Differential Association Between HDL Subclasses and the Development of Type 2 Diabetes in a Prospective Study of Japanese Americans.

OBJECTIVE: Recent studies have suggested that HDL cholesterol is inversely associated with the development of type 2 diabetes. However, little is known about the association between different HDL subclasses and the risk for future type 2 diabetes. RESEARCH DESIGN AND METHODS: The study enrolled 406 Japanese Americans (51% male) without diabetes, aged 34-75 years. Oral glucose tolerance tests were performed to determine type 2 diabetes status at baseline, 2.5 years, 5 years, and 10 years after enrollment. HDL2, HDL3, total HDL cholesterol, and visceral adipose tissue (VAT) area by computed tomography were measured at baseline. RESULTS: In univariate analysis, total HDL and HDL2 cholesterol were inversely associated with the incidence of type 2 diabetes, but HDL3 cholesterol was not. In multivariate analysis, total HDL cholesterol (odds ratio per 1-SD increment, 0.72 [95% CI 0.52-0.995], P = 0.047) and HDL2 cholesterol (odds ratio per 1-SD increment, 0.64 [95% CI 0.44-0.93], P = 0.018) were inversely associated with the risk for type 2 diabetes independent of age, sex, BMI, waist circumference, family history of diabetes, lifestyle factors, systolic blood pressure, lipid-lowering medication use, triglyceride level, HOMA-insulin resistance, and 2-h glucose; however, HDL3 cholesterol was not associated with diabetes risk. The association between diabetes risk and total HDL and HDL2 cholesterol became insignificant after adjustment for VAT area. CONCLUSIONS: Subjects with higher HDL2 cholesterol were at lower risk for incident type 2 diabetes, but this association was confounded by and not independent of VAT. Higher HDL3 cholesterol was not associated with diabetes risk.

Optimum BMI cut points to screen asian americans for type 2 diabetes.

OBJECTIVE: Asian Americans manifest type 2 diabetes at low BMI levels but may not undergo diagnostic testing for diabetes if the currently recommended BMI screening cut point of ≥25 kg/m(2) is followed. We aimed to ascertain an appropriate lower BMI cut point among Asian-American adults without a prior diabetes diagnosis. RESEARCH DESIGN AND METHODS: We consolidated data from 1,663 participants, ages ≥45 years, without a prior diabetes diagnosis, from population- and community-based studies, including the Mediators of Atherosclerosis in South Asians Living in America study, the North Kohala Study, the Seattle Japanese American Community Diabetes Study, and the University of California San Diego Filipino Health Study. Clinical measures included a 2-h 75-g oral glucose tolerance test, BMI, and glycosylated hemoglobin (HbA1c). RESULTS: Mean age was 59.7 years, mean BMI was 25.4 kg/m(2), 58% were women, and type 2 diabetes prevalence (American Diabetes Association 2010 criteria) was 16.9%. At BMI ≥25 kg/m(2), sensitivity (63.7%), specificity (52.8%), and Youden index (0.16) values were low; limiting screening to BMI ≥25 kg/m(2) would miss 36% of Asian Americans with type 2 diabetes. For screening purposes, higher sensitivity is desirable to minimize missing cases, especially if the diagnostic test is relatively simple and inexpensive. At BMI ≥23 kg/m(2), sensitivity (84.7%) was high in the total sample and by sex and Asian-American subgroup and would miss only ∼15% of Asian Americans with diabetes. CONCLUSIONS: The BMI cut point for identifying Asian Americans who should be screened for undiagnosed type 2 diabetes should be <25 kg/m(2), and ≥23 kg/m(2) may be the most practical.

HbA1c, fasting and 2 h plasma glucose in current, ex- and never-smokers: a meta-analysis.

