Adjustment For Total Body Fat Research Articles

The value of neck adipose tissue as a predictor for metabolic risk in health and type 2 diabetes

Upper-body adiposity is adversely associated with metabolic health whereas the opposite is observed for the lower-body. The neck is a unique upper-body fat depot in adult humans, housing thermogenic brown adipose tissue (BAT), which is increasingly recognised to influence whole-body metabolic health. Loss of BAT, concurrent with replacement by white adipose tissue (WAT), may contribute to metabolic disease, and specific accumulation of neck fat is seen in certain conditions accompanied by adverse metabolic consequences. Yet, few studies have investigated the relationships between neck fat mass (NFM) and cardiometabolic risk, and the influence of sex and metabolic status. Typically, neck circumference (NC) is used as a proxy for neck fat, without considering other determinants of NC, including variability in neck lean mass. In this study we develop and validate novel methods to quantify NFM using dual x-ray absorptiometry (DEXA) imaging, and subsequently investigate the associations of NFM with metabolic biomarkers across approximately 7000 subjects from the Oxford BioBank. NFM correlated with systemic insulin resistance (Homeostatic Model Assessment for Insulin Resistance; HOMA-IR), low-grade inflammation (plasma high-sensitivity C-Reactive Protein; hsCRP), and metabolic markers of adipose tissue function (plasma triglycerides and non-esterified fatty acids; NEFA). NFM was higher in men than women, higher in type 2 diabetes mellitus compared with non-diabetes, after adjustment for total body fat, and also associated with overall cardiovascular disease risk (calculated QRISK3 score). This study describes the development of methods for accurate determination of NFM at scale and suggests a specific relationship between NFM and adverse metabolic health.

The associations of leptin and adiponectin with the metabolic syndrome in an Indonesian and a Dutch population

Background and aimsAt the same BMI, Asian populations develop cardiometabolic complications earlier than Western populations. We hypothesized that a different secretion of the adipocyte-derived hormones leptin and adiponectin plays a role and investigated the associations of the two hormones with the metabolic syndrome (MetS) in an Indonesian and a Dutch population. Methods and resultsWe performed cross-sectional analyses of the Netherlands Epidemiology of Obesity Study (n = 6602) and the SUGAR Scientific Programme Indonesia–Netherlands Study (n = 1461). We examined sex-stratified associations of leptin and adiponectin with MetS, using multivariate logistic regression including adjustment for total body fat. The mean (SD) leptin (mcg/L) were 4.7 (6.0) in Indonesian men, 18.6 (12.0) in Indonesian women, 9.1 (7.7) in Dutch men, and 23.4 (17.4) in Dutch women. The mean (SD) adiponectin (mg/L) were 5.7 (5.4), 7.5 (7.1), 6.6 (3.3), and 11.3 (4.9), respectively. Within the same BMI category, leptin concentrations were similar in the two populations, whereas adiponectin was lower in the Indonesian population. Per SD of leptin, adjusted prevalence odds ratios (ORs, 95%CI) of MetS were 0.9 (0.6–1.2) in Indonesian men, 1.1 (0.9–1.4) in Indonesian women, 2.2 (1.6–2.8) in Dutch men, and 1.2 (1.0–1.5) in Dutch women. Per SD of adiponectin, the ORs were 0.9 (0.7–1.2), 0.8 (0.7–1.0), 0.6 (0.6–0.8), and 0.4 (0.4–0.5), respectively. ConclusionsDespite lower adiponectin levels, adiponectin was not related to the MetS in the Indonesian population and can not explain their increased cardiometabolic risk at the same BMI.

