The use of anthropometric and dual-energy X-ray absorptiometry (DXA) measures to estimate total abdominal and abdominal visceral fat in men and women

Relationship between indices of obesity obtained by anthropometry and dual-energy X-ray absorptiometry: The Fourth and Fifth Korea National Health and Nutrition Examination Survey (KNHANES IV and V, 2008-2011)

BACKGROUND

Body mass index (BMI), waist circumference (WC), and even dual-energy X-ray absorptiometry (DXA) are used for obesity diagnosis. However, it is not known which DXA-derived index of obesity correlates best with BMI and/or WC and it is not clear whether such an index is accurate or not.

OBJECTIVES

The aim of this study is to show the relationship between anthropometric measurements (BMI, WC) and body fat indices from DXA and to determine which DXA indices are strongly related to BMI and WC.

SUBJECTS

This study was based on data obtained from the Fourth and Fifth Korea National Health and Nutrition Examination Survey (KNHANES IV-V). DXA measurements were performed on survey subjects over 10 years old from July 2008 through to May 2011. Of these, 18 198 individuals, aged 19 years and older for whom DXA data were available, were included.

METHODS

Weighted Pearson's correlated coefficients (r) were calculated among indices, according to sex, age group and menopause, and the coefficients were compared with each other.

RESULTS

BMI correlates most with trunk body fat mass in kg (r=0.831) and then with total body fat in kg (r=0.774, P<0.00043 for difference of r). In the older age group, BMI correlates with total body fat mass (r=0.822) better than with trunk fat mass (r=0.817, P<0.00043). WC correlates with trunk body fat mass most in both genders and all age groups (0.804≤r≤0.906). Correlations of BMI (r=0.645 for men, 0.689 for women) and WC (r=0.678 for men, 0.634 for women) to body fat percentages (%) were less robust than those to body fat mass.

CONCLUSIONS

BMI and WC reflect trunk and total body fat in kg more than body fat percentage derived by DXA.

Prediction of cardiovascular disease by abdominal obesity measures is dependent on body weight and sex--results from two community based cohort studies

AIM

To study waist-hip ratio (WHR), waist circumference (WC), sagittal abdominal diameter (SAD), and waist-hip-height ratio (WHHR) as predictors of CVD, in men and women stratified by BMI (cut-off ≥25).

METHODS AND RESULTS

A cohort of n = 3741 (53% women) 60-year old individuals without CVD was followed for 11-years (375 CVD cases). To replicate the results, we also assessed another large independent cohort; The Malmö Diet and Cancer study - cardiovascular cohort (MDCC, (n = 5180, 60% women, 602 CVD cases during 16-years). After adjustment for established risk factors in normal-weight women, the hazard ratio (HR) per one standard deviation (SD) were; WHR; 1.91 (95% confidence interval (CI) 1.35-2.70), WC; 1.81 (95% CI 1.02-3.20), SAD; 1.25 (95% CI 0.74-2.11), and WHHR; 1.97 (95% CI 1.40-2.78). In men the association with WHR, WHHR and WC were not significant, whereas SAD was the only measure that significantly predicted CVD in men (HR 1.19 (95% CI 1.04-1.35). After adjustments for established risk factors in overweight/obese women, none of the measures were significantly associated with CVD risk. In men, however, all measures were significant predictors; WHR; 1.24 (955 CI 1.04-1.47), WC 1.19 (95% CI 1.00-1.42), SAD 1.21 (95% CI 1.00-1.46), and WHHR; 1.23 (95% CI 1.05-1.44). Only the findings in men with BMI ≥ 25 were verified in MDCC.

CONCLUSION

In normal weight individuals, WHHR and WHR were the best predictors in women, whereas SAD was the only independent predictor in men. Among overweight/obese individuals all measures failed to predict CVD in women, whereas WHHR was the strongest predictor after adjustments for CVD risk factors in men.

Unprotected daily sun exposure is differently associated with central adiposity and β-cell dysfunction by gender: the Korean National Health and Nutrition Examination Survey (KNHANES) V

BACKGROUND

Ultraviolet irradiation by sun exposure has been associated with both harms and benefits to metabolic health.

OBJECTIVE

The objective of this study was to determine whether unprotected daily sun exposure is associated with the prevalence of diabetes and explore the underlying mechanism.

METHODS

We analyzed the Korean National Health and Nutrition Survey V from 2010 to 2011. Participants 19-60 years of age were asked about the average amount of time they had been exposed to direct sunlight per day since the age of 19. We categorized participants into three groups with different levels of lifetime daily sun exposure and explored the association of sun exposure with the prevalence of diabetes.

RESULTS

The risk of diabetes was higher in subjects with more than 5h of unprotected sun exposure per day, with an odds ratio of 2.39 (95% CI 1.75-3.25), compared to those with less than 2h of sun exposure, and the association remained significant after adjusting for diabetes risk factors. Long-term sun exposure was associated with increased central obesity and the possibility of an increase in visceral adiposity, especially among women, and with decrease in beta cell function and peripheral adiposity or percent body fat in men.

CONCLUSIONS

Our study provides a cutoff for upper limit of sun exposure and suggests unprotected daily sun exposure for more than 5h should be avoided to prevent diabetes. Increased central adiposity and decreased beta cell function were observed in women and men, respectively, who had long-term unprotected daily sun exposure.

Bariatric endocrinology: principles of medical practice

Obesity, is a chronic, biological, preventable, and treatable disease. The accumulation of fat mass causes physical changes (adiposity), metabolic and hormonal changes due to adipose tissue dysfunction (adiposopathy), and psychological changes. Bariatric endocrinology was conceived from the need to address the neuro-endocrinological derangements that are associated with adiposopathy, and from the need to broaden the scope of the management of its complications. In addition to the well-established metabolic complications of overweight and obesity, adiposopathy leads to hyperinsulinemia, hyperleptinemia, hypoadiponectinemia, dysregulation of gut peptides including GLP-1 and ghrelin, the development of an inflammatory milieu, and the strong risk of vascular disease. Therapy for adiposopathy hinges on effectively lowering the ratio of orexigenic to anorexigenic signals reaching the the hypothalamus and other relevant brain regions, favoring a lower caloric intake. Adiposopathy, overweight and obesity should be treated indefinitely with the specific aims to reduce fat mass for the adiposity complications, and to normalize adipose tissue function for the adiposopathic complications. This paper defines the principles of medical practice in bariatric endocrinology-the treatment of overweight and obesity as means to treat adiposopathy and its accompanying metabolic and hormonal derangements.

Gender differences in GH response to GHRH+ARG in lipodystrophic patients with HIV: a key role for body fat distribution

OBJECTIVE

Gender influence on GH secretion in human immunodeficiency virus (HIV)-infected patients is poorly known.

DESIGN AND METHODS

To determine the effect of gender, we compared GH response to GH-releasing hormone plus arginine (GHRH+Arg), and body composition in 103 men and 97 women with HIV and lipodystrophy. The main outcomes were IGF1, basal GH, GH peak and area under the curve (AUC) after GHRH+Arg, body composition, visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT).

RESULTS

Men had lower GH peak and AUC than women (P<0.001). Of the study population, 21% of women and 37% of men had biochemical GH deficiency (GHD; GH peak <7.5 μg/l). VAT-to-SAT ratio was higher in men than in women with GHD (P<0.05). Unlike women, VAT, SAT, and trunk fat were greater in men with GHD than in men without GHD. IGF1 was significantly lower in women with GHD than in women without GHD, but not in men. At univariate analysis, BMI, trunk fat mass, VAT, and total adipose tissue were associated with GH peak and AUC in both sexes (P<0.05). BMI was the most significant predictive factor of GH peak, and AUC at multiregression analysis. Overall, abdominal fat had a less pronounced effect on GH in females than in males.

CONCLUSIONS

These data demonstrate that GH response to GHRH+Arg is significantly lower in HIV-infected males than females, resulting in a higher percentage of GHD in men. Adipose tissue distribution more than fat mass per se seems to account for GH gender differences and for the alteration of GH-IGF1 status in these patients.

The relationship of oxidative stress, adiposity and metabolic risk factors in healthy Black and White American youth

What is already known about this subject African Americans are disproportionately affected by obesity and other metabolic risk factors in comparison to White Americans. Increasing prevalence of obesity has been associated with concomitant increases in childhood hypertension, dyslipidaemia and type 2 diabetes. Oxidative stress is associated with obesity in both adults and children. What this study adds Oxidative stress is positively associated with total body fat and truncal fat, but not with body mass index (BMI) or BMI z-score in healthy youth. Oxidative stress is associated with diastolic blood pressure in African American but not in White American healthy youth.

BACKGROUND

Oxidative stress is elevated in obese youth, but less is known regarding racial disparities in the relationship of oxidative stress with metabolic risk factors.

OBJECTIVES

To determine the relationship between oxidative stress and metabolic risk factors, adiposity, leptin, adiponectin and cardiovascular fitness (VO2PEAK ) in healthy African American and White American youth.

