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Introduction: allostatic load score (ALS) is a measure of the biologic response to stress. The degree to which high ALS is associated with risk for diabetes and cardiovascular disease in African immigrants to the United States is unknown. Methods : ALS was calculated in 252 self-identified healthy African immigrants (age: 40±10, (mean±SD), range 21-64y), BMI 27.8±4.5, range 18.2-42.4 kg/m 2 , 69% male) using 11 variables from 3 domains: cardiac (SBP, DBP, cholesterol, triglyceride, homocysteine), metabolic (BMI, A1C, glycated albumin, eGFR) and immunological (hsCRP, albumin). High-risk was defined by the highest quartile for each variable, except for albumin and eGFR, which used the lowest quartile. One point was assigned if the variable was in the high-risk range and 0 if not. High ALS was defined by the cut-off for the highest ALS quartile (≥ 4.0). Risk factors for diabetes and cardiovascular disease were defined by newly diagnosed prediabetes or diabetes during an OGTT, low insulin sensitivity calculated by the Matsuda Index and high visceral adipose tissue (VAT) mass measured by computerized tomographic (CT) scan. Results: African immigrants with high ALS had higher fasting glucose (97±19 vs. 89±7 mg/dL, P 3 , P < 0.001). Conclusion: high ALS detects risk for diabetes and cardiovascular disease in African immigrants. Measuring ALS may prove to be a valid cost-effective way to detect risk for diabetes and cardiovascular disease in low resource areas of Africa.

Sickle cell trait (SCT) is at the intersection of genetics, social policy, and medicine. SCT occurs in three-hundred million people worldwide and in approximately 8 % of African-Americans. There has been great debate about the influence of SCT on health. Yet data exist, albeit controversial, which suggest that SCT is associated with metabolic derangements that can lead to sudden death after vigorous physical activity, renal dysfunction, thromboembolic events, and stroke. In addition, it has even been postulated that SCT might enhance the vascular complications of diabetes. This review focuses on (a) the scientific breakthroughs that led to the discovery of hemoglobin S, sickle cell disease, and SCT, (b) the history of screening programs in the United States, (c) the incidence and etiology of exercise-related sudden death in military personnel and athletes with SCT, and (d) the data examining the potential chronic disease consequences of SCT from a metabolic, renal, and vascular perspective.

SummaryContext Morphological characteristics of the glucose curve during an OGTT (time to peak and shape) may reflect different phenotypes of insulin secretion and action, but their ability to predict diabetes risk is uncertain. Objective To compare the ability of time to glucose peak and curve shape to detect prediabetes and β-cell function. Design and participants In a cross-sectional evaluation using an OGTT, 145 adults without diabetes (age 42±9y (mean±SD), range 24-62y, BMI 29.2±5.3 kg/m2, range 19.9-45.2 kg/m2) were characterized by peak (30mins vs. >30mins) and shape (biphasic vs. monophasic). Main Outcome Measures Prediabetes and disposition index (DI) – a marker of β-cell function. Results Prediabetes was diagnosed in 36% (52/145) of participants. Peak>30mins, not monophasic curve, was associated with increased odds of prediabetes (OR: 4.0 vs. 1.1; P 30 mins were associated with lower DI (P≤0.01). Time to glucose peak and glucose AUC were independent predictors of DI (adjR2=0.45, P30mins was a stronger independent indicator of prediabetes and β-cell function than the monophasic curve. Time to glucose peak may be an important tool that could enhance prediabetes risk stratification. This article is protected by copyright. All rights reserved.

The relationship between the biological effect of stress, reason for immigration and unhealthy assimilation behaviors has not been studied in African immigrants to the United States. Therefore, in 88 African immigrants to the United States (age 41±10, (mean±SD), range 22-61y, male 65% (57 of 88)) we used the allostatic load score (ALS) to assess the biological response to stress. ALS was calculated using 10 variables from 3 domains; cardiac (SBP, DBP, cholesterol, triglyceride, homocysteine), metabolic (BMI, A1C, albumin, eGFR) and immunological (hsCRP). High-risk was defined by the highest quartile for each variable, except for albumin and eGFR, which used the lowest quartile. One point was assigned if the variable was in the high-risk range and 0 if not. Participants were grouped by reason for immigration: asylum, work, study, marriage, lottery and family reunification. Unhealthy assimilation behaviors were: smoking and alcohol intake. ALS was highest for asylum seekers (3.21±2.16) and lowest for family reunification (1.78±1.35). For the other reasons of immigration, ALS was in the range between these two scores (Figure). Thirty-six percent of asylum seekers were smokers (5 of 14), whereas all other African immigrants were non-smokers (0 of 74) ( P P =0.05). In conclusion, as demonstrated by ALS, asylum seekers experience the highest degree of stress and the most unhealthy assimilation behaviors. However, Africans who come to the United States for family reunification have a low prevalence of unhealthy assimilation behaviors and the lowest ALS. Therefore, reason for immigration may have a significant impact on both health and behavior.

Vitamin D levels in people of African descent are often described as inadequate or deficient. Whether low vitamin D levels in people of African descent lead to compromised bone or cardiometabolic health is unknown. Clarity on this issue is essential because if clinically significant vitamin D deficiency is present, vitamin D supplementation is necessary. However, if vitamin D is metabolically sufficient, vitamin D supplementation could be wasteful of scarce resources and even harmful. In this review vitamin D physiology is described with a focus on issues specific to populations of African descent such as the influence of melanin on endogenous vitamin D production and lactose intolerance on the willingness of people to ingest vitamin D fortified foods. Then data on the relationship of vitamin D to bone and cardiometabolic health in people of African descent are evaluated.

