Increased C-reactive protein is associated with future development of diabetes mellitus in essential hypertensive patients

Coexistence of hypertension and diabetes mellitus (DM) increases the risk of cardiovascular disease. However, factors associated with future development of DM have not been well elucidated in patients already having essential hypertension. This study prospectively included 168 patients (mean age 41 ± 7 years, 112 men) with essential hypertension. All patients did not have DM and vascular or renal complications initially. Baseline demographic data, blood pressure, body mass index, and antihypertensive agents were carefully evaluated and serum high-sensitivity C-reactive protein (hsCRP) was measured at the beginning of the study. All of the patients were followed for at least 6 months. The study endpoint was occurrence of new DM. After a mean follow-up period of 32 ± 10 months, 22 subjects (13.1%) developed new DM. Patients with new DM had higher baseline glucose (105.2 ± 11.8 vs 94.2 ± 8.0 mg/dl, P < 0.001), triglyceride level (213.7 ± 112.4 vs 155.6 ± 83.2 mg/dl, P = 0.04), log hsCRP (0.31 ± 0.44 vs 0.19 ± 0.25 mg/dl, P = 0.016), and lower high-density lipoprotein (40.2 ± 7.8 vs 46.6 ± 14.4 mg/dl, P = 0.045). Total cholesterol, low-density lipoprotein, homeostasis model assessment index, and adiponectin were not different in patients with or without new DM. Among antihypertensive agents, only use of β-blocker was significantly associated with new DM (P = 0.008). Multivariate Cox regression analysis showed log hsCRP (hazard ratio [HR] 9.77, 95% confidence interval [CI] 2.97-32.10, P < 0.001), age (HR 1.21, 95% CI 1.06-1.38, P = 0.004), and baseline glucose level (HR 1.11, 95% CI 1.06-1.15, P < 0.001) to be independent predictors for occurrence of new DM. High-sensitivity CRP was an independent factor for future development of DM in essential hypertensive patients. Increased inflammation might have a key role in the pathogenesis of DM in hypertension.