Comparison of visceral adipose tissue mass in adult African Americans and whites

Independent Associations of Aortic Calcification with Cirrhosis and Liver Related Mortality in Veterans with Chronic Liver Disease

INTRODUCTION

Abdominal aortic calcifications (AAC) are incidentally found on medical imaging and useful cardiovascular burden approximations. The Morphomic Aortic Calcification Score (MAC) leverages automated deep learning methods to quantify and score AACs. While associations of AAC and non-alcoholic fatty liver disease (NAFLD) have been described, relationships of AAC with other liver diseases and clinical outcome are sparse. This study's purpose was to evaluate AAC and liver-related death in a cohort of Veterans with chronic liver disease (CLD).

METHODS

We utilized the VISN 10 CLD cohort, a regional cohort of Veterans with the three forms of CLD: NAFLD, hepatitis C (HCV), alcohol-associated (ETOH), seen between 2008 and 2014, with abdominal CT scans (n = 3604). Associations between MAC and cirrhosis development, liver decompensation, liver-related death, and overall death were evaluated with Cox proportional hazard models.

RESULTS

The full cohort demonstrated strong associations of MAC and cirrhosis after adjustment: HR 2.13 (95% CI 1.63, 2.78), decompensation HR 2.19 (95% CI 1.60, 3.02), liver-related death HR 2.13 (95% CI 1.46, 3.11), and overall death HR 1.47 (95% CI 1.27, 1.71). These associations seemed to be driven by the non-NAFLD groups for decompensation and liver-related death [HR 2.80 (95% CI 1.52, 5.17; HR 2.34 (95% CI 1.14, 4.83), respectively].

DISCUSSION

MAC was strongly and independently associated with cirrhosis, liver decompensation, liver-related death, and overall death. Surprisingly, stratification results demonstrated comparable or stronger associations among those with non-NAFLD etiology. These findings suggest abdominal aortic calcification may predict liver disease severity and clinical outcomes in patients with CLD.

Association of weight-adjusted waist index with all-cause mortality among non-Asian individuals: a national population-based cohort study

INTRODUCTION

The Weight-Adjusted Waist Index (WWI) is a new indicator of obesity that is associated with all-cause mortality in Asian populations. Our study aimed to investigate the linear and non-linear associations between WWI and all-cause mortality in non-Asian populations in the United States, and whether WWI was superior to traditional obesity indicators as a predictor of all-cause mortality.

METHODS

We conducted a cohort study using data from the 2011-2018 National Health and Nutrition Examination Survey (NHANES), involving 18,592 participants. We utilized Cox proportional hazard models to assess the association between WWI, BMI, WC, and the risk of all-cause mortality, and performed subgroup analyses and interaction tests. We also employed a receiver operating characteristics (ROC) curve study to evaluate the effectiveness of WWI, BMI, and WC in predicting all-cause mortality.

RESULTS

After adjusting for confounders, WWI, BMI, and WC were positively associated with all-cause mortality. The performance of WWI, BMI, and WC in predicting all-cause mortality yielded AUCs of 0.697, 0.524, and 0.562, respectively. The data also revealed a U-shaped relationship between WWI and all-cause mortality. Race and cancer modified the relationship between WWI and all-cause mortality, with the relationship being negatively correlated in African Americans and cancer patients.

CONCLUSIONS

In non-Asian populations in the United States, there is a U-shaped relationship between WWI and all-cause mortality, and WWI outperforms BMI and WC as a predictor of all-cause mortality. These findings may contribute to a better understanding and prediction of the relationship between obesity and mortality, and provide support for effective obesity management strategies.

Differences in segmental fat accumulation patterns by sex and ethnicity: An international approach

Excess fat on the body impacts obesity-related co-morbidity risk; however, the location of fat stores affects the severity of these risks. The purpose of this study was to examine segmental fat accumulation patterns by sex and ethnicity using international datasets. An amalgamated and cross-calibrated dataset of dual x-ray absorptiometry (DXA)-measured variables compiled segmental mass for bone mineral content (BMC), lean mass (LM), and fat mass (FM) for each participant; percentage of segment fat (PSF) was calculated as PSFsegment = (FMsegment/(BMCsegment + LMsegment + FMsegment)) × 100. A total of 30 587 adults (N = 16 490 females) from 13 datasets were included. A regression model was used to examine differences in regional fat mass and PSF. All populations followed the same segmental fat mass accumulation in the ascending order with statistical significance (arms < legs < trunk), except for Hispanic/Latinx males (arms < [legs = trunk]). Relative fat accumulation patterns differed between those with greater PSF in the appendages (Arab, Mexican, Asian, Black, American Caucasian, European Caucasian, and Australasian Caucasian females; Black males) and those with greater PSF in the trunk (Mexican, Asian, American Caucasian, European Caucasian, and Australasian Caucasian males). Greater absolute and relative fat accumulation in the trunk could place males of most ethnicities in this study at a higher risk of visceral fat deposition and associated co-morbidities.

Associations of Fecal Microbiota with Ectopic Fat in African Caribbean Men

OBJECTIVE

The gut microbiome has been associated with visceral fat (VAT) in European and Asian populations; however, associations with VAT and with ectopic fats among African-ancestry individuals are not known. Our objective was to investigate cross-sectional associations of fecal microbiota diversity and composition with VAT and ectopic fat, as well as body mass index (BMI), among middle-aged and older African Caribbean men.

METHODS

We included in our analysis n = 193 men (mean age = 62.2 ± 7.6 years; mean BMI = 28.3 ± 4.9 kg/m2) from the Tobago Health Study. We assessed fecal microbiota using V4 16s rRNA gene sequencing. We evaluated multivariable-adjusted associations of microbiota features (alpha diversity, beta diversity, microbiota differential abundance) with BMI and with computed tomography-measured VAT and ectopic fats (pericardial and intermuscular fat; muscle and liver attenuation).

RESULTS

Lower alpha diversity was associated with higher VAT and BMI, and somewhat with higher pericardial and liver fat. VAT, BMI, and pericardial fat each explained similar levels of variance in beta diversity. Gram-negative Prevotellaceae and Negativicutes microbiota showed positive associations, while gram-positive Ruminococcaceae microbiota showed inverse associations, with ectopic fats.

CONCLUSIONS

Fecal microbiota features associated with measures of general adiposity also extend to metabolically pernicious VAT and ectopic fat accumulation in older African-ancestry men.

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.

Recipient race modifies the association between obesity and long-term graft outcomes after kidney transplantation

Donor and recipient obesity (defined using body mass index [BMI]) are associated with worse outcomes after kidney transplant (KT). In adult KT recipients identified using the Scientific Registry of Transplant Recipients (2000-2017), we examined the modifying effect of recipient race on recipient obesity (BMI > 30 kg/m2) and combined donor and recipient (DR) obesity pairing, with death-censored graft loss (DCGL), all-cause graft loss (ACGL), and short-term graft outcomes using multivariable Cox proportional hazards models and logistic regression. Obesity was associated with a higher risk of DCGL in White (adjusted hazard ratio [aHR], 1.29; 95% CI, 1.25-1.35) than Black (aHR, 1.13; 95% CI, 1.08-1.19) recipients. White, but not Black, recipients with obesity were at higher risk for ACGL (aHR, 1.08; 95% CI, 1.05-1.11, for White recipients; aHR, 0.99; 95% CI, 0.95-1.02, for Black recipients). Relative to nonobese DR, White recipients with combined DR obesity experienced more DCGL (aHR, 1.38; 95% CI, 1.29-1.47 for White; aHR, 1.19; 95% CI, 1.10-1.29 for Black) and ACGL (aHR, 1.12; 95% CI, 1.07-1.17 for White; aHR, 1.00; 95% CI, 0.94-1.07 for Black) than Black recipients. Short-term obesity risk was similar irrespective of race. An elevated BMI differentially affects long-term outcomes in Black and White KT recipients; uniform BMI thresholds to define transplant eligibility are likely inappropriate.

