[Show abstract][Hide abstract] ABSTRACT: The overexpression of the adipose gene (adp/WDTC1) in mice inhibits lipid accumulation and improves the metabolic profile. Objective: We evaluated subcutaneous fat adp expression in humans and its relation to metabolic parameters. Design, Setting and Methods: Abdominal subcutaneous fat adp expression, insulin sensitivity (clamp) and respiratory quotient (RQ; indirect calorimetry) were assessed in: 36 obese and 56 BMI-, race- and sex-matched type 2 diabetic volunteers (Look AHEAD Adipose Ancillary Study); 37 non-diabetic Pima Indians including obese (n=18) and non-obese (n=19) subjects and; 62 non-obese non-diabetic subjects at the Pennington Center in the ADAPT study. Results: In the Look AHEAD Study, adp expression normalized for cyclophilin B was higher in males vs. females (1.27±0.06 vs. 1.11±0.04; p<0.01) but not after controlling for body fat. Adp expression was not influenced by the presence of diabetes but was related to body fat (r=-0.23; p=0.03), insulin sensitivity (r=0.23; p=0.03) and fasting/insulin-stimulated RQ (r=0.31 & 0.33; p<0.01). In Pima Indians, adp expression was also higher in males vs. females (1.00±0.05 vs. 0.77±0.05; p=0.02) and higher in non-obese vs. obese (1.02±0.05 vs. 0.80±0.06; p=0.03). In the ADAPT study, there was no difference in adp expression between males and females. Conclusion: Consistent with animal studies, our results suggest that, high adp expression in human adipose tissue is associated with lower adiposity and enhanced glucose utilization.
[Show abstract][Hide abstract] ABSTRACT: Recombinant human growth hormone (rhGH) reduces visceral adipose tissue (VAT) volume in HIV-infected patients but can worsen glucose homeostasis and lipoatrophy. We aimed to determine if adding rosiglitazone to rhGH would abrogate the adverse effects of rhGH on insulin sensitivity (SI) and subcutaneous adipose tissue (SAT) volume.
Randomized, double-blind, placebo-controlled, multicenter trial using a 2×2 factorial design in which HIV-infected subjects with abdominal obesity and insulin resistance were randomized to rhGH 3 mg daily, rosiglitazone 4 mg twice daily, combination rhGH + rosiglitazone, or double placebo (control) for 12 weeks. The primary endpoint was change in SI by frequently sampled intravenous glucose tolerance test from entry to week 12. Body composition was assessed by whole body magnetic resonance imaging (MRI) and dual Xray absorptiometry (DEXA). Seventy-seven subjects were randomized of whom 72 initiated study drugs. Change in SI from entry to week 12 differed across the 4 arms by 1-way ANCOVA (P = 0.02); by pair-wise comparisons, only rhGH (decreasing SI; P = 0.03) differed significantly from control. Changes from entry to week 12 in fasting glucose and glucose area under the curve on 2-hour oral glucose tolerance test differed across arms (1-way ANCOVA P = 0.004), increasing in the rhGH arm relative to control. VAT decreased significantly in the rhGH arms (-17.5% in rhGH/rosiglitazone and -22.7% in rhGH) but not in the rosiglitazone alone (-2.5%) or control arms (-1.9%). SAT did not change significantly in any arm. DEXA results were consistent with the MRI data. There was no significant rhGH x rosiglitazone interaction for any body composition parameter.
The addition of rosiglitazone abrogated the adverse effects of rhGH on insulin sensitivity and glucose tolerance while not significantly modifying the lowering effect of rhGH on VAT.
PLoS ONE 01/2013; 8(4):e61160. · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Recent research has shown an inverse relationship between bone marrow adipose tissue (BMAT) and bone mineral density (BMD). There is a lack of evidence at the macro-imaging level to establish whether increased BMAT is a cause or effect of bone loss. This cross-sectional study compared the BMAT and BMD relationship between a younger adult group at or approaching peak bone mass (PBM; age 18.0-39.9 years) and an older group with potential bone loss (PoBL; age 40.0-88.0 years).
Pelvic BMAT was evaluated in 560 healthy men and women with T1-weighted whole-body magnetic resonance imaging. BMD was measured using whole-body dual-energy X-ray absorptiometry.
