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.

Gender-Specific Fat Distribution and Association with Type 2 Diabetes Mellitus: A Study of Adiposity Indicators (DEXA, BMI, Waist-to-Hip Ratio) in Adults from Qatar

Aim

This study aimed to investigate the difference in adiposity measured by DEXA between people with type 2 diabetes mellitus (T2DM) and those without. Moreover, we investigated the most reliable adiposity measure for discriminating people with T2DM from those without in clinical settings.

Methods

A cross-sectional study was conducted from the database of Qatar Biobank (QBB), which comprised adults with a previous diagnosis of T2DM mellitus in Qatar. t-test and multivariable linear regression models were used to assess the association between T2DM and the difference in DEXA and BMI adiposity measures. Moreover, an evaluation of the odds of abnormal waist-hip ratio in participants with T2DM using an adjusted multivariable logistic regression was conducted.

Results

Among the participants with T2DM, males had less fat in the leg region, while females had less fat in the legs and gynoid regions, compared to individuals without T2DM. Females with T2DM had a higher average BMI. Moreover, the odds of having an abnormal waist-to-hip ratio were higher in males and females with T2DM compared to persons without T2DM.

Conclusion

There were different patterns of fat deposition in males and females with T2DM. T2DM was associated with a higher BMI in females only. The odds of abnormal waist-hip ratio were higher in individuals with T2DM of both genders. Waist-hip ratio showed reliable discrimination for T2DM and has implications for clinical practice.

Mechanisms of body fat distribution and gluteal-femoral fat protection against metabolic disorders

Obesity is a major health problem that affects millions of individuals, and it is associated with metabolic diseases including insulin resistance (IR), type 2 diabetes (T2D), and cardiovascular diseases (CVDs). However, Body fat distribution (BFD) rather than crude obesity is now considered as a more accurate factor associated with these diseases. The factors affecting BFD vary, from genetic background, epigenetic factors, ethnicity, aging, hormonal changes, to lifestyle and medication consumptions. The main goal of controlling BFD comes from the fact that fat accumulation in different depots has a different effect on the overall health and metabolic health of individuals. It is well established that fat storage in the abdominal visceral depot is associated with metabolic disorder occurrence, while gluteal-femoral subcutaneous fat depot seems to be protective against these diseases. In this paper, we will summarize the factors affecting fat distribution. Then, we will present evidence connecting gluteal-femoral fat depot with protection against metabolic disorders including IR, T2D, and CVDs. Finally, we will list the suggested mechanisms that lead to this protective effect. The abstract is visualized in Graphical Abstract.

Comparison of Eating Habits, Body Composition and Densitometric Parameters between Subjects with Normal Cognitive Function and Mild Cognitive Impairment: An Observational Study

The role of nutrition in the ageing process of the brain is pivotal. Therefore, the study aimed to compare eating habits, body composition and densitometric parameters between subjects with normal cognitive function (NCF) and mild cognitive impairment (MCI). A total of 95 subjects with NCF (74% of women) and 95 individuals with MCI (77% of women) aged 50-70 years were studied. Densitometric parameters were evaluated using dual-energy X-ray absorptiometry methods. Eating habits were assessed using the food frequency questionnaire and 3-day diary records, and advanced glycation end products (AGEs) intake was calculated. Significant differences between groups were detected for the %fat in the right arm (NCF vs. MCI: 38.4 (30.4-46.8) vs. 43.5 (35.5-49.2)%, p = 0.0407). Moreover, the MCI group had a significantly lower intake of calcium (p = 0.0010), phosphor (p = 0.0411), vitamins B2 (p = 0.0138) and B12 (p = 0.0024) compared to the NCF group, with both groups also differing in the frequency of butter (p = 0.0191) and fermented milk beverages (p = 0.0398) intake. Analysis restricted to women showed significant differences between groups in right arm %fat, VAT mass, calcium, vitamins B2, B12, butter and fermented milk products intake, while in men, differences were detected in the intake of calcium, iodine, vitamin B1, water and AGEs. In conclusion, subjects with NCF and MCI have comparable densitometric variables but differ significantly in some body composition parameters and the intake of some food groups and nutrients.

Gender Differences in the Predictive Value of Obesity Indices for Insulin Resistance in Adult Mexican Individuals

BACKGROUND

Obesity-linked insulin resistance (IR) is an important risk factor for metabolic diseases, and anthropometric indices are commonly used for risk assessment.

AIM

The study aimed to assess possible differences between women and men in the predictive value and association of nine obesity indices with IR, as assessed by HOMA-IR, in a nondiabetic adult population.

METHODS

The cross-sectional study included individuals recruited from a hospital in Mexico City. Indices evaluated were waist circumference (WC), hip circumference (HC), body mass index (BMI), waist-to-hip ratio, waist-to-height ratio, visceral adiposity index, body adiposity index (BAI), relative fat mass (RFM), and conicity index (CI). Fasting plasma glucose and insulin were measured to calculate HOMA-IR. Correlation analysis was performed between obesity indices and HOMA-IR. Receiver operating characteristics curve analyses were performed to determine predictive accuracy and cut-off values of obesity indices for IR. A binary logistic regression (BLR) analysis with OR calculation was performed to determine the strength of association with HOMA-IR.

RESULTS

We included 378 individuals (59% females, mean age 46.38 ±12.25 years). The highest Pearson coefficient value was observed for BMI among women, while among men, the highest values were found for BMI and BAI. WC among women, and BAI and RFM among men showed the highest sensitivity, while the highest specificity was observed for WHR among women and WC among men with respect to insulin prediction. In the adjusted BLR model, BMI, WC, and WHR among women and WC and RFM and BAI among men were independently associated with IR, showing the highest odds ratio (OR).

CONCLUSION

In Mexican adults, WC, WHR, RFM and BAI could be complementary tools for BMI in screening for IR.

Impaired mitochondrial respiration in upper compared to lower body differentiated human adipocytes and adipose tissue

CONTEXT

Abdominal obesity is associated with increased cardiometabolic disease risk, while lower body fat seems to confer protection against obesity-related complications. The functional differences between upper and lower body adipose tissue (AT) remain poorly understood.

OBJECTIVE

We aimed to examine whether mitochondrial respiration is impaired in abdominal as compared to femoral differentiated human multipotent adipose-derived stem cells (hMADS; primary outcome) and AT in postmenopausal women.

DESIGN

In this cross-sectional study, 23 postmenopausal women with normal weight or obesity were recruited at the University of Birmingham/Queen Elizabeth Hospital Birmingham (Birmingham, UK). We collected abdominal and femoral subcutaneous AT biopsies to determine mitochondrial oxygen consumption rates in differentiated abdominal and femoral hMADS. Furthermore, we assessed OXPHOS protein expression and mtDNA content in abdominal and femoral AT as well as hMADS. Finally, we explored in vivo fractional oxygen extraction and carbon dioxide release across abdominal and femoral subcutaneous AT in a subgroup of the same individuals with normal weight or obesity.

RESULTS

We found lower basal and maximal uncoupled mitochondrial oxygen consumption rates in abdominal compared to femoral hMADS. In line, in vivo fractional oxygen extraction and carbon dioxide release were lower across abdominal than femoral AT. OXPHOS protein expression and mtDNA content did not significantly differ between abdominal and femoral differentiated hMADS and AT.

CONCLUSION

The present findings demonstrate that in vitro mitochondrial respiration and in vivo oxygen fractional extraction are lower in upper compared to lower body differentiated hMADS and AT, respectively, in postmenopausal women.

Is fat-to-lean mass ratio a better predictor of heart variability than body mass index?

BACKGROUND

Body mass index (BMI) may not accurately predict cardiometabolic risk due to confounders like age, gender, relatively high lean mass, and the "thin-fat phenotype" prevalent in south Asian populations. Fat-to-lean mass ratio (FTLM), which assesses the balance between fat and lean body mass, may provide a more complete assessment of cardiometabolic health.

MATERIALS AND METHODS

This cross-sectional analytical study investigated the relationship between FTLM ratio, BMI, and heart rate variability (HRV) in apparently healthy male adults. 88 participants recruited through convenience sampling underwent anthropometric assessments, bioimpedance body composition analysis, and HRV testing. Pearson's or Spearman's correlation and linear regression analyses were performed where appropriate to assess the relationship between FTLM ratio, BMI, and HRV.

RESULTS

Both BMI and FTLM showed significant positive correlation with normalized LF power and LF-HF ratio and a negative correlation with normalized HF power, RMSSD, and pNN50. However, FTLM ratio showed a stronger association with HRV parameters than BMI and could explain a greater percentage of the variability in LF-HF ratio (32% compared to 18.4%, P < 0.001).

CONCLUSION

Assessment of both fat and lean mass, expressed as a ratio, is a better index of quantifying adiposity and predicting the influence of altered body composition on cardiometabolic health.

Associations of infant feeding practices with abdominal and hepatic fat measures in childhood in the longitudinal Healthy Start Study

BACKGROUND

Infant feeding patterns have been linked with obesity risk in childhood, but associations with precise measures of body fat distribution are unclear.

OBJECTIVE

We examined associations of infant feeding practices with abdominal fat and hepatic fat trajectories in childhood.