METHODS

A marker of oxidative stress (F2 -isoprostane), validated markers of metabolic risk factors, fitness and body composition were measured in African American (n = 82) and White American (n = 76) youth (8-17 years old) recruited over a range of BMI percentiles (4th to 99th).

RESULTS

F2 -isoprostane concentration was positively correlated with percentage body fat (r = 0.198) and percentage truncal fat (r = 0.173), but was not different between African American and White American males and females (P = 0.208). African American youth had significantly higher mean systolic and diastolic blood pressure (P = 0.023 and P = 0.011, respectively), body weight, BMI percentile and Tanner stage. After adjusting for gender, age, BMI and Tanner stage, African American youth varied from White Americans in the association of F2 -isoprostane with diastolic blood pressure (P = 0.047), but not with systolic blood pressure, triglycerides, VO2PEAK or homeostatic model assessment for insulin resistance (all P > 0.05).

CONCLUSIONS

Oxidative stress, as measured by urinary F2 -isoprostane concentrations, was positively associated with percent body fat and truncal fat in youth. Oxidative stress levels were similar among African American and White American youth. Among markers of the metabolic syndrome, a significant difference between African American and White American youth was demonstrated only in the association of oxidative stress with diastolic blood pressure.

Yoga's impact on inflammation, mood, and fatigue in breast cancer survivors: a randomized controlled trial

PURPOSE

To evaluate yoga's impact on inflammation, mood, and fatigue.

PATIENTS AND METHODS

A randomized controlled 3-month trial was conducted with two post-treatment assessments of 200 breast cancer survivors assigned to either 12 weeks of 90-minute twice per week hatha yoga classes or a wait-list control. The main outcome measures were lipopolysaccharide-stimulated production of proinflammatory cytokines interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and interleukin-1β (IL-1β), and scores on the Multidimensional Fatigue Symptom Inventory-Short Form (MFSI-SF), the vitality scale from the Medical Outcomes Study 36-item Short Form (SF-36), and the Center for Epidemiological Studies-Depression (CES-D) scale.

RESULTS

Immediately post-treatment, fatigue was not lower (P > .05) but vitality was higher (P = .01) in the yoga group compared with the control group. At 3 months post-treatment, fatigue was lower in the yoga group (P = .002), vitality was higher (P = .01), and IL-6 (P = .027), TNF-α (P = .027), and IL-1β (P = .037) were lower for yoga participants compared with the control group. Groups did not differ on depression at either time (P > .2). Planned secondary analyses showed that the frequency of yoga practice had stronger associations with fatigue at both post-treatment visits (P = .019; P < .001), as well as vitality (P = .016; P = .0045), but not depression (P > .05) than simple group assignment; more frequent practice produced larger changes. At 3 months post-treatment, increasing yoga practice also led to a decrease in IL-6 (P = .01) and IL-1β (P = .03) production but not in TNF-α production (P > .05).

CONCLUSION

Chronic inflammation may fuel declines in physical function leading to frailty and disability. If yoga dampens or limits both fatigue and inflammation, then regular practice could have substantial health benefits.

Glucose-stimulated oxidative stress in mononuclear cells is related to pancreatic β-cell dysfunction in polycystic ovary syndrome

CONTEXT

Oxidative stress induced by reactive oxygen species (ROS) is involved in the development of pancreatic β-cell dysfunction.

OBJECTIVE

We determined the relationship between mononuclear cell (MNC)-derived ROS generation and p47phox protein content in response to glucose ingestion and β-cell function in women with polycystic ovary syndrome (PCOS).

DESIGN

This was a cross-sectional study.

SETTING

This study was conducted at an academic medical center.

PARTICIPANTS

Twenty-nine normoglycemic women with PCOS (13 lean, 16 obese) and 25 ovulatory controls (16 lean, 9 obese) underwent a 3-h 75-g oral glucose tolerance test (OGTT).

MAIN OUTCOME VARIABLES

Pancreatic β-cell function was calculated as glucose-stimulated insulin secretion (insulin/glucose area under the curve0-30 min; GSIS)×Matsuda index-derived insulin sensitivity (ISOGTT). ROS generation was measured by chemiluminescence, and p47phox protein was quantified by Western blotting in MNC isolated from blood samples obtained at 0 and 2 hours of the OGTT.

RESULTS

Compared with controls, women with PCOS exhibited a higher percent change from baseline in ROS generation and p47phox protein in conjunction with greater GSIS and a tendency toward lower β-cell function. Lean women with PCOS exhibited a greater percent change from baseline in ROS generation and p47phox protein yet had similar GSIS responses compared with lean controls despite having lower ISOGTT. For the combined groups, β-cell function was inversely related to ROS generation and p47phox protein. GSIS was directly related to body mass index, central obesity, and circulating androgens.

CONCLUSION

In normoglycemic women, obesity plays a role in exaggerating GSIS. However, MNC-derived oxidative stress is independent of obesity and may contribute to the decline in β-cell function in women with PCOS.

Sagittal abdominal diameter is an independent predictor of all-cause and cardiovascular mortality in incident peritoneal dialysis patients

Backgrounds and Aims

Visceral fat has a crucial role in the development and progression of cardiovascular disease, the major cause of death in end-stage renal disease (ESRD). Although sagittal abdominal diameter (SAD), as an index of visceral fat, significantly correlated with mortality in the general population, the impact of SAD on clinical outcomes has never been explored in ESRD patients. Therefore, we sought to elucidate the prognostic value of SAD in incident peritoneal dialysis (PD) patients.

Methods

We prospectively determined SAD by lateral abdominal X-ray at PD initiation, and evaluated the association of SAD with all-cause and cardiovascular mortality in 418 incident PD patients.

Results

The mean SAD was 24.5±4.3 cm, and during a mean follow-up of 39.4 months, 97 patients (23.2%) died, and 49.4% of them died due to cardiovascular disease. SAD was a significant independent predictor of all-cause [3rd versus 1st tertile, HR (hazard ratio): 3.333, 95% CI (confidence interval): 1.514–7.388, P = 0.01; per 1 cm increase, HR: 1.071, 95% CI: 1.005–1.141, P = 0.03] and cardiovascular mortality (3rd versus 1st tertile, HR: 8.021, 95% CI: 1.994–32.273, P = 0.01; per 1 cm increase, HR: 1.106, 95% CI: 1.007–1.214, P = 0.03). Multivariate fractional polynomial analysis also showed that all-cause and cardiovascular mortality risk increased steadily with higher SAD values. In addition, SAD provided higher predictive value for all-cause (AUC: 0.691 vs. 0.547, P<0.001) and cardiovascular mortality (AUC: 0.644 vs. 0.483, P<0.001) than body mass index (BMI). Subgroup analysis revealed higher SAD (≥24.2 cm) was significantly associated with all-cause mortality in men, women, younger patients (<65 years), and patients with lower BMI (<22.3 kg/m²).

Conclusions

SAD determined by lateral abdominal X-ray at PD initiation was a significant independent predictor of all-cause and cardiovascular mortality in incident PD patients. Estimating visceral fat by SAD could be useful to stratify mortality risk in these patients.

Associations between measures of central adiposity and periodontitis among older adults

OBJECTIVE

To evaluate the association between measures of adiposity and periodontitis among older Puerto Rican adults.

METHODS

A cross-sectional study was conducted among 147 representative adults ≥70 years living in the San Juan metropolitan area. Height, weight, waist circumference (WC), and hip circumference were measured by trained personnel. Periodontal probing depth and attachment loss (AL) were measured by calibrated examiners. Periodontitis was classified according to the Center for Disease Control/American Academy of Periodontology (CDC-AAP) definitions and using tertiles of mean AL and percent of sites with AL ≥3 mm. Multivariable polytomous logistic regression models adjusted for age, gender, smoking, education, diabetes status, physical activity, and total fruit and vegetable intake were used to model associations between WC, waist-to-hip ratio (WHR), and periodontitis.

RESULTS

High WC (men: ≥102 cm versus <102 cm, women: ≥88 cm versus <88 cm) compared with normal showed nonsignificant associations with severe (OR = 2.56, 95% CI: 0.76-8.67), moderate periodontitis (OR = 1.53, 95% CI: 0.65-3.60), and upper tertile of mean AL (OR = 2.28, 95% CI: 0.83-6.23). Elevated WHR versus normal (men: ≥0.95 versus <0.95, women: ≥0.88 versus <0.88) was associated with moderate periodontitis (OR = 2.36, 95% CI: 1.01-5.52) and showed a borderline significant association with the upper tertile of mean AL (OR = 2.52, 95% CI: 0.96-6.63, P = 0.06).

CONCLUSIONS

Central adiposity was associated with a greater risk of periodontitis in this population of older adults, although analyses were underpowered. These results hold important public health implications given the high prevalence of adiposity and periodontitis among older adults.