An inverse correlation was observed between pelvic BMAT and pelvic, total and spine BMD in the younger PBM group (r=-0.419 to -0.461, P<0.001) and in the older PoBL group (r=-0.405 to -0.500, P<0.001). After adjusting for age, sex, ethnicity, menopausal status, total body fat, skeletal muscle, subcutaneous and visceral adipose tissue, neither subject group (younger PBM vs older PoBL) nor its interaction with pelvic BMAT significantly contributed to the regression models with BMD as dependent variable and pelvic BMAT as independent variable (P=0.434-0.928).
Our findings indicate that an inverse relationship between pelvic BMAT and BMD is present both in younger subjects who have not yet experienced bone loss and also in older subjects. These results provide support at the macro-imaging level for the hypothesis that low BMD may be a result of preferential differentiation of mesenchymal stem cells from osteoblasts to adipocytes.
European journal of clinical nutrition 04/2012; 66(9):983-8. · 3.07 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The relationship between bone marrow adipose tissue and bone mineral density is different between African Americans and Caucasians as well as between men and women. This suggests that the mechanisms that regulate the differentiation and proliferation of bone marrow stromal cells may differ in these populations.
It has long been established that there are ethnic and sex differences in bone mineral density (BMD) and fracture risk. Recent studies suggest that bone marrow adipose tissue (BMAT) may play a role in the pathogenesis of osteoporosis. It is unknown whether ethnic and sex differences exist in the relationship between BMAT and BMD.
Pelvic BMAT was evaluated in 455 healthy African American and Caucasian men and women (age 18-88 years) using whole-body T1-weighted magnetic resonance imaging. BMD was measured using whole-body dual-energy X-ray absorptiometry.
A negative correlation was observed between pelvic BMAT and total body BMD or pelvic BMD (r = -0.533, -0.576, respectively; P < 0.001). In multiple regression analyses with BMD as the dependent variable, ethnicity significantly entered the regression models as either an individual term or an interaction with BMAT. Menopausal status significantly entered the regression model with total body BMD as the dependent variable. African Americans had higher total body BMD than Caucasians for the same amount of BMAT, and the ethnic difference for pelvic BMD was greater in those participants with a higher BMAT. Men and premenopausal women had higher total body BMD levels than postmenopausal women for the same amount of BMAT.
An inverse relationship exists between BMAT and BMD in African American and Caucasian men and women. The observed ethnic and sex differences between BMAT and BMD in the present study suggest the possibility that the mechanisms regulating the differentiation and proliferation of bone marrow stromal cells may differ in these populations.
Osteoporosis International 12/2011; 23(9):2293-301. · 4.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To describe the potential long-term risk of malnutrition after Roux-en-Y gastric bypass (GBP) through an uncommon occurrence of inflammatory bowel disease (IBD) postoperatively, which posed a serious threat to the nutritional status and the life of the patient.
We present a case report of a 44-year-old woman in whom Crohn disease developed 4 years after she had undergone GBP. The double insult of IBD and GBP resulted in severe malnutrition, with a serum albumin concentration of 0.9 g/dL (reference range, 3.5 to 5.0), weight loss, and watery diarrhea necessitating 6 hospital admissions during a period of 7 months.
Ultimately, the administration of total parenteral nutrition with aggressive macronutrient, vitamin, and mineral repletion resulted in substantial improvement in the patient's strength, function, and quality of life, in parallel with diminished symptoms of IBD.
Rarely, IBD develops after GBP, but the relationship between the 2 conditions remains unclear. Regardless, in addition to the altered anatomy after bariatric surgery, the further insult of IBD poses a severe threat to the nutritional status of affected patients. Malnutrition needs to be recognized and aggressively treated. Nutritional markers should be followed closely in this population of bariatric patients in an effort to avert the onset of severe malnutrition.
Endocrine Practice 12/2011; 18(2):e21-5. · 2.49 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background Obesity is known to be associated with an in creased risk of death, but current definitions of obesity are based on data from white populations. We examined the association between body mass index (BMI) and the risk of death in a large population of adult Chinese people. Methods We examined the association between body mass index (BMI) and all-cause mortality prospectively among 58 738 men and 65 718 women aged 20 years and older enrolled in 1998-1999 from four national health screening centres in Taiwan. We used Cox proportional hazards regression analyses to estimate the relative risks of all-cause mortality for different BMI categories during a maximum follow-up of 10 years. Results A total of 3947 participants died during the follow-up period. The lowest risk of death was observed among men and women who had a BMI of 24.0-25.9 (mean 24.9). After adjustment for age, smoking status, alcohol intake, betel-nut chewing, level of physical activity, income level and education level, we observed a U-shaped association between BMI and all-cause mortality. Similar U-shaped associations were observed when we analyzed data by age (20-64 or = 65 years), smoking (never, 〈 10 pack-years or = 10 pack-years) and presence of a pre-existing chronic disease, and after we excluded deaths that occurred in the first three years of follow-up. Interpretation BMI and all-cause mortality had a U-shaped association among adult Chinese people in our study. The lowest risk of death was among adults who had a BMI of 24.0-25.9 (mean 24.9). Our findings do not support the use of a lower cutoff value for overweight and obesity in the adult Chinese population.