Glucose metabolism affects coagulation factors: The NEO study

BackgroundIt is insufficiently understood if there is an association between diabetes and VT, and what the underlying mechanism would be. ObjectivesWe aimed to study the association between glucose concentrations with several coagulation factors in the general population. MethodsThis is a cross‐sectional analysis of baseline measurements within 5778 participants of the Netherlands Epidemiology of Obesity (NEO) study, a population‐based cohort study of individuals 45 to 65 years. Associations between fasting glucose and HbA1c concentrations, and postprandial glucose response and factor (F) VIII, FIX, FXI, and fibrinogen levels were examined using linear regression analyses and by calculating mean levels per category of glucose concentrations while adjusting for confounding factors. ResultsPer each mmol/L higher fasting glucose concentration we observed higher levels of fasting FVIII (5.33%, 95% CI: 4.00‐6.65), FIX (6.19%, 95% CI: 5.15‐7.23), and FXI (2.11%, 95% CI: 1.20‐3.02). Results for fasting HbA1c and postprandial glucose response were similar. Participants with an impaired fasting glucose, high fasting glucose, and diabetes mellitus had higher mean levels of FVIII, FIX, and FXI than those with a normal glucose metabolism, with the highest differences in the levels of FVIII, FIX, and FXI between a high fasting glucose and a normal glucose metabolism. All associations attenuated after adjustment for total body fat, yet all of the above associations remained after adjustment for the confounding factors, except for fibrinogen when contrasted to glucose. ConclusionConcentrations of fasting glucose and HbA1c and postprandial glucose response were positively associated with FVIII, FIX, and FXI, and to some extent also with fibrinogen.

Adherence to dietary guidelines in relation to visceral fat and liver fat in middle-aged men and women: the NEO study

BackgroundIt is unclear to what extent adherence to dietary guidelines may specifically affect visceral fat and liver fat. We aimed to study the association between the Dutch Healthy Diet Index (DHD-index) and total body fat, visceral adipose tissue (VAT) and hepatic triglyceride content (HTGC) in middle-aged men and women.DesignIn this cross-sectional study, VAT was assessed by magnetic resonance imaging (MRI) in 2580 participants, and HTGC by proton-MR spectroscopy in 2083 participants. Habitual dietary intake and physical activity were estimated by questionnaire. Adherence to the current Dutch dietary guidelines was estimated by the 2015 DHD-index score based on the thirteen components (vegetables, fruit, wholegrain products, legumes, nuts, dairy, fish, tea, liquid fats, red meat, processed meat, sweetened beverages, and alcohol). The DHD-index ranges between 0 and 130 with a higher score indicating a healthier diet. We used linear regression to examine associations of the DHD-index with VAT and HTGC, adjusted for age, smoking, education, ethnicity, basal metabolic rate, energy restricted diet, menopausal state, physical activity, total energy intake, and total body fat. We additionally excluded the components one by one to examine individual contributions to the associations.ResultsIncluded participants (43% men) had a mean (SD) age of 56 (6) years and DHD-index score of 71 (15). A 10-point higher DHD-index score was associated with 2.3 cm2 less visceral fat (95% CI; −3.5; −1.0 cm2) and less liver fat (0.94 times, 95% CI; 0.90; 0.98). Of all components, exclusion of dairy attenuated the associations with TBF and VAT.ConclusionsAdherence to the dietary guidelines as estimated by the DHD-index was associated with less total body fat, and with less visceral and liver fat after adjustment for total body fat. These findings might contribute to better understanding of the mechanisms underlying associations between dietary habits and cardiometabolic diseases.

Habitual Sleep Measures are Associated with Overall Body Fat, and not Specifically with Visceral Fat, in Men and Women.

This study aimed to investigate the associations of sleep duration and sleep quality with visceral adipose tissue (VAT) in middle-aged individuals. In this cross-sectional analysis of baseline measurements of the Netherlands Epidemiology of Obesity (NEO) study, participants underwent anthropometry and completed the Pittsburgh Sleep Quality Index (PSQI) for assessing short sleep duration (as sex-specific age-adjusted percentiles) and poor quality (PSQI > 5). VAT was assessed by magnetic resonance imaging in a random subgroup. We performed linear regression analyses to examine associations of short sleep and poor sleep with measures of body fat, adjusted for confounding, including total body fat in models with VAT. A total of 5,094 participants (52% women; mean age of 56 [SD 6] years), 1,947 of whom had VAT measurements, were analyzed. The difference in VAT between poor sleep (PSQI > 5) and good sleep (PSQI ≤ 5) was 7.2cm2 (95% CI: 1.2-13.8) in women and 16.1cm2 (95% CI: 6.2-26.0) in men. These differences attenuated toward the null after the adjustment for total body fat. Similar patterns of associations were observed for short sleep (lowest 10% compared with median 60%). Our results suggest that measures of sleep are not specifically associated with a higher amount of VAT.

