Association of Three Simple Insulin Resistance Indexes with Prehypertension in Normoglycemic Subjects.

Background: Insulin resistance (IR) is the common pathophysiology of prehypertension and prediabetes. Recognition of IR in one of the two disease states is critical for carrying out preventive strategies of another disease state. This study aimed to explore which simple IR indexes were significantly associated with prehypertension in subjects with normoglycemia. Methods: A total of 108,370 adults without elevated fasting plasma glucose and hypertension were included in this study. The three simple IR indexes [triglycerides to high-density lipoprotein cholesterol ratio, the product of fasting triglycerides and glucose, and metabolic score for IR (METS-IR)] were calculated. Partial correlation was used to analyze the correlation between the three indicators and blood pressure (BP) levels, and logistic regression analysis was used to explore their association with prehypertension. Results: Among the three indicators, only METS-IR had positive correlations with systolic and diastolic blood pressure levels. Furthermore, METS-IR was also significantly associated with prehypertension, irrespective of the categorization of waist circumference (WC). The odds ratios of the highest quartile were 2.223 (95% confidence interval [CI]: 2.044-2.417) in all subjects, 2.022 (95% CI: 1.501-2.725) in elevated WC subgroup, and 1.815 (95% CI: 1.620-2.034) in normal WC subgroup. Conclusions: METS-IR was associated with prehypertension in normoglycemic Chinese subjects, which bypasses the impact of WC and might be valuable for the management of prehypertension and the prevention of prediabetes in different ethnic groups.

Race or vitamin D: A determinant of intima media thickness in obese adolescents?

OBJECTIVE: Carotid intima media thickness (IMT), a predictor of cardiovascular events, is reported to be higher in African-American (AA) vs White (AW) individuals. We investigated whether racial differences in IMT in obese adolescents could be explained by differences in 25 hydroxy-vitamin D [25(OH)D]. RESEARCH DESIGN AND METHODS: A total of 63 obese adolescents had 25(OH)D levels, determination of IMT, body composition, insulin sensitivity (IS) by hyperinsulinemic-euglycemic clamp, lipids and blood pressure (BP). RESULTS: IMT was higher and 25(OH)D lower in AA vs AW. IMT correlated with 25(OH)D level (r = -0.38, P = .002) but not with IS. In multiple regression analysis, race, HbA1c, BP and age, and not 25(OH)D, BMI or IS, were the significant determinants of IMT (R2 = 0.44, P < .001). Without race in the model, 25(OH)D (ß = -0.36, P = .009) contributed to the variance in IMT (R2 = 0.32, P = .007). CONCLUSION: Obese AA adolescents vs AW, have higher IMT, explained by race, BP, and HbA1c. Although 25(OH)D levels contribute to the variance in IMT, the observed racial difference in IMT could be mediated through other unknown race-related factors besides 25(OH)D.