METHODS

This study included 356 children in the Healthy Start Study, a prospective prebirth cohort in Colorado. Infant feeding practices were assessed by postnatal interviews and categorized as any human milk <6 mo compared with ≥6 mo; complementary foods introduced ≤4 mo compared with >4 mo; soda introduced ≤18 mo compared with >18 mo. Abdominal subcutaneous (SAT) and visceral adipose tissue (VAT) areas and hepatic fat (%) were assessed by magnetic resonance imaging in early and middle childhood (median 5 and 9 y old, respectively). We examined associations of infant feeding with adiposity trajectories across childhood using linear mixed models.

RESULTS

In the sample of children, 67% consumed human milk ≥6 mo, 75% were introduced to complementary foods at >4 mo, and 81% were introduced to soda at >18 mo. We did not find any associations between duration of any human milk consumption and childhood adiposity trajectories. Early introduction to complementary foods (≤4 mo) was associated with faster rates of change for SAT and VAT during childhood (Slope [95% CI]: 15.1 [10.7,19.4] cm2/y for SAT; 2.5 [1.9,2.9] cm2/y for VAT), compared with introduction at >4 mo (5.5 [3.0,8.0] cm2/y and 1.6 [1.3,1.9] cm2/y, respectively). Similarly, early introduction to soda (≤18 mo) was associated with faster rates of change for all 3 outcomes during childhood (Slope [95% CI]: 20.6 [15.0,26.1] cm2/y for SAT, 2.7 [2.0,3.3] cm2/y for VAT, 0.3 [0.1,0.5] %/year for hepatic fat) compared with delayed introduction (5.4 [2.8,8.0] cm2/y, 1.7 [1.3, 2.0] cm2/y, -0.1 [-0.2,0.0] %/y, respectively).

CONCLUSIONS

The timing of introduction and quality of complementary foods in infancy was associated with rates of abdominal and hepatic fat accrual during childhood. Experimental studies are needed to assess underlying mechanisms.

Development and validation of a clinical factors and body fat distribution-based nomogram to predict refractoriness of transarterial chemoembolization in hepatocellular carcinoma

Background

Transarterial chemoembolization (TACE) is an important treatment modality for hepatocellular carcinoma (HCC). However, some patients may develop TACE refractoriness during treatment. We aimed to construct a prediction model incorporating computed tomography (CT) body composition and clinical factors to preoperatively predict the risk of developing TACE refractoriness in patients with HCC, enabling the rapid identification of patients at high risk of TACE refractoriness.

Methods

This study included 128 HCC patients treated with TACE who were randomly assigned to the training (n=89) and validation groups (n=39) in a 7:3 ratio. Multiple body-composition parameters were outlined from CT images of the third lumbar vertebra level of each patient. Standardized values of body-composition parameters were calculated, such as visceral-to-subcutaneous adipose tissue area ratio (VSR). Multifactor logistic regression analysis was performed to identify independent predictors of TACE-refractoriness in patients and to develop predictive models. High- and low-risk subgroup analyses were performed for the predictive model.

Results

Alpha-fetoprotein (AFP) level (P=0.041), tumor size (P=0.001), and VSR (P=0.043) were independent risk factors for TACE refractoriness. The combined clinical-body composition model had an area under the curve (AUC) value of 0.875 in the training cohort and an AUC value of 0.837 in the validation cohort. Calibration curves and decision curves revealed the specific optimal performance and clinical utility of the combined model. Subgroup analysis showed differences in predicted TACE refractoriness between the high- and low-risk groups (P<0.001).

Conclusions

The combined clinical-body fat distribution model has the good performance in predicting a patient's risk of TACE refractoriness preoperatively and can help clinicians make the best clinical decisions in advance for the treatment of high-risk patients.

Diagnostic Performance of the Measurement of Skinfold Thickness for Abdominal and Overall Obesity in the Peruvian Population: A 5-Year Cohort Analysis

The escalating prevalence of overall and abdominal obesity, particularly affecting Latin America, underscores the urgent need for accessible and cost-effective predictive methods to address the growing disease burden. This study assessed skinfold thicknesses' predictive capacity for overall and abdominal obesity in Peruvian adults aged 30 or older over 5 years. Data from the PERU MIGRANT 5-year cohort study were analyzed, defining obesity using BMI and waist circumference. Receiver operating characteristic curves and area under the curve (AUC) with 95% confidence intervals (CI) were calculated. Adults aged ≥ 30 (n = 988) completed the study at baseline, with 47% male. A total of 682 participants were included for overall and abdominal obesity analysis. The 5-year prevalence values for overall and abdominal obesity were 26.7% and 26.6%, respectively. Subscapular skinfold (SS) best predicted overall obesity in men (AUC = 0.81, 95% CI: 0.75-0.88) and women (AUC = 0.77, 95% CI: 0.67-0.88). Regarding abdominal obesity, SS exhibited the highest AUC in men (AUC = 0.83, 95% CI: 0.77-0.89), while SS and the sum of trunk skinfolds showed the highest AUC in women. In secondary analysis excluding participants with type-2 diabetes mellitus (DM2) at baseline, SS significantly predicted DM2 development in men (AUC = 0.70, 95% CI: 0.58-0.83) and bicipital skinfold (BS) did in women (AUC = 0.73, 95% CI: 0.62-0.84). The findings highlight SS significance as an indicator of overall and abdominal obesity in both sexes among Peruvian adults. Additionally, SS, and BS offer robust predictive indicators for DM2.

An Evolutionary Model for the Ancient Origins of Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a common endocrinopathy of reproductive-aged women, characterized by hyperandrogenism, oligo-anovulation and insulin resistance and closely linked with preferential abdominal fat accumulation. As an ancestral primate trait, PCOS was likely further selected in humans when scarcity of food in hunter-gatherers of the late Pleistocene additionally programmed for enhanced fat storage to meet the metabolic demands of reproduction in later life. As an evolutionary model for PCOS, healthy normal-weight women with hyperandrogenic PCOS have subcutaneous (SC) abdominal adipose stem cells that favor fat storage through exaggerated lipid accumulation during development to adipocytes in vitro. In turn, fat storage is counterbalanced by reduced insulin sensitivity and preferential accumulation of highly lipolytic intra-abdominal fat in vivo. This metabolic adaptation in PCOS balances energy storage with glucose availability and fatty acid oxidation for optimal energy use during reproduction; its accompanying oligo-anovulation allowed PCOS women from antiquity sufficient time and strength for childrearing of fewer offspring with a greater likelihood of childhood survival. Heritable PCOS characteristics are affected by today's contemporary environment through epigenetic events that predispose women to lipotoxicity, with excess weight gain and pregnancy complications, calling for an emphasis on preventive healthcare to optimize the long-term, endocrine-metabolic health of PCOS women in today's obesogenic environment.

Evaluation of thyroid functions and obesity in obstructive sleep apnea syndrome

OBJECTIVE

Obstructive sleep apnea syndrome is associated with many chronic diseases.

METHODS

Obesity and thyroid function tests were evaluated retrospectively and cross-sectionally for 782 obstructive sleep apnea syndrome patients.

RESULTS

The mean patient age was 49.3±11.5 years, and the majority were obese (67.9%) or overweight (26.6%). The mean age of the patients in Group 2 (moderate/severe obstructive sleep apnea syndrome) was higher than that of Group 1 (simple snoring/mild obstructive sleep apnea syndrome). The rate of severe obstructive sleep apnea syndrome among obese patients (35.2%) was significantly higher than that of normal-weight (11.6%) and overweight (18.3%) patients (p=0.001). The oxygen desaturation index/apnea-hypopnea index and levels of leukocytes and C-reactive protein were significantly higher, while mean/minimum saturation values and hemoglobin, hematocrit, and free triiodothyronine levels were significantly lower among obese patients compared with overweight and normal-weight patients (p=0.001). Leukocytes, C-reactive protein, and apnea-hypopnea index/oxygen desaturation index values were higher, and mean/minimum saturation values were lower in Group 2 than in Group 1.

CONCLUSION

There were relationships between obstructive sleep apnea syndrome severity and body mass index. Obesity could be a critical predisposing factor for sleep disturbances. The prevention and control of obesity is important while being treated for obstructive sleep apnea syndrome.

Activin E-ACVR1C cross talk controls energy storage via suppression of adipose lipolysis in mice

Body fat distribution is a heritable risk factor for cardiovascular and metabolic disease. In humans, rare Inhibin beta E (INHBE, activin E) loss-of-function variants are associated with a lower waist-to-hip ratio and protection from type 2 diabetes. Hepatic fatty acid sensing promotes INHBE expression during fasting and in obese individuals, yet it is unclear how the hepatokine activin E governs body shape and energy metabolism. Here, we uncover activin E as a regulator of adipose energy storage. By suppressing β-agonist-induced lipolysis, activin E promotes fat accumulation and adipocyte hypertrophy and contributes to adipose dysfunction in mice. Mechanistically, we demonstrate that activin E elicits its effect on adipose tissue through ACVR1C, activating SMAD2/3 signaling and suppressing PPARG target genes. Conversely, loss of activin E or ACVR1C in mice increases fat utilization, lowers adiposity, and drives PPARG-regulated gene signatures indicative of healthy adipose function. Our studies identify activin E-ACVR1C as a metabolic rheostat promoting liver-adipose cross talk to restrain excessive fat breakdown and preserve fat mass during prolonged fasting, a mechanism that is maladaptive in obese individuals.

