OBJECTIVE

The study objective was to examine the associations among visceral fat (VF), all-cause mortality, and obesity-related mortality.

RESEARCH DESIGN AND METHODS

A total of 733 Japanese Americans were followed for 16.9 years. Hazard ratios (HRs) per interquartile range increase in VF were calculated using time-dependent Cox proportional hazard models censored at age 82 years, with age as the time axis adjusted for sex and smoking.

RESULTS

Higher VF was associated with all-cause mortality (HR 1.39 [95% CI 1.11–1.75] 107 deaths) and obesity-related mortality (1.39 [1.04–1.85], 68 deaths from cardiovascular disease, diabetes, or obesity-related cancer). After further adjustment for waist circumference, VF remained significantly associated with all-cause mortality (1.41 [1.04–1.92]) but not with obesity-related mortality. The associations between mortality and VF were not independent of BMI.

CONCLUSIONS

VF was associated with all-cause mortality and obesity-related mortality in Japanese Americans. VF did not significantly improve mortality risk assessment beyond that of BMI.

Aims

We evaluated whether changes over 10–11 years in weight, subcutaneous abdominal fat (SQAF), and intra-abdominal fat (IAF) differ by age and contrasted age-related adiposity changes by gender.

Methods

This is a prospective cohort study of non-diabetic, Japanese-American men and women aged 34–74 years. IAF and SQAF were measured by CT scan at baseline and 10–11 year follow-up visits.

Results

The youngest participants gained the most weight, SQAF and IAF over 10–11 years. Older age at baseline was associated with significantly less change in weight (β-coefficient: −0.19, 95% CI −0.22, −0.15), SQAF (β-coefficient −0.07: 95% CI −0.11, −0.02) and IAF (β-coefficient −0.74: 95% CI −1.03, −0.45) that persisted even after adjustments for sex, smoking, caloric intake, adiposity at baseline, and change in physical activity. Age was positively correlated with change in SQAF (β-coefficient 0.14: 95% CI 0.10, 0.18) and IAF (β-coefficient 0.51: 95% CI 0.21, 0.81) in separate models after further adjustment for weight change. Gender did not alter the associations between adiposity change and age.

Conclusions

Men and women gained the greatest absolute amount of weight, SQAF, and IAF at younger ages; however, older adults with comparable weight changes had relatively greater fat accumulation within IAF and SQAF depots.

Attempts to explain the associations among metabolic syndrome (MetS) features using factor analysis to identify unobserved potential causes have resulted in inconsistent findings. We examined whether an unobserved categorical factor explains the associations among MetS features using latent class analysis. A cross-sectional analysis of 499 nondiabetic Japanese-Americans who underwent measurements of fasting blood, waist circumference (WC) and CT-measured intra-abdominal fat (IAF) area was conducted. MetS components were defined by IDF criteria. IAF and fasting serum insulin (FI) were dichotomized at the 75th percentile. Latent two- and three-class models were fit that included hypertension, dyslipidemia, hyperglycemia, and either WC, IAF, or FI for a total of six models. A three-class latent model fit the data well, while a two-class model did not. In the three-class model, one latent class was strongly associated with all MetS components, while another was associated with hyperglycemia and hypertension only. IAF was associated with only one latent class. Latent class analysis supports the presence of an unobserved factor linked to the co-occurrence of MetS features. One class of this factor was associated with hypertension and hyperglycemia but not central adiposity or FI, suggesting another pathway for observed MetS features.

OBJECTIVE

To test the hypothesis that A1C is associated with subclinical cardiovascular disease (CVD) in a population without evident diabetes, after adjusting for traditional CVD risk factors and BMI.

RESEARCH DESIGN AND METHODS

This was a cross-sectional study of 5,121 participants without clinically evident CVD or diabetes (fasting glucose ≥7.0 mmol/l or use of diabetes medication), aged 47–86 years, enrolled in the Multi-Ethnic Study of Atherosclerosis (MESA). Measurements included carotid intimal-medial wall thickness (CIMT) and coronary artery calcification (CAC). Results were adjusted for age, sex, ethnicity, smoking, systolic blood pressure, LDL cholesterol, HDL cholesterol, antihypertensive medication use, lipid-lowering medication use, and BMI.

RESULTS

Compared with those in the lowest quartile for A1C ([mean ± SD] 5.0 ± 0.2%), participants in the highest quartile (6.0 ± 0.3%) had higher adjusted mean values for common CIMT (0.85 vs. 0.87 mm, P = 0.003) and internal CIMT (1.01 vs. 1.08 mm, P = 0.003). A1C quartile was not associated with prevalence of CAC in the entire cohort (P = 0.27); however, the association was statistically significant in women (adjusted prevalence of CAC in lowest and highest A1C quartiles 37.5 vs. 43.0%, P = 0.01). Among those with some CAC, higher A1C quartile tended to be associated with higher CAC score, but the results were not statistically significant (adjusted P = 0.11).