Introduction Allostatic load score (ALS) summarizes the physiological effect of stress on cardiovascular, metabolic and immune systems. As immigration is stressful, ALS could be affected. Objective Associations between age of immigration, reason for immigration, and unhealthy assimilation behavior and ALS were determined in 238 African immigrants to the United States (age 40 ± 10, mean ± SD, range 21–64 years). Methods ALS was calculated using 10 variables from three domains; cardiovascular (SBP, DBP, cholesterol, triglyceride, homocysteine), metabolic [BMI, A1C, albumin, estimated glomerular filtration rate (eGFR)], and immunological [high-sensitivity C-reactive protein (hsCRP)]. Variables were divided into sex-specific quartiles with high-risk defined by the highest quartile for each variable except for albumin and eGFR, which used the lowest quartile. One point was assigned if the variable was in the high-risk range and 0 if not. Unhealthy assimilation behavior was defined by a higher prevalence of smoking, alcohol consumption, or sedentary activity in immigrants who lived in the US for ≥10 years compare to

BACKGROUNDFollowing immigration to the US, many Africans transition from a low-normal to a high-normal or overweight body mass index (BMI). This weight change is associated with a high rate of prediabetes in the nonobese. Studies in East Asians reveal that glycated albumin is effective in identifying prediabetes in nonobese Asians. Whether this is true in African immigrants is unknown. Therefore, we evaluated the ability of hemoglobin A1c (Hb A1c) and glycated albumin to detect prediabetes in nonobese (BMI METHODSOral glucose tolerance tests (OGTTs) were performed in 236 self-identified healthy African immigrants [mean (SD) BMI 27.6 (4.4) kg/m2]. Prediabetes diagnosis was based on glucose criteria for the OGTT. Diagnostic sensitivity of Hb A1c and glycated albumin was determined by thresholds at the upper quartile for each [Hb A1c ≥5.7% (39 mmol/mol), glycated albumin ≥13.77%].RESULTSBased on glucose criteria for the OGTT, prediabetes was detected in 36% (85/236). BMI and Hb A1c were positively correlated (r = 0.22, P < 0.001), whereas BMI and glycated albumin were negatively correlated (r = −0.24, P < 0.001). Although the sensitivities of Hb A1c and glycated albumin were similar in nonobese immigrants (37% vs 42%, P = 0.75), prediabetes was detected in 21 nonobese Africans by glycated albumin alone, in 18 by Hb A1c alone, and in 4 by both tests. Therefore, sensitivity of the combined tests was better than for Hb A1c alone(72% vs 37%, P < 0.01). In the obese, Hb A1c was a much better diagnostic test than glycated albumin (64% vs 16%, P < 0.01) and combining the tests did not improve sensitivity (72% vs 64%, P = 0.50).CONCLUSIONSGlycated albumin contributes by identifying prediabetes not detected by Hb A1c in nonobese African immigrants. ClinicalTrials.gov Identifier: NCT00001853

African immigrants living in the United States are exposed to the stress of changing continents and cultures. Therefore African immigrants are exposed to two types of environmental stress; first, stress related to navigating new social and economic realities; and second, stress due to work, education and a sedentary lifestyle in the United States. To evaluate the effect of these stressors on health, we calculated the allostatic load score in two groups of Africans: childhood immigrants who came to the United States before 18 years of age, and adulthood immigrants who came to the United States at 18 years of age or older. Allostatic load is a measure of the influence of environmental stress on physiological function. It is calculated for each individual by assigning one point for each high risk cardiovascular, inflammatory, and metabolic biomarker present. The higher the allostatic load score, the greater the impact of stress on physiologic dysregulation. As no consensus exists on which biomarkers to include in the calculation of allostatic load score, we used four different published equations to evaluate allostatic load in 213 African immigrants (age: 40±10y,(mean±SD) range 21-64y; BMI: 27.7±4.5 kg/m 2 ; male: 70% (149 of 213); adulthood immigrants: 81% (181 of 213)). By multiple regression, the effect of age, age at immigration, duration of stay in the United States, income, education and exercise on allostatic load score was determined. Overall, childhood immigrants were younger than adulthood immigrants (29±7 vs. 41±9y, P P P P P >0.6). For both groups of immigrants, low income, lack of a college education and low levels of exercise did not increase allostatic load score ( P >0.3). Overall, the factor which appears to have the greatest impact on the physiologic health of African immigrants is age of immigration. Africans who emigrated as children experience less physiologic stress than their counterparts who emigrated as adults.

Food insecurity is defined as limited or uncertain ability to acquire nutritionally adequate and safe foods in socially acceptable ways. The United States Department of Agriculture (USDA) has divided food insecurity into two categories: low food security and very low food security. Low food security is characterized by irregular access to food, binge eating when food is available, overconsumption of energy-dense foods, obesity, and even type 2 diabetes. This type of food insecurity occurs in impoverished urban areas of high-income countries such as the United States. In contrast, very low food security is distinctly different from low food security and can lead to undernutrition and frank starvation. Very low food security is found in developing countries in both rural areas and urban slums. In these countries, food insecurity is often exacerbated by natural disasters and climate changes that compromise food availability. With a focus on the social, economic, and behavioral factors that promote obesity and cardiometabolic disease in food insecure households in the United States, this review will first define the key terms and concepts associated with food insecurity. Then, the characteristics of food insecure households and the relationship to cardiometabolic disease will be discussed. Finally, the cardiac consequences of food insecurity in developing countries will be briefly described.

Obesity and diabetes are more common in African-Americans than whites. Because free fatty acids (FFA) participate in the development of these conditions, studying race differences in the regulation of FFA and glucose by insulin is essential.The objective of the study was to determine whether race differences exist in glucose and FFA response to insulin.This was a cross-sectional study.The study was conducted at a clinical research center.Thirty-four premenopausal women (17 African-Americans, 17 whites) matched for age [36 ± 10 yr (mean ± sd)] and body mass index (30.0 ± 6.7 kg/m²).Insulin-modified frequently sampled iv glucose tolerance tests were performed with data analyzed by separate minimal models for glucose and FFA.Glucose measures were insulin sensitivity index (S(I)) and acute insulin response to glucose (AIRg). FFA measures were FFA clearance rate (c(f)).Body mass index was similar but fat mass was higher in African-Americans than whites (P0.01). Compared with whites, African-Americans had lower S(I) (3.71 ± 1.55 vs. 5.23 ± 2.74 [×10⁻⁴ min⁻¹/(microunits per milliliter)] (P = 0.05) and higher AIRg (642 ± 379 vs. 263 ± 206 mU/liter⁻¹ · min, P0.01). Adjusting for fat mass, African-Americans had higher FFA clearance, c(f) (0.13 ± 0.06 vs. 0.08 ± 0.05 min⁻¹, P0.01). After adjusting for AIRg, the race difference in c(f) was no longer present (P = 0.51). For all women, the relationship between c(f) and AIRg was significant (r = 0.64, P0.01), but the relationship between c(f) and S(I) was not (r = -0.07, P = 0.71). The same pattern persisted when the two groups were studied separately.African-American women were more insulin resistant than white women, yet they had greater FFA clearance. Acutely higher insulin concentrations in African-American women accounted for higher FFA clearance.