Distinct inflammatory signatures of upper and lower body adipose tissue and adipocytes in women with normal weight or obesity

Introduction

Upper and lower body fat accumulation poses an opposing obesity-related cardiometabolic disease risk. Depot-differences in subcutaneous adipose tissue (SAT) function may underlie these associations. We aimed to investigate the inflammatory signatures of abdominal (ABD) and femoral (FEM) SAT in postmenopausal women with normal weight or obesity.

Methods

We included 23 postmenopausal women with normal weight (n = 13) or obesity (n = 10). In vivo secretion of adipokines from ABD and FEM SAT was measured using the arterio-venous balance technique. Adipokine gene expression and adipocyte morphology were examined in ABD and FEM SAT. Furthermore, adipokine expression and secretion were investigated in vitro using differentiated human primary ABD and FEM subcutaneous adipocytes derived from the study participants.

Results

Plasma leptin and plasminogen activator inhibitor (PAI)-1 concentrations were higher, and ABD and FEM adipocytes were larger in women with obesity than normal weight. No differences in adipocyte size and blood flow were apparent between ABD and FEM SAT. We found significant release of leptin and monocyte chemoattractant protein (MCP)-1 from ABD and FEM SAT, with higher fractional release of MCP-1 from ABD than FEM SAT. Gene expression of leptin, PAI-1, and tumor necrosis factor-α was lower in ABD than FEM SAT and higher in women with obesity than normal weight. In ABD adipocytes, interleukin-6, PAI-1, and leptin gene expression were higher, while adiponectin and dipeptidyl-peptidase-4 gene expression were lower than in FEM adipocytes. Finally, ABD adipocytes secreted less MCP-1 compared to FEM adipocytes.

Discussion

These findings demonstrate that upper and lower body SAT and adipocytes are characterized by distinct inflammatory signatures in postmenopausal women, which seem independent of adipocyte size.

Is functional training an efficient approach to improve body composition in older people? A systematic review

Introduction: Increases in fat mass and reductions in lean mass are associated with the frailty and mortality of older people. In this context, Functional Training (FT) is an option to increase lean mass and reduce fat mass in older people. Thus, this systematic review aims to investigate the effects of FT on body fat and lean mass in older people. Methods: We included randomized controlled clinical trials, with at least one intervention group that employed FT, with the age of participants ≥60 years; and participants physically independent and healthy. We performed the systematic investigation in Pubmed MEDLINE, Scopus, Web of Science, Cochrane Library, and Google Scholar. We extracted the information and used the PEDro Scale to assess the methodological quality of each study. Results: Our research found 3,056 references with five appropriate studies. Of the five studies, three presented reductions in fat mass, all of them with interventions between three and 6 months, different training dose parameters, and 100% of the sample was composed of women. On the other hand, two studies with interventions between 10 and 12 weeks presented conflicting results. Conclusion: Despite the limited literature about lean mass, it appears that long-term FT interventions may reduce fat mass in older women. Clinical Trial Registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=399257, identifier CRD42023399257.

Predicting mechanisms of action at genetic loci associated with discordant effects on type 2 diabetes and abdominal fat accumulation

Obesity is a major risk factor for cardiovascular disease, stroke, and type 2 diabetes (T2D). Excessive accumulation of fat in the abdomen further increases T2D risk. Abdominal obesity is measured by calculating the ratio of waist-to-hip circumference adjusted for the body-mass index (WHRadjBMI), a trait with a significant genetic inheritance. Genetic loci associated with WHRadjBMI identified in genome-wide association studies are predicted to act through adipose tissues, but many of the exact molecular mechanisms underlying fat distribution and its consequences for T2D risk are poorly understood. Further, mechanisms that uncouple the genetic inheritance of abdominal obesity from T2D risk have not yet been described. Here we utilize multi-omic data to predict mechanisms of action at loci associated with discordant effects on abdominal obesity and T2D risk. We find six genetic signals in five loci associated with protection from T2D but also with increased abdominal obesity. We predict the tissues of action at these discordant loci and the likely effector Genes (eGenes) at three discordant loci, from which we predict significant involvement of adipose biology. We then evaluate the relationship between adipose gene expression of eGenes with adipogenesis, obesity, and diabetic physiological phenotypes. By integrating these analyses with prior literature, we propose models that resolve the discordant associations at two of the five loci. While experimental validation is required to validate predictions, these hypotheses provide potential mechanisms underlying T2D risk stratification within abdominal obesity.

Adiposity and sex-specific cancer risk

Obesity is associated with several types of cancer and fat distribution, which differs dramatically between sexes, has been suggested to be an independent risk factor. However, sex-specific effects on cancer risk have rarely been studied. Here we estimate the effects of fat accumulation and distribution on cancer risk in females and males. We performed a prospective study in 442,519 UK Biobank participants, for 19 cancer types and additional histological subtypes, with a mean follow-up time of 13.4 years. Cox proportional hazard models were used to estimate the effect of 14 different adiposity phenotypes on cancer rates, and a 5% false discovery rate was considered statistically significant. Adiposity-related traits are associated with all but three cancer types, and fat accumulation is associated with a larger number of cancers compared to fat distribution. In addition, fat accumulation or distribution exhibit differential effects between sexes on colorectal, esophageal, and liver cancer.

The gut microbiome and regional fat distribution: Findings from the Baltimore Longitudinal Study of Aging

OBJECTIVE

The aim of this study was to examine associations of gut microbiome diversity and composition with directly measured regional fat distribution, including central fat, in a large community-based cohort.

METHODS

A cross-sectional investigation was conducted in the Baltimore Longitudinal Study of Aging (N = 815, 55.2% female, 65.9% White). The fecal microbiome was assessed using whole-genome shotgun metagenomic sequencing, and trunk and leg fat was measured using dual x-ray absorptiometry. Multivariable-adjusted associations of regional fat measures, BMI, or waist circumference with microbiome alpha diversity metrics, microbiome beta diversity metrics, and species differential abundance (verified using two compositional statistical approaches) were examined.

RESULTS

Trunk fat, leg fat, BMI, and waist circumference all significantly explained similar amounts of variance in microbiome structure. Differential abundance testing identified 11 bacterial species significantly associated with at least one measure of body composition or anthropometry. Ruminococcus gnavus was strongly and consistently associated with trunk fat mass, which is congruent with prior literature.

CONCLUSIONS

Microbiome diversity and composition, in particular higher abundance of Ruminococcus gnavus, were associated with greater trunk fat, in addition to other measures of obesity. Longitudinal studies are needed to replicate these findings, and if replicated, randomized trials are needed to determine whether interventions targeting microbiome features such as abundance of Ruminococcus gnavus can lead to reductions in trunk fat and its metabolic sequelae.

Randomized clinical trial: effect of low-dose flutamide on abdominal adipogenic function in normal-weight women with polycystic ovary syndrome

OBJECTIVE

To examine whether low-dose flutamide administration to normal-weight women with polycystic ovary syndrome (PCOS) reduces abdominal fat deposition, attenuates accelerated lipid accumulation in newly formed adipocytes derived from subcutaneous (SC) abdominal adipose stem cells (ASCs), and/or alters glucose-lipid metabolism.

DESIGN

A double-blind, placebo-controlled randomized clinical trial.

SETTING

An academic medical center.

PATIENT(S)

Twelve normal-weight women with PCOS and 12 age- and body mass index-matched controls.

INTERVENTION(S)

Women underwent circulating hormonal and metabolic determinations, intravenous glucose tolerance testing, total body dual-energy roentgenogram absorptiometry, and SC abdominal fat biopsy. Interventions were repeated in women with PCOS after 6-month administration of flutamide (125 mg orally daily) vs. placebo.

MAIN OUTCOME MEASURE(S)

Clinical parameters and lipid accumulation in newly formed adipocytes derived from SC abdominal ASCs in vitro were compared between controls and the women with PCOS receiving flutamide vs. placebo.

RESULTS

Serum luteinizing hormone and androgen levels as well as lipid accumulation in newly formed SC abdominal adipocytes were greater in the women with PCOS than controls. Flutamide vs. placebo reduced percent android fat, lowered serum log low-density lipoprotein and log non-high-density lipoprotein levels, and increased fasting circulating glucose levels. In all women with PCOS, changes in percent android fat positively correlated with serum log non-high-density lipoprotein and log low-density lipoprotein levels, with correlations influenced by serum free testosterone levels. Flutamide vs. placebo also attenuated lipid accumulation in newly-formed PCOS SC abdominal adipocytes in vitro relative to controls, which was unrelated to serum lipid levels.

CONCLUSION

Low-dose flutamide administration to normal-weight PCOS women reduces preferential abdominal fat deposition, attenuates accelerated lipid accumulation in newly-formed adipocytes derived from SC abdominal ASCs in vitro, and alters glucose-lipid homeostasis.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01889199 (URL, clinicaltrials.gov; date of registration, 6/28/2013; enrollment date of first subject, 6/28/2013).