Implication of high-body-fat percentage on cardiometabolic risk in middle-aged, healthy, normal-weight adults

OBJECTIVE

This study investigated the number of Korean adults who had a normal body mass index (BMI) but high body-fat percentage (BF%) and determined their increased risk factors for cardiovascular diseases, including high blood pressure, hyperglycemia, and dyslipidemia.

DESIGN AND METHODS

This cross-sectional study was based on 12,386 subjects (6,534 men and 5,852 women), with a normal BMI, between 30 and 49 years of age. Subjects were categorized into two groups by BF% (normal BF% group, BF% <25 for men, and BF% <30 for women; high BF(%) group, BF% ≥25 for men, and BF% ≥30 for women).

RESULTS

The proportion of subjects with a normal BMI and high BF% was 12.7% (n = 1,572; 291 [4.5%] men and 1,281 [21.9%] women). Subjects with a high BF% had a significantly higher prevalence of high blood pressure (men only), hyperglycemia, and dyslipidemia. Multiple logistic regression analyses revealed that subjects with a normal BMI and high BF% had a 1.63 (adjusted odds ratio, 95% confidence interval: 1.21-2.19) in men and 1.56 (adjusted odds ratio, 95% confidence interval: 1.36-1.80) in women increased risk of one or more cardiovascular risk factors compared to subjects in the normal BMI and normal BF% group, even after adjusting for abdominal obesity.

CONCLUSION

High BF% is associated with a high cardiometabolic risks, regardless of abdominal obesity, in normal-weight Korean adults. Thus, follow-up screening of those with a high BF% may be necessary to detect and prevent cardiometabolic diseases, particularly for women with a normal BMI.

Use of dual X-ray absorptiometry to measure body mass during short- to medium-term trials of nutrition and exercise interventions

Dual X-ray absorptiometry (DXA) has a range of clinical applications, from assessing associations between adipose or lean body mass and the risk of disease to measuring the effects of dietary interventions on adipose deposition and oxidation and/or muscle accumulation. Many lifestyle-related studies, however, are short- to medium-term interventions, and inter- or intradevice variation between DXA scanners can facilitate type I and type II errors during data analysis. Studies demonstrate that variation in body composition measurements exist not only between DXA instruments using fan-beam and pencil-beam technologies but also between DXA instruments produced by different manufacturers. Moreover, studies show inter- and intrainstrument variation between identical DXA instruments. Such inter- and intrascan variability between instruments can be compounded by the particular patient population being investigated. The objective of this review is to discuss inter- and intradevice variation of DXA instruments and to outline quality control procedures that should be implemented prior to initiating short-term single or multicenter clinical trials that use DXA to investigate the effects of an intervention on loss or accretion of lean or fat mass.

Body fat and breast cancer risk in postmenopausal women: a longitudinal study

Associations between anthropometric indices of obesity and breast cancer risk may fail to capture the true relationship between excess body fat and risk. We used dual-energy-X-ray-absorptiometry- (DXA-) derived measures of body fat obtained in the Women's Health Initiative to examine the association between body fat and breast cancer risk; we compared these risk estimates with those for conventional anthropometric measurements. The study included 10,960 postmenopausal women aged 50–79 years at recruitment, with baseline DXA measurements and no history of breast cancer. During followup (median: 12.9 years), 503 incident breast cancer cases were diagnosed. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox proportional hazards models. All baseline DXA-derived body fat measures showed strong positive associations with breast cancer risk. The multivariable-adjusted HR for the uppermost quintile level (versus lowest) ranged from 1.53 (95% CI 1.14–2.07) for fat mass of the right leg to 2.05 (1.50–2.79) for fat mass of the trunk. Anthropometric indices (categorized by quintiles) of obesity (BMI (1.97, 1.45–2.68), waist circumference (1.97, 1.46–2.65), and waist : hip ratio (1.91, 1.41–2.58)) were all strongly, positively associated with risk and did not differ from DXA-derived measures in prediction of risk.

Sagittal abdominal diameter is a more independent measure compared with waist circumference to predict arterial stiffness in subjects with type 2 diabetes--a prospective observational cohort study

Background

Anthropometric measurements are useful in clinical practice since they are non-invasive and cheap. Previous studies suggest that sagittal abdominal diameter (SAD) may be a better measure of visceral fat depots. The aim of this study was to prospectively explore and compare how laboratory and anthropometric risk markers predicted subclinical organ damage in 255 patients, with type 2 diabetes, after four years.

Methods

Baseline investigations were performed in 2006 and were repeated at follow-up in 2010. Carotid intima-media thickness (IMT) was evaluated by ultrasonography and aortic pulse wave velocity (PWV) was measured with applanation tonometry over the carotid and femoral arteries at baseline and at follow-up in a cohort of subjects with type 2 diabetes aged 55–65 years old.

Results

There were significant correlations between apolipoprotein B (apoB) (r = 0.144, p = 0.03), C - reactive protein (CRP) (r = 0.172, p = 0.009) at baseline and IMT measured at follow-up. After adjustment for sex, age, treatment with statins and Hba1c, the associations remained statistically significant. HbA1c, total cholesterol or LDL-cholesterol did not correlate to IMT at follow-up. Baseline body mass index (BMI) (r = 0.130, p = 0.049), waist circumference (WC) (r = 0.147, p = 0.027) and sagittal Abdominal Diameter (SAD) (r = 0.184, p = 0.007) correlated to PWV at follow-up. Challenged with sex, SBP and HbA1c, the association between SAD, not WC nor BMI, and PWV remained statistically significant (p = 0.036). In a stepwise linear regression, entering both SAD and WC, the association between SAD and PWV was stronger than the association between WC and PWV.

Conclusions

We conclude that apoB and CRP, but not LDL-cholesterol predicted subclinical atherosclerosis. Furthermore, SAD was more independent in predicting arterial stiffness over time, compared with WC, in middle-aged men and women with type 2 diabetes.

Sagittal abdominal diameter to triceps skinfold thickness ratio: a novel anthropometric index to predict premature coronary atherosclerosis

OBJECTIVE

We aimed to compare the accuracy of a novel index defined by us, as a ratio of Sagittal abdominal diameter (SAD) and triceps skinfold thickness (TSF) with other indices of adiposity for prediction of presence, severity and extension of premature coronary artery disease (CAD).

METHODS

A cross-sectional study was conducted on 238 younger patients (females <55 years; males <45 years) who underwent coronary angiography. Anthropometric indices including TSF, SAD, waist circumference, and hip circumference were measured before catheterization and body mass index, waist-to-hip ratio, abdominal diameter index, index of central obesity as well as our proposed index, SAD-to-TSF ratio, were calculated accordingly. Evaluation of severity and extension of coronary stenosis was by Gensini score and extent score, respectively.

RESULTS

After adjustment for age and sex in multivariate regression models, the SAD-to-TSF ratio was the best predictor for the presence (OR = 2.49, 95% CI = 1.44-4.30; p = 0.001) and extension (β = 1.10, p = 0.004) of premature CAD. TSF and the SAD-to-TSF ratio were the only indices that significantly predicted the Gensini score and the correlation remained significant even after adjustment for age and sex (β = -7.28, p < 0.0001 and β = 3.76, p < 0.0001, respectively).

CONCLUSION

We showed that our proposed index, SAD-to-TSF ratio, has a substantially better accuracy than do the known indices of obesity like body mass index, waist circumference, and waist-to-hip ratio for the prediction of premature CAD. Furthermore, our index was the only index that positively correlated with the severity of premature CAD.

Omega-3 fatty acids, oxidative stress, and leukocyte telomere length: A randomized controlled trial

Shorter telomeres have been associated with poor health behaviors, age-related diseases, and early mortality. Telomere length is regulated by the enzyme telomerase, and is linked to exposure to proinflammatory cytokines and oxidative stress. In our recent randomized controlled trial, omega-3 (n-3) polyunsaturated fatty acid (PUFA) supplementation lowered the concentration of serum proinflammatory cytokines. This study assessed whether n-3 PUFA supplementation also affected leukocyte telomere length, telomerase, and oxidative stress. In addition to testing for group differences, changes in the continuous n-6:n-3 PUFA ratio were assessed to account for individual differences in adherence, absorption, and metabolism. The double-blind four-month trial included 106 healthy sedentary overweight middle-aged and older adults who received (1) 2.5g/day n-3 PUFAs, (2) l.25g/day n-3 PUFAs, or (3) placebo capsules that mirrored the proportions of fatty acids in the typical American diet. Supplementation significantly lowered oxidative stress as measured by F2-isoprostanes (p=0.02). The estimated geometric mean log-F2-isoprostanes values were 15% lower in the two supplemented groups compared to placebo. Although group differences for telomerase and telomere length were nonsignificant, changes in the n-6:n-3 PUFA plasma ratios helped clarify the intervention's impact: telomere length increased with decreasing n-6:n-3 ratios, p=0.02. The data suggest that lower n-6:n-3 PUFA ratios can impact cell aging. The triad of inflammation, oxidative stress, and immune cell aging represents important pre-disease mechanisms that may be ameliorated through nutritional interventions. This translational research broadens our understanding of the potential impact of the n-6:n-3 PUFA balance. ClinicalTrials.gov identifier: NCT00385723.