Although waist circumference (WC) is a marker of visceral adipose tissue (VAT), WC cut-points are based on BMI category. We compared WC–BMI and WC–VAT relationships in blacks and whites. Combining data from five studies, BMI and WC were measured in 1,409 premenopausal women (148 white South Africans, 607 African–Americans, 186 black South Africans, 445 West Africans, 23 black Africans living in United States). In three of five studies, participants had VAT measured by computerized tomography (n = 456). Compared to whites, blacks had higher BMI (29.6 ± 7.6 (mean ± s.d.) vs. 27.6 ± 6.6 kg/m2, P = 0.001), similar WC (92 ± 16 vs. 90 ± 15 cm, P = 0.27) and lower VAT (64 ± 42 vs. 101 ± 59 cm2, P < 0.001). The WC–BMI relationship did not differ by race (blacks: β (s.e.) WC = 0.42 (.01), whites: β (s.e.) WC = 0.40 (0.01), P = 0.73). The WC–VAT relationship was different in blacks and whites (blacks: β (s.e.) WC = 1.38 (0.11), whites: β (s.e.) WC = 3.18 (0.21), P < 0.001). Whites had a greater increase in VAT per unit increase in WC. WC–BMI and WC–VAT relationships did not differ among black populations. As WC–BMI relationship did not differ by race, the same BMI-based WC guidelines may be appropriate for black and white women. However, if WC is defined by VAT, race-specific WC thresholds are required.

The disposition index, the product of the insulin sensitivity index (S(I)) and the acute insulin response to glucose, is linked in African Americans to chromosome 11q. This link was determined with S(I) calculated with the nonlinear regression approach to the minimal model and data from the reduced-sample insulin-modified frequently-sampled intravenous glucose tolerance test (Reduced-Sample-IM-FSIGT). However, the application of the nonlinear regression approach to calculate S(I) using data from the Reduced-Sample-IM-FSIGT has been challenged as being not only inaccurate but also having a high failure rate in insulin-resistant subjects. Our goal was to determine the accuracy and failure rate of the Reduced-Sample-IM-FSIGT using the nonlinear regression approach to the minimal model. With S(I) from the Full-Sample-IM-FSIGT considered the standard and using the nonlinear regression approach to the minimal model, we compared the agreement between S(I) from the Full- and Reduced-Sample-IM-FSIGT protocols. One hundred African Americans (body mass index, 31.3 +/- 7.6 kg/m(2) [mean +/- SD]; range, 19.0-56.9 kg/m(2)) had FSIGTs. Glucose (0.3 g/kg) was given at baseline. Insulin was infused from 20 to 25 minutes (total insulin dose, 0.02 U/kg). For the Full-Sample-IM-FSIGT, S(I) was calculated based on the glucose and insulin samples taken at -1, 1, 2, 3, 4, 5, 6, 7, 8,10, 12, 14, 16, 19, 22, 23, 24, 25, 27, 30, 40, 50, 60, 70, 80, 90, 100, 120, 150, and 180 minutes. For the Reduced-Sample-FSIGT, S(I) was calculated based on the time points that appear in bold. Agreement was determined by Spearman correlation, concordance, and the Bland-Altman method. In addition, for both protocols, the population was divided into tertiles of S(I). Insulin resistance was defined by the lowest tertile of S(I) from the Full-Sample-IM-FSIGT. The distribution of subjects across tertiles was compared by rank order and kappa statistic. We found that the rate of failure of resolution of S(I) by the Reduced-Sample-IM-FSIGT was 3% (3/100). For the remaining 97 subjects, S(I) for the Full- and Reduced-Sample-IM-FSIGTs were as follows: 3.76 +/- 2.41 L mU(-1) min(-1) (range, 0.58-14.50) and 4.29 +/- 2.89 L mU(-1) min(-1) (range, 0.52-14.42); relative error, 21% +/- 18%; Spearman r = 0.97; and concordance, 0.94 (both P.001). After log transformation, the Bland-Altman limits of agreement were -0.29 and 0.53. The exact agreement for distribution of the population in the insulin-resistant tertile vs the insulin-sensitive tertiles was 92%, kappa of 0.82 +/- 0.06. Using the nonlinear regression approach and data from the Reduced-Sample-IM-FSIGT in subjects with a wide range of insulin sensitivity, failure to resolve S(I) occurred in only 3% of subjects. The agreement and maintenance of rank order of S(I) between protocols support the use of the nonlinear regression approach to the minimal model and the Reduced-Sample-IM-FSIGT in clinical studies.

The effects of insulin on the suppression of lipolysis are neither fully understood nor quantified. We examined a variety of mathematical models analogous to the minimal model of glucose disposal (MMG) to quantify the combined influence of insulin on lipolysis and glucose disposal during an insulin-modified frequently sampled intravenous glucose tolerance test. The tested models, which include two previously published ones, consisted of separate compartments for plasma free fatty acids (FFA), glucose, and insulin. They differed in the number of compartments and in the action of insulin to suppress lipolysis that decreased the plasma FFA level. In one category of models, a single insulin compartment acted on both glucose and FFA simultaneously. In a second category, there were two insulin compartments, each acting on FFA and glucose independently. For each of these two categories, we tested 11 variations of how insulin suppressed lipolysis. We also tested a model with an additional glucose compartment that acted on FFA. These 23 models were fit to the plasma FFA and glucose concentrations of 102 subjects individually. Using Bayesian model comparison methods, we selected the model that best balanced fit and minimized model complexity. In the best model, insulin suppressed lipolysis via a Hill function through a remote compartment that acted on both glucose and FFA simultaneously, and glucose dynamics obeyed the classic MMG.

Total body size and central fat distribution are important determinants of insulin resistance. The BMI and waist circumference (WC) thresholds in African Americans that best predict insulin resistance are unknown. Our goal was to determine the BMI and WC values in African Americans, which optimally predict insulin resistance. The subjects were African Americans (68 men, 63 women), aged 35 +/- 8 years (mean +/- s.d.), with a BMI of 30.9 +/- 7.5, in the range of 18.5-54.7 kg/m(2), and with a WC of 98 +/- 18, in the range of 69-173 cm. Insulin resistance was defined by the lowest tertile of the insulin sensitivity index (S(I)). The Youden index was calculated to determine the WC and BMI thresholds that predict insulin resistance with an optimal combination of sensitivity and specificity. In men the thresholds that optimally predicted insulin resistance were a BMIor =30 kg/m(2) or a WCor =102 cm. For women, insulin resistance was best predicted by a BMIor =32 kg/m(2) or a WCor =98 cm. In African Americans, insulin resistance (in men) was best predicted by a WCor =102 cm, and in women by a WCor =98 cm, or by a BMI value that fell in the obese category (men:or =30 kg/m(2), women:or =32 kg/m(2)).

