Black Determinants of Health.

This graffiti-esque mosaic considers legacies of slavery and segregation as manifested in present-day health inequities. Racist American structures and practices are maintained by social policies and cultural attitudes informed by old stereotypes.

Postprandial Insulin Response and Clearance Among Black and White Women: The Federal Women's Study.

Context: Postprandial hyperinsulinemia might be an important cardiometabolic risk determinant in black compared with white women. However, the contributions of insulin clearance and ß-cell function to racial differences in postprandial insulin response are unknown. Objective: To compare, by race and menopause, early insulin response to oral and intravenous glucose and to measure postprandial intact glucagon-like peptide 1 (GLP-1) concentrations, insulin clearance, and ß-cell function. Design and Participants: 119 federally employed women without diabetes [87 premenopausal (52 black, 35 white) and 32 postmenopausal (19 black, 13 white)] underwent an oral glucose tolerance test, insulin-modified frequently sampled intravenous glucose test (IM-FSIGT), and mixed meal tolerance test (MMTT). Outcome Measures: Early insulin response was measured as follows: (i) insulinogenic index (oral glucose tolerance test); (ii) acute insulin response to glucose (IM-FSIGT); and (iii) ratio of incremental insulin/glucose area under the curve in the first 30 minutes of the MMTT. Insulin clearance was assessed during the IM-FSIGT and MMTT. During the MMTT, intact GLP-1 was measured and ß-cell function assessed using the insulin secretion rate and ß-cell responsivity indexes. Results: Black pre-menopausal and postmenopausal women had a greater insulin response and lower insulin clearance and greater dynamic ß-cell responsivity (P ≤ 0.05 for all). No differences were found in the total insulin secretion rates or intact GLP-1 concentrations. Conclusions: Greater postprandial hyperinsulinemia in black pre-menopausal and postmenopausal women was associated with lower hepatic insulin clearance and heightened ß-cell capacity to rapid changes in glucose, but not to higher insulin secretion. The relationship of increased ß-cell secretory capacity, reduced insulin clearance, and ambient hyperinsulinemia to the development of cardiometabolic disease requires further investigation.

Two- vs one-hour glucose tolerance testing: Predicting prediabetes in adolescent girls with obesity.

BACKGROUND: During an oral glucose tolerance test (OGTT), morphological features of the glucose curve (monophasic curve, glucose peak >30 minutes and 1-hour glucose ≥ 155 mg/dL) maybe associated with higher prediabetes risk, but their reproducibility and predictive ability in adolescents with obesity are unknown. METHODS: Nondiabetic adolescent girls with obesity underwent a multiple-sample OGTT at baseline (n = 93), 6 weeks (n = 83), and 1 year (n = 72). Short-term reproducibility (baseline to 6 weeks) and the predictive ability for prediabetes (baseline to 1 year) for each feature were compared with standard fasting and 2-hour OGTT diagnostic criteria. RESULTS: There was fair/moderate short-term reproducibility (κ < 0.5) for all morphological features. At 1 year, compared with standard OGTT criteria, the areas under the receiver operating curve (ROC-AUCs) for glucose peak > 30 minutes, 1 hour ≥155 mg/dL or a combination of the two criteria were comparable (all P > 0.05), but the monophasic curve had the lowest ROC-AUC (P < 0.001). CONCLUSIONS: In adolescent girls with obesity, glucose peak > 30 minutes and/or glucose ≥155 mg/dL had similar reproducibility and 1-year predictive ability for prediabetes compared with standard OGTT criteria. The shortened 1-hour OGTT may provide diagnostic equivalence for prediabetes risk with the additional advantage of a less time-consuming risk assessment.

Gluconeogenesis and risk for fasting hyperglycemia in Black and White women.

Black women, compared with White women, have high rates of whole-body insulin resistance but a lower prevalence of fasting hyperglycemia and hepatic steatosis. This dissociation of whole-body insulin resistance from fasting hyperglycemia may be explained by racial differences in gluconeogenesis, hepatic fat, or tissue-specific insulin sensitivity. Two groups of premenopausal federally employed women, without diabetes were studied. Using stable isotope tracers, [2H2O] and [6,62-H2]glucose, basal glucose production was partitioned into its components (gluconeogenesis and glycogenolysis) and basal whole-body lipolysis ([2H5]glycerol) was measured. Indices of insulin sensitivity, whole-body (SI), hepatic (HISIGPR), and adipose tissue, were calculated. Hepatic fat was measured by proton magnetic resonance spectroscopy. Black women had less hepatic fat and lower fractional and absolute gluconeogenesis. Whole-body SI, HISIGPR, and adipose tissue sensitivity were similar by race, but at any given level of whole-body SI, Black women had higher HISIGPR. Therefore, fasting hyperglycemia may be a less common early pathological feature of prediabetes in Black women compared with White women, because gluconeogenesis remains lower despite similar whole-body SI.

Cardiometabolic risk in obese children.

Obesity in childhood remains a significant and prevalent public health concern. Excess adiposity in youth is a marker of increased cardiometabolic risk (CMR) in adolescents and adults. Several longitudinal studies confirm the strong association of pediatric obesity with the persistence of adult obesity and the future development of cardiovascular disease, diabetes, and increased risk of death. The economic and social impact of childhood obesity is further exacerbated by the early onset of the chronic disease burden in young adults during their peak productivity years. Furthermore, rising prevalence rates of severe obesity in youth from disadvantaged and/or minority backgrounds have prompted the creation of additional classification schemes for severe obesity to improve CMR stratification. Current guidelines focus on primary obesity prevention efforts, as well as screening for clustering of multiple CMR factors to target interventions. This review summarizes the scope of the pediatric obesity epidemic, the new severe obesity classification scheme, and examines the association of excess adiposity with cardiovascular and metabolic risk. We will also discuss potential questions for future investigation.

Time to glucose peak during an oral glucose tolerance test identifies prediabetes risk.

CONTEXT: Morphological characteristics of the glucose curve during an oral glucose tolerance test (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 ß-cell function. DESIGN AND PARTICIPANTS: In a cross-sectional evaluation using an OGTT, 145 adults without diabetes (age 42±9 years (mean±SD), range 24-62 years, BMI 29.2±5.3 kg/m2 , range 19.9-45.2 kg/m2 ) were characterized by peak (30 minutes vs >30 minutes) and shape (biphasic vs monophasic). MAIN OUTCOME MEASURES: Prediabetes and disposition index (DI)-a marker of ß-cell function. RESULTS: Prediabetes was diagnosed in 36% (52/145) of participants. Peak>30 minutes, not monophasic curve, was associated with increased odds of prediabetes (OR: 4.0 vs 1.1; P<.001). Both monophasic curve and peak>30 minutes were associated with lower DI (P≤.01). Time to glucose peak and glucose area under the curves (AUC) were independent predictors of DI (adjR2 =0.45, P<.001). CONCLUSION: Glucose peak >30 minutes was a stronger independent indicator of prediabetes and ß-cell function than the monophasic curve. Time to glucose peak may be an important tool that could enhance prediabetes risk stratification.