Physiological Oxygen Levels Differentially Regulate Adipokine Production in Abdominal and Femoral Adipocytes from Individuals with Obesity Versus Normal Weight

Adipose tissue (AT) inflammation may increase obesity-related cardiometabolic complications. Altered AT oxygen partial pressure (pO₂) may impact the adipocyte inflammatory phenotype. Here, we investigated the effects of physiological pO₂ levels on the inflammatory phenotype of abdominal (ABD) and femoral (FEM) adipocytes derived from postmenopausal women with normal weight (NW) or obesity (OB). Biopsies were collected from ABD and FEM subcutaneous AT in eighteen postmenopausal women (aged 50-65 years) with NW (BMI 18-25 kg/m², n = 9) or OB (BMI 30-40 kg/m², n = 9). We compared the effects of prolonged exposure to different physiological pO₂ levels on adipokine expression and secretion in differentiated human multipotent adipose-derived stem cells. Low physiological pO₂ (5% O₂) significantly increased leptin gene expression/secretion in ABD and FEM adipocytes derived from individuals with NW and OB compared with high physiological pO₂ (10% O₂) and standard laboratory conditions (21% O₂). Gene expression/secretion of IL-6, DPP-4, and MCP-1 was reduced in differentiated ABD and FEM adipocytes from individuals with OB but not NW following exposure to low compared with high physiological pO₂ levels. Low physiological pO₂ decreases gene expression and secretion of several proinflammatory factors in ABD and FEM adipocytes derived from individuals with OB but not NW.

An improved method to assess skeletal muscle mass in patients with liver cirrhosis based on computed tomography images

AIM

Conventionally, the skeletal muscle area with computed tomography (CT) attenuation ranging from -29 to +150 Hounsfield unit (HU) divided by height squared (the conventional skeletal muscle index [SMI]) was used as an index of skeletal muscle mass. However, it includes fat-infiltrated skeletal muscle, which is known to have poor function. This study aims to determine whether the low-fat SMI, which uses skeletal muscle mass with CT attenuation ranging from +30 to +150 HU, or conventional SMI appropriately reflects the function of skeletal muscle.

METHODS

We retrospectively analyzed 120 patients with cirrhosis whose handgrip strength was measured. Among them, 48 patients underwent a physical performance assessment such as liver frailty index (LFI) and short physical performance battery (SPPB), and 80 underwent quality of life (QOL) assessment. The relationships between each SMI and handgrip strength, LFI, SPPB, and QOL were evaluated.

RESULTS

Low-fat SMI was significantly correlated with handgrip strength (males, R = 0.393, p = 0.002; females, R = 0.423, p < 0.001) and LFI (males, R = -0.535, p = 0.035; females, R = -0.368, p = 0.039), whereas conventional SMI was not. When using low-fat SMI, patients with low skeletal muscle mass had significantly low handgrip strength, LFI, SPPB, and physical and social-related QOL score than those without. By contrast, no significant differences were found for any items when using conventional SMI.

CONCLUSIONS

Low-fat SMI is a good index of skeletal muscle mass that appropriately reflects skeletal muscle function.

Body composition trajectories from birth to 5 years and hepatic fat in early childhood

BACKGROUND

Adiposity is an established risk factor for pediatric nonalcoholic fatty liver disease (NAFLD), but little is known about the influence of body composition patterns earlier in life on NAFLD risk.

OBJECTIVES

We aimed to examine associations of body composition at birth and body composition trajectories from birth to early childhood with hepatic fat in early childhood.

METHODS

Data were from the longitudinal Healthy Start Study in Colorado. Fat-free mass index (FFMI), fat mass index (FMI), percentage body fat (BF%), and BMI were assessed at birth and/or ∼5 y in >1200 children by air displacement plethysmography and anthropometrics. In a subset (n = 285), hepatic fat was also assessed at ∼5 y by MRI. We used a 2-stage modeling approach: first, we fit body composition trajectories from birth to early childhood using mixed models with participant-specific intercepts and linear slopes (i.e., individual deviations from the population average at birth and rate of change per year, respectively); second, associations of participant-specific trajectory deviations with hepatic fat were assessed by multivariable-adjusted linear regression.

RESULTS

Participant-specific intercepts at birth for FFMI, FMI, BF%, and BMI were inversely associated with log-hepatic fat in early childhood in models adjusted for offspring demographics and maternal/prenatal variables [back-transformed β (95% CI) per 1 SD: 0.93 (0.88, 0.99), 0.94 (0.88, 0.99), 0.94 (0.89, 0.99), and 0.90 (0.85, 0.96), respectively]. Whereas, faster velocities for BF% and BMI from birth to ∼5 y were positively associated with log-hepatic fat [back-transformed β (95% CI) per 1 SD: 1.08 (1.01, 1.15) and 1.08 (1.02, 1.15), respectively]. These latter associations of BF% and BMI velocities with childhood hepatic fat were attenuated to the null when adjusted for participant-specific intercepts at birth.

CONCLUSIONS

Our findings suggest that a smaller birth weight, combined with faster adiposity accretion in the first 5 y, predicts higher hepatic fat in early childhood. Strategies aiming to promote healthy body composition early in life may be critical for pediatric NAFLD prevention.This study was registered voluntarily at clinicaltrials.gov as NCT02273297.

Trimester-Specific Serum Fructosamine in Association with Abdominal Adiposity, Insulin Resistance, and Inflammation in Healthy Pregnant Individuals

This study aimed to (1) characterize the variations in serum fructosamine across trimesters and according to pre-pregnancy BMI (ppBMI), and (2) examine associations between fructosamine and adiposity/metabolic markers (ppBMI, first-trimester adiposity, leptin, glucose homeostasis, and inflammation measurements) during pregnancy. Serum fructosamine, albumin, fasting glucose and insulin, leptin, adiponectin, interleukin-6 (IL-6), and C-reactive protein (CRP) concentrations were measured at each trimester. In the first trimester, subcutaneous (SAT) and visceral (VAT) adipose tissue thicknesses were estimated by ultrasound. In the 101 healthy pregnant individuals included (age: 32.2 ± 3.5 y.o.; ppBMI: 25.5 ± 5.5 kg/m2), fructosamine concentrations decreased during pregnancy whereas albumin-corrected fructosamine concentrations increased (p < 0.0001 for both). Notably, fructosamine concentrations were inversely associated with ppBMI, first-trimester SAT, VAT, and leptin (r = −0.55, r = −0.61, r = −0.48, r = −0.47, respectively; p < 0.0001 for all), first-trimester fasting insulin and HOMA-IR (r = −0.46, r = −0.46; p < 0.0001 for both), and first-trimester IL-6 (r = −0.38, p < 0.01). However, once corrected for albumin, most of the correlations lost strength. Once adjusted for ppBMI, fructosamine concentrations were positively associated with third-trimester fasting glucose and CRP (r = 0.24, r = 0.27; p < 0.05 for both). In conclusion, serum fructosamine is inversely associated with adiposity before and during pregnancy, with markers of glucose homeostasis and inflammation, but the latter associations are partially influenced by albumin concentrations and ppBMI.

Vitamin D3 Supplementation in Overweight/Obese Pregnant Women: No Effects on the Maternal or Fetal Lipid Profile and Body Fat Distribution-A Secondary Analysis of the Multicentric, Randomized, Controlled Vitamin D and Lifestyle for Gestational Diabetes Prevention Trial (DALI)

Vitamin D deficiency is a common finding in overweight/obese pregnant women and is associated with increased risk for adverse pregnancy outcome. Both maternal vitamin D deficiency and maternal obesity contribute to metabolic derangements in pregnancy. We aimed to assess the effects of vitamin D3 supplementation in pregnancy versus placebo on maternal and fetal lipids. Main inclusion criteria were: women <20 weeks’ gestation, BMI ≥ 29 kg/m2. Eligible women (n = 154) were randomized to receive vitamin D3 (1600 IU/day) or placebo. Assessments were performed <20, 24−28 and 35−37 weeks and at birth. Linear regression models were used to assess effects of vitamin D on maternal and cord blood lipids. In the vitamin D group significantly higher total 25-OHD and 25-OHD3 levels were found in maternal and cord blood compared with placebo. Adjusted regression models did not reveal any differences in triglycerides, LDL-C, HDL-C, free fatty acids, ketone bodies or leptin between groups. Neonatal sum of skinfolds was comparable between the two groups, but correlated positively with cord blood 25-OH-D3 (r = 0.34, p = 0.012). Vitamin D supplementation in pregnancy increases maternal and cord blood vitamin D significantly resulting in high rates of vitamin D sufficiency. Maternal and cord blood lipid parameters were unaffected by Vitamin D3 supplementation.

Sex Differences in Adiposity and Cardiovascular Diseases

Body fat distribution is a well-established predictor of adverse medical outcomes, independent of overall adiposity. Studying body fat distribution sheds insights into the causes of obesity and provides valuable information about the development of various comorbidities. Compared to total adiposity, body fat distribution is more closely associated with risks of cardiovascular diseases. The present review specifically focuses on the sexual dimorphism in body fat distribution, the biological clues, as well as the genetic traits that are distinct from overall obesity. Understanding the sex determinations on body fat distribution and adiposity will aid in the improvement of the prevention and treatment of cardiovascular diseases (CVD).