The consequences of the worldwide epidemic of obesity include a global increase in cardiovascular disease and diabetes. Guidelines to achieve early diagnosis of obesity, particularly central obesity, have been created by several organizations. These guidelines have been developed in Caucasian populations, but evidence is emerging that suggests substantial ethnic and sex differences in the relationships between body size, body fat distribution, and the risk of obesity-related long-term diseases. Comparisons by ethnicity and sex have revealed that the universal application of criteria for obesity and central obesity developed in Caucasians leads to an overestimation of risk in African Americans and an underestimation of risk in South Asians. Research is warranted to determine if ethnic-and sex-specific criteria for the diagnosis of obesity improve risk estimation and the development of effective interventions.

Background African Americans commonly have normal high-density lipoprotein cholesterol (HDL-C) and low triglyceride levels despite having insulin resistance and obesity. The higher than expected HDL-C levels are usually attributed to low levels of hepatic triglyceride lipase (HTGL) activity. Factors that regulate HTGL in African Americans are not well delineated. Methods In the current study, HTGL activity was examined in relation to indices of body fat (body mass index [BMI] and waist circumference [WC]), insulin resistance (fasting plasma insulin and homeostasis model assessment of insulin resistance [HOMA-IR] index), and adipokines (adiponectin and leptin). Sixty-three African Americans (33 men, 30 women; median age 31 years, range 20-50 years; median BMI 28.6 kg/m2, range 19.7-54.7 kg/m2) had anthropometry and measurement of postheparin lipase activities (HTGL), plasma HDL-C, triglycerides, and plasma adiponectin. Results HTGL correlated strongly with HDL-C ( r = −.52, p < .0001) and adiponectin ( r = −.49, p < .001). HTGL increased with BMI and WC ( r = .297, p = .018 and r = .301, p = .016, respectively). Adiponectin correlated strongly with HDL-C ( r = .50, p < .0001) and triglycerides ( r = −.493, p < .001). From multiple regression models, 28% of HTGL variability among African Americans can be explained by adiponectin levels in combination with gender and 35% of HTGL is explained with HDL-C included in the model. Conclusion The data suggest that adiponectin is a significant metabolic concomitant of HTGL activity in African Americans.

OBJECTIVE Slowing the diabetes epidemic in Africa requires improved detection of prediabetes. A1C, a form of glycated hemoglobin A, is recommended for diagnosing prediabetes. The glycated proteins, fructosamine and glycated albumin (GA), are hemoglobin-independent alternatives to A1C, but their efficacy in Africans is unknown. Our goals were to determine the ability of A1C, fructosamine, and GA to detect prediabetes in U.S.-based Africans and the value of combining A1C with either fructosamine or GA. RESEARCH DESIGN AND METHODS Oral glucose tolerance tests (OGTT) were performed in 217 self-identified healthy African immigrants (69% male, age 39 ± 10 years [mean ± SD], BMI 27.6 ± 4.5 kg/m2). A1C, fructosamine, and GA were measured. Prediabetes was diagnosed by American Diabetes Association criteria for glucose obtained from a 2-h OGTT. The thresholds to diagnose prediabetes by A1C, fructosamine, and GA were the cutoff at the upper tertile for each variable: ≥5.7% (39 mmol/mol) (range 4.2–6.6% [22.4–48.6 mmol/mol]), ≥230 µmol/L (range 161–269 µmol/L), and ≥13.35% (range 10.20–16.07%), respectively. RESULTS Prediabetes occurred in 34% (74 of 217). The diagnostic sensitivities of A1C, fructosamine, and GA were 50%, 41%, and 42%, respectively. The P values for comparison with A1C were both >0.3. Combining A1C with either fructosamine or GA increased sensitivities. However, the sensitivity of A1C combined with fructosamine was not better than for A1C alone (72% vs. 50%, P = 0.172). In contrast, the sensitivity of A1C combined with GA was higher than for A1C alone (78% vs. 50%, P < 0.001). CONCLUSIONS As individual tests, A1C, fructosamine, and GA detected ≤50% of Africans with prediabetes. However, combining A1C with GA made it possible to identify nearly 80% of Africans with prediabetes.

African ancestry is associated with low vitamin D levels but high bone density. Fifty percent of African immigrants had low vitamin D levels, but10 % had evidence of deficiency. The value of providing vitamin D supplementation to African immigrants without evidence of deficiency needs to be determined.The Endocrine Society and Institute of Medicine (IOM) have concluded from studies in largely white populations that 25(OH)D is necessary for bone health. However, their definition of vitamin D insufficiency differs. The Endocrine Society recommends a 25(OH)D threshold of30 ng/mL. The IOM uses a lower threshold of 25(OH)D of20 ng/mL. As African ancestry is associated with decreased 25(OH)D but increased bone mineral density (BMD), the applicability of these thresholds to Africans is unknown. Therefore, we examined in African immigrants the relationship of 25(OH)D to parathyroid hormone (PTH) and BMD.One hundred eighty-six African immigrants(69 % male, age 38 ± 10 (mean ± SD), range 20-64 years) living in metropolitan Washington, DC, were enrolled. BMD was determined from whole-body dual-energy X-ray absorptiometry (DXA) scans. Decreased BMD required T-scores ≤-1.0. The threshold for low 25(OH)D was the concentration of 25(OH)D at which PTH became suppressed. This is known as the inflection point. Biochemical deficiency required low 25(OH)D and PTH of65 pg/mL. Clinical deficiency required low 25(OH)D and T-scores ≤-1.0.25(OH)D30 and20 ng/mL occurred in 83 and 46 % of African immigrants, respectively. PTH inversely correlated with 25(OH)D (r = -0.31, P = 0.002). The inflection point occurred at a 25(OH)D concentration of 20 ng/mL. Biochemical and clinical deficiency occurred in only 8 and 3 % of immigrants, respectively.As PTH became suppressed at 25(OH)D of 20 ng/mL, the 25(OH)D20 ng/mL threshold for insufficiency may apply to African immigrants. However, ~50 % of African immigrants have 25(OH)D20 ng/mL, but only10 % had evidence of deficiency. The value of providing vitamin D supplementation to the large number of African immigrants with 25(OH)D20 ng/mL and no detectable evidence of deficiency needs to be determined.