Understanding health disparities affecting people of West Central African descent in the United States: An evolutionary perspective

Human populations adapting to diverse aspects of their environment such as climate and pathogens leave signatures of genetic variation. This principle may apply to people of West Central African descent in the United States, who are at increased risk of certain chronic conditions and diseases compared to their European counterparts. Less well known is that they are also at reduced risk of other diseases. While discriminatory practices in the United States continue to affect access to and the quality of healthcare, the health disparities affecting African Americans may also be due in part to evolutionary adaptations to the original environment of sub-Saharan Africa, which involved continuous exposure to the vectors of potentially lethal endemic tropical diseases. Evidence is presented that these organisms selectively absorb vitamin A from the host, and its use in parasite reproduction contributes to the signs and symptoms of the respective diseases. These evolutionary adaptations included (1) sequestering vitamin A away from the liver to other organs, to reduce accessibility to the invaders; and (2) reducing the metabolism and catabolism of vitamin A (vA), causing it to accumulate to subtoxic concentrations and weaken the organisms, thereby reducing the risk of severe disease. However, in the environment of North America, lacking vA-absorbing parasites and with a mainly dairy-based diet that is high in vA, this combination of factors is hypothesized to lead to the accumulation of vA and to increased sensitivity to vA as a toxin, which contribute to the health disparities affecting African Americans. vA toxicity is linked to numerous acute and chronic conditions via mitochondrial dysfunction and apoptosis. Subject to testing, the hypothesis suggests that the adoption of traditional or modified West Central African-style diets that are low in vA and high in vA-absorbing fiber hold promise for disease prevention and treatment, and as a population-based strategy for health maintenance and longevity.

Visceral Adipose Tissue is Negatively Associated With Bone Mineral Density in NHANES 2011-2018

Context

The relationship of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) with bone mineral density (BMD) is not well established.

Objective

To examine the associations of VAT and SAT with total body BMD in a large, nationally representative population with a wide range of adiposity.

Methods

We analyzed 10 641 subjects aged 20 to 59 years in National Health and Nutrition Examination Survey 2011-2018 who had undergone total body BMD and had VAT and SAT measured by dual-energy X-ray absorptiometry. Linear regression models were fitted while controlling for age, sex, race or ethnicity, smoking status, height, and lean mass index.

Results

In a fully adjusted model, each higher quartile of VAT was associated with an average of 0.22 lower T-score (95% CI, -0.26 to -0.17, P < 0.001), whereas SAT had a weak association with BMD but only in men (-0.10; 95% CI, -0.17 to -0.04, P = 0.002). However, the association of SAT to BMD in men was no longer significant after controlling for bioavailable sex hormones. In subgroup analysis, we also found differences in the relationship of VAT to BMD in Black and Asian subjects, but these differences were eliminated after accounting for racial and ethnic differences in VAT norms.

Conclusions

VAT has a negative association with BMD. Further research is needed to better understand the mechanism of action and, more generally, to develop strategies for optimizing bone health in obese subjects.

Trends in the prevalence of metabolically healthy and unhealthy obesity in the US adult population: analysis of eight NHANES cross-sectional survey cycles, 1999-2014

OBJECTIVE

To exam the time trend of the prevalence of metabolically healthy obesity (MHO) in the US adult population.

DESIGN

Eight cross-sectional survey cycles.

SETTING

National Health and Nutrition Examination Survey (NHANES), 1999-2014.

PARTICIPANTS

16 459 NHANES participants aged 20 years and older.

PRIMARY OUTCOME MEASURE

MHO was defined as central obesity (waist circumference ≥102 cm for men and ≥88 cm for women) without any of the following conditions: elevated levels of blood pressure (≥130/85 mm Hg), glucose (≥100 mg/dL) and triglycerides (≥150 mm/dL); reduced levels of high-density lipoprotein cholesterol (<40 mg/dL for men and <50 mg/dL for women) or any medication use for high cholesterol, hypertension or diabetes.

RESULTS

The prevalence of central obesity significantly increased from 45.2% in 1999-2000 to 56.7% in 2013-2014 (p=0.003). Over the same period, MHO prevalence among those with central obesity only slightly and non-significantly increased from 11.0% to 15.7% (p=0.38). However, MHO prevalence among women increased significantly (p=0.04) from 7.1% to 13.7%. Female gender, a younger age, being Hispanic and non-Hispanic black and high education (some college or above) were significantly (p<0.05) associated with higher prevalence of MHO.

CONCLUSIONS

While the prevalence of central obesity in the US population has increased since 1999, the prevalence of MHO among those who are centrally obese remained fairly stable.

The Sex and Race/Ethnicity-Specific Relationships of Abdominal Fat Distribution and Anthropometric Indices in US Adults

The purpose of this study was to examine demographic-specific relationships between direct abdominal fat measures and anthropometric indices. A cross-sectional study was conducted utilizing abdominal fat measures (visceral fat area, VFA; visceral to subcutaneous adipose area ratio, VSR) and anthropometrics (body mass index, BMI; waist circumference, WC) data from the 2011-2018 National Health and Nutrition Examination Survey. Linear or polynomial linear regression models were used to examine the relationships of abdominal fat measures to anthropometrics with adjustment for demographics. The results revealed that while VFA was linearly related to BMI and WC across all demographics (p < 0.001), the relationships between VSR and both BMI and WC were concave in men and convex in women. The relationships between VFA, VSR, and BMI, WC varied by sex and race/ethnicity. In conclusion, increasing BMI and WC were linearly associated with increased VFA, but their relationships with VSR were nonlinear and differed by sex.

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.

Metabolic syndrome and pesticides: A systematic review and meta-analysis

The relation between pesticides exposure and metabolic syndrome (MetS) has not been clearly identified. Performing a systematic review and meta-analysis, PubMed, Cochrane Library, Embase, and ScienceDirect were searched for studies reporting the risk of MetS following pesticides exposure and their contaminants. We included 12 studies for a total of 6789 participants, in which 1981 (29.1%) had a MetS. Overall exposure to pesticides and their contaminants increased the risk of MetS by 30% (95CI 22%-37%). Overall organochlorine increased the risk of MetS by 23% (14-32%), as well as for most types of organochlorines: hexachlorocyclohexane increased the risk by 53% (28-78%), hexachlorobenzene by 40% (0.01-80%), dichlorodiphenyldichloroethylene by 22% (9-34%), dichlorodiphenyltrichloroethane by 28% (5-50%), oxychlordane by 24% (1-47%), and transnonchlor by 35% (19-52%). Sensitivity analyses confirmed that overall exposure to pesticides and their contaminants increased the risk by 46% (35-56%) using crude data or by 19% (10-29%) using fully-adjusted model. The risk for overall pesticides and types of pesticides was also significant with crude data but only for hexachlorocyclohexane (36% risk increase, 17-55%) and transnonchlor (25% risk increase, 3-48%) with fully-adjusted models. Metaregressions demonstrated that hexachlorocyclohexane increased the risk of MetS in comparison to most other pesticides. The risk increased for more recent periods (Coefficient = 0.28, 95CI 0.20 to 0.37, by year). We demonstrated an inverse relationship with body mass index and male gender. In conclusion, pesticides exposure is a major risk factor for MetS. Besides organochlorine exposure, data are lacking for other types of pesticides. The risk increased with time, reflecting a probable increase of the use of pesticides worldwide. The inverse relationship with body mass index may signify a stockage of pesticides and contaminants in fat tissue.

Obesity and cancer death in white and black adults: A prospective cohort study

OBJECTIVE

This study aimed to determine whether race modifies the association between obesity and cancer death.

METHODS

The Pennington Center Longitudinal Study included 18,296 adults; 35.0% were male and 34.3% were Black. The primary end point was death from cancer.