National Health and Nutrition Examination Survey 2001-2016

BACKGROUND

Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants that may contribute to the etiology of obesity. However, it is unclear whether PAHs from environmental sources are associated with regional body fat distribution, and whether the association varies across racial/ethnic groups who may have differential PAH exposure patterns.

OBJECTIVES

To examine correlations between PAHs and body fat distribution, and potential racial/ethnic differences among U.S. adults.

METHODS

Ten PAHs were measured in spot urine samples from 2691 non-smoking adults (age ≥ 20 years) in the NHANES 2001-2016. Dual-energy X-ray absorptiometry was used to measure fat mass percent (FM%). Partial Pearson correlation coefficients (r) with multivariable adjustment were used to assess PAH-FM% associations.

RESULTS

In the total population, 1-naphthalene, 3-fluorene, and 1-pyrene were inversely correlated with total FM% or trunk FM% (adjusted r ranged: - 0.06 to - 0.08), while 2-naphthalene, 9-fluorene, and 4-phenanthrene were positively correlated with the FM% measurements (r: 0.07-0.11). PAH levels are highest among non-Hispanic Blacks, followed by Hispanics and Whites and some of the correlations were different by these races/ethnicities. Among non-Hispanic Whites, no PAH was correlated with FM%. In contrast, 9-fluorene was positively correlated with total FM% (r = 0.20) and trunk FM% (r = 0.22) among Blacks, and 4-phenanthrene was positively correlated with total FM% (r = 0.23) and trunk FM% (r = 0.24) among Hispanics (P-interaction: 0.010-0.025).

DISCUSSION

In this US adult population, certain PAHs are significantly associated with higher body fat contents among non-Hispanic Blacks and Hispanics but not non-Hispanic Whites, suggesting that minority groups might be particularly susceptible to PAH's obesogenic effects or the effects of other factors that determine the PAH exposure levels. Alternatively, differences in body composition may contribute to differential PAH metabolism in minority groups. Future studies are warranted to explore the racial/ethnic disparity in PAH exposures, drivers of these exposure differences, and mechanisms through which PAHs may influence body composition by races/ethnicities.

Changes in circulating microRNAs-99/100 and reductions of visceral and ectopic fat depots in response to lifestyle interventions: the CENTRAL trial

BACKGROUND

MicroRNAs (miRNAs) are short noncoding RNAs and important posttranscriptional regulators of gene expression. Adipose tissue is a major source of circulating miRNAs; adipose-related circulating miRNAs may regulate body fat distribution and glucose metabolism.

OBJECTIVES

We investigated how changes in adipose-related circulating microRNAs-99/100 (miR-99/100) in response to lifestyle interventions were associated with improved body fat distribution and reductions of diabetogenic ectopic fat depots among adults with abdominal obesity.

METHODS

This study included adults with abdominal obesity from an 18-mo diet and physical activity intervention trial. Circulating miR-99a-5p, miR-99b-5p, and miR-100-5p were measured at baseline and 18 mo; changes in these miRNAs in response to the interventions were evaluated. The primary outcomes were changes in abdominal adipose tissue [visceral (VAT), deep subcutaneous (DSAT), and superficial subcutaneous (SSAT) adipose tissue; cm2] (n = 144). The secondary outcomes were changes in ectopic fat accumulation in the liver (n = 141) and pancreas (n = 143).

RESULTS

Greater decreases in miR-100-5p were associated with more reductions of VAT (β ± SE per 1-SD decrease: -9.63 ± 3.13 cm2; P = 0.0025), DSAT (β ± SE: -5.48 ± 2.36 cm2; P = 0.0218), SSAT (β ± SE: -4.64 ± 1.68 cm2; P = 0.0067), and intrahepatic fat percentage (β ± SE: -1.54% ± 0.49%; P = 0.0023) after the interventions. Similarly, participants with greater decrease in miR-99a-5p had larger 18-mo reductions of VAT (β ± SE: -10.12 ± 3.31 cm2 per 1-SD decrease; P = 0.0027) and intrahepatic fat percentage (β ± SE: -1.28% ± 0.52%; P = 0.015). Further, decreases in circulating miR-99b-5p (β ± SE: per 1-SD decrease: -0.44% ± 0.21%; P = 0.038) and miR-100-5p (β ± SE: -0.50% ± 0.23%; P = 0.033) were associated with a decrease in pancreatic fat percentage, as well as improved glucose metabolism and insulin secretion at 18 mo.

CONCLUSIONS

Decreases in circulating miR-99-5p/100-5p expression induced by lifestyle interventions were related to improved body fat distribution and ectopic fat accumulation. Our study suggests that changes in circulating adipose-related miR-99-5p/100-5p may be linked to reducing diabetogenic fat depots in patients with abdominal obesity.This trial was registered at clinicaltrials.gov as NCT01530724.

Body Fat Distribution, Glucose Metabolism, and Diabetes Status Among Older Adults: The Multiethnic Cohort Adiposity Phenotype Study

BACKGROUND

As the proportion of visceral (VAT) to subcutaneous adipose tissue (SAT) may contribute to type 2 diabetes (T2D) development, we examined this relation in a cross-sectional design within the Multiethnic Cohort that includes Japanese Americans known to have high VAT. The aim was to understand how ectopic fat accumulation differs by glycemic status across ethnic groups with disparate rates of obesity, T2D, and propensity to accumulate VAT.

METHODS

In 2013-2016, 1,746 participants aged 69.2 (standard deviation, 2.7) years from five ethnic groups completed questionnaires, blood collections, and whole-body dual X-ray absorptiometry and abdominal magnetic resonance imaging scans. Participants with self-reported T2D and/or medication were classified as T2D, those with fasting glucose >125 and 100-125 mg/dL as undiagnosed cases (UT2D) and prediabetes (PT2D), respectively. Using linear regression, we estimated adjusted means of adiposity measures by T2D status.

RESULTS

Overall, 315 (18%) participants were classified as T2D, 158 (9%) as UT2D, 518 (30%) as PT2D, and 755 (43%) as normoglycemic (NG), with significant ethnic differences (P < 0.0001). In fully adjusted models, VAT, VAT/SAT, and percent liver fat increased significantly from NG, PT2D, UT2D, to T2D (P < 0.001). Across ethnic groups, the VAT/SAT ratio was lowest for NG participants and highest for T2D cases. Positive trends were observed in all groups except African Americans, with highest VAT/SAT in Japanese Americans.

CONCLUSION

These findings indicate that VAT plays an important role in T2D etiology, in particular among Japanese Americans with high levels of ectopic adipose tissue, which drives the development of T2D to a greater degree than in other ethnic groups.

Total and regional body adiposity increases during menopause-evidence from a follow-up study

For women, menopausal transition is a time of significant hormonal changes, which may contribute to altered body composition and regional adipose tissue accumulation. Excess adiposity, and especially adipose tissue accumulation in the central body region, increases women's risk of cardiovascular and metabolic conditions and affects physical functioning. We investigated the associations between menopausal progression and total and regional body adiposity measured with dual-energy X-ray absorptiometry and computed tomography in two longitudinal cohort studies of women aged 47-55 (n = 230 and 148, mean follow-up times 1.3 ± 0.7 and 3.9 ± 0.2 years, mean baseline BMI 25.5 kg/m² ). We also examined associations between menopausal progression and skeletal muscle fiber characteristics, as well as adipose tissue-derived adipokines. Relative increases of 2%-14% were observed in regional and total body adiposity measures, with a pronounced fat mass increase in the android area (4% and 14% during short- and long-term follow-ups). Muscle fiber oxidative and glycolytic capacities and intracellular adiposity were not affected by menopause, but were differentially correlated with total and regional body adiposity at different menopausal stages. Menopausal progression and regional adipose tissue masses were positively associated with serum adiponectin and leptin, and negatively associated with resistin levels. Higher diet quality and physical activity level were also inversely associated with several body adiposity measures. Therefore, healthy lifestyle habits before and during menopause might delay the onset of severe metabolic conditions in women.

Earlier Age at Menarche Is Associated with Body Fat and Negative Body Image in Adult Life

Earlier age at menarche is one of the well-documented antecedents of a range of adverse health effects in adulthood including obesity and psychopathological effects. Yet, few researchers have examined the potential association of menarcheal age with body fat distribution, self-perception, and body image. We retrospectively tested a sample (N = 392) of adult women (18-80 years) to examine the associations of age at menarche with body composition and body image indices. Analyses of covariance and multivariable logistic and linear regression were fitted adjusting for age, physical activity level, smoking, and alcohol consumption. Further adjustment was made for body mass index (BMI) and percentage of fat mass. Earlier age at menarche was associated with slightly increased odds of higher BMI and abdominal fat percentage; of note is the positive correlation with lower body composition indices including hip and calf circumferences/skinfolds. Additionally, earlier age at menarche was associated with higher scores in the negative body image scales, namely overweight preoccupation and self-classified weight, whereas lower risks were found for higher scores in the positive body image scales, namely appearance evaluation and body area satisfaction scales. These findings remained significant after correcting for body fat percentage. The present results showed positive associations for earlier age at menarche with gross indices of obesity with the associations mainly confined to distribution of body fat in the lower part of the body, whereas an increased risk of negative body image was also found. Future research could refine our understanding of the biological and psychological mechanisms underlying these associations.