As both diabetes and pre-diabetes are common in Africa, screening tests must be rapid, simple, and accurate. Hemoglobin A1C (A1C), fructosamine, and glycated albumin (GA) are screening tests of long term glycemia which only require one blood sample obtained any time of day without consideration of recent nutrient intake. A1C is already recommended as a screening test for diabetes by the American Diabetes Association and the International Diabetes Federation, but fructosamine and GA are under active evaluation. Fructosamine is a measure of circulating glycated protein. GA is a subfraction of fructosamine. Data on the effectiveness of fructosamine and GA in African descent populations are scant. Therefore, our goal was to compare the ability of A1C, fructosamine, and GA to predict diabetes. Two hour OGTT were performed in 230 African immigrants (67% male; age 37±10y (mean±SD); BMI: 27.6±4.6 kg/m2). Glucose tolerance category was defined by 2h glucose levels (normal: 2h glucose

Levels of physical activity (PA), an important risk factor for cardiometabolic disease, may decline in Africans after immigration and it is unknown whether PA type differs by sex. To determine PA profile and perceived activity in African immigrants, we examined PA type and intensity using the self-report Multi-Ethnic Study of Atherosclerosis (MESA) Typical Week Physical Activity Survey (TWPAS). Physical activity levels were defined as time spent in total and moderate-vigorous PA in 80 African immigrants living in the DC metro area, who self-identified as healthy (66% male; age 39.1±9.4y (mean±SD), range 22-58y; BMI 28.2±4.4 kg/m 2 , range 19.7-41.2). Total and moderate-vigorous PA were 1952.1±1759.6 and 717.6±840.3 min•wk -1 , respectively and did not vary by sex, P=0.9 (Fig 1). Men and women reported spending equal amounts of time in each moderate-vigorous PA category (household, occupational, childcare, intentional and volunteer, P=0.7). Ninety-five percent of Africans reported meeting moderate-vigorous PA guidelines > 150 min•wk -1 (Fig 1A). However, 10% of Africans reported more total PA than there are minutes in a week (Fig 1B) and 1/3 reported excessive weekly moderate-vigorous PA (total >5hr•dy -1 and intentional > 2 hr•dy -1 ). In the 26 Africans with >5 hr•dy -1 of total moderate-vigorous PA, those with an annual income of ≥$30,000 reported greater levels of moderate-vigorous PA than those with an income 0.3). Self-reported PA profiles were similar among African immigrant men and women, but were over-reported by at least 10% of respondents. Over-reporting may be more common in Africans of higher socioeconomic status. The MESA TWPAS questionnaire provides insight into PA profiles in African immigrants, but is suboptimal for quantitative examination of PA levels.

OBJECTIVE Metabolic risk and metabolic syndrome (MetSyn) prevalence were compared in Africans who immigrated to the U.S. and African Americans. If MetSyn were an effective predictor of cardiometabolic risk, then the group with a worse metabolic risk profile would have a higher rate of MetSyn. RESEARCH DESIGN AND METHODS Cross-sectional analyses were performed on 95 men (39 Africans, 56 African Americans, age 38 ± 6 years [mean ± SD]). Glucose tolerance was determined by oral glucose tolerance test, visceral adipose tissue (VAT) was determined by computerized tomography, and MetSyn was determined by the presence of three of five factors: central obesity, hypertriglyceridemia, low levels of HDL cholesterol, hypertension, and fasting hyperglycemia. RESULTS MetSyn prevalence was similar in Africans and African Americans (10 vs. 13%, P = 0.74), but hypertension, glycemia (fasting and 2-h glucose), and VAT were higher in Africans. CONCLUSIONS African immigrants have a worse metabolic profile than African Americans but a similar prevalence of MetSyn. Therefore, MetSyn may underpredict metabolic risk in Africans.

Kidney disease disparately affects those of African descent. Age trends have generally been established for kidney function in the overall US population, but the contribution of age at the time of immigration for African immigrants is unknown. To examine the independent and joint effects of age and age at the time of immigration, and kidney function. Estimated glomerular filtration rate (eGFR) was calculated for 93 African immigrants (60 % male; mean age = 33.5). Hierarchical regression and post hoc analyses revealed a significant age × age at the time of immigration interaction after accounting for traditional risk factors among those who immigrated at age ≤21. Younger age at the time of immigration to the US may exacerbate an inverse relationship between age and kidney function in a self-identified healthy African immigrant sample. Investigation of biopsychosocial factors associated with kidney health among African immigrants is warranted.

Paradigms for the early detection of cardiometabolic disease usually incorporate both elevated triglyceride (TG) and low high density lipoprotein -cholesterol (HDL-C). However, African-Americans with cardiometabolic disease usually have normal TG levels. The HDL-C pattern of African-Americans with cardiometabolic disease is uncertain. The TG and HDL-C pattern in Africans with cardiometabolic disease is unknown. To clarify the TG and HDL-C pattern in African descent populations with cardiometabolic disease, 377 blacks (167 African-Americans, 210 African immigrants, 59% male, age 36±9y, mean±SD, range 20-64y, BMI 29.0±6.3 kg/m2, range 18.5-54.7) had glucose tolerance status determined by OGTT, lipid profiles and insulin resistance determined by the insulin sensitivity index (SI). Insulin resistance was defined as the lowest quartile of SI (

OBJECTIVE Abnormal glucose tolerance is rising in sub-Saharan Africa. Hemoglobin A1c by itself and in combination with fasting plasma glucose (FPG) is used to diagnose abnormal glucose tolerance. The diagnostic ability of A1C in Africans with heterozygous variant hemoglobin, such as sickle cell trait or hemoglobin C trait, has not been rigorously evaluated. In U.S.-based Africans, we determined by hemoglobin status the sensitivities of 1) FPG ≥5.6 mmol/L, 2) A1C ≥ 5.7% (39 mmol/mol), and 3) FPG combined with A1C (FPG ≥5.6 mmol/L and/or A1C ≥5.7% [39 mmol/mol]) for the detection of abnormal glucose tolerance. RESEARCH DESIGN AND METHODS An oral glucose tolerance test (OGTT) was performed in 216 African immigrants (68% male, age 37 ± 10 years [mean ± SD], range 20–64 years). Abnormal glucose tolerance was defined as 2-h glucose ≥7.8 mmol/L. RESULTS Variant hemoglobin was identified in 21% (46 of 216). Abnormal glucose tolerance occurred in 33% (72 of 216). When determining abnormal glucose tolerance from the OGTT (2-h glucose ≥7.8 mmol/L), sensitivities of FPG for the total, normal, and variant hemoglobin groups were 32%, 32%, and 33%, respectively. Sensitivities for A1C were 53%, 54%, and 47%. For FPG and A1C combined, sensitivities were 64%, 63%, and 67%. Sensitivities for FPG and A1C and the combination did not vary by hemoglobin status (all P > 0.6). For the entire cohort, sensitivity was higher for A1C than FPG and for both tests combined than for either test alone (all P values ≤ 0.01). CONCLUSIONS No significant difference in sensitivity of A1C by variant hemoglobin status was detected. For the diagnosis of abnormal glucose tolerance in Africans, the sensitivity of A1C combined with FPG is significantly superior to either test alone.