RESULTS

During a follow-up of 14.3 years, 346 cancer deaths occurred. Among men, race modified the association of BMI and cancer death (p_interaction = 0.045); compared with a BMI of 22 kg/m² , a BMI of 35 in White men was associated with a hazard ratio of 1.74 (95% CI: 1.38-2.21), and in Black men, the hazard ratio was 0.64 (95% CI: 0.45-0.90). Among women, race did not modify the association of BMI and cancer death (p_interaction =0.43); however, compared with a BMI of 22, a BMI of 35 in White women was associated with a hazard ratio of 1.42 (95% CI: 1.18-1.70) and in Black women, the hazard ratio was 0.99 (95% CI: 0.82-1.20).

CONCLUSIONS

In this diverse cohort of adults, having obesity was associated with an increased risk of cancer death in White men and women. In contrast, having obesity was associated with a reduced risk of cancer death in Black men and did not influence risk in Black women.

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.

Obesity and Cancer Risk in White and Black Adults: A Prospective Cohort Study

OBJECTIVE

Anthropometric measures of obesity, including BMI and waist circumference (WC), do not quantify excess adiposity and metabolic abnormalities consistently across racial populations. This study tested the hypothesis that participant race modifies the association of anthropometric measures of obesity and cancer risk.

METHODS

This prospective cohort (The Pennington Center Longitudinal Study) included 18,296 adults, 6,405 (35.0%) male sex and 6,273 (34.3%) Black race. The primary exposures were BMI (weight in kilograms/height in meters squared) and WC (centimeters). The primary end point was the time from study enrollment to diagnosis of histologically confirmed invasive cancer.

RESULTS

During a median follow-up of 14.0 years (interquartile range: 9.8-19.0 years), invasive cancer occurred in 1,350 participants. Among men, race modified the association of BMI (P_interaction = 0.02) and WC (P_interaction = 0.01) with cancer incidence; compared with a BMI of 22 kg/m² , a BMI of 35 kg/m² in White men was associated with a hazard ratio of 1.83 (95% CI: 1.58-2.12), whereas in Black men, the hazard ratio was 0.89 (95% CI: 0.72-1.11). Among women, race did not modify the association of BMI (P_interaction = 0.41) or WC (P_interaction = 0.36) with cancer incidence.

CONCLUSIONS

In this diverse cohort of adults, participant race and sex modified the prognostic associations of anthropometric measures of obesity and cancer risk.

Disparities in cardio metabolic risk between Black and White women with polycystic ovary syndrome: a systematic review and meta-analysis

OBJECTIVE

We conducted a systematic review and meta-analysis to summarize and quantitatively pool evidence on cardiometabolic health disparities between Black and White women with polycystic ovary syndrome in the United States in response to the call for further delineation of these disparities in the international evidence-based guideline for the assessment and management of polycystic ovary syndrome.

DATA SOURCES

Databases of MEDLINE, Web of Science, and Scopus were searched initially through March 05, 2020, and confirmed on September 11, 2020.

STUDY ELIGIBILITY CRITERIA

Observational studies documenting cardiometabolic risk profile (glucoregulatory, lipid profile, anthropometric, and blood pressure status) in Black and White women with polycystic ovary syndrome were included. Studies on children (<17 years old) and pregnant or menopausal-aged women (>50 years) were excluded. The primary outcome was fasting glucose. Furthermore, data on major cardiovascular events (stroke, coronary heart disease, heart failure) and mortality rate (cardiovascular death, total mortality) were evaluated.

METHODS

Data were pooled by random-effects models and expressed as mean differences and 95% confidence intervals. Studies were weighted based on the inverse of the variance. Heterogeneity was evaluated by Cochran Q and I2 statistics. Study methodologic quality was assessed by the Newcastle-Ottawa scale.

RESULTS

A total of 11 studies (N=2851 [652 Black and 2199 White]) evaluated cardiometabolic risk profile and all had high quality (Newcastle-Ottawa scale score of ≥8). No studies reported on cardiovascular events and mortality rate. Black women had comparable fasting glucose (-0.61 [-1.69 to 2.92] mg/dL; I2=62.5%), yet exhibited increased fasting insulin (6.76 [4.97-8.56] μIU/mL; I2=59.0%); homeostatic model assessment of insulin resistance (1.47 [0.86-2.08]; I2=83.2%); systolic blood pressure (3.32 [0.34-6.30] mm Hg; I2=52.0%); and decreased triglyceride (-32.56 [-54.69 to -10.42] mg/dL; I2=68.0%) compared with White women (all, P≤.03). Groups exhibited comparable total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and diastolic blood pressure (all, P≥.06).

CONCLUSIONS

Black women with polycystic ovary syndrome have a greater tendency for an adverse cardiometabolic risk profile (increased insulin, homeostatic model assessment of insulin resistance, and systolic blood pressure) despite lower triglycerides than White women. Our observations support the consideration of these disparities for diagnostic, monitoring, and management practices in Black women and for future guideline recommendations. Given the heterogeneity among studies, future research should address the relative contributions of biologic, environmental, socioeconomic, and healthcare factors to the observed disparities. Furthermore, longitudinal research is required to address patient-pressing complications, including cardiovascular events and mortality rate in Black women with polycystic ovary syndrome as a high-risk yet understudied population.

Racial differences in body composition and cardiometabolic risk during the menopause transition: a prospective, observational cohort study

BACKGROUND

Obesity disproportionately affects more women than men. The loss of ovarian function during the menopause transition coincides with weight gain, increases in abdominal adiposity, and impaired metabolic health. Racial differences in obesity prevalence that results from the menopause transition are not well understood.

OBJECTIVE

The purpose of the study was to assess longitudinal changes in body composition and cardiometabolic risk among black and white women during the menopausal transition.

STUDY DESIGN

In a secondary analysis of a prospective, observational cohort study (the Healthy Transitions study), 161 women ≥43 years old with a body mass index of 20-40 kg/m² and who had not yet transitioned through menopause were enrolled at Pennington Biomedical Research Center. Women were seen annually for body composition by dual-energy X-ray absorptiometry, for abdominal adipose tissue distribution by computed tomography, for sex steroid hormones, and for cardiometabolic risk factors that include fasting glucose, insulin, and lipids. Surrogate measures of insulin sensitivity were also calculated.

RESULTS

Ninety-four women (25 black, 69 white) transitioned through menopause and were included within the analyses. At menopause onset, black women weighed more (77.8±3.0 vs 70.8±1.8 kg) and had a higher systolic (125±16 vs 118±14 mm Hg) and diastolic (80±8 vs 74±7 mm Hg) blood pressure compared with white women (all P≤.05). No other differences in body composition, sex steroid hormones, or cardiometabolic risk factors were observed at menopause onset. Before menopause, white women gained significant weight (3 kg), total body adiposity (6% percent body fat, 9% fat mass, 12% trunk fat mass) and abdominal adipose tissue (19% subcutaneous fat, 15% visceral fat, 19% total adipose tissue), which coincided with significant decreases in estradiol, sex hormone-binding globulin, and estrone sulfate and increases in follicle-stimulating hormone, total cholesterol, and low-density lipoprotein cholesterol. Conversely, black women had more abdominal adipose tissue before menopause, which was maintained across the menopause transition. Black women also had significant decreases in estrone sulfate and total testosterone and increases in follicle-stimulating hormone before menopause. In the postmenopausal years, abdominal subcutaneous adipose tissue, total adipose tissue, follicle-stimulating hormone, total cholesterol, and low-density and high-density lipoprotein cholesterol increased only in white women.