CONCLUSIONS

In this multiethnic cohort, there were small, positive associations between A1C, common CIMT, and internal CIMT in the absence of clinically evident diabetes. An association between higher A1C and CAC prevalence was evident only in women.

OBJECTIVE—We sought to determine whether an oral disposition index (DIO) predicts the development of diabetes over a 10-year period. First, we assessed the validity of the DIO by demonstrating that a hyperbolic relationship exists between oral indexes of insulin sensitivity and β-cell function.

RESEARCH DESIGN AND METHODS—A total of 613 Japanese-American subjects (322 men and 291 women) underwent a 75-g oral glucose tolerance test (OGTT) at baseline, 5 years, and 10 years. Insulin sensitivity was estimated as 1/fasting insulin or homeostasis model assessment of insulin sensitivity (HOMA-S). Insulin response was estimated as the change in insulin divided by change in glucose from 0 to 30 min (ΔI0–30/ΔG0–30).

RESULTS—ΔI0–30/ΔG0–30 demonstrated a curvilinear relationship with 1/fasting insulin and HOMA-S with a left and downward shift as glucose tolerance deteriorated. The confidence limits for the slope of the loge-transformed estimates included −1 for ΔI0–30/ΔG0–30 versus 1/fasting insulin for all glucose tolerance groups, consistent with a hyperbolic relationship. When HOMA-S was used as the insulin sensitivity measure, the confidence limits for the slope included −1 only for subjects with normal glucose tolerance (NGT) or impaired fasting glucose (IFG)/impaired glucose tolerance (IGT) but not diabetes. On the basis of this hyperbolic relationship, the product of ΔI0–30/ΔG0–30 and 1/fasting insulin was calculated (DIO) and decreased from NGT to IFG/IGT to diabetes (P < 0.001). Among nondiabetic subjects at baseline, baseline DIO predicted cumulative diabetes at 10 years (P < 0.001) independent of age, sex, BMI, family history of diabetes, and baseline fasting and 2-h glucose concentrations.

CONCLUSIONS—The DIO provides a measure of β-cell function adjusted for insulin sensitivity and is predictive of development of diabetes over 10 years.

Background:

Diagnosing and managing obesity in individuals with spinal cord injury (SCI) remain challenging.

Methods:

Literature on the epidemiology, impact, and management of obesity in individuals with SCI was reviewed.

Findings:

Although nearly 66% of individuals with SCI are either overweight or obese, little guidance is available to measure and monitor obesity in the clinical setting. The use of anthropometric indices and specific cut points available for able-bodied persons is limited by the body composition changes that follow SCI. Indices of upper body obesity warrant examination in SCI because they provide an index of central obesity, which is more closely linked to some obesity-related conditions than is overall obesity. Investigations into the sequelae of excess body fat and its distribution are also needed in SCI because past research in this area has been inconclusive. Although limited, evidence regarding obesity interventions in SCI may be promising.

Conclusions:

The best anthropometric tool to define obesity in the clinical setting remains unknown. SCI-specific assessment tools and a better understanding of the sequelae of excess body weight will lead to better targeting of prevention and treatment efforts. More research is needed on the individual components of a weight management program unique to SCI. Until then, providers are urged to use a team approach and draw on existing resources and applicable research in able-bodied individuals to facilitate weight management in individuals with SCI.

The Cockcroft-Gault and the Modification of Diet in Renal Disease (MDRD) Study equations have not been validated in Asian Americans with varying degrees of glucose tolerance. We compared both equations to 24 hour urinary creatinine clearance, the latter as a standard measurement of glomerular filtration rate (GFR), in 398 Japanese Americans (62.1±5.8y, mean±SD) who had normal glucose tolerance (n=138), impaired glucose tolerance (n=136) and diabetes (n=124). Although both the Cockcroft-Gault (r=0.65, P<0.001) and the MDRD (r=0.74, P<0.001) equations correlated well with creatinine clearance, the latter was significantly superior (P=0.013 between r values). ROC curve analysis showed that the area under the curve (AUC) for the MDRD equation was significantly greater than for the Cockcroft-Gault equation (AUC 0.86 vs. 0.80, P=0.015) in classifying subjects as having mildly reduced GFR (<90 ml/min per 1.73 m2). However, both equations overestimated the number of individuals with decreased GFR. We conclude therefore that while the MDRD equation more accurately identifies Asians who are in the early stages of kidney disease, as for other groups, a correction term appears necessary in order to reduce the number of Asian subjects being falsely diagnosed with CKD.