Background African-Americans have higher HDL, less visceral adipose tissue (VAT) and lower triglyceride (TG) and apoCIII concentrations than whites, despite being more insulin-resistant. We studied in African-American and white women the influences of insulin resistance and VAT on the apoAI concentrations of two HDL subspecies, one that contains apoCIII that is associated with increased risk of coronary heart disease (CHD) and one that does not have apoCIII that is associated with decreased CHD; and on the apoCIII concentrations of HDL and of the apoB lipoproteins. Methods The participants were 32 women (14 African-Americans, 18 white) of similar age (39 ± 12 vs. 42 ± 11y). Mean BMI was 34 kg/m2 in the African-Americans compared to 30 in the whites. A standard diet (33% fat, 52% carbohydrate, 15% protein) was provided for 7 days followed by a test meal (40% fat, 40% carbohydrate, 20% protein) on Day 8. Insulin sensitivity index (SI) was calculated from the minimal model. Results After controlling for SI, African-Americans have a higher mean apoAI level in HDL with apoCIII compared with whites (12.9 ± 2.8 and 10.9 ± 2.9 mg/dL, respectively, P = 0.05). SI was associated with higher apoAI in HDL with apoCIII, whereas VAT was not associated with this HDL subspecies. This pattern of results was reversed for apoCIII concentrations in apoB lipoproteins. After adjusting for SI, African-Americans had lower apoCIII in apoB lipoproteins. SI was associated with lower apoCIII in total apoB lipoproteins, whereas VAT was associated with higher apoCIII in all the apoB lipoproteins. Additional adjustment for VAT tended to reduce the difference in apoCIII between the groups. Conclusions African-American women have a higher HDL with apoCIII level than whites when controlled for insulin sensitivity. African-Americans have lower insulin sensitivity. Insulin sensitivity is associated with higher levels of HDL with apoCIII. ApoCIII levels in VLDL are lower in African-American women than whites, also affected by insulin sensitivity which is associated with low apoCIII in VLDL. VAT has a strong association with apoCIII in apoB lipoproteins but not with apoAI in HDL with apoCIII. Trial registration ClinicalTrials.gov Identifier: NCT00484861

The healthy immigrant effect is a phrase that has been used for decades to describe better cardiometabolic health in African immigrants than African Americans. The recent global increase in cardiometabolic diseases raises the possibility that immigrant health may be changing. Therefore, a new assessment of cardiometabolic health in African immigrants is warranted.Glucose tolerance status, blood pressure, and visceral adipose tissue (VAT) volume were compared in 214 self-identified healthy men comprised of 138 African immigrants, 76 African Americans, mean age 36±9 years [mean±standard deviation (SD); range 20-64 years]. Insulin resistance was defined by the lowest quartile of the insulin sensitivity index (SI≤2.28 mU/L(-1)·min(-1)). The waist circumference (WC) which predicts insulin resistance was determined using receiver operating characteristic curves and the Youden index.Body mass index (BMI) and WC were lower in African immigrants than African Americans (BMI, 27.4±3.8 vs. 29.3±5.5 kg/m(2), P0.01; WC, 91±11 vs. 97±16 cm, P0.01). However, blood pressure, fasting glucose, and 2-hr glucose were higher in the African immigrants (all P0.01). In addition, African immigrants had a higher prevalence of previously undiagnosed diabetes (8% vs. 0%, P0.01) and prediabetes (35% vs. 22%, P0.01). After adjusting for WC, African immigrants had more visceral adipose tissue (VAT) than African Americans (P0.01). Consequently, the WC that predicted insulin resistance was 92 cm in African immigrants but 102 cm in African Americans.African immigrants were less obese than African Americans but had worse cardiometabolic health, specifically higher glucose levels, more hypertension, and greater visceral adiposity. Overall, the healthy immigrant effect may no longer be valid.

Controversy exists as to whether low vitamin D levels contribute to the development of cardiometabolic disease. As African descent populations have a high prevalence of low vitamin D levels and cardiometabolic disease, clarification is important. However, current cross-sectional studies linking low vitamin D concentrations to cardiometabolic disease not only provide conflicting results, data specifically on people of African descent is very limited. Therefore, we evaluated the association between vitamin D levels, measured as 25(OH)D, and cardiometabolic risk factors in 78 African immigrants (77% male, age 35±y (mean±SD) age range 22-63y). Participants had oral glucose tolerance tests, insulin sensitivity index (S I ) determined with the minimal model and abdominal computerized tomographic scans to measure visceral adipose tissue (VAT). Cardiometabolic risk factors were related to 25(OH)D levels by Pearson correlations and one-way ANOVA across quartiles of 25(OH)D. Mean 25(OH)D levels were 22±7, range 10-36 ng/mL. BMI was 27.9±4.4 kg/m2 and 74% of Africans were either overweight or obese. Nine percent had newly identified diabetes and 33% had pre-diabetes. Mean arterial BP was 88±10 mmHg and 44% of Africans had either pre-hypertension or hypertension. Cardiometabolic variables did not change across quartiles of 25(OH)D (Table). In addition, there were no significant correlations between 25(OH)D and the cardiometabolic variables listed in the Table (all rP >0.1). As cardiometabolic risk factors do not become more severe as 25(OH)D levels decline, vitamin D may not modulate cardiometabolic risk in people of African descent.