CONCLUSION

White women gained more abdominal adiposity during the menopause transition compared with black women, which, in part, may be due to differences in the pattern of sex steroid hormone changes between women of different racial backgrounds. The gains in abdominal adiposity in white women were observed in tandem with increased cardiometabolic risk factors. Future studies should consider comprehensive lifestyle approaches to target these increased gains in abdominal adiposity (ie, nutrition and physical activity coaching), while taking into account the potential interactions of race, body adiposity, sex steroid hormones, and their influence on cardiometabolic risk.

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.

Ethnicity and Metabolic Syndrome: Implications for Assessment, Management and Prevention

The metabolic syndrome (MetS) is a constellation of cardiometabolic risk factors that identifies people at increased risk for type 2 diabetes and cardiovascular disease. While the global prevalence is 20%–25% of the adult population, the prevalence varies across different racial/ethnic populations. In this narrative review, evidence is reviewed regarding the assessment, management and prevention of MetS among people of different racial/ethnic groups. The most popular definition of MetS considers race/ethnicity for assessing waist circumference given differences in visceral adipose tissue and cardiometabolic risk. However, defining race/ethnicity may pose challenges in the clinical setting. Despite 80% of the world’s population being of non-European descent, the majority of research on management and prevention has focused on European-derived populations. In these studies, lifestyle management has proven an effective therapy for reversal of MetS, and randomised studies are underway in specific racial/ethnic groups. Given the large number of people at risk for MetS, prevention efforts need to focus at community and population levels. Community-based interventions have begun to show promise, and efforts to improve lifestyle behaviours through alterations in the built environment may be another avenue. However, careful consideration needs to be given to take into account the unique cultural context of the target race/ethnic group.

Optimal cut-points of visceral adipose tissue areas for cardiometabolic risk factors in a Chinese population: a cross-sectional study

AIM

To determine the optimal cut-points of visceral adipose tissue (VAT) areas at different anatomic levels to discriminate participants with cardiometabolic risk factors in a Chinese middle-aged population.

METHODS

A total of 1744 individuals who underwent regular health checks in Nanjing BENQ Medical Center from January 2013 to December 2016 were included in this cross-sectional study. VAT areas were measured by abdominal quantitative computed tomography at the L2/3 intervertebral disk and umbilicus levels. Cardiometabolic risk factors including serum triglycerides, HDL cholesterol levels, plasma glucose and blood pressure were defined using IDF 2005 criteria for metabolic syndrome.

RESULTS

The cut-points for VAT area at the umbilicus level were 111 cm² for men and 96 cm² for women to identify people with one or more cardiometabolic risk factors. For VAT area at the L2/3 level, the optimal cut-points were 142 cm² for men and 115 cm² for women. A VAT area at the L2/3 level of ≥ 142 cm² for men or 115 cm² for women significantly increased the prevalence of hyperglycaemia [odds ratio (OR) 3.18, 95% confidence interval (CI) 2.45-4.13], hypertension (OR 2.81, 95% CI 2.27-3.49) and dyslipidaemia (OR 4.37, 95% CI 3.50-5.45) after adjusting age.

CONCLUSIONS

The optimal cut-points for VAT area at the umbilicus level and L2/3 level were 111 cm² and 142 cm² for men and 96 cm² and 115 cm² for women to identify participants with one or more cardiometabolic risk factors.

Sex and Ethnic Differences in the Relationship between Changes in Anthropometric Measurements and Visceral Fat in Adolescents with Obesity

OBJECTIVE

To examine sex and ethnic differences in how baseline and changes in anthropometric measures relate with change in visceral fat with interventions in adolescents.

STUDY DESIGN

Black and white adolescents (n = 143: body mass index [BMI] ≥85th percentile, 12-18 years) who participated in intervention studies (3-6 months) were included and had assessments of anthropometric measures (weight, BMI, waist circumference, waist-to-hip ratio [WHR], and waist-to-thigh ratio) and visceral fat at L4-L5 by magnetic resonance imaging before and after interventions.

RESULTS

At baseline, all of the anthropometric measures were positively associated with visceral fat (P < .05), with weight, waist circumference, and WHR having the largest variance explained (model adjusted R² = 0.35-0.47 vs 0.32-0.35). Blacks had 11.5-23.3 cm² less visceral fat compared with whites for a given anthropometric value. Girls tended to have less visceral fat for a given anthropometric value, but the sex differences were not consistently significant (range: 0.7-12.9 cm²). Changes in waist circumference, BMI, and weight, but not WHR, remained significantly associated with changes in visceral fat. There were no sex differences, and much more minimal ethnic differences (<4.9 cm²).

CONCLUSIONS

At baseline, there are sex and ethnic differences in how anthropometric measures correlate with visceral fat. However, there were minimal sex and ethnic differences in how changes in anthropometric measures related with changes in visceral fat. Although all of the anthropometric measures were associated with visceral fat at baseline, waist circumference, BMI, and weight, but not WHR were associated with changes in visceral fat.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT00739180, NCT01323088, and NCT01938950.

Association Between Regional Adipose Tissue Distribution and Risk of Heart Failure Among Blacks

BACKGROUND

Obesity is highly prevalent among blacks and is associated with a greater risk of heart failure (HF). However, the contribution of regional adiposity depots such as visceral adipose tissue (VAT) and abdominal subcutaneous adipose tissue toward risk of HF in blacks is unknown.

METHODS AND RESULTS

We included 2602 participants (mean age: 59 years, 35% men) from the Jackson Heart Study without prevalent HF who underwent computed tomography quantification of VAT and subcutaneous adipose tissue during the second visit (2005-2009). The associations between different adiposity measures and HF were evaluated using adjusted Cox models. There were 122 incident HF events over a median follow-up of 7.1 years. Higher amounts of VAT were associated with greater risk of HF in age- and sex-adjusted analyses (hazard ratio [95% CI] per 1-SD higher VAT: 1.29 [1.09-1.52]). This association was attenuated and not significant after additional adjustment for traditional HF risk factors and body mass index. Overall obesity, represented by body mass index, was associated with higher risk of HF independent of risk factors and VAT (hazard ratio [95% CI] per 1-kg/m² higher body mass index: 1.06 [1.02-1.11]). Subcutaneous adipose tissue was not associated with risk of HF in adjusted analyses.

CONCLUSIONS

In a community-dwelling black population, higher amounts of overall and visceral adiposity are associated with higher risk of HF. The association between VAT and HF risk in blacks may reflect differences in traditional HF risk factor burden. Future studies are needed to confirm this observation and clarify the independent role of different measures of adiposity on HF outcomes.

Stronger associations of waist circumference and waist-to-height ratio with diabetes than BMI in Chinese adults

AIMS

To compare the magnitude of associations of the obesity indicators with the risk of prediabetes and diabetes.

METHODS

We performed an individually region-, sex-, and age-matched case and control analysis involving 42 918 Chinese adults aged 20-88 years (6876 matched prediabetes and normal glucose regulation [NGR] groups and 2873 matched newly diagnosed diabetes mellitus [NDM] and NGR groups).

RESULTS

Compared with their respective NGR controls, the participants with prediabetes or NDM had significantly higher mean levels of obesity indices as follows: waist circumference (cm), 85.3 vs. 81.8 and 87.9 vs. 82.9; waist-to-height ratio (WHtR), 0.531 vs. 0.509 and 0.546 vs. 0.514; and body mass index (BMI) (kg/m²), 25.4 vs. 24.1 and 25.9 vs. 24.2 (all P < 0.001). The odds ratios (95% confidence intervals) of NDM with waist circumference, WHtR, and BMI per standard deviation (SD) increase were 1.88 (1.80-1.97), 1.88 (1.80-1.97), and 1.69 (1.62-1.76) in the total population.

CONCLUSIONS

Mean differences in the three obesity indices were around 0.3 SD between matched prediabetes cases and NGR controls, and around 0.5 SD between matched NDM cases and NGR controls. Waist circumference and WHtR were more strongly associated with diabetes than BMI among Chinese adults.