AIMS/HYPOTHESIS: The relationships between smoking and glycaemic variables have not been well explored. We compared HbA1c, fasting plasma glucose (FPG) and 2 h plasma glucose (2H-PG) in current, ex- and never-smokers. METHODS: This meta-analysis used individual data from 16,886 men and 18,539 women without known diabetes in 12 DETECT-2 consortium studies and in the French Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR) and Telecom studies. Means of three glycaemic variables in current, ex- and never-smokers were modelled by linear regression, with study as a random factor. The I (2) statistic was used to evaluate heterogeneity among studies. RESULTS: HbA1c was 0.10% (95% CI 0.08, 0.12) (1.1 mmol/mol [0.9, 1.3]) higher in current smokers and 0.03% (0.01, 0.05) (0.3 mmol/mol [0.1, 0.5]) higher in ex-smokers, compared with never-smokers. For FPG, there was no significant difference between current and never-smokers (-0.004 mmol/l [-0.03, 0.02]) but FPG was higher in ex-smokers (0.12 mmol/l [0.09, 0.14]). In comparison with never-smokers, 2H-PG was lower (-0.44 mmol/l [-0.52, -0.37]) in current smokers, with no difference for ex-smokers (0.02 mmol/l [-0.06, 0.09]). There was a large and unexplained heterogeneity among studies, with I (2) always above 50%; I (2) was little changed after stratification by sex and adjustment for age and BMI. In this study population, current smokers had a prevalence of diabetes that was 1.30% higher as screened by HbA1c and 0.52% lower as screened by 2H-PG, in comparison with never-smokers. CONCLUSION/INTERPRETATION: Across this heterogeneous group of studies, current smokers had a higher HbA1c and lower 2H-PG than never-smokers. This will affect the chances of smokers being diagnosed with diabetes.

Patterns of insulin concentration during the OGTT predict the risk of type 2 diabetes in Japanese Americans.

OBJECTIVE: To examine whether the patterns of insulin concentration during the oral glucose tolerance test (OGTT) predict type 2 diabetes. RESEARCH DESIGN AND METHODS: We followed 400 nondiabetic Japanese Americans for 10-11 years. Insulin concentrations at 30, 60, and 120 min during a 2-h 75-g OGTT at baseline were used to derive the following possible patterns of insulin: pattern 1 (30-min peak, higher insulin level at 60 than at 120 min), pattern 2 (30-min peak, lower or equal level at 60 vs. 120 min), pattern 3 (60-min peak); pattern 4 (120-min peak, lower level at 30 than at 60 min), and pattern 5 (120-min peak, equal or higher level at 30 vs. 60 min). Insulin sensitivity was estimated by homeostasis model assessment of insulin resistance (HOMA-IR) and Matsuda index. Insulin secretion was estimated by the insulinogenic index (IGI) [Δinsulin/Δglucose (30-0 min)] and disposition index (IGI/HOMA-IR). RESULTS: There were 86 incident cases of type 2 diabetes. The cumulative incidence was 3.2, 9.8, 15.4, 47.8, and 37.5% for patterns 1, 2, 3, 4, and 5, respectively. Compared with pattern 1, patterns 4 and 5, characterized by a lasting late insulin response, were associated with significantly less insulin sensitivity as measured by the Matsuda index and lower early insulin response by the disposition index. The multiple-adjusted odds ratios of type 2 diabetes were 12.55 (95% CI 4.79-32.89) for pattern 4 and 8.34 (2.38-29.27) for pattern 5 compared with patterns 1 and 2. This association was independent of insulin secretion and sensitivity. CONCLUSIONS: The patterns of insulin concentration during an OGTT strongly predict the development of type 2 diabetes.

Impact of differences in glucose tolerance on the prevalence of a negative insulinogenic index.

OBJECTIVE: To determine the prevalence of a negative insulinogenic index (change in plasma insulin/change in plasma glucose from 0 to 30 min) from an oral glucose tolerance test according to glucose tolerance category. MATERIALS AND METHODS: Data from the San Antonio Heart Study (n=2494), Japanese American Community Diabetes Study (JACDS; n=594) and Genetics of NIDDM Study (n=1519) were examined. Glucose tolerance was defined by ADA criteria. RESULTS: In the combined cohort, the prevalence of a negative insulinogenic index was significantly higher in diabetes 20/616 (3.2%) compared to normal glucose tolerance 43/2667 (1.6%) (p<0.05). Longitudinally, in the JACDS cohort, the prevalence did not change from baseline (3/594; 0.5%) to 5 (4/505; 0.7%) and 10 years (8/426; 1.9%) (p=0.9) and no subject had a repeat negative insulinogenic index. CONCLUSIONS: A negative insulinogenic index occurs at a low prevalence across glucose tolerance categories although more often in diabetes, but without recurrence over time.

Change in visceral adiposity independently predicts a greater risk of developing type 2 diabetes over 10 years in Japanese Americans.