As the obesity epidemic overtakes Africa, practical methods to measure percent body fat need identification. Possibilities which have not been validated in Africans are the Body Adiposity Index (BAI), which uses hip circumference and height and the same formula for men and women, and bioelectric impedance (BIA) derived from NHANES III data and uses different equations for men and women. Using dual-energy X-ray absorptiometry (DXA) scans as the reference method, 107 Africans (71% male; age 39.5∓10.3 y, range 22 to 64 y; BMI 27.9∓4.5 kg/m 2 , range 19.7 to 41.2 kg/m 2 ) had percent body fat assessed in two ways. Method 1 was: BAI (Hip circumference/Height 1.5 )-18). Method 2 was: BIA (Men: weight - (-10.678 + 0.262*weight + 0.652*height 2 /resistance + 0.015*resistance))/weight*100; Women: (weight - (-9.529 + 0.168*weight + 0.696*height 2 /resistance + 0.016*resistance))/weight*100)). Percent body fat by DXA, BAI and BIA are shown in the Figure. Concordance was between 0.5 and 0.6 with P

Without regard to race, the Institute of Medicine states that to protect bone health vitamin D, measured as 25(OH)D, should be >20 ng/mL while levels of 12-19 ng/mL are inadequate and levels of

Diabetes is reaching epidemic proportions in Africa. Therefore it is critical to invest scarce resources in effective tests. Both the World Health Organization and the American Diabetes Association have approved A1C and fasting plasma glucose (FPG) as diagnostic alternatives to the OGTT for the detection of pre-diabetes and diabetes. However, A1C thresholds for the diagnosis of abnormal glucose tolerance are dependent on >90% of hemoglobin (Hb) being HbA. This could be problematic for Africans, as the prevalence of variant Hb including both sickle (S) and HbC are high. When either HbS or HbC is present as a trait, the concentration of HbA is usually

In decades past, African immigrants were considered to have better cardiometabolic health than African Americans. Whether this health advantage continues to exist in the 21st century is unknown. To explore differences in markers of cardiometabolic health, oral glucose tolerance tests, blood pressure (BP), visceral adipose tissue (VAT) volume and the waist circumference (WC) which predicts insulin resistance were compared in 210 men (134 African immigrants, 76 African Americans, mean age 36±9y (mean±SD), range 20-64y) who self-identified as healthy. Insulin resistance was defined by the lowest quartile of the insulin sensitivity index (SI≤2•28mU/L-1.min-1). Receiver operating characteristic curves and the Youden Index were used to identify the WC which optimally predicts insulin resistance. BMI was lower in African immigrants than African Americans (27.4±3.9 vs. 29.3±5.5kg/m2, P

The prevalence of cardiometabolic disease in Africa now rivals that of Western nations. Therefore, screening programs that lead to effective prevention of cardiometabolic disease in Africans is imperative. Most screening tests for cardiometabolic disease use triglyceride (TG) levels as a criterion. However, the failure rate of TG-based screening tests in African Americans is high. In Africans, the efficacy of TG-based screening tests is unknown. Our goal was to determine the association between hypertriglyceridemia (TG ≥150 mg/dL) and cardiometabolic disease in African and African-American men.This was a cross-sectional study of 155 men (80 African immigrants, 75 African Americans) [age, 35±9 years, mean±standard deviation (SD), body mass index (BMI) 28.5±5.2 kg/m(2)] who self-identified as healthy. Lipid profiles were performed. Glucose tolerance and insulin resistance was determined by oral glucose tolerance tests (OGTT) and the insulin sensitivity index (S(I)), respectively. Cardiometabolic disease was defined by four possible subtypes--prediabetes, diabetes, insulin resistance, or metabolic triad [hyperinsulinemia, hyperapolipoprotein B, small low-density lipoprotein (LDL) particles].TG levels were higher in men with cardiometabolic disease than without (88±43 versus 61±26 mg/dL, P0.01). However,10% of men with cardiometabolic disease had TG ≥150 mg/dL. Even within each cardiometabolic disease subtype, the prevalence of TG ≥150 mg/dL was10%. Furthermore, TG levels in the 5% of men identified by OGTT as diabetic were ≤100 mg/dL (mean 71±24, range 45-100 mg/dL).Hypertriglyceridemia is a poor marker of cardiometabolic disease in men of African descent. Therefore TG-based screening tests fail to identify both African immigrants and African-American men with cardiometabolic disease. As a consequence, the opportunity for early intervention and prevention is lost.

Women of African descent have a high prevalence of diseases caused by insulin resistance. To positively impact cardiometabolic health in Black women, effective screening tests for insulin resistance must be identified. Recently, the TG/HDL-C ratio has been recommended as a tool to predict insulin resistance in overweight people. While the ratio predicts insulin resistance in White women, it is ineffective in African American women. As there are no data for African women, we tested the ability of the TG/HDL-C ratio to predict insulin resistance in Black women from South Africa, West Africa and the United States. For comparison, the ratio was also tested in White women from South Africa. Participants were 801 women (157 Black South African, 382 African American, 119 West African, 143 White South African, age 36 +/- 9y [mean +/- SD]). Standardized scores were created from log-transformed homeostasis model assessment-insulin resistance values from each population. Participants in the upper third of their population distribution were classified as insulin-resistant. To predict insulin resistance by the TC/HDL-C ratio, area under the receiver operating characteristic (AUC-ROC) curve was used and criteria were: 0.50 for no discrimination andor = 0.70 for acceptable. Seventy-one percent of the Black women were overweight vs 51% of White women (P.01). In overweight White women, AUC-ROC curve for prediction of insulin resistance by TG/HDL-C was 0.76 +/- 0.06, but below the 0.70 threshold in each group of overweight Black women (Black South African: 0.64 +/- 0.06, African American: 0.66 +/- 0.03, and West African: 0.63 +/- 0.07). Therefore, TG/HDL-C does not predict insulin resistance in overweight African American women and this investigation extends that finding to overweight Black South African and West African women. Resources to identify effective markers of insulin resistance are needed to improve cardiometabolic health in women of African descent.