Visceral Adipose Tissue Accumulation and Residual Cardiovascular Risk

PURPOSE OF THE REVIEW

Low-grade systemic inflammation increases residual cardiovascular risk. The pathogenesis of low-grade systemic inflammation is not well understood.

RECENT FINDINGS

Visceral adipose tissue accumulates when the subcutaneous adipose tissue can no longer store excess nutrients. Visceral adipose tissue inflammation initially facilitates storage of nutrients but with time become maladaptive and responsible for low-grade systemic inflammation. Control of low-grade systemic inflammation requires reversal of visceral adipose tissue accumulation with intense and sustained aerobic exercise or bariatric surgery. Alternatively, pharmacologic inhibition of the inflammatory signaling pathway may be considered. Reversal visceral adipose tissue accumulation lowers residual cardiovascular risk.

Global genetic differentiation of complex traits shaped by natural selection in humans

There are mean differences in complex traits among global human populations. We hypothesize that part of the phenotypic differentiation is due to natural selection. To address this hypothesis, we assess the differentiation in allele frequencies of trait-associated SNPs among African, Eastern Asian, and European populations for ten complex traits using data of large sample size (up to ~405,000). We show that SNPs associated with height ([Formula: see text]), waist-to-hip ratio ([Formula: see text]), and schizophrenia ([Formula: see text]) are significantly more differentiated among populations than matched "control" SNPs, suggesting that these trait-associated SNPs have undergone natural selection. We further find that SNPs associated with height ([Formula: see text]) and schizophrenia ([Formula: see text]) show significantly higher variance in linkage disequilibrium (LD) scores across populations than control SNPs. Our results support the hypothesis that natural selection has shaped the genetic differentiation of complex traits, such as height and schizophrenia, among worldwide populations.

Adipose tissue depot volume relationships with spinal trabecular bone mineral density in African Americans with diabetes

Changes in select adipose tissue volumes may differentially impact bone mineral density. This study was performed to assess cross-sectional and longitudinal relationships between computed tomography-determined visceral (VAT), subcutaneous (SAT), inter-muscular (IMAT), and pericardial adipose tissue (PAT) volumes with respective changes in thoracic vertebral and lumbar vertebral volumetric trabecular bone mineral density (vBMD) in African Americans with type 2 diabetes. Generalized linear models were fitted to test relationships between baseline and change in adipose volumes with change in vBMD in 300 African American-Diabetes Heart Study participants; adjustment was performed for age, sex, diabetes duration, study interval, smoking, hypertension, BMI, kidney function, and medications. Participants were 50% female with mean ± SD age 55.1±9.0 years, diabetes duration 10.2±7.2 years, and BMI 34.7±7.7 kg/m². Over 5.3 ± 1.4 years, mean vBMD decreased in thoracic/lumbar spine, while mean adipose tissue volumes increased in SAT, IMAT, and PAT, but not VAT depots. In fully-adjusted models, changes in lumbar and thoracic vBMD were positively associated with change in SAT (β[SE] 0.045[0.011], p<0.0001; 0.40[0.013], p = 0.002, respectively). Change in thoracic vBMD was positively associated with change in IMAT (p = 0.029) and VAT (p = 0.016); and change in lumbar vBMD positively associated with baseline IMAT (p<0.0001). In contrast, vBMD was not associated with change in PAT. After adjusting for BMI, baseline and change in volumes of select adipose depots were associated with increases in thoracic and lumbar trabecular vBMD in African Americans. Effects of adiposity on trabecular bone appear to be site-specific and related to factors beyond mechanical load.

An epigenome-wide association study in whole blood of measures of adiposity among Ghanaians: the RODAM study

BACKGROUND

Epigenome-wide association studies (EWAS) have identified DNA methylation loci involved in adiposity. However, EWAS on adiposity in sub-Saharan Africans are lacking despite the high burden of adiposity among African populations. We undertook an EWAS for anthropometric indices of adiposity among Ghanaians aiming to identify DNA methylation loci that are significantly associated.

METHODS

The Illumina 450k DNA methylation array was used to profile DNA methylation in whole blood samples of 547 Ghanaians from the Research on Obesity and Diabetes among African Migrants (RODAM) study. Differentially methylated positions (DMPs) and differentially methylation regions (DMRs) were identified for BMI and obesity (BMI ≥ 30 kg/m2), as well as for waist circumference (WC) and abdominal obesity (WC ≥ 102 cm in men, ≥88 cm in women). All analyses were adjusted for age, sex, blood cell distribution estimates, technical covariates, recruitment site and population stratification. We also did a replication study of previously reported EWAS loci for anthropometric indices in other populations.

RESULTS

We identified 18 DMPs for BMI and 23 for WC. For obesity and abdominal obesity, we identified three and one DMP, respectively. Fourteen DMPs overlapped between BMI and WC. DMP cg00574958 annotated to gene CPT1A was the only DMP associated with all outcomes analysed, attributing to 6.1 and 5.6% of variance in obesity and abdominal obesity, respectively. DMP cg07839457 (NLRC5) and cg20399616 (BCAT1) were significantly associated with BMI, obesity and with WC and had not been reported by previous EWAS on adiposity.

CONCLUSIONS

This first EWAS for adiposity in Africans identified three epigenome-wide significant loci (CPT1A, NLRC5 and BCAT1) for both general adiposity and abdominal adiposity. The findings are a first step in understanding the role of DNA methylation in adiposity among sub-Saharan Africans. Studies on other sub-Saharan African populations as well as translational studies are needed to determine the role of these DNA methylation variants in the high burden of adiposity among sub-Saharan Africans.

Why are there race/ethnic differences in adult body mass index-adiposity relationships? A quantitative critical review

Body mass index (BMI) is now the most widely used measure of adiposity on a global scale. Nevertheless, intense discussion centers on the appropriateness of BMI as a phenotypic marker of adiposity across populations differing in race and ethnicity. BMI-adiposity relations appear to vary significantly across race/ethnic groups, but a collective critical analysis of these effects establishing their magnitude and underlying body shape/composition basis is lacking. Accordingly, we systematically review the magnitude of these race-ethnic differences across non-Hispanic (NH) white, NH black and Mexican American adults, their anatomic body composition basis and potential biologically linked mechanisms, using both earlier publications and new analyses from the US National Health and Nutrition Examination Survey. Our collective observations provide a new framework for critically evaluating the quantitative relations between BMI and adiposity across groups differing in race and ethnicity; reveal new insights into BMI as a measure of adiposity across the adult age-span; identify knowledge gaps that can form the basis of future research and create a quantitative foundation for developing BMI-related public health recommendations.

Novel Risk Factors for Type 2 Diabetes in African-Americans

In the USA, compared to whites, African-Americans are disproportionately impacted by the diabetes epidemic. Traditional diabetes risk factors, such as obesity, are more common among African-Americans, but these traditional risk factors do not explain all of the disparity in diabetes risk. Recent research has identified novel environmental, lifestyle, physiologic, and genetic risk factors for diabetes, some of which appear to impact African-Americans more than whites. This manuscript reviews the recent literature to highlight some of these novel risk factors that may be contributing to the racial disparity in diabetes risk. Further study is needed of the modifiable risk factors for development of interventions to reduce the risk of diabetes in African-Americans, as well as other high-risk populations.

Duration and Degree of Weight Gain and Incident Diabetes in Younger Versus Middle-Aged Black and White Adults: ARIC, CARDIA, and the Framingham Heart Study

OBJECTIVE

To determine whether duration and degree of weight gain are differentially associated with diabetes risk in younger versus middle-aged black and white adults.

RESEARCH DESIGN AND METHODS

We combined data from three cohort studies: Atherosclerosis Risk in Communities (ARIC), Coronary Artery Risk Development in Young Adults (CARDIA), and the Framingham Heart Study. A total of 17,404 participants (56% women; 21% black) were stratified by baseline age (younger: ≥30 and <45 years; middle-aged: ≥45 and <60 years) and examined for incident diabetes (median follow-up 9 years). Duration and degree of gain in BMI were calculated as "BMI-years" above one's baseline BMI.