Canadian Medical Association Journal 03/2011; · 6.47 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Left ventricular assist devices (LVADs) are increasingly used as therapeutic options for patients with advanced congestive heart failure (CHF), many of whom suffer from diabetes mellitus (DM). The aim of this study was to evaluate the effect of restoration of normal cardiac output using LVAD support on diabetes control in patients with advanced CHF.
A retrospective chart review of all clinic patients supported with long-term LVADs between July 2008 and July 2009 at Columbia University Medical Center was performed. Patients with DM diagnosed prior to device implantation were included in this analysis. Clinical and laboratory data within 1 month preceding and 6 months following LVAD implantation were collected. Of 43 LVAD patients followed in our clinic during the study period, 15 had a diagnosis of DM. Thirteen of the 15 patients were male, mean age was 63 ± 11 years, and the pre-LVAD left ventricular ejection fraction (LVEF) was 16.5 ± 5.7%. Fasting glucose levels, HbA1c, and daily insulin requirement within 1 month before and an average of 4.0 ± 2.3 months after LVAD placement were 157.7 ± 50.6 vs. 104.1 ± 21.4 mg/dL, 7.7 ± 0.9 vs. 6.0 ± 0.8.%, and 53.3 ± 51.7 vs. 24.2 ± 27.2 IU, respectively (P < 0.05 for all comparisons). Six of the 15 patients were completely free of antidiabetic medications and had blood glucose < 126 mg/dL as well as HbA1c < 6% after LVAD. Body mass index (BMI) was slightly increased after LVAD (28.7 ± 5.3 vs. 30.2 ± 4.1 kg/m², P NS).
Restoration of normal cardiac output after LVAD implantation improves diabetic control in patients with advanced CHF. Additional studies are warranted to determine the mechanisms that worsen or possibly induce DM in patients with advanced CHF.
European Journal of Heart Failure 02/2011; 13(2):195-9. · 5.25 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Nutritional status is assessed by measuring BMI or percent body fat (%fat). BMI can misclassify persons who carry more weight as fat-free mass and %fat can be misleading in cases of malnutrition or in disease states characterized by wasting of lean tissue. The fat-free mass index (FFMI) is proposed to assess body composition in individuals who have a similar body composition but differ in height allowing identification of those suffering from malnutrition, wasting or those that possess a relatively high muscle mass. The purpose was to determine whether the FFMI differs in a group of racially/ethnically diverse adults.
Subjects were a multi-ethnic sample (Caucasian, CA; African American, AA; Hispanic, HIS and Asian, AS) of 1339 healthy males (n = 480) and females (n = 859) ranging in age from 18-110 years. Total body fat, total fat-free mass and bone mineral density were estimated using dual energy X-ray absorptiometry.
FFMI differed among the four ethnic groups (P ≤ 0.05) for both genders. A curvilinear relationship was found between age and FFMI for both genders although the coefficients in the quadratic model differed between genders (P ≤ 0.001) indicating the rate of change in FFMI differed between genders. The estimated turning point where FFMI started to decline was in the mid 20s for male and mid 40s for female participants. An age × gender interaction was found such that the rate of decline was greater in male than female participants (P ≤ 0.001). For both genders, FFMI was greatest in AA and the least in AS (P ≤ 0.001). There was no significant interaction between race and age or age(2) (P = 0.06). However, male participants consistently had a greater FFMI than female participants (P ≤ 0.001).
These findings have clinical implications for identifying individuals who may not be recognized as being malnourished based on their BMI or %fat but whose fat-free mass corrected for height is relatively low.
International journal of obesity (2005) 01/2011; 35(1):121-7. · 5.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To investigate the association between body mass index (BMI) and waist circumference (WC) and all-cause mortality of Chinese residents in long-term care facilities in Taiwan.