Body Composition Interactions with Physical Fitness: A Cross-Sectional Study in Youth Soccer Players

This study aimed to: (i) analyze fat mass and physical fitness variations among age-groups and playing positions, and (ii) explore the relationship between fat mass and physical fitness in youth male soccer players. A total of 66 players from under-16, under-17, and under-19 were tested. Body mass, skinfolds, countermovement jump (CMJ), single-leg triple hop jump (SLTH), bilateral triple hop jump (BTH), and yo-yo intermittent recovery Level 2 (YYIR-2) were assessed. A two- and one-way ANOVA were conducted, and the effect size was measured. Interactions were found in skin folds and fat mass. The under-19 group was taller, heavier, with a greater BMI and muscle mass than the under-16 group. They also exceeded the under-16 and under-17 in SLTH, BTH, and YYIRT-2. The under-17 group jumped higher and longer than under-16 group. Goalkeepers were taller and heavier than the midfielders. Central defenders were taller and had more muscle mass than midfielders and were heavier than the midfielders and wingers. The wingers jumped higher than the midfielders and showed better YYIRT-2. BMI was small correlated with YYIRT-2 and moderately with CMJ. Fat mass had a moderate negative correlation with CMJ and YYIRT-2. Muscle mass largely correlated with CMJ, UTH, very large with BTH and moderate with YYIRT-2. Summarily, with increasing age, better performances and body compositions were registered. Muscle mass better influences performance than body fat. Body composition can distinguish players positions.

The associations between body fat distribution and bone mineral density in the Oxford Biobank: a cross sectional study

BACKGROUND

Body composition is associated with bone mineral density (BMD), but the precise associations between body fat distribution and BMD remain unclear. The regional adipose tissue depots have different metabolic profiles. We hypothesized that they would have independent associations with BMD.

RESEARCH DESIGN AND METHODS

We used data from 4,900 healthy individuals aged 30-50 years old from the Oxford Biobank to analyze associations between regional fat mass, lean mass and total BMD.

RESULTS

Total lean mass was strongly positively associated with BMD. An increase in total BMD was observed with increasing mass of all the fat depots, as measured either by anthropometry or DXA, when accounting for lean mass. However, on adjustment for both total fat mass and lean mass, fat depot specific associations emerged. Increased android and visceral adipose tissue mass in men, and increased visceral adipose tissue mass in women, were associated with lower BMD.

CONCLUSIONS

Fat distribution alters the association between adiposity and BMD.

The predictive value of trunk/leg fat ratio for type 2 diabetes mellitus remission after bariatric surgery: A new observation and insight

BACKGROUND

Emerging evidence supported the significant role of body composition and fat distribution in the etiology and pathogenesis of Type 2 diabetes mellitus (T2DM).

OBJECTIVE

To assess the predictive value of representative parameters of body composition and fat distribution for T2DM remission after bariatric surgery.

METHODS

A total of 72 patients with T2DM who underwent bariatric surgery in our center between September 2010 and December 2018 were included in this retrospective observational study. Diabetes remission was defined according to the American Diabetes Association criteria released in 2021. Body fat percentage, skeletal muscle index, Android/Gynoid ratio and trunk/leg fat ratio were derived from dual-energy X-ray absorptiometry and assessed.

RESULTS

A total of 40 patients (56%) achieved remission among 72 patients. Patients in the remission group had higher body fat percentage and lower trunk/leg fat ratio than those in the non-remission group. The area under the receiver operating characteristic curve (AUC) for predicting T2DM remission was higher for trunk/leg fat ratio (0.784), compared to BMI (AUC 0. 0.690) and body fat percentage (AUC 0.688). The prediction model (AUC 0.883) including age, duration of T2DM, and trunk/leg fat ratio performed better than the ABCD score (AUC 0.809) and the DiaRem score (AUC 0.792). A nonlinear relationship was observed between trunk/leg fat ratio and BMI.

CONCLUSION

Trunk/leg fat ratio is a promising predictor for T2DM remission after bariatric surgery.

Relationship between body composition, insulin resistance, and hormonal profiles in women with polycystic ovary syndrome

OBJECTIVE

To investigate how body fat influences glucose metabolism and hormone profiles in women with polycystic ovary syndrome (PCOS), compared to women without PCOS.

METHODS

We conducted a cross-sectional study of 166 women with PCOS and 139 age-matched control women at Peking University Third Hospital (Beijing, China) from March 2016 to December 2021. All participants underwent bioimpedance rate assessment of clinical, anthropometric, hormonal, and metabolic features. In particular, body composition parameters were assessed, based on the methods used in a previous study. Homeostasis model assessment-insulin resistance (HOMA-IR) and other indices calculated from fasting glucose and insulin were used to measure insulin resistance. The hormonal profiles [follicle-stimulating hormone (FSH), luteinizing hormone (LH), estrogen (E2), prolactin (PRL), total testosterone (T), and androstenedione (A2)] were assessed by using biochemical methods. Two subgroup analyses were conducted according to waist-to-hip ratio (WHR; < 0.85, non-central obesity and ≥ 0.85, central obesity) and body fat percentage (BFP; < 35% for lean and ≥35% for obesity). The indices above were analyzed using a two-sided t-test or Wilcoxon rank sum test. Linear regression was used to investigate the effects of body composition on metabolism and sex hormones in the PCOS and control groups.

RESULTS

Compared to women without PCOS, women with PCOS and central obesity (P=0.021), PCOS and noncentral obesity (P<0.001), PCOS and high BFP (P<0.001), and PCOS and low BFP (P<0.001) had more severe glucose metabolism evaluated with HOMA-IR. Women with PCOS experienced greater insulin sensitivity impairment than did the normal population for every equal increase in BFP. LH, LH/FSH, total testosterone, and androstenedione were significantly higher in patients with PCOS than in healthy controls, regardless of WHR and BFP stratification. However, negative correlations existed between body fat indices (i.e., BFP and body mass index) and hormone indices (i.e., LH and androstenedione) in the PCOS group, but were absent in the control group.

CONCLUSIONS

Obese and non-obese women with PCOS have more severe insulin resistance and sex-hormone disorders than women without PCOS. The effect of body fat on sex-hormone disorders is only exist in women with PCOS. These findings suggested that PCOS clinical guidelines should be more specific to body fat.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov/, Registration No. NCT04264832.

Waist-To-Hip Ratio Predicts Abnormal Overnight Oximetry in Men Independent of Body Mass Index

Background: Ambulatory overnight oximetry (OXI) has emerged as a cost-effective initial test for sleep disordered breathing. Obesity is closely associated with obstructive sleep apnea (OSA); however, whether body mass index (BMI) or waist-to-hip ratio (WHR) predicts abnormal overnight OXI remains unknown. Methods: We performed a retrospective cross-sectional study of 393 men seen in the Executive Health Program at Mayo Clinic in Rochester, Minnesota who underwent ambulatory overnight OXI ordered by preventive medicine physicians between January 1, 2004 through December 31, 2010. We compared participant/spouse-reported symptoms (sleepiness, snoring), physician indications for OXI (obesity, fatigue), Epworth Sleepiness Scale scores, anthropomorphic measurements (WHR, BMI), and comorbid medical conditions (hypertension, diabetes) with OXI results. Results: 295 of the 393 men who completed OXI had abnormal results. During multivariate analysis, the strongest independent predictor of abnormal OXI for men was WHR (≥1.0, OR = 5.59) followed by BMI (≥30.0 kg/m2, OR = 2.75), age (≥55 yrs, OR = 2.06), and the presence of snoring (OR = 1.91, P < 0.05 for all). A strong association was observed between WHR and abnormal OXI in obese (BMI ≥ 30.0 kg/m2, OR = 6.28) and non-obese (BMI < 29.9 kg/m2, OR = 6.42, P < 0.01 for both) men. Furthermore, 88 men with abnormal OXI underwent polysomnography with 91% being subsequently diagnosed with OSA. Conclusions: In ambulatory, predominantly middle-aged men undergoing preventive services evaluation many physician indications for OXI were not predictors of abnormal results; however, WHR strongly predicted abnormal OXI in obese and non-obese men. As such, we suggest middle-aged men who snore and have a WHR ≥1.0 should be directly referred to a sleep clinic for polysomnography.

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.

Body Fat Distribution and Risk of Breast, Endometrial, and Ovarian Cancer: A Two-Sample Mendelian Randomization Study

Simple Summary

The causal impact of body fat distribution on female-specific cancers is largely unknown. For the first time we used a two-sample multivariable Mendelian randomization (MR) approach to elucidate the role and causal relations of body composition assessed by segmental bioelectrical impedance analysis on the risks of breast, endometrial and ovarian cancers and their subtypes. We found that abdominal fat content increases the risk for ovarian cancer and its endometrioid and clear cell subtypes independent of overall fat content. General adiposity has a protective effect on risk of breast cancer and its ER- and ER+ subtypes but increases the risk for endometrial cancer, ovarian cancer, and the endometrioid ovarian cancer subtype. This study extends the literature by addressing specifically the causal role of visceral fat on female-specific cancers.