RESULTS

Diabetes incidence per 1,000 person-years in the younger and middle-aged groups was 7.2 (95% CI 5.7, 8.7) and 24.4 (22.0, 26.8) in blacks, respectively, and 3.4 (2.8, 4.0) and 10.5 (9.9, 11.2) in whites, respectively. After adjusting for sex, baseline BMI and other cardiometabolic factors, and age and race interaction terms, gains in BMI-years were associated with higher risk of diabetes in the younger compared with middle-aged groups: hazard ratios for 1-unit increase in log BMI-years in younger versus middle-aged blacks were 1.18 (P = 0.02) and 1.02 (P = 0.39), respectively (P for interaction by age-group = 0.047), and in whites were 1.35 (P < 0.001) and 1.11 (P < 0.001), respectively (P for interaction by age-group = 0.008).

CONCLUSIONS

Although middle-aged adults have higher rates of diabetes, younger adults are at greater relative risk of developing diabetes for a given level of duration and degree of weight gain.

The Interplay Between Sex, Ethnicity, and Adipose Tissue Characteristics

The obesity epidemic in the USA affects disproportionately women and the ethnic minorities. On the other hand, female sex is traditionally associated with a favorable fat distribution preferentially in the subcutaneous depots of the lower body and with improved endocrine and metabolic function of the adipose tissue. However, these data are derived from predominantly non-Hispanic white populations. This review discusses fat distribution patterns in women of diverse ethnic backgrounds, together with data on the release of adipokines from adipose tissue in these populations. Very little information is available on how the metabolic function of the adipocyte differs depending on ethnicity. Thus, it becomes clear that future clinical and translational research should explicitly discuss and take into account the sex and ethnic background of the populations studied.

Impact of increased visceral adiposity with normal weight on the progression of arterial stiffness in Japanese patients with type 2 diabetes

OBJECTIVE

Normal-weight abdominal obesity has been reported to be associated with poor mortality. We aimed to investigate the impact of increased visceral adiposity with normal weight (OB(-)VA(+)) on the progression of arterial stiffness in patients with type 2 diabetes.

METHODS

This was a cross-sectional study of 414 patients with type 2 diabetes (mean age 64±12 years; 40.3% female). Visceral fat area (VFA, cm(2)) was measured by a dual bioelectrical impedance analyzer. Arterial stiffness was assessed by brachial-ankle pulse wave velocity (baPWV, cm/s). Patients were divided into four groups by VFA and body mass index (BMI, kg/m(2)) as the following: BMI<25 kg/m(2) and VFA<100 cm(2) (obesity (OB)(-)visceral adiposity (VA)(-)), BMI≥25 kg/m(2) and VFA<100 cm(2) (OB(+)VA(-)), BMI<25 kg/m(2) and VFA≥100 cm(2) (OB(-)VA(+)), and BMI≥25 kg/m(2) and VFA≥100 cm(2) (OB(+)VA(+)). Multivariate linear regression analysis was done to determine the impact of OB(-)VA(+) on arterial stiffness.

RESULTS

Among the patients, 7.2% were OB(-)VA(+) with higher baPWV levels (1956±444 cm/s) than those with OB(+)VA(-) (1671±416 cm/s, p=0.014), those with OB(+)VA(+) (1744±317 cm/s, p=0.048), and those with OB(-)VA(-) (1620±397 cm/s, p=0.024). In multivariate linear regression analysis, OB(-)VA(+) remained independently associated with baPWV (standardized β 0.184, p=0.001).

CONCLUSIONS

This study provides evidence for the burden of arterial stiffness in OB(-)VA(+) patients with type 2 diabetes; therefore, evaluation of visceral adiposity is of clinical relevance for the better management of non-obese individuals as well as obese populations.

Risk stratification of patients with barrett's esophagus and low-grade dysplasia or indefinite for dysplasia

BACKGROUND & AIMS

In patients with Barrett's esophagus (BE), low-grade dysplasia (LGD) is a risk factor for esophageal adenocarcinoma (EAC), progressing at variable rates. Patients at higher risk for progression could benefit from intervention. We assessed rates of progression of LGD and indefinite for dysplasia (IND) and risk factors for progression to high-grade dysplasia (HGD) and EAC.

METHODS

We analyzed data from Cleveland Clinic Barrett's Registry on patients with BE and LGD or IND at least 1 year of follow-up from January 1, 2002 through December 31, 2012. Prevalent cases were those diagnosed at or within 1 year of the first endoscopy, and the rest were incident cases.

RESULTS

Among 299 patients with BE and LGD or IND, there were 32 cases of HGD and 10 cases of EAC during a follow-up period of 1577.4 patient-years. The annual incidence rates were 2.4% (95% confidence interval [CI], 1.7%-3.3%) for HGD, 0.6% (95% CI, 0.3%-1.2%) for EAC, and 2.7% (95% CI, 1.9%-3.6%) for HGD or EAC. The rates were higher in men than in women with BE and LGD or IND. Prevalent cases were 3-fold more likely to progress than incident cases. Multifocality and nodules were associated with higher risk of progression to HGD or EAC. None of the patients with IND at index biopsy developed EAC. For every 5-year increase in age, chance of regression increased by 7% (P = .04). Also, for every 1-cm increase in BE length, probability of regression decreased by 6% (P = .016). LGD at index biopsy was associated with 56% lower chance of regression compared with IND (P < .001).

CONCLUSIONS

On the basis of a database analysis of patients with BE, prevalent LGD, male sex, multifocality, and nodules were associated with higher risk for progression to EAC. Older age at LGD diagnosis, IND at index biopsy, and shorter BE length were associated with regression. These findings help in risk stratification of patients with BE and LGD or IND.

Obesity-induced increases in sympathetic nerve activity: sex matters

Abundant evidence obtained largely from male human and animal subjects indicates that obesity increases sympathetic nerve activity (SNA), which contributes to hypertension development. However, recent studies that included women reported that the strong relationships between muscle SNA and waist circumference or body mass index (BMI) found in men are not present in overweight and obese women. A similar sex difference in the association between adiposity and hypertension development has been identified in animal models of obesity. In this brief review, we consider two possible mechanisms for this sex difference. First, visceral adiposity, leptin, insulin, and angiotensin II have been identified as potential culprits in obesity-induced sympathoexcitation in males. We explore if these factors wield the same impact in females. Second, we consider if sex differences in vascular reactivity to sympathetic activation contribute. Our survey of the literature suggests that premenopausal females may be able to resist obesity-induced sympathoexcitation and hypertension in part due to differences in adipose disposition as well as its muted inflammatory response and reduced production of pressor versus depressor components of the renin-angiotensin system. In addition, vascular responsiveness to increased SNA may be reduced. However, more importantly, we identify the urgent need for further study, not only of sex differences per se, but also of the mechanisms that may mediate these differences. This information is required not only to refine treatment options for obese premenopausal women but also to potentially reveal new therapeutic avenues in obese men and women.

Consequences of Abdominal Adiposity within the Metabolic Syndrome Paradigm in Black People of African Ancestry

The metabolic syndrome (MetS) is a constellation of risk factors that are associated with increased risks for coronary heart disease and type 2 diabetes. Although the cause is unknown, abdominal adiposity is considered the underpinning of these metabolic alterations. Hence, increased abdominal adiposity contributes to dyslipidemia, hyperglycemia, beta cell dysfunction, insulin resistance, hypertension and inflammation. The role of abdominal adiposity in the causation of metabolic alterations that lead to the clinical expression of the MetS has become a focus of active research. In addition, there are ethnic/racial differences in the manifestation of the MetS. Therefore, the focus of this current review is to: (1) explore the consequences of abdominal obesity within the MetS paradigm; and (2) discuss the impact of ethnicity/race on MetS in Black People of African Ancestry (PAA).