Prospective cohort study.
Eight long-term care facilities in Taiwan.
Three hundred fifty-four residents aged 60 and older (median 78.4, range 60-101; 156 men, 198 women) were recruited during the study period.
Anthropometrics and metabolic parameters were measured at baseline. Mean BMI was 21.7 ± 4.2 kg/m(2) (range 11.6-35.3 kg/m(2) , and mean WC was 82.4 ± 10.9 cm (range 55.0-124.0 cm). Mortality data were from the Department of Health in Taiwan.
There were 219 deaths during the 5 years of follow-up. After adjusting for age, sex, albumin, Karnofsky performance status scale, hypertension, and diabetes mellitus, subjects in the highest quartile of BMI (27.3 ± 2.8 kg/m(2) ) and WC (96.7 ± 7.4 cm) had a significantly lower mortality rate than did subjects in the lowest quartile (BMI, 16.7 ± 1.7 kg/m(2) ; WC, 69.6 ± 4.2 cm). After further stratification according to central obesity status, the subjects in the two highest BMI quartiles had a lower mortality rate than those in the lowest BMI quartile but only in the central obesity group (≥ 90 cm in men or ≥ 80 cm in women). The adjusted relative risk for all-cause mortality in the highest versus lowest BMI quartile was 0.17 (95% confidence interval = 0.05-0.57).
BMI and WC were negative predictors for all-cause mortality in older Chinese adults living in long-term care facilities. Participants with higher WC and BMI had lower all-cause mortality.
Journal of the American Geriatrics Society 11/2010; 58(11):2092-8. · 3.98 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Insulin and glucose may influence cancer mortality via their proliferative and anti-apoptotic properties. Using longitudinal data from the nationally representative Third National Health and Nutrition Examination Survey (NHANES III; 1988-1994), with an average follow-up of 8.5 years to death, we evaluated markers of glucose and insulin metabolism, with cancer mortality, ascertained using death certificates or the National Death Index. Plasma glucose, insulin, C-peptide, and lipid concentrations were measured. Anthropometrics, lifestyle, medical, and demographic information was obtained during in-person interviews. After adjusting for age, race, sex, smoking status, physical activity, and body mass index, for every 50 mg/dl increase in plasma glucose, there was a 22% increased risk of overall cancer mortality. Insulin resistance was associated with a 41% (95% confidence interval (CI) (1.07-1.87; p = 0.01) increased risk of overall cancer mortality. These associations were stronger after excluding lung cancer deaths for insulin-resistant individuals (HR: 1.67; 95% CI: 1.15-2.42; p = 0.01), specifically among those with lower levels of physical activity (HR: 2.06; 95% CI: 1.4-3.0; p = 0.0001). Similar associations were observed for other blood markers of glucose and insulin, albeit not statistically significant. In conclusion, hyperglycemia and insulin resistance may be 'high-risk' conditions for cancer mortality. Managing these conditions may be effective cancer control tools.
Cancer Causes and Control 04/2010; 21(4):631-42. · 3.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Epidemiologic studies suggest that insulin-like growth factor-1 (IGF-1) is associated with obesity and, more recently, cancer. This study investigates multiple lifestyle, physiologic, and anthropometric determinants of circulating IGF-1 concentrations.
Nationally representative data were used from the cross-sectional Third National Health and Nutrition Examination (NHANES III, 1988-1994) survey, which measured IGF-1 concentrations in blood, from a subsample of participants who were examined in the morning. After exclusion of persons with missing data, 6,058 men and women 20 years of age or older were included in the study.
The mean IGF-1 concentrations were 260 ng/mL in the entire population and were higher among men as compared with women (278.8 vs. 241.3 ng/mL; p<0.0001). IGF-1 decreased with increasing age (p<0.0001), body mass index (p<0.0001), and waist circumference (p<0.0001). Individuals with metabolic syndrome had lower IGF-1 concentrations after adjustment for covariates (p=0.0008). IGF-1 was inversely associated with increasing number of metabolic syndrome abnormalities (p=0.0008). All associations were stronger among women compared with men except across concentrations of glucose. IGF-1 concentrations did not vary by any other lifestyle or physiologic factors.
Age, adiposity, hyperglycemia, and metabolic syndrome influenced circulating IGF-1 concentrations. Diet and physical activity had no impact on IGF-1 in this nationally representative population.