VAT=TAAT-SAAT: innovative anthropometric model to predict visceral adipose tissue without resort to CT-Scan or DXA

OBJECTIVE

To investigate whether a combination of a selected but limited number of anthropometric measurements predicts visceral adipose tissue (VAT) better than other anthropometric measurements, without resort to medical imaging.

HYPOTHESIS

Abdominal anthropometric measurements are total abdominal adipose tissue indicators and global measures of VAT and SAAT (subcutaneous abdominal adipose tissue). Therefore, subtracting the anthropometric measurement the more correlated possible with SAAT while being the least correlated possible with VAT, from the most correlated abdominal anthropometric measurement with VAT while being highly correlated with TAAT, may better predict VAT.

DESIGN AND METHODS

BMI participants' range was from 16.3 to 52.9 kg m(-2) . Anthropometric and abdominal adipose tissues data by computed tomography (CT-Scan) were available in 253 patients (18-78 years) (CHU Nord, Marseille) and used to develop the anthropometric VAT prediction models.

RESULTS

Subtraction of proximal thigh circumference from waist circumference, adjusted to age and/or BMI, predicts better VAT (Women: VAT = 2.15 × Waist C - 3.63 × Proximal Thigh C + 1.46 × Age + 6.22 × BMI - 92.713; R(2) = 0.836. Men: VAT = 6 × Waist C - 4.41 × proximal thigh C + 1.19 × Age - 213.65; R(2) = 0.803) than the best single anthropometric measurement or the association of two anthropometric measurements highly correlated with VAT. Both multivariate models showed no collinearity problem. Selected models demonstrate high sensitivity (97.7% in women, 100% in men). Similar predictive abilities were observed in the validation sample (Women: R(2) = 76%; Men: R(2) = 70%). Bland and Altman method showed no systematic estimation error of VAT.

CONCLUSION

Validated in a large range of age and BMI, our results suggest the usefulness of the anthropometric selected models to predict VAT in Europides (South of France).

Omega-3 supplementation lowers inflammation in healthy middle-aged and older adults: a randomized controlled trial

Observational studies have linked lower levels of omega-3 (n-3) polyunsaturated fatty acids (PUFAs) with inflammation and depression. This study was designed to determine whether n-3 supplementation would decrease serum cytokine production and depressive symptoms in 138 healthy middle-aged and older adults (average age=51.04, SD=7.76) who were sedentary and overweight (average BMI=30.59, SD=4.50). This three-arm randomized, placebo-controlled, double-blind 4-month trial compared responses to (1) 2.5 g/d n-3 PUFAs, or (2) 1.25 g/d n-3 PUFAs, or (3) placebo capsules that mirrored the proportions of fatty acids in the typical American diet. Serum interleukin-6 decreased by 10% and 12% in our low and high dose n-3 groups, respectively, compared to a 36% increase in the placebo group. Similarly, low and high dose n-3 groups showed modest 0.2% and -2.3% changes in serum tumor necrosis factor alpha, compared to a 12% increase in the control group. Depressive symptoms were quite low at baseline and did not change significantly in response to supplementation. Our data suggest that n-3 PUFAs can reduce inflammation in overweight, sedentary middle-aged and older adults, and thus could have broad health benefits. These data provide a window into the ways in which the n-3 PUFAs may impact disease initiation, progression, and resolution. ClinicalTrials.gov identifier: NCT00385723.

Central but not peripheral fat mass percentage is associated with blood pressure components in the elderly

BACKGROUND

the human body composition changes with advances in age. Particularly, the central fat amount increases. Because the central fat mass is a cardiovascular risk factor, we investigated whether in an elderly population, fat mass (measured at different bodily locations) is associated with peripheral and central blood pressure components.

METHODS

cross-sectional design. Using dual-energy X-ray absorptiometry (DEXA), fat mass was measured within a geriatric outpatient clinic population. Blood pressure was measured with an oscillometric device, and aortic blood pressure and augmentation index (AIx) were obtained by radial artery tonometry, using the SphygmoCor system. Multivariate adjustment for confounders was performed using linear regression analyses.

RESULTS

totally, 216 subjects were included (age 77.3 years ± 6.1, 34.7% male). The truncal fat mass percentage, but not the peripheral fat mass percentage, was positively associated with the peripheral systolic blood pressure (SBP) [beta 0.07 (95% CI: 0.02 to 0.11)] and the peripheral pulse pressure (PP) [beta 0.07 (95% CI: 0.02 to 0.11)], but negatively with the peripheral diastolic blood pressure (DBP) [beta -0.16 (95% CI -0.27 to -0.04)]. The truncal fat mass percentage was similarly associated with estimated aortic blood pressure components, but no association was found between the truncal fat mass percentage and the AIx.

CONCLUSION

in older persons, the truncal fat mass percentage as a reflection of the central fat mass percentage, but not the peripheral fat mass percentage is associated with peripheral and aortic blood pressure components.

Dual-energy X-ray absorptiometry for quantification of visceral fat

Obesity is the major risk factor for metabolic syndrome and through it diabetes as well as cardiovascular disease. Visceral fat (VF) rather than subcutaneous fat (SF) is the major predictor of adverse events. Currently, the reference standard for measuring VF is abdominal X-ray computed tomography (CT) or magnetic resonance imaging (MRI), requiring highly used clinical equipment. Dual-energy X-ray absorptiometry (DXA) can accurately measure body composition with high-precision, low X-ray exposure, and short-scanning time. The purpose of this study was to validate a new fully automated method whereby abdominal VF can be measured by DXA. Furthermore, we explored the association between DXA-derived abdominal VF and several other indices for obesity: BMI, waist circumference, waist-to-hip ratio, and DXA-derived total abdominal fat (AF), and SF. We studied 124 adult men and women, aged 18-90 years, representing a wide range of BMI values (18.5-40 kg/m(2)) measured with both DXA and CT in a fasting state within a one hour interval. The coefficient of determination (r(2)) for regression of CT on DXA values was 0.959 for females, 0.949 for males, and 0.957 combined. The 95% confidence interval for r was 0.968 to 0.985 for the combined data. The 95% confidence interval for the mean of the differences between CT and DXA VF volume was -96.0 to -16.3 cm(3). Bland-Altman bias was +67 cm(3) for females and +43 cm(3) for males. The 95% limits of agreement were -339 to +472 cm(3) for females and -379 to +465 cm(3) for males. Combined, the bias was +56 cm(3) with 95% limits of agreement of -355 to +468 cm(3). The correlations between DXA-derived VF and BMI, waist circumference, waist-to-hip ratio, and DXA-derived AF and SF ranged from poor to modest. We conclude that DXA can measure abdominal VF precisely in both men and women. This simple noninvasive method with virtually no radiation can therefore be used to measure VF in individual patients and help define diabetes and cardiovascular risk.

GH response to GHRH plus arginine is impaired in lipoatrophic women with human immunodeficiency virus compared with controls

OBJECTIVE

GH secretion is impaired in lipodystrophic human immunodeficiency virus (HIV) patients and inversely related to lipodystrophy-related fat redistribution in men. Less is known about the underlying mechanisms involved in reduced GH secretion in HIV-infected women.

DESIGN

A case-control, cross-sectional study comparing GH/IGF1 status, body composition, and metabolic parameters in 92 nonobese women with HIV-related lipodystrophy and 63 healthy controls matched for age, ethnicity, sex, and body mass index (BMI).

METHODS

GH, IGF1, IGF binding protein 3 (IGFBP3), GH after GHRH plus arginine (GHRH+Arg), several metabolic variables, and body composition were evaluated.

RESULTS

GH response to GHRH+Arg was lower in HIV-infected females than in controls. Using a cutoff of peak GH ≤ 7.5 μg/l, 20.6% of HIV-infected females demonstrated reduced peak GH response after GHRH+Arg. In contrast, none of the control subjects demonstrated a peak GH response ≤ 7.5 μg/l. Bone mineral density (BMD), quality of life, IGF1, and IGFBP3 were lowest in the HIV-infected females with a GH peak ≤ 7.5 μg/l. BMI was the main predictive factor of GH peak in stepwise multiregression analysis followed by age, with a less significant effect of visceral fat in the HIV-infected females.

CONCLUSIONS

This study establishes that i) GH response to GHRH+Arg is lower in lipoatrophic HIV-infected women than in healthy matched controls, ii) BMI more than visceral adipose tissue or trunk fat influences GH peak in this population, and iii) HIV-infected women with a GH peak below or equal to 7.5 μg/l demonstrate reduced IGF1, IGFBP3, BMD, and quality of life.