Abstract

Background: Mounting evidence shows that adiposity increases female-specific cancer risk, but the role of body fat distribution is less clear. We used a two-sample Mendelian randomization (MR) approach to elucidate causal relations of body fat distribution to the risks of breast, endometrial and ovarian cancers and their subtypes. Methods: Body composition was assessed using segmental bioelectrical impedance analysis, yielding trunk, arm, and leg fat ratios (TFR, AFR, LFR) and BMI including 195,043 and 434,794 European women, respectively. The sample sizes for the outcomes ranged between 58,396 and 228,951. Causal effects were estimated per one standard deviation increment in the respective exposure within the radial regression framework. Robust sensitivity analyses were performed to verify MR assumptions. In a multivariable MR setting, the proportion of risk attributable to overall and abdominal fat content was assessed. Results: TFR, which represents abdominal fat content, was associated with ovarian cancer and its clear cell and endometrioid histotypes independent of overall fat content. BMI was inversely associated with breast cancer and its ER− and ER+ subtypes, but positively with endometrial cancer and ovarian cancer, including its endometrioid histotype. These estimates were confirmed using AFR as proxy for overall body fat. Conclusions: Visceral adiposity seems to be a driver of elevated ovarian cancer risk, particularly of the endometrioid and clear cell ovarian cancer histotypes. General adiposity decreases the risk of breast cancer but increases the risk of endometrial and ovarian cancer.

Abdominal and gluteofemoral fat depots show opposing associations with postprandial lipemia

BACKGROUND

High postprandial lipemia is associated with increased risk of cardiovascular disease, independently of fasting lipid concentrations. Abdominal and gluteofemoral fat depots handle lipoproteins differently, which could affect postprandial lipemia and contribute to the relation between abdominal fat distribution and cardiovascular disease risk.

OBJECTIVES

We aimed to study the influences of higher abdominal compared with gluteofemoral fat on postprandial lipemia after a high-fat meal in individuals with obesity.

METHODS

A total of 755 adults with obesity from a randomized controlled trial in 7 European countries consumed a liquid high-fat meal. Concentrations of triglycerides (TG), glycerol, free fatty acids, and the cholesterol component of remnant-like particles (RLP), LDL, and HDL were measured postprandially for 3 h. Associations of waist circumference (WC), hip circumference (HC), and waist-hip ratio (WHR) with changes in postprandial lipid concentrations, adjusted for fasting concentrations and BMI, were examined using linear regression models. To assess whether the association of WHR with postprandial lipemia could be causal, we performed instrumental variable analyses using a genetic score of 442 variants known to be associated with WHR adjusted for BMI in 2-stage least-squares regression models.

RESULTS

WHR was associated with higher TG and RLP cholesterol concentrations, independent of fasting lipid concentrations and BMI. Instrumental variable analyses suggested that the associations of WHR with postprandial TG (β = 0.038 μmol/L*min, SE = 0.019 μmol/L*min, P = 0.044) and RLP cholesterol concentrations (β = 0.059 mmol/L, SE = 0.025 mmol/L, P = 0.020) may be causal. WC and HC showed opposite effects: higher WC was associated with higher TG and RLP cholesterol concentrations whereas higher HC was associated with lower concentrations.

CONCLUSIONS

Our results suggest that higher fat deposition abdominally versus gluteofemorally may be causally associated with elevated postprandial lipemia after a high-fat meal, independent of fasting lipid concentrations and BMI. Furthermore, higher abdominal and gluteofemoral fat depots show opposing effects on postprandial lipemia.This trial was registered at www.isrctn.com as ISRCTN25867281.

Altered responses of end-expiratory lung volume and upper airway patency to body posture in diet-induced obese mice

OBJECTIVE

Although both obesity and body posture are important factors affecting end-expiratory lung volume (EELV) and upper airway patency, the influence of those factors on EELV and the association between EELV and upper airway calibers are still unknown in mice. This study examined such interaction effects in obese mice to test the hypothesis that obese mice have decreased EELV accompanied by structural alterations of the upper airway.

METHODS

A high-resolution in vivo micro-computed tomography was utilized to scan anesthetized lean and diet-induced obese mice in the prone and supine positions, followed by quantifying lung volume and analyzing upper airway morphology.

RESULTS

There was a statistically significant interaction between the effects of body weight and posture on both EELV (p = 0.0049, η 2  = 0.1041) and upper airway calibers (p = 0.0215, η 2  = 0.6304). In lean mice, EELV in the prone position was significantly larger than in the supine position (prone EELV = 193.22 ± 9.10 µl vs. supine EELV = 176.01 ± 10.91 µl; p = 0.0072), whereas obese mice did not have such an improvement in EELV in the prone position (prone EELV = 174.37 ± 20.23 µl vs. supine EELV = 183.39 ± 17.49 µl; p = 0.0981) and tended to have a smaller upper airway when EELV was low based on Spearman's correlation analysis.

CONCLUSIONS

These data indicate that obesity is an important factor compromising both EELV and upper airway calibers in a posture-dependent manner even in mice, which should be taken into consideration in future studies regarding upper airway collapse and lung mechanical properties using mice.

Unsupervised Exercise Training Was Not Found to Improve the Metabolic Health or Phenotype over a 6-Month Dietary Intervention: A Randomised Controlled Trial with an Embedded Economic Analysis

Ectopic fat leads to metabolic health problems. This research aimed to assess the effectiveness of a hypocaloric diet intervention together with an unsupervised exercise training program in comparison with a hypocaloric diet alone to reduce ectopic fat deposition. Sixty-one premenopausal women with overweight or obesity participated in this controlled trial and were each randomised into either a usual care group (hypocaloric diet) or intervention group (hypocaloric diet + unsupervised exercise training). Ectopic fat deposition, metabolic parameters, incremental costs from a societal perspective and incremental quality-adjusted life years (QALYs) were assessed before, during and after the six-month intervention period. In the total sample, there was a significant decrease in visceral adipose tissue (VAT: -18.88 cm², 95% CI -11.82 to -25.95), subcutaneous abdominal adipose tissue (SAT: -46.74 cm², 95% CI -29.76 to -63.18), epicardial fat (ECF: -14.50 cm³, 95% CI -10.9 to -18.98) and intrahepatic lipid content (IHL: -3.53%, 95% CI -1.72 to -5.32). Consequently, an "adapted" economic analysis revealed a non-significant decrease in costs and an increase in QALYs after the intervention. No significant differences were found between groups. A multidisciplinary lifestyle approach seems successful in reducing ectopic fat deposition and improving the metabolic risk profile in women with overweight and obesity. The addition of unsupervised exercise training did not further improve the metabolic health or phenotype over the six months.

Body fat distribution in trunk and legs are associated with cardiometabolic risk clustering among Chinese adolescents aged 10-18 years old

OBJECTIVES

The aim of the present study was to evaluate the association of body fat distribution with cardiometabolic risk factors clustering among Chinese adolescents.

METHODS

In this cross sectional study a total of 1,175 adolescents aged 10-18 years underwent a comprehensive assessment of cardimetabolic risk factors. Body fat analysis was performed with bioelectrical impedance analysis (BIA).

RESULTS

Individuals with the CVRFs≥1 or CVRFs≥2 had higher indices of body fat distribution such as body fat mass (BFM) compared to those with normal CVRFs (all p<0.001). The prevalence of CVRFs≥1, CVRFs≥2 increased with increasing of the quartile of BFM, TBFM, ABFM, LBFM, PBF, VFL compared to normal subjects. After adjusted for age and sex, the study indicated an linear relationship between TBFM (β = 0.693, 95% CI:0.363, 1.023), LBFM (β = -1.471, 95% CI:-2.768, -0.175) and CVRFs z-score. Logistic regression models suggested TBFM was associated with CVRFs≥1 and CVRFs≥2 by higher odds. Lower odds of LBFM was associated with CVRFs≥2.

CONCLUSIONS

The contribution of the fat mass in specific region on the cardiovascular risk factors clustering is different among adolescents. The trunk fat is associated with higher clustered cardiometabolic risk, while leg fat mass is the protective factor.

Genetics of Body Fat Distribution: Comparative Analyses in Populations with European, Asian and African Ancestries

Preferential fat accumulation in visceral vs. subcutaneous depots makes obese individuals more prone to metabolic complications. Body fat distribution (FD) is regulated by genetics. FD patterns vary across ethnic groups independent of obesity. Asians have more and Africans have less visceral fat compared with Europeans. Consequently, Asians tend to be more susceptible to type 2 diabetes even with lower BMIs when compared with Europeans. To date, genome-wide association studies (GWAS) have identified more than 460 loci related to FD traits. However, the majority of these data were generated in European populations. In this review, we aimed to summarize recent advances in FD genetics with a focus on comparisons between European and non-European populations (Asians and Africans). We therefore not only compared FD-related susceptibility loci identified in three ethnicities but also discussed whether known genetic variants might explain the FD pattern heterogeneity across different ancestries. Moreover, we describe several novel candidate genes potentially regulating FD, including NID2, HECTD4 and GNAS, identified in studies with Asian populations. It is of note that in agreement with current knowledge, most of the proposed FD candidate genes found in Asians belong to the group of developmental genes.