OBJECTIVE: Visceral adiposity is an important risk factor for cardiovascular disease and type 2 diabetes. We sought to determine whether change in intraabdominal fat area (IAF) over time predicts subsequent development of diabetes. RESEARCH DESIGN AND METHODS: We followed up 436 nondiabetic Japanese-American subjects (mean age 51.9 years, mean BMI 24.2 kg/m(2), 54% male) for development of diabetes. We fit a logistic regression model to examine the association over a 10-year follow-up between change in IAF at 5-year follow-up and other fat areas (measured by computed tomography) and development of incident diabetes, adjusted for age, sex, family history of diabetes in a first-degree relative, second-generation versus third-generation Japanese American (Nisei vs. Sansei), baseline IAF, BMI, weight change over time, smoking status, physical activity level, and subcutaneous fat (SCF) depot areas. RESULTS: Cumulative incidence of diabetes was 20.4% at 10 years. Mean change in IAF was 10.9 cm(2). An increase of 1 SD in IAF was associated with a 1.65-fold increase in the odds of diabetes over 10 years (OR = 1.65, 95% CI 1.21-2.25) after adjusting for the above covariates. This association was also independent of changes in thoracic, thigh, and abdominal SCF, as well as change in weight. CONCLUSIONS: We conclude that baseline IAF and accumulation of fat in this area over time are independent predictors of the development of type 2 diabetes in Japanese Americans.

Risk Factors for Type 2 Diabetes: Lessons Learned from Japanese Americans in Seattle.

Migrant Japanese populations in both the United States and Brazil have for a long time shown a higher prevalence of type 2 diabetes than in native Japanese, suggesting an interaction of lifestyle and genetic predisposition in the etiology of type 2 diabetes. The overall objective of the Seattle Japanese American Community Diabetes Study was to learn more about the etiology and pathogenesis of type 2 diabetes in Japanese Americans. This metabolically based epidemiologic study included extensive assessments of insulin sensitivity, insulin response, and adiposity with the latter including measurements of body fat distribution by both anthropometry and computed tomography. Because of this, the importance of visceral adiposity as a risk factor for abnormal glucose tolerance, hypertension, coronary heart disease, and the metabolic syndrome was demonstrated. In conjunction with an examination of diet and physical activity patterns, the result was a clearer understanding of the etiology and pathogenesis of type 2 diabetes in Japanese Americans. Wepropose that a lifestyle that fosters increased weight gain, especially in the visceral adipose depot, promotes the development of insulin resistance which in turn exposes an underlying reduced beta-cell reserve in susceptible individuals, resulting in glucose intolerance and eventually in many the development of diabetes. We have shown that it may be possible to delay or prevent the development of diabetes through dietary and exercise interventions in individuals identified as having impaired glucose tolerance. The lessons learned from studying migrant Japanese in Seattle may in many ways be applicable to other populations of Asian origin.

Associations among visceral fat, all-cause mortality, and obesity-related mortality in Japanese Americans.

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.

Intra-abdominal fat accumulation is greatest at younger ages in Japanese-American adults.

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 (beta-coefficient: -0.19, 95% CI -0.22, -0.15), SQAF (beta-coefficient: -0.07, 95% CI -0.11, -0.02) and IAF (beta-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 (beta-coefficient: 0.14, 95% CI 0.10, 0.18) and IAF (beta-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.

Association between obesity and diabetes mellitus in veterans with spinal cord injuries and disorders.

OBJECTIVES: To examine the association between body mass index (BMI) and clinically diagnosed diabetes in veterans with spinal cord injuries and disorders. We also sought to determine whether there is evidence to support a 10% reduction in BMI cut points, which would lower the upper limit of normal BMI from 24.99 to 22.49 kg/m, for persons with spinal cord injuries and disorders. DESIGN: Cross-sectional analysis using clinical data on 1938 male veterans. Prevalence ratios (95% confidence intervals) were calculated using a generalized linear model and adjusted for age, race, tobacco use, and paraplegia/tetraplegia status. RESULTS: Compared with the National Heart Lung Blood Institute normal BMI category (18.5-24.99 kg/m), the prevalence of diabetes was 50% higher (adjusted prevalence ratio: 1.50, 95% CI: 1.11-2.01) in the overweight category (25-29.99 kg/m) and approximately 3-fold higher (for obese classes 1-3, adjusted prevalence ratio: 2.74-3.03) in the obese category (BMI >or= 30 kg/m). Compared with the World Health Organization low-normal category (BMI, 18.5-22.99 kg/m), there was no significant difference in the prevalence of diabetes for those in the high normal weight (BMI, 23-24.99 kg/m) or low overweight (BMI, 25-27.49 kg/m) categories. However, the prevalence of diabetes was 2-fold higher among those in the high overweight category (BMI, 27.5-29.99 kg/m; adjusted prevalence ratio: 2.00, 95% CI: 1.33-2.99). CONCLUSIONS: BMI >or=25 kg/m was associated with significantly higher diabetes prevalence in male veterans with spinal cord injuries and disorders, and this risk was especially pronounced at BMI >or=27.5 kg/m. These findings do not support the need to create spinal cord injuries and disorder-specific BMI definitions of overweight for purposes of determining diabetes risk.