Ectopic cardiovascular fat in middle-aged men: effects of race/ethnicity, overall and central adiposity. The ERA JUMP study

BACKGROUND/OBJECTIVES

Higher volumes of ectopic cardiovascular fat (ECF) are associated with greater risk of coronary heart disease (CHD). Identifying factors that are associated with ECF volumes may lead to new preventive efforts to reduce risk of CHD. Significant racial/ethnic differences exist for overall and central adiposity measures, which are known to be associated with ECF volumes. Whether racial/ethnic differences also exist for ECF volumes and their associations with these adiposity measures remain unclear.

SUBJECTS/METHODS

Body mass index (BMI), computerized tomography-measured ECF volumes (epicardial, pericardial and their summation) and visceral adipose tissue (VAT) were examined in a community-based sample of 1199 middle-aged men (24.2% Caucasians, 7.0% African-Americans, 23.6% Japanese-Americans, 22.0% Japanese, 23.2% Koreans).

RESULTS

Significant racial/ethnic differences existed in ECF volumes and their relationships with BMI and VAT. ECF volumes were the highest among Japanese-Americans and the lowest among African-Americans. The associations of BMI and VAT with ECF differed by racial/ethnic groups. Compared with Caucasians, for each 1-unit increase in BMI, African-Americans had lower, whereas Koreans had higher increases in ECF volumes (P-values<0.05 for both). Meanwhile, compared with Caucasians, for each 1-unit increase in log-transformed VAT, African-Americans, Japanese-Americans and Japanese had similar increases, whereas Koreans had a lower increase in ECF volumes (P-value<0.05).

CONCLUSIONS

Racial/ethnic groups differed in their propensity to accumulate ECF at increasing level of overall and central adiposity. Future studies should evaluate whether reducing central adiposity or overall weight will decrease ECF volumes more in certain racial/ethnic groups. Evaluating these questions might help in designing race-specific prevention strategy of CHD risk associated with higher ECF.

Racial variation in sex steroid hormone concentration in black and white men: a meta-analysis

Sex steroid hormones are associated with chronic diseases and mortality with risk associations that differ between racial and ethnic groups. However, it is currently unclear whether sex steroid hormone levels differ between black and white men. The aim of this study was to assess racial variation in circulating testosterone, free testosterone, sex hormone-binding globulin (SHBG) and estradiol levels in men. We searched PubMed for articles comparing circulating hormones in black and white men. A meta-analysis was performed using weighted mean differences (WMD) to compare hormones levels between black and white men. Fifteen eligible studies were identified; three did not report adjusted means. After age adjustment, free testosterone levels were significantly higher in black than in white men (WMD = 4.07 pg/mL, 95% CI 1.26, 6.88). Depending on the free testosterone concentration in white men, this WMD translates into a racial difference ranging from 2.5 to 4.9%. Total testosterone (WMD = 0.10 ng/mL, 95% CI -0.02, 0.22), estradiol (WMD = 0.67 pg/mL, 95% CI -0.04, 1.38) and SHBG (WMD = -0.45 nmol/L, 95% CI -1.75, 0.85) concentrations did not differ comparing blacks with whites. After adjustment for age, black men have a modestly but significantly 2.5 to 4.9% higher free testosterone level than white men. Based on previous studies on effects of sex steroid hormones on risk of chronic diseases or mortality, this modest difference is unlikely to explain racial differences in disease risk.

Differential associations of abdominal visceral, subcutaneous adipose tissue with cardiometabolic risk factors between African and European Americans

OBJECTIVE

To examine the relative association of abdominal visceral adipose tissue (VAT) with cardiometabolic risk factors between African and European Americans.

METHODS

A cross-sectional study of 2,035 African Americans from the Jackson Heart Study (JHS) and 3,170 European Americans from the Framingham Heart Study (FHS) who underwent computed tomography assessment of VAT and subcutaneous adipose tissue (SAT) was conducted. The FHS participants were weighted to match the age distribution of the JHS participants, and the metabolic risk factors were examined by study groups in relation to VAT.

RESULTS

JHS participants had higher rates of obesity, hypertension, diabetes, and metabolic syndrome than FHS participants (all P = 0.001). The associations were weaker in JHS women for VAT with blood pressure, triglycerides, HDL-C, and total cholesterol (Pinteraction = 0.03-0.001) than FHS women. In contrast, JHS men had stronger associations for VAT with high triglycerides, low HDL, and metabolic syndrome (all Pinteraction = 0.001) compared to FHS men. Similar associations and gender patterns existed for SAT with most metabolic risk factors.

CONCLUSIONS

The relative association between VAT and cardiometabolic risk factors is weaker in JHS women compared to FHS women, whereas stronger associations with triglycerides and HDL were observed in JHS men.

Relationships between body roundness with body fat and visceral adipose tissue emerging from a new geometrical model

OBJECTIVE

To develop a new geometrical index that combines height, waist circumference (WC), and hip circumference (HC) and relate this index to total and visceral body fat.

DESIGN AND METHODS

Subject data were pooled from three databases that contained demographic, anthropometric, dual energy X-ray absorptiometry (DXA) measured fat mass, and magnetic resonance imaging measured visceral adipose tissue (VAT) volume. Two elliptical models of the human body were developed. Body roundness was calculated from the model using a well-established constant arising from the theory. Regression models based on eccentricity and other variables were used to predict %body fat and %VAT.

RESULTS

A body roundness index (BRI) was derived to quantify the individual body shape in a height-independent manner. Body roundness slightly improved predictions of %body fat and %VAT compared to the traditional metrics of body mass index (BMI), WC, or HC. On this basis, healthy body roundness ranges were established. An automated graphical program simulating study results was placed at http://www.pbrc.edu/bodyroundness.

CONCLUSION

BRI, a new shape measure, is a predictor of %body fat and %VAT and can be applied as a visual tool for health status evaluations.

Episodic migraine and obesity and the influence of age, race, and sex

OBJECTIVE

To evaluate the episodic migraine (EM)-obesity association and the influence of age, race, and sex on this relationship.

METHODS

We examined the EM-obesity association and the influence of age, race, and sex in 3,862 adult participants of both black and white race interviewed in the National Comorbidity Survey Replication. EM diagnostic criteria were based on the International Classification of Headache Disorders. Body mass index was classified as underweight (<18.5 kg/m(2)), normal (18.5-24.9 kg/m(2)), overweight (25-29.9 kg/m(2)), or obese (≥30 kg/m(2)). Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for EM were estimated using logistic regression. Models were stratified by age (<50/≥50 years), race (white/black), and sex (male/female).

RESULTS

A total of 188 participants fulfilled criteria for EM. In all participants, the adjusted odds of EM were 81% greater in individuals who were obese compared with those of normal weight (OR 1.81; 95% CI: 1.27-2.57; p = 0.001), with a significant trend of increasing odds of EM with increasing obesity status from normal weight to overweight to obese (p = 0.001). In addition, stratified analyses demonstrated that the odds of EM were greater in obese as compared with normal-weight individuals who were 1) younger than 50 years of age (OR 1.86; 95% CI: 1.20-2.89; p for trend = 0.008), 2) white (OR 2.06; 95% CI: 1.41-3.01; p for trend ≤0.001), or 3) female (OR 1.95; 95% CI: 1.38-2.76; p for trend ≤0.001).

CONCLUSION

The odds of EM are increased in those with obesity, with the strongest relationships among those younger than 50 years, white individuals, and women.

Different associations of subscapular and triceps skinfold thicknesses with pathogen load: an ecogeographical analysis

OBJECTIVES

The dominant evolutionary perspective on adipose tissue has considered it a relatively inert energy store. However, variability in adipose tissue distribution has recently been associated with age, parity, thermal environment and immune function. Genes regulating the innate immune system are more strongly expressed in deep-lying than peripheral adipose tissue. We hypothesized that central adiposity would correlate more strongly than peripheral adiposity with pathogen load across populations.