Abstract P363: Ectopic Adiposity is Associated With Abdominal Aorto-Illiac but Not Coronary Artery Calcification Independent of Total Body Adiposity in African Ancestry Men

Objective: While ectopic adiposity is considered a risk factor for many chronic diseases, including cardiovascular disease, the extent to which this association is independent of total adiposity is yet to be established. Vascular calcification, which is associated with greater adiposity, is a subclinical marker of cardiovascular disease that may have varying etiology and clinical implications in different vascular beds. Therefore, our objective was to assess the potential independent associations of total, regional and ectopic adiposity measures with abdominal aorto-iliac calcification (AAC) and coronary artery calcification (CAC). Methods: Detailed health history, clinical exam, dual x-ray absorptiometry and computed tomography (CT) scans were obtained in 798 African ancestry men aged ≥40 years (mean(SD): 62.0(8.6)years) recruited without regard to health status from the Tobago Heart Health Study. Vascular calcification was measured by CT in the abdomen (AAC) and chest (CAC). Calcification was scored using the Agatston method and a score ≥10 was considered to be a prevalent calcification. Severity of calcification was modeled using continuous Agatston score in those with any calcification. Multivariable logistic and linear regression models were used to assess the cross-sectional association of adiposity measures with vascular calcification prevalence and severity. All models were adjusted for age, hypertension, diabetes, dyslipidemia, smoking, alcohol intake and sedentary lifestyle. In addition, models of ectopic adiposity (abdominal visceral adipose tissue, liver attenuation and calf skeletal muscle fat) were adjusted for total body fat. Results: AAC was present in 63% and CAC was present in 29% of men. After adjustment for traditional cardiovascular risk factors, 1SD greater total, trunk, or abdominal subcutaneous adiposity was associated with 1.3-1.5-fold increased odds of AAC (all p<0.05). After additional adjustment for total body fat, 1SD lower liver attenuation (indicative of greater liver adiposity) or 1SD greater skeletal muscle fat were each associated with a 1.2-1.3-fold increased odds of AAC. In fully adjusted models, only greater BMI or waist circumference was associated with increased odds of CAC (OR 1.2, p<0.05 for both). In fully adjusted linear models of calcification severity, no significant association was observed between any adiposity measure and AAC or CAC. Conclusions: Independent of total adiposity, measures of ectopic adiposity were associated with greater AAC, but not CAC, prevalence in African ancestry men. These results highlight potential differences in the adiposity-vascular disease relationship that may vary by ectopic fat depot and vascular bed location. Future vascular disease research should explore potential underlying biologic mechanisms for these findings.

Individual contributions of visceral fat and total body fat to subclinical atherosclerosis: The NEO study.

Both overall and abdominal adiposity are established risk factors for cardiovascular disease. Visceral adipose tissue (VAT) and total body fat (TBF) are strongly correlated and previous studies did not make this distinction. We aimed to distinguish individual contributions of TBF, VAT, and the ratio of VAT to abdominal subcutaneous adipose tissue (VAT/SAT) to subclinical atherosclerosis in men and women. In this cross-sectional analysis of the Netherlands Epidemiology of Obesity (NEO) study, we assessed VAT and SAT with magnetic resonance imaging, TBF with bio-electrical impendence analysis, and carotid Intima-Media Thickness (cIMT) with ultrasound. We performed linear regression analyses of standardized values of TBF, VAT, VAT/SAT with cIMT. We adjusted the models for confounding factors (age, sex, ethnicity, education, smoking, alcohol, physical activity), and either for VAT or TBF. This analysis included 2451 participants, 53% men with mean (SD) cIMT of 615 (91)μm. After adjustment for confounding factors, the difference in cIMT (95% CI) per SD in VAT was 14 (8,21)μm in men and 18 (13,24)μm in women. After adjustment for TBF, this attenuated to 5 (-3,13)μm in men and 13 (5,20)μm in women. In the full model, differences in cIMT (95% CI) per SD of TBF were 14 (6,22)μm in men and 8 (0,16)μm in women, and per SD of VAT/SAT were 7 (-1,15)μm and 9 (3,16)μm respectively. In this population-based study, VAT contributed beyond overall adiposity to subclinical atherosclerosis, particularly in women. This implies a specific role of VAT in the early development of atherosclerosis.

