Background Primary insulin hypersecretion predicts type 2 diabetes (T2DM) independent of insulin resistance. Enhanced β-cell glucose responsivity contributes to insulin hypersecretion. African Americans (AAs) are at a higher risk for T2DM than non-Hispanic Whites (NHWs). Whether AAs manifest primary insulin hypersecretion is an important topic that has not been examined systematically. Objective To examine if nondiabetic AA adults have a higher β-cell glucose responsivity compared with NHWs. Methods Healthy nondiabetic AA (n = 18) and NHW (n=18) subjects were prospectively recruited. Indices of β-cell function, acute C-peptide secretion (X0); basal (Φ B), first-phase (Φ 1), second-phase (Φ 2), and total β-cell responsivity to glucose (Φ TOT), were derived from modeling of insulin, C-peptide, and glucose concentrations during an intravenous glucose tolerance test. Insulin sensitivity was assessed by the hyperinsulinemic–euglycemic glucose clamp technique. Results Glucose disposal rate (GDR) during clamp was similar in AAs and NHWs (GDR: [AA] 12.6 ± 3.2 vs [NHW] 12.6 ± 4.2 mg/kg fat free mass +17.7/min, P = .49). Basal insulin secretion rates were similar between the groups. AA had significantly higher X0 (4423 ± 593 vs 1807 ± 176 pmol/L, P = .007), Φ 1 [377.5 ± 59.0 vs 194.5 ± 26.6 (109) P = 0.03], and Φ TOT [76.7 ± 18.3 vs 29.6 ± 4.7 (109/min), P = 0.03], with no significant ethnic differences in Φ B and Φ 2. Conclusions Independent of insulin sensitivity, AAs showed significantly higher first-phase and total β-cell responsivity than NHWs. We propose that this difference reflects increased β-cell responsivity specifically to first-phase readily releasable insulin secretion. Future studies are warranted to identify mechanisms leading to primary β-cell hypersensitivity in AAs.

OBJECTIVE To examine the ethnic differences in insulin sensitivity (S I ) as measured by the minimal model approach (S I -MM) and the reference method, the euglycemic-hyperinsulinemic clamp (EHC). RESEARCH DESIGN AND METHODS In a prospective study design, thirty Black Americans (BA) were age, sex, and BMI matched with non-Hispanic Whites (NHW). Participants underwent frequently sampled intravenous tolerance test (FSIVGTT) and EHC on 2 separate days during a single visit. RESULTS S I -MM values were significantly lower in BA when compared with NHW (0.035 ± 0.025 vs. 0.058 ± 0.036 [dL/min]/[μU/mL]; P = 0.003). However, there were no ethnic differences in S I measured by EHC (0.028 ± 0.012 vs. 0.035 ± 0.019 [dL/min]/[μU/mL]; P = 0.18). CONCLUSIONS S I -MM systematically underestimates S I in BA when compared with NHW. These findings suggest that studies inferring lower S I in BA based on FSIVGTT and S I -MM should be interpreted cautiously.

Introduction. The goal of this systematic review and meta-analysis was to consolidate the available data on the role of the neutrophil to lymphocyte ratio (NLR) in predicting adnexal torsion (AT), to help guide clinical decision-making and outcomes. Methods. We used Web of Science, PubMed, and Scopus to conduct a systematic search for relevant publications published before June 26, 2022. We reported standardized mean difference (SMD) with a 95% confidence interval (CI). Because a significant level of heterogeneity was found, we used the random-effects model to calculate pooled effects. We used the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) too for quality assessment. Results. Overall, 15 articles were included in the analysis. A random-effects model revealed that patients with AT had elevated levels of NLR compared to those with other adnexal masses ( SMD = 1.06 , 95 % CI = 0.67 to 1.45, p < 0.001 ). So, NLR had diagnostic value. In the subgroup analysis according to ethnicity, we found that Caucasian patients with AT had elevated levels of NLR compared to patients who were operated due to adnexal mass and reported as having a benign ovarian cyst, without torsion ( SMD = 1.12 , 95 % CI = 0.71 to 1.54, p < 0.001 ). However, in the case of East Asian patients, there was no difference between cases and controls ( SMD = 0.86 , 95 % CI = − 0.21 to 1.94, p = 0.11 ). The pooled sensitivity of NLR was 0.79 ( 95 % CI = 0.72 – 0.85 ), and the pooled specificity was 0.84 (95% CI, 0.74–0.91). Conclusion. In conclusion, there has been an interest in the use of NLR as a diagnostic marker for AT.