Subclinical functional and structural renal abnormalities predict new onset type 2 diabetes in patients with primary hypertension

Recent studies suggest a close relationship between renal dysfunction and new onset diabetes (NOD). The aim of the study was to investigate the association between subclinical functional and structural renal abnormalities and NOD in primary hypertension (PH). This observational prospective study (9.1±2.2 years follow-up) includes 231 consecutive untreated non-diabetic patients with PH and without overt nephropathy. The primary end point was NOD. Albuminuria (albumin to creatinine ratio, ACR), glomerular filtration rate (eGFR), and renal structure and hemodynamics (ultrasound scan and Doppler) were evaluated at baseline. During 2106 person-years of follow-up, 10 patients developed diabetes (incidence rate 4.7/1000 person-years). Patients with NOD showed a higher body mass index, serum uric acid, serum creatinine and ACR, and lower eGFR and renal volume (RV) to resistive index (RI) ratio (RV/RI) at baseline, as compared with the 221 controls that did not develop diabetes. When all renal variables were taken into consideration, RV/RI was the only variable significantly related to diabetes (hazard ratio 1.04, P=0.0342). Patients in the lowest tertile of RV/RI were more likely to develop diabetes (10.4 vs 2.6 vs 0%, P=0.0044). For each s.d. decrease of RV/RI, the risk of NOD increased by 68% (P=0.0012). Subclinical functional and structural renal abnormalities are independent predictors of diabetes in PH