Adiponectin, leptin, and yoga practice

To address the mechanisms underlying hatha yoga's potential stress-reduction benefits, we compared adiponectin and leptin data from well-matched novice and expert yoga practitioners. These adipocytokines have counter-regulatory functions in inflammation; leptin plays a proinflammatory role, while adiponectin has anti-inflammatory properties. Fifty healthy women (mean age=41.32, range=30-65), 25 novices and 25 experts, provided fasting blood samples during three separate visits. Leptin was 36% higher among novices compared to experts, P=.008. Analysis of adiponectin revealed a borderline effect of yoga expertise, P=.08; experts' average adiponectin levels were 28% higher than novices across the three visits. In contrast, experts' average adiponectin to leptin ratio was nearly twice that of novices, P=.009. Frequency of self-reported yoga practice showed significant negative relationships with leptin; more weeks of yoga practice over the last year, more lifetime yoga sessions, and more years of yoga practice were all significantly associated with lower leptin, with similar findings for the adiponectin to leptin ratio. Novices and experts did not show even marginal differences on behavioral and physiological dimensions that might represent potential confounds, including BMI, central adiposity, cardiorespiratory fitness, and diet. Prospective studies addressing increased risk for type II diabetes, hypertension, and cardiovascular disease have highlighted the importance of these adipocytokines in modulating inflammation. Although these health risks are clearly related to more extreme values then we found in our healthy sample, our data raise the possibility that longer-term and/or more intensive yoga practice could have beneficial health consequences by altering leptin and adiponectin production.

Effect of the protein:carbohydrate ratio in hypoenergetic diets on metabolic syndrome risk factors in exercising overweight and obese women

Overweight and obesity are growing problems both in Canada and around the world. Obesity is associated with a number of chronic diseases including type 2 diabetes and CVD, which puts a tremendous burden on the health care systems in place. The present study sought to investigate whether there were differences in the effectiveness of three low-fat, hypo- and isoenergetic diets differing in protein:carbohydrate ratio, low protein (LP, 1 g protein:4 g carbohydrate), normal protein (NP, 1 g protein:2 g carbohydrate) or high protein (HP, 1 g protein:1 g carbohydrate), on weight loss and markers of the metabolic syndrome (MetS) in overweight women. Subjects were randomly assigned to receive one of three intervention diets, all of which included a 60 min exercise programme three times/week for 12 weeks. Of the total subjects, fifty-four overweight and obese local women with MetS risk factors completed the study. All groups had similar improvements in body weight, insulin sensitivity, lipid profile, blood pressure and fitness. Subjects reported that the NP diet was easier to comply with and achieved better improvements in body fat, waist circumference and waist:hip ratio, and preservation of lean mass compared with the other two diets. In conclusion, energy restriction and exercise both facilitate weight loss in overweight and obese subjects and reduce symptoms of the MetS. A diet with a 1:2 protein:carbohydrate ratio promoted better improvements than either the LP or HP diets, and may be superior in reducing long-term chronic disease risk in this population.

Obesity, whole blood serotonin and sex differences in healthy volunteers

BACKGROUND

Obesity is a growing problem throughout Europe, where the rate has more than doubled over the past 20 years. Reduced circulating serotonin may contribute to the development of obesity. This study aimed to explore associations between whole blood (WB) serotonin concentrations and anthropometric measures.

METHODS

Healthy adult volunteers (N = 68) gave whole blood samples for measurement of WB serotonin, and underwent BMI waist circumference (WC) and waist-to-hip ratio (WHR) assessment as well as DEXA (dual energy X-ray absorptiometry) scans for anthropometric parameters. Student's t-tests determined differences in WB serotonin and anthropometric measures between sexes. Partial Pearson's correlations were carried out on anthropometric measures and WB serotonin.

RESULTS

For the whole sample, WB serotonin was significantly negatively correlated with BMI, WC, WHR as well as android, gynoid and total % body fat. Analysis by sex showed significant negative correlations between WB serotonin and android, gynoid as well as total fat in males, but not in females.

CONCLUSION

This dichotomy between the sexes implies that there may be sex differences in the way that serotonin interplays with the development of obesity and body fat distribution.

Omega-3 supplementation lowers inflammation and anxiety in medical students: a randomized controlled trial

Observational studies have linked lower omega-3 (n-3) polyunsaturated fatty acids (PUFAs) and higher omega-6 (n-6) PUFAs with inflammation and depression, but randomized controlled trial (RCT) data have been mixed. To determine whether n-3 decreases proinflammatory cytokine production and depressive and anxiety symptoms in healthy young adults, this parallel group, placebo-controlled, double-blind 12-week RCT compared n-3 supplementation with placebo. The participants, 68 medical students, provided serial blood samples during lower-stress periods as well as on days before an exam. The students received either n-3 (2.5 g/d, 2085 mg eicosapentaenoic acid and 348 mg docosahexanoic acid) or placebo capsules that mirrored the proportions of fatty acids in the typical American diet. Compared to controls, those students who received n-3 showed a 14% decrease in lipopolysaccharide (LPS) stimulated interleukin 6 (IL-6) production and a 20% reduction in anxiety symptoms, without significant change in depressive symptoms. Individuals differ in absorption and metabolism of n-3 PUFA supplements, as well as in adherence; accordingly, planned secondary analyses that used the plasma n-6:n-3 ratio in place of treatment group showed that decreasing n-6:n-3 ratios led to lower anxiety and reductions in stimulated IL-6 and tumor necrosis factor alpha (TNF-α) production, as well as marginal differences in serum TNF-α. These data suggest that n-3 supplementation can reduce inflammation and anxiety even among healthy young adults. The reduction in anxiety symptoms associated with n-3 supplementation provides the first evidence that n-3 may have potential anxiolytic benefits for individuals without an anxiety disorder diagnosis. ClinicalTrials.gov identifier: NCT00519779.

Dairy Foods in a Moderate Energy Restricted Diet Do Not Enhance Central Fat, Weight, and Intra-Abdominal Adipose Tissue Losses nor Reduce Adipocyte Size or Inflammatory Markers in Overweight and Obese Adults: A Controlled Feeding Study

Background. Research on dairy foods to enhance weight and fat loss when incorporated into a modest weight loss diet has had mixed results. Objective. A 15-week controlled feeding study to determine if dairy foods enhance central fat and weight loss when incorporated in a modest energy restricted diet of overweight and obese adults. Design. A 3-week run-in to establish energy needs; a 12-week 500 kcal/d energy reduction with 71 low-dairy-consuming overweight and obese adults randomly assigned to diets: ≤1 serving dairy/d (low dairy, LD) or ≤4 servings dairy/d (adequate dairy, AD). All foods were weighed and provided by the metabolic kitchen. Weight, fat, intra-abdominal adipose tissue (IAAT), subcutaneous adipose tissue (SAT) macrophage number, SAT inflammatory gene expression, and circulating cytokines were measured. Results. No diet differences were observed in weight, fat, or IAAT loss; nor SAT mRNA expression of inflammation, circulating cytokines, fasting lipids, glucose, or insulin. There was a significant increase (P = 0.02) in serum 25-hydroxyvitamin D in the AD group. Conclusion. Whether increased dairy intake during weight loss results in greater weight and fat loss for individuals with metabolic syndrome deserves investigation. Assessment of appetite, hunger, and satiety with followup on weight regain should be considered.

Reference curves for BMI, waist circumference and waist-to-height ratio for Azorean adolescents (Portugal)

Objective

There are no percentile curves for BMI, waist circumference (WC) or waist-to-height ratio (WHtR) available for Portuguese children and adolescents. The purpose of the present study was to develop age- and sex-specific BMI, WC and WHtR percentile curves for a representative sample of adolescents living in the Portuguese islands of Azores, one of the poorest regions of Europe, and to compare them with those from other countries.

Design

Cross-sectional school-based study. Weight, height and WC were objectively measured according to standard procedures. Smoothed percentile curves were estimated using Cole's LMS method.

Setting

Azores, Portugal.

Subjects

Proportionate stratified random sample of 1500 adolescents, aged 15–18 years.

Results

Results showed some sex differences in the shape of the BMI curves: in girls, the upper percentile values tend to decrease by the age of 16 and 17 years; whereas in boys, the upper percentiles tend to be flat between 15 and 16 years and then increase until the age of 18 years. In both sexes, the upper percentile values of both WC and WHtR decreased slightly by the age of 16 years and then increased steeply. In both sexes, the Azorean values for the 50th and 90th WC percentiles were higher than those reported for adolescents from the majority of other countries.

Conclusions

The reference curves presented herein provide baseline data for the long-term surveillance of Azorean adolescents, as well as for national and international comparisons.

Accuracy, reproducibility and repeatability of ultrasonography in the assessment of abdominal adiposity

RATIONALE AND OBJECTIVES

Despite improvements in the methods used in body composition analysis, some goals remain far from clinical practice. Among them, the most important is the quantification of intra-abdominal adipose tissue. Fat distribution is a key point in the assessment of cardiovascular and metabolic risk status. The aim of this study was to define the accuracy, reproducibility, and repeatability of ultrasonography in the evaluation of abdominal adiposity.