Annals of epidemiology 03/2010; 20(3):182-93. · 2.95 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The degree to which interindividual variation in the mass of select high metabolic rate organs (HMROs) mediates variability in resting energy expenditure (REE) is unknown.
The objective was to investigate how much REE variability is explained by differences in HMRO mass in adults and whether age, sex, and race independently predict REE after adjustment for HMRO.
A cross-sectional evaluation of 55 women [30 African Americans aged 48.7 +/- 22.2 y (mean +/- SD) and 25 whites aged 46.4 +/- 17.7 y] and 32 men (8 African Americans aged 34.3 +/- 18.2 y and 24 whites aged 51.3 +/- 20.6 y) was conducted. Liver, kidney, spleen, heart, and brain masses were measured by magnetic resonance imaging, and fat and fat-free mass (FFM) were measured by dual-energy X-ray absorptiometry. REE was measured by indirect calorimetry.
REE estimated from age (P = 0.001), race (P = 0.006), sex (P = 0.31), fat (P = 0.001), and FFM (P < 0.001) accounted for 70% (adjusted (2)) of the variability in REE. The addition of trunk HMRO (P = 0.001) and brain (P = 0.006) to the model increased the explained variance to 75% and rendered the contributions of age, sex, and race statistically nonsignificant, whereas fat and FFM continued to make significant contributions (both P < 0.05). The addition of brain to the model rendered the intercept (69 kcal . kg(-1) . d(-1)) consistent with zero, which indicated zero REE for zero body mass.
Relatively small interindividual variation in HMRO mass significantly affects REE and reduces the role of age, race, and sex in explaining REE. Decreases in REE with increasing age may be partly related to age-associated changes in the relative size of FFM components.
American Journal of Clinical Nutrition 02/2010; 91(4):907-12. · 6.50 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To characterize the relationships among long-term improvements in peripheral insulin sensitivity (glucose disposal rate [GDR]), fasting glucose, and free fatty acids (FFAs) and concomitant changes in weight and adipose tissue mass and distribution induced by lifestyle intervention in obese individuals with type 2 diabetes.
We measured GDR, fasting glucose, and FFAs during a euglycemic clamp and adipose tissue mass and distribution, organ fat, and adipocyte size by dual-energy X-ray absorptiometry, CT scan, and adipose tissue biopsy in 26 men and 32 women in the Look-AHEAD trial before and after 1 year of diet and exercise aimed at weight loss.
Weight and fasting glucose decreased significantly (P < 0.0001) and significantly more in men than in women (-12 vs. -8% and -16 vs. -7%, respectively; P < 0.05), while FFAs during hyperinsulinemia decreased and GDR increased significantly (P < 0.00001) and similarly in both sexes (-53 vs. -41% and 63 vs. 43%; P = NS). Men achieved a more favorable fat distribution by losing more from upper compared with lower and from deeper compared with superficial adipose tissue depots (P < 0.01). Decreases in weight and adipose tissue mass predicted improvements in GDR but not in fasting glucose or fasting FFAs; however, decreases in FFAs during hyperinsulinemia significantly determined GDR improvements. Hepatic fat was the only regional fat measure whose change contributed independently to changes in metabolic variables.
Patients with type 2 diabetes undergoing a 1-year lifestyle intervention had significant improvements in GDR, fasting glucose, FFAs and adipose tissue distribution. However, changes in overall weight (adipose tissue mass) and hepatic fat were the most important determinants of metabolic improvements.
[Show abstract][Hide abstract] ABSTRACT: The impact of obesity on cardiovascular disease (CVD) outcomes in patients with type 2 diabetes mellitus (T2DM) and established coronary artery disease (CAD) is controversial; whether BMI and/or waist circumference correlate with atherothrombotic risk factors in such patients is uncertain. We sought to evaluate whether higher BMI or waist circumference are associated with specific risk factors among 2,273 Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) study participants with T2DM and documented CAD (baseline data, mean age 62 years, 66% non-Hispanic white, 71% men). Multiple linear regression models were constructed after adjusting for sex, age, race/ethnicity, US vs. non-US site, diabetes duration, exercise, smoking, alcohol, and relevant medication use. First-order partial correlations of BMI with risk factors after controlling for waist circumference and of waist circumference with risk factors after controlling for BMI were also evaluated. Ninety percent of the patients were overweight (BMI > or =25 kg/m(2)); 68% of men and 89% of women had high-risk waist circumference measures (> or =102 and > or =88 cm, respectively). BMI and waist circumference, in separate models, explained significant variation in metabolic (insulin, lipids, blood pressure (BP)) and inflammatory/procoagulation (C-reactive protein, PAI-1 activity and antigen, and fibrinogen) risk factors. In partial correlation analyses BMI was independently associated with BP and inflammatory/procoagulation factors, waist circumference with lipids, and both BMI and waist circumference with insulin. We conclude that, in cross-sectional analyses, both BMI and waist circumference, independently, are associated with increased atherothrombotic risk in centrally obese cohorts such as the BARI 2D patients with T2DM and CAD.