Total body fat and the risk of Barrett's oesophagus – A bioelectrical impedance study

BackgroundBody mass index is associated with the risk of Barrett's oesophagus (BO). It is uncertain whether this is related to total body fat or other factors that correlate with body mass index. We aimed to quantify the association between total body fat (measured by bioelectrical impedance) and risk of BO and examine if this association was modified by gastro-oesophageal reflux (GOR) and abdominal obesity. MethodsIn 2007–2009, we surveyed 235 cases (69% Males, Mean age 62.1 years) and 244 age and sex matched population controls from a population based case–control study of BO. We conducted structured interviews, standard anthropometry and bioimpedance analysis of total body fat. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using multivariable logistic regression analysis. ResultsThere was a significantly increased risk of BO among those in the highest tertile of total body fat weight (OR 2.01; 95%CI 1.26–3.21) and total body fat percentage (OR 1.86; 95%CI 1.10–3.15). These risks were largely attenuated after adjustment for GOR and waist circumference. There was a significantly increased risk of BO among those in the highest tertile of waist circumference (OR 2.21; 95%CI 1.39–3.51) and this was minimally attenuated after adjustment for total body fat and moderately attenuated after adjustment for GOR. ConclusionsTotal body fat is associated with an increased risk of BO but this appears to be mediated via both abdominal obesity and GOR. These findings provide evidence that abdominal obesity is more important than total body fat in the development of BO.

Swimming training down-regulates plasma leptin levels, but not adipose tissue ob mRNA expression

The aim of the present study was to assess the effects of endurance training on leptin levels and adipose tissue gene expression and their association with insulin, body composition and energy intake. Male Wistar rats were randomly divided into two groups: trained (N = 18) and sedentary controls (N = 20). The trained group underwent swimming training for 9 weeks. Leptin and insulin levels, adiposity and leptin gene expression in epididymal and inguinal adipose tissue were determined after training. There were no differences in energy intake between groups. Trained rats had a decreased final body weight (-10%), relative and total body fat (-36 and -55%, respectively) and insulin levels (-55%) compared with controls (P < 0.05). Although trained animals showed 56% lower leptin levels (2.58 +/- 1.05 vs 5.89 +/- 2.89 ng/mL in control; P < 0.05), no difference in leptin gene expression in either fat depot was demonstrable between groups. Stepwise multiple regression analysis showed that lower leptin levels in trained rats were due primarily to their lower body fat mass. After adjustment for total body fat, leptin levels were still 20% (P < 0.05) lower in exercised rats. In conclusion, nine weeks of swimming training did not affect leptin gene expression, but did lead to a decrease in leptin levels that was independent of changes in body fat.

Behavioral risk factors in relation to visceral adipose tissue deposition in adolescent females

To characterize visceral adipose tissue (VAT) and subcutaneous abdominal adipose tissue (SAAT) deposition in girls over the pubertal period and to assess the influence of behavioral risk factors on their deposition. In total, 41 subjects of mean age of 13.5 years (standard deviation, SD=0.9) were assessed at menarche. At 4 years after menarche, follow-up data were available for 24 of these subjects. VAT and SAAT were measured by magnetic resonance imaging (MRI) and total body fat by isotopic dilution of (18)O water at menarche and 4 years after menarche in a subset of subjects enrolled in a larger study of growth and development. Smoking, alcohol use, and physical activity were assessed by self-report at both time points. Smoking, alcohol use, and physical activity at 4 years after menarche were assessed in relation to concurrent VAT and SAAT, and to the 4-year change in VAT and SAAT. Smoking and alcohol use at 4 years after menarche was associated with the change in VAT over the 4-year period, before (p<0.03 and p<0.02, respectively), and after adjustment for total body fat (p<0.01 and p<0.02, respectively). In addition to the established health risks, smoking and drinking, even at low levels, appear to be associated with increased VAT deposition in adolescent females.