Latent class analysis of the metabolic syndrome.

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 non-diabetic 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 75(th) 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.

Body mass index is associated with increased creatinine clearance by a mechanism independent of body fat distribution.

CONTEXT: Although obesity has been, in general, associated with glomerular hyperfiltration, visceral adiposity has been suggested to be associated with reduced glomerular filtration. OBJECTIVE: The aim of the study was to evaluate the differential effects of obesity and body fat distribution on glomerular filtration. DESIGN AND SETTING: We conducted a cross-sectional study of the Japanese-American community in Seattle, Washington. PARTICIPANTS: We studied a representative sample of second-generation Japanese-American men and women with normal glucose tolerance (n = 124) and impaired glucose metabolism (impaired fasting glucose and/or impaired glucose tolerance) (n = 144) residing in King County, Washington. MAIN OUTCOME MEASURES: Glomerular filtration rate was estimated by 24-h urinary creatinine clearance, body size by body mass index (BMI), and intra-abdominal fat (IAF), sc fat (SCF), and lean thigh areas by CT scan. RESULTS: Creatinine clearance was positively correlated with BMI (r = 0.429; P < 0.001), fasting glucose (r = 0.198; P = 0.001), and insulin levels (r = 0.125; P = 0.042), as well as IAF (r = 0.239; P < 0.001), SCF (r = 0.281; P < 0.001), and lean thigh (r = 0.353; P < 0.001) areas. The association between creatinine clearance and BMI remained significant after adjustments for IAF, SCF areas, and fasting insulin levels (r = 0.337; P < 0.001); whereas IAF and SCF areas were not independently associated with creatinine clearance after adjusting for BMI. Creatinine clearance increased with increasing BMI after adjusting for fasting insulin, fasting glucose, IAF and SCF areas in subjects with normal glucose tolerance (r = 0.432; P < 0.001) and impaired glucose metabolism (r = 0.471; P < 0.001). CONCLUSIONS: BMI rather than body fat distribution is an independent determinant of creatinine clearance in nondiabetic subjects. Lean body mass, rather than adiposity, may explain this association.

The association between A1C and subclinical cardiovascular disease: the multi-ethnic study of atherosclerosis.

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 > or =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.

Oral disposition index predicts the development of future diabetes above and beyond fasting and 2-h glucose levels.

OBJECTIVE: We sought to determine whether an oral disposition index (DI(O)) predicts the development of diabetes over a 10-year period. First, we assessed the validity of the DI(O) by demonstrating that a hyperbolic relationship exists between oral indexes of insulin sensitivity and beta-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 (DeltaI(0-30)/DeltaG(0-30)). RESULTS: DeltaI(0-30)/DeltaG(0-30) 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 log(e)-transformed estimates included -1 for DeltaI(0-30)/DeltaG(0-30) 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 DeltaI(0-30)/DeltaG(0-30) and 1/fasting insulin was calculated (DI(O)) and decreased from NGT to IFG/IGT to diabetes (P < 0.001). Among nondiabetic subjects at baseline, baseline DI(O) 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 DI(O) provides a measure of beta-cell function adjusted for insulin sensitivity and is predictive of development of diabetes over 10 years.

Clinical assessment and management of obesity in individuals with spinal cord injury: a review.

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.

Visceral adiposity, not abdominal subcutaneous fat area, is associated with an increase in future insulin resistance in Japanese Americans.

