Surrogate markers of insulin resistance in assessing individuals with new categories "prehypertension" and "prediabletes"

Background: There are few data on the impact of insulin resistance on the recently defined categories of prehypertension (PHT) and prediabetes (PDM). The aim of this study was to examine associations of surrogate markers of insulin resistance with PHT/PDM. Methods: Subjects included 554 individuals who underwent a 75-g oral glucose tolerance test (OGTT). They were classified into four groups using a severity score for high blood pressure and glucose tolerance. Insulin resistance was measured using the homeostasis model assessment of insulin resistance (HOMA-R) and three surrogate markers obtained from 75-g OGTT values (ISI-composite, Stumvoll index, and OGIS index). Results: HOMA-R increased significantly, but the other three surrogate indices decreased with increasing severity score. Of these markers, the OGIS index was mostly associated with prevalent PHT/PDM and the odds ratio for insulin resistance was 3.61 (95% Cl 1.68-7.76, p=0.001) for subjects with either PHT or PDM and 29.98 (12.81-70.18, p < 0.001) for subjects with both PHT and PDM. Conclusions: PHT and PDM frequently coexist in relatively lean Japanese subjects. Decreased insulin sensitivity may contribute to the underlying status of PHT/PDM. Among the surrogate markers of insulin resistance, the OGIS index is the most sensitive for assessment of PHT/PDM status.