[Show abstract][Hide abstract] ABSTRACT: The size of adipocytes influences their function suggesting a differential responsiveness to intervention. We hypothesized that weight loss in patients with type 2 diabetes mellitus (T2DM) predominantly decreases the size of large and very-large adipocyte subfractions in parallel with beneficial changes in serum adipokines and improved insulin sensitivity. A total of 44 volunteers from the Look Action for Health in Diabetes trial, who lost weight after 1-year of intense lifestyle intervention, were included. Insulin sensitivity (hyperinsulinemic-euglycemic clamp), size of subcutaneous abdominal adipocytes (osmium fixation), and selected serum adipokines were measured. A 13% weight loss was accompanied by 46% improvement in insulin sensitivity (increased glucose disposal rate from 5.9+/-2.2 to 8.6+/-2.7 mg/min/kg fat-free mass, P<0.05) in parallel with a 36% increase in plasma adiponectin concentration (6.1+/-3.1 to 8.3+/-3.9 microg/ml, P<0.05], but no changes in the proinflammatory cytokines interleukin-6 and tumor necrosis factor-alpha. Change in adiponectin correlated with changes in glucose disposal rate (r=0.34, P<0.05). Mean adipocyte size decreased (0.84+/-0.25 to 0.64+/-0.23 microl, P<0.05), mainly due to changes in the large adipocyte subfraction (size 0.75-0.44 microl, relative number 19-26%; P<0.05). Our data suggest that change in the large adipocyte subfraction may contribute to the improvement in insulin sensitivity via an increase in serum adiponectin. Such a relationship, which does not imply cause and effect, could not be obtained by measuring only mean adipocyte size. These data provide support for the measures of adipocyte size distribution in concert with in vitro adipokine secretion and lipolysis in future studies.
[Show abstract][Hide abstract] ABSTRACT: Metabolic derangements are common in human immunodeficiency virus (HIV)-positive subjects undergoing antiretroviral therapy, but little is known about postprandial conditions.
We investigated the relationship between leptin, adiponectin, nonesterified fatty acids (NEFA), and insulin in response to a day-long meal pattern and evaluated gender differences in HIV-positive men (n = 12) and women (n = 13) undergoing highly active antiretroviral therapy (HAART).
For both men and women, a significant decrease in postprandial NEFA levels was observed following breakfast (0.53 vs. 0.22 mmol/L, P < 0.001, baseline and at 3 hours, respectively), whereas day-long postprandial leptin and adiponectin levels showed small nonsignificant oscillations. In contrast to NEFA and adiponectin, postprandial leptin levels were significantly higher among women compared to men (P < 0.05). Postprandial NEFA levels correlated positively with fasting insulin levels (r(2) = 0.25, P = 0.016), and the postbreakfast decrease in NEFA levels correlated significantly with the postbreakfast increase in insulin levels (r(2) = 0.17, P = 0.038). No significant association between postprandial adipokines and insulin was observed.
In HAART-treated, HIV-infected men and women, levels of NEFA, but not adipokines, showed significant postprandial variation. Furthermore, food intake resulted in significant NEFA suppression in proportion to the food-stimulated insulin increase.
Metabolic syndrome and related disorders 04/2009; 7(3):199-204.