Associations of size at birth and dual-energy X-ray absorptiometry measures of lean and fat mass at 9 to 10 y of age

Birth weight has been positively associated with risk of overweight in later life. However, little information exists on how weight and length at birth are associated with subsequent lean and total body fat. We investigated the association between weight and length at birth and body composition and fat distribution in childhood. Body composition was measured by using dual-energy X-ray absorptiometry in 9-10-y-old subjects (n = 3006 boys and 3080 girls). Weight and length at birth were measured or taken from hospital records. Birth weight was positively associated with both lean body mass (LBM) and total body fat at 9-10 y of age in both sexes. LBM rose by 320 g per 1-SD increase in birth weight (P < 0.001), and total body fat rose by 2.5% (P = 0.001), but birth weight was unassociated with the fat-to-lean mass ratio (FLR). Ponderal index (PI) at birth (ie, weight/length3) was positively associated with LBM, total body fat, and the FLR in both sexes; the FLR increased by 2.7% in boys (P = 0.021) and by 5.0% in girls per 1-SD increase in PI (P < 0.001). Weight and length at birth did not predict central adiposity; although trunk fat had a strong positive association with PI at birth, this association disappeared after adjustment for total body fat. Higher PI at birth is associated with both higher fat and lean mass in childhood but also with an increase in the FLR. PI at birth is a better predictor of subsequent adiposity than is birth weight.

Influence of Body Fat Content and Distribution on Variation in Metabolic Risk

Several reports indicate that the body fat compartments, especially ip fat, predict metabolic risk better than total body fat. The objective of the study was to determine whether this can be confirmed and generalized throughout the population. A representative sample of 1934 Black and White women and men of the Dallas Heart Study participated in the study. We measured the fat in total body, trunk, and lower body with dual-energy x-ray absorptiometry and in abdominal compartments (sc, ip, and retroperitoneal) with magnetic resonance imaging. Other measurements included body mass index (BMI), waist circumference, blood pressure, plasma lipids, glucose, insulin (including homeostasis model), and C-reactive protein. In all groups, total body fat correlated positively with key metabolic risk factors, i.e. homeostasis model, triglyceride/high-density lipoprotein-cholesterol ratios, C-reactive protein, and blood pressure; however, it explained less than one third of the variability of all the risk factors. After adjustment for total body fat, truncal fat conferred additional positive correlation with risk factors. Furthermore, with multivariable regression analysis, ip fat conferred independent correlation with plasma lipids beyond a combination of other compartments including truncal fat. Still, except for insulin levels, all combinations including ip fat still explained less than one third of the variability in risk-factor levels. Conversely, lower body fat correlated negatively with risk factors; i.e. lower body fat appeared to offer some protection against risk factors. Body fat distribution has some influence on risk factors beyond total body fat content. Both waist circumference and BMI significantly predicted risk factors after adjustment for total body fat, and for clinical purposes, most of the predictive power for men was contained in waist circumference, whereas for women, BMI and waist circumference were similarly predictive. Finally, even though the correlations between combined body fat parameters and risk factors explained only a portion of the variation in the latter, the average number of categorical metabolic risk factors increased progressively with increasing obesity. Hence, obesity seemingly has more clinical impact than revealed in these correlative studies.

Apolipoprotein A-II polymorphism and visceral adiposity in African-American and white women.

To determine the association between the -265 T to C substitution in the apolipoprotein A-II (APOA-II) gene and levels of visceral adipose tissue (VAT) in a group of premenopausal African-American and white women, we genotyped 237 women (115 African-American and 122 white) for this polymorphism. Body composition was assessed by DXA, and VAT was determined from a single computed tomography scan. In addition to VAT, we examined the association between the polymorphism and other phenotypes (total body fat, total abdominal adipose tissue, and subcutaneous abdominal adipose tissue). The mutant C allele in the APOA-II gene was less frequent in African-American compared with white women, 23% vs. 36%, respectively (p < 0.01). VAT was significantly higher in carriers of the C allele compared with noncarriers after adjustment for total body fat (p < 0.05). When separate analyses by ethnic group were conducted, the association between the polymorphism and VAT was observed in white (p < 0.05) but not African-American (p = 0.57) women. There was no association between the polymorphism and the other phenotypes. These results indicate a significant association between the T265C APOA-II polymorphism and levels of VAT in premenopausal women. This association is present in white but not African-American women.