OBJECTIVE: Visceral adiposity is generally considered to play a key role in the metabolic syndrome. We sought to determine whether greater visceral adiposity directly measured by computed tomography (CT) is associated with increased future insulin resistance independent of other adipose depots. RESEARCH DESIGN AND METHODS: We followed 306 nondiabetic Japanese Americans over 10-11 years. Baseline variables included BMI; waist circumference; and abdominal, thoracic, and thigh fat areas measured by CT. Total fat area was estimated by the sum of all of these fat areas. Visceral adiposity was measured as intra-abdominal fat area at the umbilicus level. Total subcutaneous fat area was defined as total fat area minus intra-abdominal fat area. Insulin resistance was evaluated by homeostasis model assessment for insulin resistance (HOMA-IR), fasting plasma insulin level, Matsuda index, and area under the oral glucose tolerance test curve (AUC) of insulin. RESULTS: Both baseline intra-abdominal fat area (P = 0.002) and HOMA-IR (P < 0.001) were independently associated with increased HOMA-IR at 10-11 years in a multiple linear regression model after adjustment for abdominal subcutaneous fat area, age, sex, 2-h plasma glucose level, and incremental insulin response. Intra-abdominal fat area remained a significant predictor of increased HOMA-IR at 10-11 years even after adjustment for total subcutaneous fat area, total fat area, BMI, or waist circumference, but no other measure of CT-measured regional or total adiposity was significantly related with HOMA-IR at 10-11 years in models that contained intra-abdominal fat area. Similar results were obtained for predicting future fasting plasma insulin level, Matsuda index, and AUC of insulin. CONCLUSIONS: Greater visceral adiposity is associated with an increase in future insulin resistance.

The association between birth weight and visceral fat in middle-age adults.

OBJECTIVE: Low birth weight, a proxy for fetal underdevelopment, is associated with increased risk of developing type 2 diabetes during adulthood. Low birth weight is also associated with central obesity, but little is known about the association between birth weight and visceral adiposity. The purpose of this study is to test the hypothesis that lower birth weight is associated with increased amounts of visceral fat in middle-age adults. RESEARCH METHODS AND PROCEDURES: This is an observational study of 91 adults (58 men and 33 women) 40+/-6 years of age (mean+/-standard deviation). Ethnicity was either Japanese American (79%) or non-Hispanic white (21%). Birth weight was obtained from State Departments of Health. Measurements included smoking status, BMI, and visceral (intra-abdominal) fat measured by computed tomography. RESULTS: Visceral fat was not associated with birth weight after adjustment for age, sex, ethnicity, BMI, or smoking status (p=0.76). There was no evidence that the association between birth weight and visceral fat varied by age, sex, or ethnicity. DISCUSSION: We found no evidence that low birth weight is associated with increased visceral fat in middle-age adults.

Minimum waist and visceral fat values for identifying Japanese Americans at risk for the metabolic syndrome.

OBJECTIVE: Japanese American is an ethnic group with a high risk for type 2 diabetes, which is linked to the metabolic syndrome. Central adiposity is considered to play a key role in the metabolic syndrome. Not known are the optimal cut point values for central and visceral adiposity to identify Japanese Americans at risk for the metabolic syndrome. RESEARCH DESIGN AND METHODS: Study subjects included 639 Japanese Americans. The nonadipose variables of the metabolic syndrome were defined using modified International Diabetes Federation criteria, and the accuracy of identifying at least two of these by intra-abdominal fat area (IAFA) as measured by computed tomography and waist circumference was cross-sectionally assessed using area under receiver operating characteristic (ROC) curves. The values for IAFA and waist circumference that resulted in maximizing the Youden index were defined as "optimal." RESULTS: The area under the ROC curve for IAFA exceeded that for waist circumference (men 0.787 vs. 0.686; women 0.792 vs. 0.721). For women, the optimal cut points for IAFA and waist circumference were 51.5 cm(2) and 80.8 cm (age < or = 56 years) and 86.3 cm(2) and 89.0 cm (age > 56 years). For men, the optimal cut points for IAFA and waist circumference were 88.6 cm(2) and 90.0 cm (age < or = 57 years) and 96.1 cm(2) and 87.1 cm (age > 57 years). CONCLUSIONS: These results argue that current Japanese waist circumference cut points for the metabolic syndrome need to be revised. Moreover, the waist circumference and IAFA cut points should be age specific, especially in women. Appropriate waist circumference cut points are from 80 to 90 cm in women and from 87 to 90 cm in men.