin-to-adiponectin ratio (LAR) throughout pregnancy and to assess their association with gestational weight gain (GWG) and infant birth weight while considering the effects of race and pre-pregnancy body mass index (BMI). Serum levels of adiponectin, leptin, gestational weight gain, and infant birth weight were measured in 80 pregnant women at early (12.4 ​± ​1.3 weeks gestation), mid (20.6 ​± ​1.3 weeks gestation), late pregnancy (29.2 ​± ​1.4 weeks gestation), and 7-11 weeks postpartum (8.8 ​± ​0.8 weeks). In women overall, serum adiponectin decreased across pregnancy and increased at postpartum (p ​= ​0.17.) At each prenatal timepoint, both black race and obesity were associated with lower adiponectin (ps ​< ​0.05). In women overall, serum leptin increased across pregnancy, and declined at postpartum. At every assessment, a stepwise increase in leptin was observed in relation to BMI class. Black women with obesity had markedly higher LAR in mid- and late pregnancy and postpartum than all other groups (p ​< ​0.05). Serum leptin during pregnancy was significantly associated with total GWG in both black and white women (ps ​< ​0.005). Neither adiponectin, leptin, nor LAR were associated with infant birth weight. Race and BMI both have significant effects on serum adiponectin, leptin, and LAR levels in pregnancy and postpartum. Notably, the combined effects of race and BMI result in markedly higher LAR among black women with obesity. Implications for racial disparities in metabolic syndrome and postpartum weight retention remain to be explicated.

Associations of Thigh and Abdominal Adipose Tissue Radiodensity with Glucose and Insulin in Nondiabetic African-Ancestry Men

OBJECTIVE

Decreased radiodensity of adipose tissue (AT) located in the visceral AT (VAT), subcutaneous AT (SAT), and intermuscular AT (IMAT) abdominal depots is associated with hyperglycemia, hyperinsulinemia, and insulin resistance independent of AT volumes. These associations were sought in African-ancestry men, who have higher risk for type 2 diabetes and have been underrepresented in previous studies.

METHODS

This cross-sectional analysis included 505 nondiabetic men of African-Caribbean ancestry (median age: 61 years; median BMI: 26.8 kg/m² ) from the Tobago Health Study. AT volumes and radiodensities were assessed using computed tomography, including abdominal (VAT and SAT) and thigh (IMAT) depots. Associations between AT radiodensities were assessed with fasting serum glucose and insulin and with insulin resistance (updated homeostatic model assessment of insulin resistance, HOMA2-IR).

RESULTS

Higher radiodensity in any AT depot was associated with lower log-insulin and log-HOMA2-IR (β range: -0.16 to -0.18 for each; all P < 0.0001). No AT radiodensity was associated with glucose. Thigh IMAT radiodensity associations were independent of, and similar in magnitude to, VAT radiodensities. Model fit statistics suggested that AT radiodensities were a better predictor for insulin and insulin resistance compared with AT volumes in individuals with overweight and obesity.

CONCLUSIONS

AT radiodensities at multiple depots are significantly associated with insulin and insulin resistance in African-ancestry men.

Effect of race on the relationship between child maltreatment and obesity in Whites and Blacks

This cross-sectional study was designed to determine what role race plays in the relationship between obesity and child maltreatment (CM), which is currently unknown. One hundred fifteen participants successfully completed the study, including Whites (n = 60) and Blacks (n = 55) of both sexes. CM was assessed using the Childhood Trauma Questionnaire. Total fat, trunk/total fat ratio, visceral adipose tissue (VAT), and VAT/trunk ratio, were measured through Dual Energy X-ray Absorptiometry (DXA) and Corescan software estimation. A significant interaction between identifying as White and having a history of CM was found to predict body mass index (BMI) (β = 5.02, p = .025), total fat (kg) (β = 9.81, p = .036), and VAT (kg) (β = 0.542, p = .025), whereas race by itself was an insignificant predictor. An interaction between having history of physical abuse and identifying as White was found to predict BMI (β = 6.993, p = .003), total fat (β = 12.683, p = .010), and VAT (β = 0.591, p = .018). An interaction between having multiple CM subtypes and identifying as White predicts increased total fat (β = 5.667, p = .034) and VAT (β = 0.335, p = .014). Our findings indicate that the relationship between CM and obesity, measured through BMI, total body fat, and VAT, is seen in Whites but not in Blacks. Future research should investigate the nature of this racial influence to guide obesity prevention and target at-risk populations.

Ethnic Disparities in Adiposity: Focus on Non-alcoholic Fatty Liver Disease, Visceral, and Generalized Obesity

PURPOSE OF REVIEW

Excessive adiposity has become a public health problem worldwide, contributing to the rise in obesity-related diseases and associated morbidity and mortality. This review details the relative significance of race/ethnicity as it pertains to adiposity and non-alcoholic fatty liver disease (NAFLD).

RECENT FINDINGS

Fat distribution remains a more reliable measure of adiposity than anthropometric measures, with visceral adipose tissue (VAT) associated with increased risk of cardiometabolic disease. While obesity is the most common risk factor for NAFLD, the racial/ethnic prevalence of obesity does not completely parallel NAFLD risk. Combating racial/ethnic disparities in obesity requires understanding differential risk among various groups. Hispanics are disproportionally impacted by NAFLD and have high rates of obesity, VAT, and insulin resistance (IR). This contrasts with Blacks, who have high prevalence of obesity and IR, accompanied by a paradoxically favorable lipid profile and low prevalence of VAT and NAFLD. Many features of adiposity and NAFLD are mediated by genetic and environmental factors, the latter being modifiable and the focus of interventions.

Impact of Abdominal Obesity on Proximal and Distal Aorta Wall Thickness in African Americans: The Jackson Heart Study

OBJECTIVE

Abdominal obesity and wall thickness of the central arteries have been associated with higher risk of cardiovascular disease. Despite the higher burden of overweight and cardiovascular disease among African Americans, limited data are available on the association of abdominal obesity with aortic wall thickness in African Americans. We assessed the cross-sectional and the longitudinal associations of abdominal obesity with aortic intima-media thickness (aIMT) in a cohort of African Americans from the Jackson Heart Study.

METHODS

Data on aIMT and repeated measures of waist circumference (WC) and waist to height ratio from 1,572 participants, as well as on abdominal subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), and aIMT from 1,223 participants, were analyzed. aIMT was measured at proximal ascending aorta (PA-aIMT), proximal descending aorta (PD-aIMT), and distal aorta (bifurcation) using cardiac magnetic resonance. SAT and VAT were measured using computerized tomography.

RESULTS

WC and WHtR were longitudinally associated with PA-aIMT and PD-aIMT; SAT and VAT were associated with PA-aIMT only. Only WC was associated with distal aIMT.

CONCLUSIONS

Abdominal obesity measures are associated with increased proximal aIMT in adult African Americans. Only WC is associated with wall thickness in all three segments of the aorta.