Association Between Insulin Sensitivity and Post-Glucose Challenge Plasma Insulin Values in Overweight Latino Youth

To determine associations between directly measured insulin sensitivity (SI) and oral glucose tolerance test (OGTT)-derived plasma insulin values, or calculated SI indices, in overweight peripubertal Latino children at risk for type 2 diabetes. Thirty overweight Latino children with a family history of type 2 diabetes, aged 8-13 years, Tanner stages 1-2, underwent an OGTT. Fasting and 2-h plasma insulin values and OGTT-derived SI indices were compared with SI derived from a frequently sampled intravenous glucose tolerance test (FSIGTT) with minimal model analysis, before and after adjustment for total body fat and lean tissue mass, or BMI. FSIGTT-derived SI for all subjects was 1.62 +/- 0.78 x 10(-4) min (-1) x (microU/ml), with no sex differences. SI correlated (all P values < 0.001) with fasting (r = -0.57) and 2-h (r = -0.58) plasma insulin and all SI indices (r = -0.57 to 0.67). After adjusting for total body fat and lean tissue mass, or BMI, the associations between SI and either fasting insulin or fasting SI indices were no longer significant. However, the 2-h insulin and post-glucose challenge SI indices maintained significant independent associations with SI, even after adjustment for body composition. In overweight, peripubertal Latino children at risk for type 2 diabetes, the 2-h plasma insulin value and postchallenge SI indices are better independent correlates of SI than fasting values, after accounting for body composition. The 2-h insulin may therefore be superior to fasting insulin as a single blood sample value for clinical or epidemiological estimates of SI, especially when combined with assessment of body composition.

Relationships of blood pressure to fibrinolysis: influence of anthropometry, metabolic profile and behavioural variables

To investigate the relationship between blood pressure and the plasma fibrinolytic system and to verify whether this association was independent or mediated by one or more potential confounding factor. A random sample of 94 males aged 38 years subdivided into normotensives, hypertensives and those hypertensives with the highest blood pressure values. Overall and regional obesity, blood lipids, fasting and 2-h post-load glucose, C-peptide and insulin levels, and main behavioural variables, including adipose tissue fatty acid composition (an objective index of dietary fat intake), were measured. The plasma fibrinolytic system was evaluated by determining activities and total plasma concentrations of both tissue-type plasminogen activator before and after venous occlusion, and its inhibitor plasminogen activator inhibitor type-1 (PAI-1). PAI-1 activity was significantly higher in the hypertensives than in the normotensives. PAI-1 antigen tended to parallel PAI-1 activity, and levels of tissue-type plasminogen activator antigen and activity tended to be lower in the hypertensives at baseline and after venous occlusion, but not significantly different from those in the normotensives. The hypertensives also had significantly higher body mass index and body fat content (measured by bio-impedance), increased plasma triglycerides, uric acid, fasting and 2-h glucose, C-peptide and insulin concentrations. In univariate linear regression analysis both systolic and diastolic blood pressures were found to be positively correlated with PAI-1 levels (r = 0.27, P < 0.01, for both). This correlation was maintained after adjustment for total body fat, fasting glucose, fasting insulin concentration or adipose tissue alpha-linolenic acid; however, it was no longer significant after adjustment for plasma 2-h insulin, 2-h C-peptide, 2-h glucose or triglyceride levels. Multivariate regression analysis revealed that only 2-h insulin and triglyceride concentration showed an independent association with PAI-1 levels. This study confirms that, in 38-year-old males, hypertension is associated with increased PAI-1 activity. It supports the possibility that the relationship between blood pressure and PAI-1 may reflect the overall effect of the insulin resistance syndrome (in particular hyperinsulinaemia and hypertriglyceridaemia) rather than a direct effect of blood pressure on the fibrinolytic system.