Higher Waist Circumference, Fasting Hyperinsulinemia and Insulin Resistance Characterize Hypertensive Patients with Impaired Glucose Metabolism

Hypertensive patients are at higher risk of pre-diabetes (impaired fasting glucose [IFG] and impaired glucose tolerance [IGT]) and type 2 DM. This study was done to examine whether some general, anthropometric, hormone, and metabolic parameters are different between subjects with normal and impaired glucose metabolism (IGM) in hypertensive subjects, thus possibly identifying some variable characterizing glucose metabolism derangement in these patients. A cohort of 134 hypertensive patients, 55 women and 79 men, aged 37-70 years, were examined. IGM patients were considered showing IFG and/or IGT or type 2 DM after an oral glucose tolerance test (OGTT), and/or HbA1c >= 48 mmol/1 (6.5%) and/or glucose levels >155 mg/dL after 1 hour of the OGTT. Body mass index (BMI), waist circumference, and fasting insulin, TSH, FT3, FT4, glucose, and lipid (cholesterol, HDL-cholesterol and triglycerides) plasma concentrations were measured. Insulin resistance was also assessed by the homeostasis model assessment (HOMA(IR)). Results: Waist circumference (p < 0.05), fasting glucose (p < 0.05) and insulin levels (p < 0.05) and HOMA(IR) (p < 0.05) were significantly higher in patients with IGM than in control group. All other investigated parameters, as well as the number of antihypertensive drugs per single patient, were not different between the two groups. Conclusion: The present study, performed in a selected population of hypertensive subjects, shows that derangement of glucose metabolism is associated to central fat accumulation, hyperinsulinemia and insulin resistance.