[Show abstract][Hide abstract] ABSTRACT: Autopsy/cadaver data indicate that many organs and tissues are smaller in the elderly compared with young adults; however, in vivo data are lacking. The aim of this study was to determine whether the mass of specific high-metabolic-rate organs is different with increasing age, using MRI. Seventy-five healthy women (41 African-Americans and 34 Caucasians, age range 19-88 yr) and 36 men (8 African-Americans and 28 Caucasians, age range 19-84 yr) were studied. MRI-derived in vivo measures of brain, heart, kidneys, liver, and spleen were acquired. Left ventricular mass (LVM) was measured by either echocardiography or cardiac gated MRI. Total body fat mass and fat-free mass (FFM) were measured with a whole body dual-energy X-ray absorptiometry (DXA) scanner. Multiple regression analysis was used to investigate the association between the organ mass and age after adjustment for weight and height (or DXA measures of FFM), race, sex, and interactions among these variable. No statistically significant interaction was found among age, sex, and race in any regression model. Significant negative relationships between organ mass and age were found for brain (P < 0.0001), kidneys (P = 0.01), liver (P = 0.001), and spleen (P < 0.0001). A positive relationship between LVM and age was found after adjustment for FFM (P = 0.037). These findings demonstrate that age has a significant effect on brain, kidneys, liver, spleen, and heart mass. The age effect was independent of race and sex.
Journal of Applied Physiology 04/2009; 106(6):1780-4. · 3.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The extent to which adipose tissue (AT) distribution is different between persons with type 2 diabetes (T2DM) and nondiabetic control subjects remains unclear.
The aim of this study was to establish whether total body adiposity and its distribution, quantified by using state-of-the-art whole-body magnetic resonance imaging, differs between these 2 groups.
This cross-sectional evaluation included 93 participants (n = 56 women and 37 men) in the Look AHEAD (Action for HEAlth in Diabetes) Trial with T2DM who had a mean (+/-SD) age of 58.3 +/- 6.6 y and body mass index (in kg/m(2)) of 31.6 +/- 3.1 and 93 healthy non-T2DM control subjects (n = 64 women and 29 men) who had a mean (+/-SD) age of 60.6 +/- 17.1 y and body mass index of 29.6 +/- 3.0. All participants self-reported being of African American or white ancestry. Magnetic resonance imaging-derived in vivo measures of total-body AT (TAT) and its distribution, subcutaneous AT (SAT), visceral AT (VAT), and intermuscular AT (IMAT) were acquired. Linear regression models were developed for each AT compartment to adjust for important covariates of race, sex, age, height, and weight and to examine potential interactions of covariates.
These models showed significantly less SAT (African American: -1.2 kg; white: -2.4 kg; both P = 0.001), including less femoral-gluteal SAT, more VAT (African American: 0.7 kg, P < 0.001; white: 1.8 kg, P = 0.007), and more IMAT (0.5 kg, P = 0.001) in the T2DM group.
We concluded that AT distribution is significantly altered in T2DM, ie, more VAT and IMAT--2 depots known to exacerbate insulin resistance--and less SAT in persons with T2DM than in healthy control subjects, a novel finding that we posit may compound the risk of insulin resistance.
American Journal of Clinical Nutrition 01/2009; 89(3):807-14. · 6.50 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Loss of subcutaneous (SAT) with sparing of visceral (VAT) adipose tissue (AT) has been documented in HIV + men and women. Intermuscular AT (IMAT) rivals VAT in independent associations with cardiovascular risk. OBJECTIVE: To determine whether the size and distribution of IMAT differs in HIV+ vs. HIV- men and/or women. DESIGN: We used whole-body MRI to measure VAT, IMAT and four SAT compartments and compared them by HIV status using whole-body skeletal muscle (SM) or total AT (TAT) as co-variates in multi-ethnic groups of healthy HIV- (n=86) and stable HIV+ (n=76) men and women. RESULTS: The sizes of AT depots (adjusting for SM) did not differ by HIV status, except for smaller gluteal SAT (lower trunk, between L(4)-L(5) to greater trochanter) in both sexes (P<0.05). The AT distribution (adjusting for TAT) was significantly different, with larger VAT (P<0.05) and smaller gluteal and limb SAT (P<0.05) in both HIV+ sexes; IMAT increased more with TAT in HIV+ vs. HIV- men (P<0.05 for slope interaction) but there were no significant differences in women. There were significant race by HIV interactions in AT distribution with more pronounced VAT differences in non-Hispanic white men and larger trunk SAT in African Americans HIV+ vs. HIV-. CONCLUSION: The AT distribution differed markedly in HIV+ vs. HIV- with limb and lower body SAT representing a smaller proportion of TAT in HIV+ in both sexes and IMAT representing a larger proportion of TAT in HIV+ vs. HIV- men.
International journal of body composition research 01/2009; 7(2):73-78.