Insulin resistance is associated with endothelial dysfunction. Because African-American women are more insulin-resistant than white women, it is assumed that African-American women have impaired endothelial function. However, racial differences in postprandial endothelial function have not been examined. In this study, we test the hypothesis that African-American women have impaired postprandial endothelial function compared with white women. Postprandial endothelial function following a breakfast (20% protein, 40% fat, and 40% carbohydrate) was evaluated in 36 (18 African-American women, 18 white women) age- and body mass index (BMI)-matched (age: 37 ± 11 yr; BMI: 30 ± 6 kg/m2) women. Endothelial function, defined by percent change in brachial artery flow-mediated dilation (FMD), was measured at 0, 2, 4, and 6 h following a meal. There were no significant differences between the groups in baseline FMD, total body fat, abdominal visceral fat, and fasting levels of glucose, insulin, total cholesterol, low-density lipoprotein cholesterol, or serum estradiol. Although African-American women were less insulin-sensitive [insulin sensitivity index (mean ± SD): 3.6 ± 1.5 vs. 5.2 ± 2.6, P = 0.02], both fasting triglyceride (TG: 56 ± 37 vs. 97 ± 49 mg/dl, P = 0.007) and incremental TG area under the curve (AUC0–6hr: 279 ± 190 vs. 492 ± 255 mg·dl−1·min−1·10−2, P = 0.008) were lower in African-American than white women. Breakfast was associated with a significant increase in FMD in whites and African-Americans, and there was no significant difference in postprandial FMD between the groups ( P > 0.1 for group × time interactions). Despite being insulin-resistant, postprandial endothelial function in African-American women was comparable to white women. These results imply that insulin sensitivity may not be an important determinant of racial differences in endothelial function.

Context: The effect of oral contraceptive pill (OCP) use on cardiovascular risk in African-American women is unknown. Objective: Our objective was to examine in African-American women the effect of OCP use on insulin resistance, glucose intolerance, and triglycerides (TGs). Design: This was a cross-sectional study. Setting: The study was conducted at the National Institutes of Health Clinical Research Center. Participants: A total of 104 healthy nondiabetic African-American women [21 OCP users, 83 controls, age mean ± sd, 34.7 ± 7.6 yr, body mass index (BMI) 31 ± 8.4 kg/m2] was included in the study. Interventions: Subjects had oral glucose tolerance tests, insulin-modified frequently sampled iv glucose tolerance tests, and fasting lipid profiles. Insulin resistance was determined by the insulin sensitivity index (SI). Main Outcome Measures: Insulin resistance, glucose tolerance status, and TG levels were determined. Results: Fasting glucose did not differ between OCP users and controls (P = 0.27). In contrast, compared with controls, 2-h glucose (135 ± 23 vs.120 ± 25 mg/dl; P = 0.01) and fasting TGs (73 ± 31 vs.57 ± 27 mg/dl; P = 0.02) were higher in OCP users. OCP users tended to be more insulin resistant than controls (SI: 2.51 ± 2.01 vs. 3.46 ± 2.09; P = 0.09). Multiple regression analysis revealed that BMI, age, and OCP use were significant determinants of 2-h glucose (adjusted R2 = 0.37; P < 0.001) and TG levels (adjusted R2 = 0.21; P < 0.001). As BMI was a determinant of both 2-h glucose and TGs, participants were divided into nonobese and obese groups, and the analyses repeated. Among the nonobese women, the OCP users were more insulin resistant (SI: 2.91 ± 1.58 vs. 4.35 ± 1.88; P = 0.03) and had a higher prevalence of glucose intolerance than controls (odds ratio 5.7; 95% confidence interval 1.4–24; P = 0.01). Conclusion: In African-American women, OCP use is associated with an increase in markers of cardiovascular risk manifested by increased insulin resistance, glucose intolerance, and elevated TGs.

Objective: African Americans (AAs) have less visceral and more subcutaneous fat than whites, thus the relationship of adiponectin and leptin to body fat and insulin sensitivity in AA may be different from that in whites. Methods and Procedures: Sixty-nine non-diabetic AA (37 men and 32 women), aged 33 ± 1 year participated. The percent fat was determined by dual-energy X-ray absorptiometry, abdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) volume by computerized tomography (CT), and insulin sensitivity by homeostasis model assessment (HOMA). Results: VAT was greater in men (1,619 ± 177 cm3 vs. 1,022 ± 149 cm3; P = 0.01); women had a higher percentage of body fat (34.1 ± 1.4 vs. 24.0 ± 1.2; P < 0.0001), adiponectin (15.8 ± 1.2 μg/ml vs. 10.4 ± 0.8 μg/ml; P = 0.0004) and leptin (23.2 ± 15.8 ng/ml vs. 9.2 ± 7.2 ng/ml; P < 0.0001). SAT and HOMA did not differ because of the sex. Adiponectin negatively correlated with VAT (r = −0.41, P < 0.05) in men, and with VAT (r = −0.55, P < 0.01), and SAT (r = −0.35, P < 0.05) in women. Adiponectin negatively correlated with HOMA in men (r = −0.38, P < 0.05) and women (r = −0.44, P < 0.05). In multiple regression, sex (P = 0.02), HOMA (P = 0.03) and VAT (P = 0.003) were significant predictors of adiponectin (adj R 2 = 0.38, P < 0.0001). Leptin positively correlated with VAT, SAT, percent fat and HOMA in men (r = 0.79, r = 0.86, r = 0.89, and r = 0.53; P < 0.001) and women (r = 0.62, r = 0.75, r = 0.83, and r = 0.55; P < 0.01). In multiple regression VAT (P = 0.04), percent body fat (P < 0.0001) and sex (P = 0.01), but not HOMA were significant predictors of serum leptin (adj R 2= 0.82, P < 0.0001). Discussion: The relationship of adiponectin and leptin to body fat content and distribution in AA is dependent on sex. Although VAT and insulin sensitivity are significant determinants of adiponectin, VAT and percent body fat determine leptin.

Background African-Americans are more insulin-resistant than whites but have lower triglyceride (TG) concentrations. The metabolic basis for this is unknown. Our goal was to determine in a cross-sectional study the effect of insulin resistance, visceral adipose tissue (VAT) and the apolipoproteins, B, C-III and E, on race differences in TG content of very low density lipoproteins (VLDL). Methods The participants were 31 women (16 African-American, 15 white) of similar age (37 ± 9 vs. 38 ± 11y (mean ± SD), P = 0.72) and BMI (32.4 ± 7.2 vs. 29.3 ± 6.0 kg/m2, P = 0.21). A standard diet (33% fat, 52% carbohydrate, 15% protein) was given for 7 days followed by a test meal (40% fat, 40% carbohydrate, 20% protein) on Day 8. Insulin sensitivity index (SI) was calculated from the minimal model. VAT was measured at L2-3. The influence of race, SI, VAT and apolipoproteins on the TG content of VLDL was determined by random effects models (REM). Results African-Americans were more insulin-resistant (SI: 3.6 ± 1.3 vs. 5.6 ± 2.6 mU/L-1.min-1, P