Association between Visceral or Subcutaneous Fat Accumulation and B-Type Natriuretic Peptide among Japanese Subjects: A Cross-Sectional Study

Background: Some previous studies have shown reduced levels of plasma B-type natriuretic peptide (BNP) in individuals with obesity. We aimed to estimate the relationship between BNP and abdominal fat distribution, adjusted for confounding factors. Methods: This cross-sectional study included 1806 Japanese individuals (981 men and 825 women) who underwent a medical health check-up. Analyzed data included age, sex, visceral fat area (VFA), and subcutaneous fat area (SFA) as obtained from computed tomography, blood pressure, and blood test results including BNP. Multiple linear regression analysis was used to examine the association between BNP, VFA, and SFA after adjusting for age, sex, comorbidities, and body mass index. Results: In the models analyzed separately for VFA and SFA, BNP correlated independently with VFA in multiple linear regression analysis among all subjects and in both men and women, while SFA correlated inversely with BNP in all subjects and women but not in men. In the model that included both VFA and SFA, BNP correlated independently with VFA, but SFA and BNP were not correlated in any models. Conclusion: Higher VFA showed an independent, significant association with lower BNP. In addition, the inverse correlation with BNP was stronger for VFA than for SFA.

Modeling Risk Factors for Sleep- and Adiposity-Related Cardiometabolic Disease: Protocol for the Short Sleep Undermines Cardiometabolic Health (SLUMBRx) Observational Study

Background

Obesity and short sleep duration are significant public health issues. Current evidence suggests that these conditions are associated with cardiovascular disease, metabolic syndrome, inflammation, and premature mortality. Increased interest in the potential link between obesity and short sleep duration, and its health consequences, has been driven by the apparent parallel increase in the prevalence of both conditions in recent decades, their overlapping association with cardiometabolic outcomes, and the potential causal connection between the two health issues. The SLUMBRx (Short Sleep Undermines Cardiometabolic Health) study seeks to contribute to the development of a comprehensive adiposity-sleep model while laying the groundwork for a future research program that will be designed to prevent and treat adiposity- and sleep-related cardiometabolic disease risk factors.

Objective

This SLUMBRx study aims to address 4 topics pertinent to the adiposity-sleep hypothesis: the relationship between adiposity and sleep duration; sex-based differences in the relationship between adiposity and sleep duration; the influence of adiposity indices and sleep duration on cardiometabolic outcomes; and the role of socioecological factors as effect modifiers in the relationship between adiposity indices, sleep, and cardiometabolic outcomes.

Methods

SLUMBRx will employ a large-scale survey (n=1000), recruiting 159 participants (53 normal weight, 53 overweight, and 53 obese) to be assessed in 2 phases.

Results

SLUMBRx was funded by the National Institutes of Health, Heart, Lung, and Blood Institute through a K01 grant award mechanism (1K01HL145128-01A1) on July 23, 2019. Institutional Review Board (IRB) approval for the research project was sought and obtained on July 10, 2019. Phase 1 of SLUMBRx, the laboratory-based component of the study, will gather objective adiposity indices (air displacement plethysmography and anthropometrics) and cardiometabolic data (blood pressure, pulse wave velocity and pulse wave analysis, and a blood-based biomarker). Phase 2 of SLUMBRx, a 1-week, home-based component of the study, will gather sleep-related data (home sleep testing or sleep apnea, actigraphy, and sleep diaries). During phase 2, detailed demographic and socioecological data will be collected to contextualize hypothesized adiposity and sleep-associated cardiometabolic disease risk factors. Collection and analyses of these data will yield information necessary to customize future observational and intervention research.

Conclusions

Precise implementation of the SLUMBRx protocol promises to provide objective and empirical data on the interaction between body composition and sleep duration. The hypotheses that will be tested by SLUMBRx are important for understanding the pathogenesis of cardiometabolic disease and for developing future public health interventions to prevent its conception and treat its consequences.

International Registered Report Identifier (IRRID)

PRR1-10.2196/27139

Ethnic differences in beta cell function occur independently of insulin sensitivity and pancreatic fat in black and white men

INTRODUCTION

It is increasingly recognized that type 2 diabetes (T2D) is a heterogenous disease with ethnic variations. Differences in insulin secretion, insulin resistance and ectopic fat are thought to contribute to these variations. Therefore, we aimed to compare postprandial insulin secretion and the relationships between insulin secretion, insulin sensitivity and pancreatic fat in men of black West African (BA) and white European (WE) ancestry.

RESEARCH DESIGN AND METHODS

A cross-sectional, observational study in which 23 WE and 23 BA men with normal glucose tolerance, matched for body mass index, underwent a mixed meal tolerance test with C peptide modeling to measure beta cell insulin secretion, an MRI to quantify intrapancreatic lipid (IPL), and a hyperinsulinemic-euglycemic clamp to measure whole-body insulin sensitivity.

RESULTS

Postprandial insulin secretion was lower in BA versus WE men following adjustment for insulin sensitivity (estimated marginal means, BA vs WE: 40.5 (95% CI 31.8 to 49.2) × 10³ vs 56.4 (95% CI 48.9 to 63.8) × 10³ pmol/m² body surface area × 180 min, p=0.008). There was a significantly different relationship by ethnicity between IPL and insulin secretion, with a stronger relationship in WE than in BA (r=0.59 vs r=0.39, interaction p=0.036); however, IPL was not a predictor of insulin secretion in either ethnic group following adjustment for insulin sensitivity.

CONCLUSIONS

Ethnicity is an independent determinant of beta cell function in black and white men. In response to a meal, healthy BA men exhibit lower insulin secretion compared with their WE counterparts for their given insulin sensitivity. Ethnic differences in beta cell function may contribute to the greater risk of T2D in populations of African ancestry.

Imaging-Based Body Fat Distribution in Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis

BACKGROUND

Women with polycystic ovary syndrome (PCOS) are generally considered to be central obese and at higher risks of metabolic disturbances. Imaging methods are the golden standards for detecting body fat distribution. However, evidence based on magnetic resonance imaging (MRI) and computed tomography (CT) is conflicting. This study systematically reviewed the imaging-based body fat distribution in PCOS patients and quantitatively evaluated the difference in body fat distribution between PCOS and BMI-matched controls.

METHODS

PUBMED, EMBASE, and Web of Science were searched up to December 2019, and studies quantitatively compared body fat distribution by MRI, CT, ultrasound, or X-ray absorptiometry (DXA) between women with PCOS and their BMI-matched controls were included. Two researchers independently reviewed the articles, extract data and evaluated the study quality based on Newcastle-Ottawa Scale (NOS).

RESULTS

47 studies were included in systematic review and 39 were eligible for meta-analysis. Compared to BMI-matched controls, higher accumulations of visceral fat (SMD 0.41; 95%CI: 0.23-0.59), abdominal subcutaneous fat (SMD 0.31; 95%CI: 0.20-0.41), total body fat (SMD 0.19; 95% CI: 0.06-0.32), trunk fat (SMD 0.47; 95% CI: 0.17-0.77), and android fat (SMD 0. 36; 95% CI: 0.06-0.66) were identified in PCOS group. However, no significant difference was identified in all the above outcomes in subgroups only including studies using golden standards MRI or CT to evaluate body fat distribution (SMD 0.19; 95%CI: -0.04-0.41 for visceral fat; SMD 0.15; 95%CI: -0.01-0.31 for abdominal subcutaneous fat). Moreover, meta-regression and subgroup analyses showed that young and non-obese patients were more likely to accumulate android fat.

CONCLUSIONS

PCOS women seem to have abdominal fat accumulation when compared with BMI-matched controls. However, MRI- and CT- assessed fat distribution was similar between PCOS and controls, suggesting central obesity may be independent of PCOS. These findings will help us reappraise the relationship between PCOS and abnormal fat deposition and develop specialized lifestyle interventions for PCOS patients.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, identifier CRD42018102983.

Correlation Between Serum Uric Acid and Body Fat Distribution in Patients With Polycystic Ovary Syndrome

OBJECTIVE

This study aims to investigate the correlation between serum uric acid levels and body fat distribution in patients with polycystic ovary syndrome (PCOS).

METHODS

Between May 2017 and March 2021, a total of 199 patients with PCOS were recruited from the Department of Endocrinology and Metabolism at the Shanghai Tenth People's Hospital. Anthropometric characteristics, metabolic parameters, and reproductive hormones were measured. Hyperuricemia was defined as serum uric acid (SUA) greater than 420 μmol/l. Dual-energy X-ray absorptiometry (DEXA) was used to measure body fat distribution.

RESULTS

The prevalence of hyperuricemia in patients with PCOS was 28.64%. PCOS patients with hyperuricemia are more obese and have a higher waist-to-hip ratio (WHR) and worse lipid metabolism than those without hyperuricemia. According to SUA quartiles, patients in the highest quartile had higher total testosterone (TT), body fat accumulation, and lower sex hormone-binding globulin (SHBG) than patients in the lowest quartile. SUA was correlated with percentage of total body fat, arm fat mass, leg fat mass, trunk fat mass, android/gynoid (A/G) ratio, and visceral adipose tissue (VAT) mass. After controlling possible confounders, logistic regression analysis found that only excessive VAT mass could significantly increase the risk of hyperuricemia in patients with PCOS.

CONCLUSION

In patients with PCOS, a high level of VAT mass, but not other fat compartments, will exacerbate the risk of hyperuricemia. Attention should be paid to the role of excessive VAT in the occurrence and development of PCOS with hyperuricemia.