METHODS

Primary outcomes were subscapular and triceps skinfolds from 133 male and 106 female populations. National values for disability-adjusted life years lost, attributable to infectious diseases, were used to index pathogen load. Linear mixed-effects models were fitted, including a random effect term by country to investigate the association of each skinfold with pathogen load, adjusting for the other skinfold, mean annual temperature and clustering of the populations across countries.

RESULTS

Adjusting for subscapular skinfold, triceps skinfold was not associated with pathogen load in either sex. Adjusting for triceps skinfold, subscapular skinfold was negatively associated with pathogen load in both sexes (P < 0.02). These associations were independent of variability in annual temperature. Adjusting for pathogen load and temperature, Oceanic populations had a different fat distribution compared to other populations.

CONCLUSIONS

Across populations, higher pathogen load was associated with reduced central but not peripheral skinfolds, supporting the hypothesis that central adiposity is more closely associated with immune function. This scenario might explain why some populations increase disproportionately in central adiposity when the environment shifts from low-energy high-pathogen status to high-energy low-pathogen status.

DXA estimates of fat in abdominal, trunk and hip regions varies by ethnicity in men

Objective:

The aim of this study was to determine whether the quantity of fat is different across the central (that is, android, trunk) and peripheral (that is, arm, leg and gynoid) regions among young African-American (AA), Asian (AS), Hispanic (HI) and non-Hispanic White (NHW) men.

Subjects and Methods:

A cohort of 852 men (18–30 years; mean total body fat percent (TBF%)=18.8±7.9, range=3.7–45.4) were assessed for body composition in five body regions via dual-emission X-ray absorptiometry (DXA).

Results:

HI men (21.8±8.3) had higher TBF% than AA (17.0±10.0), NHW (17.9±7.2) and AS (18.9±8.0) groups (P-values <0.0001). AS had a lower BMI (23.9±3.4) than all other groups, and NHW (24.7±3.2) had a lower BMI than HI (25.7±3.9) and AA (26.5±4.7; P-values<0.0001). A linear mixed model (LMM) revealed a significant ethnicity by region fat% interaction (P<0.0001). HI men had a greater fat% than NHW for every region (adjusted means (%); android: 29.6 vs 23.3; arm: 13.3 vs 10.6; gynoid: 27.2 vs 23.8; leg: 21.2 vs 18.3; trunk: 25.5 vs 20.6) and a greater fat% than AA for every region except the arm. In addition, in the android and trunk regions, HI had a greater fat% than AS, and AS had a higher fat% than AA. Finally, the android fat% for AS was higher than that of NHW. When comparing the region fat% within ethnicities, the android region was greater than the gynoid region for AS and HI, but did not differ for AA and NHW, and the arm region had the least fat% in all ethnicities.

Conclusions:

Fat deposition and body fat patterning varies by ethnicity.

Clinical utility of visceral adipose tissue for the identification of cardiometabolic risk in white and African American adults

BACKGROUND

Visceral adipose tissue (VAT) has been identified as a harmful fat depot, and sex and race differences in VAT have been reported in white and African Americans.

OBJECTIVES

We determined the clinical utility of VAT in the identification of individuals at elevated cardiometabolic risk in white and African American adults and compared the clinical utility with measures obtained by using dual-energy X-ray absorptiometry (DXA) and anthropometric measures.

DESIGN

The sample included 429 white women, 311 African American women, 406 white men, and 100 African American men who were 18-74 y of age. VAT was measured by using computed tomography, fat mass (FM) and percentage of body fat were measured by using DXA, and waist circumference (WC) and BMI were assessed. Receiver operating characteristic curves were used to compare the utility of measures in the identification of participants in the upper quintile of a continuous score derived from principal components analysis of fasting glucose, HDL cholesterol, triglycerides, and blood pressure.

RESULTS

The clinical utility of measures varied across sex-by-race groups. In the overall sample, the areas under the curve were significantly higher for VAT and WC in comparison with the other indicators. Identified VAT thresholds were higher in white men (140 cm(2)) and women (141 cm(2)) than in African American men (82 cm(2)) and women (97 cm(2)).

CONCLUSIONS

VAT and WC showed greater clinical utility than did other obesity measures. Because of the complexity of measuring VAT, the use of WC is recommended for the identification of adults with elevated cardiometabolic risk factors. The Pennington Center Longitudinal Study was registered at clinicaltrials.gov as NCT00959270.

Racial/ethnic differences in serum sex steroid hormone concentrations in US adolescent males

OBJECTIVE

Contrary to the hypothesis that the racial/ethnic disparity in prostate cancer has a hormonal basis, we did not observe a difference in serum testosterone concentration between non-Hispanic black and white men in the Third National Health and Nutrition Examination Survey (NHANES III), although non-Hispanic black men had a higher estradiol level. Unexpectedly, Mexican-American men had the highest testosterone level. Next, we evaluated whether the same patterns are observed during adolescence, the time of prostate maturation.

METHODS

We measured serum testosterone, estradiol, and sex hormone-binding globulin (SHBG) by immunoassay in 134 males aged 12-19 in NHANES III. Mean concentrations were compared by race/ethnicity adjusting for age, Tanner stage, percent body fat, waist, physical activity, tobacco smoke, and the other hormones.

RESULTS

After multivariable adjustment, in the 12-15-year-old males, testosterone concentration was lower in non-Hispanic blacks than whites (p = 0.043), SHBG concentration did not significantly differ between the two groups. Mexican-Americans had the highest testosterone (versus non-Hispanic black: p = 0.002) and lowest SHBG (versus non-Hispanic white: p = 0.010; versus non-Hispanic black: p = 0.047) concentrations. Estradiol concentration was lower in non-Hispanic blacks (p = 0.11) and Mexican-Americans (p = 0.033) compared with non-Hispanic whites. After multivariable adjustment, in the 16-19-year-old males, testosterone, estradiol, and SHBG concentrations did not differ between non-Hispanic blacks and whites. Mexican-Americans had the highest testosterone concentration (versus non-Hispanic white: p = 0.08), but did not differ from the other groups on estradiol and SHBG concentrations. In both age groups, these patterns were generally present, but less pronounced after adjusting for age and Tanner stage only.

CONCLUSION

In adolescent males, non-Hispanic blacks did not have a higher testosterone concentration than non-Hispanic whites, and Mexican-Americans had the highest testosterone concentration, patterns similar to adult males.

Mapping body fat distribution: a key step towards the identification of the vulnerable patient?

Although excess body fat is a significant health hazard, estimation of body fat content with the body mass index may not adequately reflect the amount of atherogenic adipose tissue (AT), i.e. visceral and ectopic fat. As opposed to subcutaneous AT that supposedly acts as a metabolic sink buffering excess dietary energy, visceral or intra-abdominal AT depots respond to several external stimuli that trigger lipolysis and secretion of free fatty acids (FFAs). Reaching the liver, FFAs accumulate in the liver and, over time, promote a chronic condition known as non-alcoholic fatty liver disease (NAFLD). The liver of the typical NAFLD patient secretes large amounts of very-low-density lipoproteins, the lipid content of which may accumulate in additional organs (skeletal muscle, heart, and pancreas). Here, we review the evidence emerging from functional and population studies that point towards an important role of ectopic fat accumulation in the pathophysiology of type 2 diabetes and cardiovascular disease. We conclude that although patients with impaired glycemic control or type 2 diabetes are at increased cardiovascular disease (CVD) risk, estimating cardiovascular risk goes wellbeyond the assessment of glycemic control and traditional CVD risk factors, and the estimation of visceral/ectopic fat deposition via readily available imaging techniquesshould be considered.