MATERIALS AND METHODS

Twenty-six nonobese patients (group A) who underwent computed tomographic (CT) abdominal imaging and 29 obese patients (group B) were enrolled. Patients from both groups were independently evaluated using ultrasound by three radiologists; computed tomography-like conditions were reproduced, and six main parameters of subcutaneous and internal adiposity were measured (as well as three derived indexes) with both linear and convex probes. In group A, the same measurements were also obtained on CT images. Time spent for every ultrasound session was recorded. Results were analyzed using Lin's concordance correlation (ρ), intraclass correlation, and linear regression analysis (and analysis of variance).

RESULTS

Three patients were excluded from group A after CT scans because of technical problems. Mesenteric fat thickness did not show significant correlations and reliability. Strong correlations between ultrasound and CT measurements were observed for all other visceral and subcutaneous parameters (ρ = 0.85-0.96). Intraobserver and interobserver agreement was excellent in both groups (repeatability: ρ = 0.83-0.99 for group A, ρ = 0.90-0.99 for group B; reproducibility: intraclass correlation coefficient = 0.90-0.99 for groups A and B). The mean time spent was 95 ± 21 seconds for group A (mean body mass index, 27.4 ± 2.4 kg/m(2)) and 129 ± 33 seconds for group B (mean body mass index, 37.3 ± 11.9 kg/m(2)).

CONCLUSIONS

Ultrasound is accurate, reproducible, and fast in the analysis of abdominal adiposity. It offers a regional, easy, and close-at-hand evaluation of subcutaneous and visceral fat compartments. This should be taken into consideration when clinical routine examinations are performed or to evaluate patients with specific metabolic diseases before and after treatment.

Effect of exercise combined with phytoestrogens on quality of life in postmenopausal women

BACKGROUND

Postmenopausal women seem to favor alternative therapies such as exercise and phytoestrogens as a substitute for potentially harmful hormone replacement therapy. Based on previous research, we hypothesized that phytoestrogens combined with exercise could have a synergic effect on women's health.

OBJECTIVE

To verify whether phytoestrogens enhance the response to mixed training regarding menopausal symptoms and quality of life in postmenopausal women.

METHODS

From a pool of women participating in a 6-month randomized, controlled exercise study, 21 received a placebo (mean age 58.3 ± 5.4 years, body mass index 29.8 ± 5.1 kg/m(2)) and 19 received phytoestrogen supplements (mean age 60.1 ± 3.4 years; body mass index 30.3 ± 4.6 kg/m(2)). Body weight, fat mass and lean body mass (dual-energy X-ray absorptiometry) were assessed. Quality of life was estimated by the Short Form-36 (SF-36) and Perceived Stress Scale-10 (PSS-10) questionnaires, and menopausal symptoms by the Kupperman index. All measurements were performed before and after the intervention.

RESULTS

Although the Kupperman index and PSS-10 remained unchanged in both groups, the SF-36 Physical Component Summary and almost all the SF-36 subscales (except for role-emotional and mental health) increased only in the exercise group taking phytoestrogens (0.001 < p < 0.04).

CONCLUSION

While phytoestrogens combined with mixed exercise were not sufficient to improve menopausal symptoms, it seemed to be a better strategy than exercise alone to improve the general quality of life in postmenopausal women.

Urinary bisphenol A and obesity: NHANES 2003-2006

BACKGROUND

Bisphenol A (BPA) is a chemical suspected of causing endocrine and metabolic disruption in animals and humans. In rodents, in utero exposure to low-dose BPA is associated with weight gain. Detectable levels of BPA are found in most Americans due to its widespread use in the manufacture of food and drink packaging. We hypothesized that urinary BPA concentrations would be positively associated with general and central obesity.

METHODS

Cross-sectional analysis of urinary BPA concentrations, body mass index, and waist circumference in 2747 adults (aged 18-74), using pooled data from the 2003/04 and 2005/06 National Health and Nutrition Examination Surveys.

RESULTS

The creatinine-adjusted geometric mean urinary BPA concentration was 2.05μg/g creatinine (25th percentile: 1.18, 75% percentile: 3.33). Relative to those in the lowest BPA quartile, participants in the upper BPA quartiles were more likely to be classified as obese (quartile 2 odds ratio (OR): 1.85, 95% confidence interval (CI): 1.22, 2.79; quartile 3 OR: 1.60, 95% CI: 1.05-2.44; quartile 4 OR: 1.76, 95% CI: 1.06-2.94). Higher BPA concentration was also associated with abdominal obesity (quartile 2 OR: 1.62, 95% CI: 1.11, 2.36; quartile 3 OR: 1.39, 95% CI: 1.02-1.90; quartile 4 OR: 1.58, 95% CI: 1.03-2.42).

CONCLUSIONS

Higher BPA exposure is associated with general and central obesity in the general adult population of the United States. Reverse causation is of concern due to the cross-sectional nature of this study; longitudinal studies are needed to clarify the direction of the association.

Increases in central fat mass and decreases in peripheral fat mass are associated with accelerated arterial stiffening in healthy adults: the Amsterdam Growth and Health Longitudinal Study

BACKGROUND

Central fatness is associated with higher arterial stiffness, a mechanism that may explain adiposity-related increases in cardiovascular disease risk. In contrast, peripheral fat and lean masses may counteract such adverse effects, but evidence of this contention, as derived from longitudinal studies at the general population level, is lacking.

OBJECTIVE

The objective was to investigate the associations between changes in central (ie, trunk) fat mass, peripheral (ie, limbs) fat mass, and lean masses with changes in arterial stiffness.

DESIGN

A longitudinal study in 277 (145 women) healthy adults was conducted. Body composition (dual-energy X-ray absorptiometry) and arterial stiffness estimates (ultrasound imaging) were measured repeatedly at the ages of 36 and 42 y.

RESULTS

Changes (per 10 kg) in trunk fat mass were positively associated and changes in peripheral fat mass were inversely associated with carotid Young's elastic modulus (in 10(3) ⋅ kPa) [β = 0.14 (95% CI: 0.02, 0.25) and -0.16 (-0.30, -0.01), respectively] and carotid-femoral pulse wave velocity (in m/s) [β = 1.54 (0.02, 3.07) and -1.46 (-3.48, 0.56), respectively]. Individuals in whom trunk fat increased and peripheral fat decreased over the 6-y follow-up (33% of the study population) had the steepest increases in these stiffness estimates. Notably, these changes were accompanied by minor increases in body weight, which remained within the limits of the normal range throughout.

CONCLUSIONS

Increases in trunk mass and decreases in peripheral fat mass are associated with accelerated arterial stiffening. These findings emphasize the importance of assessing regional changes in body composition, because it may enable identification of individuals with an unrecognized increased cardiovascular disease risk.

Associations between anthropometrical measurements, body composition, single-nucleotide polymorphisms of the hypothalamus/pituitary/adrenal (HPA) axis and HPA axis functioning

BACKGROUND

The relationship between hypothalamus/pituitary/adrenal (HPA) axis functioning and (visceral) obesity may be explained by single-nucleotide polymorphisms (SNPs) of the HPA axis. Objective  To investigate the relationship between the HPA axis SNP's 'BclI' in the glucocorticoid receptor gene and C8246T in the POMC gene and anthropometric measurements, body composition, 5-h cortisol concentrations, HPA axis feedback sensitivity, as well as HPA axis feedback sensitivity under stress in men and women. DESIGN/SUBJECTS/MEASUREMENTS: We assessed in 92 men and 102 women (18-55 years, BMI 19-41 kg/m(2) ) anthropometry, body composition using hydrodensitometry and deuterium dilution method, cortisol variability by measuring 5-h cortisol concentrations, HPA axis feedback functioning using a dexamethasone suppression test and HPA axis functioning under a challenged condition consisting of a standardized high intensity test with ingestion of 4 mg dexamethasone.

RESULTS

In female participants, the 8246C allele carriers compared to the 8246T allele carries were associated with a higher 5-h cortisol exposure (1·52 × 10(5) ± 0·8 vs 1·18 × 10(5) ± 0·6 nm·min, P < 0·05) and higher baseline postdexamethasone cortisol concentrations (54·5 ± 35·6 vs 37·4 ± 18·5 nm, P < 0·05). In male participants regarding the C8246T allele carriers and in both male and female participants regarding the BclI genotypes, no significant differences in anthropometric measurements, body composition and HPA axis functioning were observed. Multiple regression analysis showed that only increased 5-h cortisol exposure significantly related to changes in anthropometric measurements and body composition; the BclI and C8246T genotypes were not associated.

CONCLUSION

Our preliminary data show that in both men and women (18-55 years, BMI 19-41 kg/m(2) ), the SNP's BclI and C8246T of the HPA axis were primarily related to altered HPA axis functioning, rather than to altered anthropometric measurements and body composition.

Assessment of measures for abdominal adiposity in persons with spinal cord injury

Ultrasound may be a useful tool to assess abdominal adiposity, but it has not been validated in the spinal cord injury (SCI) population. This study evaluated associations between abdominal ultrasound and other methods to assess adiposity in 24 men with SCI and 20 able-bodied (AB) men. Waist (WC) and hip circumference (HC) and waist-to-hip ratio (WHR) were measured. Trunk (TRK%), android (A%) and waist fat (W%) were determined by dual energy x-ray absorptiometry (DXA); ultrasonography determined abdominal subcutaneous (SF) and visceral fat (VF). The SCI group had greater TRK% (40.0 ± 9.6 vs. 32.0 ± 10.3), W% (47.0 ± 9.7 vs. 40.6 ± 9.4), A% (43.0 ± 9.8 vs. 35.8 ± 10.6) and WHR (0.99 ± 0.1 vs. 0.92 ± 0.06) than the AB group. WC and WHR correlated with VF in the SCI group. These associations suggest that ultrasound may be a useful tool in clinical practice for the measurement of VF in weight loss programs and for the assessment of cardiometabolic disorders.

Body composition, metabolic syndrome and insulin resistance in type 1 diabetes mellitus

OBJECTIVE: Our aim was to determine the relationship between body fat composition, metabolic syndrome (MS), and insulin resistance in type 1 diabetes (DM1). SUBJECTS AND METHODS: Forty-five DM1 women (36 ± 9 years; body mass index 24.6 ± 4.4 kg/m²) had body composition and insulin resistance determined by dual-energy X-ray absorptiometry and estimated glucose disposal ratio (eGDR), respectively. Twenty patients (45%) had MS according to World Health Organization (WHO) criteria. RESULTS: Women with DM1 and MS had increased central fat and lower eGDR than women without MS (41.9 ± 2.0 vs. 33.7 ± 1.8%; p = 0.004 and 4.99 ± 0.40 vs. 8.37 ± 0.39; p < 0.0001, respectively). Total body fat and peripheric fat were similar between the groups. Central fat negatively correlated with eGDR (r = -0.33; p = 0.03). CONCLUSION: Central fat deposition in young non-obese DM1 women was related to MS and insulin resistance. Thus, body fat composition analysis might be important to identify DM1 patients with increased metabolic risk.

Adiposity, adult weight gain and mammographic breast density in US Chinese women

The association of adiposity with dense tissue area in the breast is unclear, but suggests a mechanism by which adiposity might increase breast cancer risk. We examined associations of body mass index (BMI), usual BMI from age 20 to 29, waist circumference and adult weight gain with breast density in a sample of premenopausal United States Chinese immigrant women. Analyses included 415 participants in a longitudinal breast density study in Philadelphia. In addition to detailed questionnaire information, data collection included measures of anthropometry, and assessment of mammographic breast density using a computer-assisted method. We used multivariate linear regression to quantify cross-sectional associations with dense and nondense tissue area and percent breast density assessed at baseline. In adjusted models, BMI and waist circumference were significantly positively associated with nondense tissue area and inversely associated with percent density. BMI was also significantly positively associated with dense tissue area. Adult weight gain was associated with dense tissue area after adjusting for weight from age 20 to 29. In stratified analyses, BMI and adult weight gain were significantly associated with dense tissue area among women with BMI < 23 kg/m², and BMI was associated with nondense tissue area among women with BMI ≥ 23 kg/m². In this sample, adiposity and weight gain were associated with dense breast tissue area, although associations differed by level of adiposity. Given the potential implications of these findings for breast cancer prevention in premenopausal women, comparable studies in other population groups and with longitudinal data are needed. Reasons for the noted differences in associations by level of adiposity also warrant further investigation.

Increased epicardial adipose tissue in type 1 diabetes is associated with central obesity and metabolic syndrome

AIMS

The present study evaluated the relationship between metabolic syndrome (MS), body fat composition and epicardial adipose tissue (EAT) in type 1 diabetes. Epicardial adipose tissue is a new independent marker of coronary artery disease (CAD).

METHODS

forty-five type 1 diabetic women were evaluated (age 36 ± 9 years; body mass index 24.6 ± 4.4 kg/m(2)). Metabolic syndrome was defined by the World Health Organization criteria. Body fat composition and EAT were analyzed by dual-energy-X-ray absorptiometry and echocardiogram, respectively.

RESULTS

twenty patients (45%) had MS. Patients with MS had greater android (central) fat deposition than patients without MS (41.9 ± 2.0% vs. 33.7 ± 1.8%, p=0.004). Total body fat and gynoid (peripheric) fat distribution were similar between the groups. Mean EAT was higher in patients with MS (6.15 ± 0.34 mm vs. 4.96 ± 0.25 mm; p=0.006) and EAT was positively correlated with android (central) fat distribution (r=0.44; p=0.002), however no correlation was found with gynoid (peripheric) fat distribution.

CONCLUSIONS

there was a high incidence of MS in type 1 diabetes related to increased central adiposity, despite the absence of obesity. Metabolic syndrome and central obesity were associated with increased EAT. Thus, young non-obese type 1 diabetic women with central adiposity and/or MS may have increased EAT, what may predict CAD risk.

Association between Abdominal Fat (DXA) and Its Subcomponents (CT Scan) before and after Weight Loss in Obese Postmenopausal Women: A MONET Study

Introduction. Subcutaneous fat (ScF) and visceral fat (VF) measurements using CT scan are expensive and may imply significant radiation doses. Cross-sectional studies using CT scan showed that ScF and VF are significantly correlated with abdominal fat measured by DXA (AF-DXA). The association has not been studied after a weight loss. Objective. To determine (1) the associations between AF-DXA and ScF and VF before and after weight loss and (2) the associations between their changes. Methods. 137 overweight/obese postmenopausal women were divided in two groups (1-caloric restriction or 2-caloric restriction + resistance training). AF was assessed using DXA and CT scan. Results. Correlations between AF-DXA and ScF (before: r = 0.87, after; r = 0.87; P < .01) and, AF-DXA and VF (before: r = 0.61, after; r = 0.69; P < .01) are not different before and after the weight loss. Correlations between delta AF-DXA and delta ScF (r = 0.72; P < .01) or delta VF (r = 0.51; P < .01) were found. Conclusion. The use of AF-DXA as a surrogate for VF after weight loss is questionable, but may be interesting for ScF.

DXA surrogates for visceral fat are inversely associated with bone density measures in adolescent athletes with menstrual dysfunction

OBJECTIVE

Lean mass is associated with bone mineral density (BMD) in athletes, attributable to the anabolic pull of muscle on bone. Fat mass is also important, and subcutaneous fat positively and visceral fat negatively correlates with BMD in obese adolescents. The contribution of regional body composition to low BMD in amenorrheic athletes (AA) has not been elucidated. We hypothesized that in adolescent athletes (runners), BMD is associated positively with total fat (surrogate for subcutaneous fat) and lean mass, and inversely with percent trunk fat and trunk-to-extremity fat ratio (surrogates for visceral fat).

DESIGN

Cross-sectional study.

SUBJECTS AND METHODS

We examined BMD and body composition using dual energy X-ray absorptiometry (DXA) in 21 AA and 19 eumenorrheic athletes (EA) (12-18 years) (runners). We report total hip and height-adjusted BMD [lumbar bone mineral apparent density (LBMAD) and whole body bone mineral content/height (WBBMC/Ht)].

RESULTS

AA had lower BMD than EA. Lean mass was less strongly associated with hip BMD in AA than EA; fat mass was positively associated with LBMAD in EA. Percent trunk fat and trunk-to-extremity fat ratio were inversely associated with lumbar and WB measures in AA. In a regression model, lean and fat mass were positively, and percent trunk fat and trunk-to-extremity fat ratio negatively associated with LBMAD and WBBMC/Ht for all athletes, even after controlling for serum estradiol.

CONCLUSIONS

DXA surrogates for visceral fat are inversely associated with bone density in athletes.

Comparison of dual-energy x-ray absorptiometric and anthropometric measures of adiposity in relation to adiposity-related biologic factors

Dual-energy x-ray absorptiometry (DXA) can provide accurate measurements of body composition. Few studies have compared the relative validity of DXA measures with anthropometric measures such as body mass index (BMI) and waist circumference (WC). The authors compared correlations of DXA measurements of total fat mass and fat mass percent in the whole body and trunk, BMI, and WC with obesity-related biologic factors, including blood pressure and levels of plasma lipids, C-reactive protein, and fasting insulin and glucose, among 8,773 adults in the National Health and Nutrition Examination Survey (1999-2004). Overall, the magnitudes of correlations of BMI and WC with the obesity-related biologic factors were similar to those of fat mass or fat mass percent in the whole body and trunk, respectively. These observations were largely consistent across different age, gender, and ethnic groups. In addition, in both men and women, BMI and WC demonstrated similar abilities to distinguish between participants with and without the metabolic syndrome in comparison with corresponding DXA measurements. These data indicate that the validity of simple anthropometric measures such as BMI and WC is comparable to that of DXA measurements of fat mass and fat mass percent, as evaluated by their associations with obesity-related biomarkers and prevalence of metabolic syndrome.

Waist to hip ratio and trunk to extremity fat (DXA) are better surrogates for IMCL and for visceral fat respectively than for subcutaneous fat in adolescent girls

BACKGROUND

Increased visceral adipose tissue (VAT) and intramyocellular lipids (IMCL) are associated with increased metabolic risk. Clinical and DXA body composition measures that are associated with VAT are generally even more strongly associated with subcutaneous adipose tissue (SAT) reflecting general adiposity, and thus are not specific for VAT. Measures more strongly associated with VAT than SAT (thus more specific for VAT), and predictors of IMCL have not been reported.

SUBJECTS/METHODS

We studied 30 girls 12-18 years; 15 obese, 15 normal-weight. The following were assessed: (1) anthropometric measures: waist circumference at the umbilicus and iliac crest (WC-UC and WC-IC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), (2) DXA measures: total fat, percent body fat (PBF), percent trunk fat (PTF), trunk-to-extremity fat ratio (TEFR), (3) MRI and 1H-MRS: VAT and SAT (L4-L5), soleus-IMCL.

RESULTS

Group as a whole: WC, trunk fat and PBF were more strongly associated with SAT than VAT; none were specific for VAT. In contrast, PTF and TEFR were more significantly associated with VAT (r = 0.83 and 0.81 respectively, p <0.0001 for both) than SAT (r = 0.77 and 0.75, p < 0.0001 for both). Strongest associations of S-IMCL were with WHR (r = 0.66, p = 0.0004). Subgroup analysis: In obese girls, WHR and WHtR were more strongly correlated with VAT (r = 0.62 and 0.82, p = 0.04 and 0.001) than SAT (r = 0.41 and 0.73, p not significant and 0.007), and for DXA measures, PTF and TEFR were more significantly associated with VAT (r = 0.70 and 0.72, p = 0.007 and 0.006) than SAT (r = 0.52 and 0.53, p = 0.07 and 0.06). In controls, PTF and TEFR were more strongly correlated with VAT (r = 0.79, p = 0.0004 for both) than SAT (r = 0.71 and 0.72, p = 0.003 for both). WHR was associated with IMCL in obese girls (r = 0.78, p = 0.008), but not controls.

CONCLUSION

Overall, WHR (anthropometry), and PTF and TEFR (DXA) are good surrogates for IMCL and for visceral fat respectively in adolescent girls.

Stronger associations of sagittal abdominal diameter with atherogenic lipoprotein subfractions than waist circumference in middle-aged US white and Japanese men

Both sagittal abdominal diameter (SAD) and waist circumference (WC) highly correlate with visceral adipose tissue (VAT) being linked to an atherogenic lipoprotein profile. However, it is uncertain whether SAD is a better correlate of atherogenic lipoprotein subfractions than WC. We examined relative associations of SAD vs WC with lipoprotein subfractions for US white and Japanese men, concurrently examining the associations of VAT vs subcutaneous adipose tissue with lipoprotein subfractions. A population-based sample of 260 white and 282 Japanese men aged 40 to 49 years was examined for VAT and subcutaneous adipose tissue by computed tomography; SAD and WC by a portable sliding-beam caliper and a measuring tape, respectively; and lipoprotein subfractions by nuclear magnetic resonance spectroscopy. Both SAD and WC were significantly and positively associated with large very low-density lipoprotein and total and small low-density lipoprotein particle concentrations, and inversely associated with large high-density lipoprotein particle concentration for both white and Japanese men. In body mass index-adjusted regression models, the significant associations of SAD remained for both white and Japanese men, whereas those of WC became nonsignificant for white men. When SAD and WC were simultaneously included into the body mass index-adjusted models, the associations of SAD remained significant and statistically stronger than those of WC for both white and Japanese men. Furthermore, the pattern of the associations of SAD with those lipoprotein subfractions was comparable to that of the associations of VAT. Sagittal abdominal diameter was comparable to VAT and stronger than WC in the associations with atherogenic lipoprotein subfractions for middle-aged, nondiabetic, white and Japanese men.

Effects of weight reduction on serum vaspin concentrations in obese subjects: modification by insulin resistance

Visceral adipose tissue-derived serpin (vaspin) has been regarded as a novel adipokine with potential insulin sensitizing properties. We investigated the changes of serum vaspin concentration in response to weight reduction, and the associations between changes in serum vaspin concentrations and changes of anthropometric and metabolic variables in obese subjects after weight reduction. We performed a longitudinal clinical intervention study on 63 obese persons enrolled in a 12-week weight reduction program that included lifestyle modification and adjuvant treatment with the antiobesity agent orlistat. Anthropometric variables, lipid profiles, fasting glucose, fasting insulin, and serum vaspin concentrations were measured. Statistical analyses were performed according to the homeostasis model assessment of insulin resistance (HOMA(IR)). Serum vaspin concentrations decreased significantly in responders (≥2% reduction in baseline weight), but not in nonresponders (<2% reduction in baseline weight). Changes in serum vaspin concentrations were significantly correlated with body weight, BMI, waist circumference, and hip circumference in the higher, but not in the lower, HOMA(IR) group. In multivariate linear regression analysis, change in serum vaspin concentrations in the higher, but not in the lower, HOMA(IR) group was positively correlated with change in BMI and negatively correlated with initial HOMA(IR) level. The associations between changes in serum vaspin concentrations and changes in anthropometric and metabolic parameters differed according to insulin resistance status in obese subjects. These relationships were more prominent in the higher HOMA(IR) group. Insulin resistance may influence the correlations between changes in serum vaspin concentration and related metabolic variables.

Relationship between visceral adiposity and bone mineral density in Korean adults

The objective of the study was to investigate the relationship between visceral and subcutaneous adiposity measured by computed tomography and bone mineral density (BMD) and to identify the metabolic factors associated with BMD. We studied 461 subjects recruited from the health-care center at Severance Hospital, Yonsei University College of Medicine. Multivariate regression analyses were conducted to examine the cross-sectional associations between body composition-related or metabolic parameters and BMD. After adjusting for body weight and other confounders, visceral fat area had an inverse association with BMD in men (beta = -0.133, P = 0.049 for lumbar spine; beta = -0.135, P = 0.037 for femoral neck; beta = -0.179, P = 0.005 for total hip) and women (beta = -0.424, P < 0.001 for lumbar spine; beta = -0.302, P = 0.005 for femoral neck; beta = -0.274, P = 0.014 for total hip). However, the subcutaneous fat area showed no statistically significant relationship with BMD at most sites. Among the metabolic parameters, HDL cholesterol was positively associated with BMD, while LDL cholesterol was negatively associated with BMD in men. In women, total and LDL cholesterol were negatively associated with BMD at the lumbar spine. We conclude that visceral adiposity is inversely associated with BMD after adjusting for confounders and that metabolic factors may partly contribute to this inverse relation.

Hypothalamic-pituitary-adrenal (HPA) axis functioning in relation to body fat distribution

OBJECTIVE

To relate hypothalamic-pituitary-adrenal (HPA) axis functioning and HPA feedback functioning to body fat distribution in normal weight to obese subjects.

PATIENTS

91 men and 103 women [age 18-45 years, BMI 19-35 kg/m(2), waist-to-hip ratio (WHR) 0.6-1.1].

MEASUREMENTS

Anthropometry, body composition using hydrodensitometry and deuterium dilution method, cortisol variability by measuring 5-h cortisol concentrations, HPA axis feedback functioning using a dexamethasone suppression test, and HPA axis functioning under a challenged condition consisting of a standardized high-intensity test with ingestion of 4 mg dexamethasone.

RESULTS

In men, an inverse relationship was observed between 5-h cortisol exposure (nmol/ml) and fat mass index (FMI) (kg/m(2)) (r = -0.55, P < 0.001). In women, relationships were observed between 5-h cortisol exposure (nmol/ml.min) and WHR (r = -0.49, P < 0.001), maximal workload (r = 0.32, P < 0.001) as well as oral contraceptive use (r = 0.38, P < 0.001). Similarly, in men, an inverse relationship was observed between negative feedback expressed as baseline concentrations minus post dexamethasone cortisol concentrations (nmol/ml) and FMI (r = -0.53, P < 0.001). In women, relationships were observed between negative feedback expressed as baseline concentrations minus post dexamethasone cortisol concentrations (nmol/ml) and WHR (r = -0.43, P < 0.001), maximal workload (r = 0.30, P < 0.001) as well as oral contraceptive use (r = 0.43, P < 0.001) in women. Moreover, an inverse relationship was observed between HPA axis functioning in a challenged condition expressed as percentage increase of cortisol concentrations after standardized high-intensity test with ingestion of 4 mg dexamethasone (%) and waist circumference (r = -0.21, P < 0.10) in men and WHR (r = -0.21, P < 0.05) in women. In men, strong positive relationships were observed between FMI and waist circumference (r = 0.85, P < 0.001), as well as waist-to-hip ratio (r = 0.70, P < 0.001).

CONCLUSION

Disturbance of HPA axis functioning under basal and challenged conditions is related to visceral fat accumulation.