Possible relationship between hyperinsulinemia and glomerular hypertrophy in nephrosclerosis

Hyperinsulinemia is potentially associated with the development of vascular sclerosis. On the other hand, the relationship between hyperinsulinemia and nephrosclerosis has not been elucidated. In this investigation clinicopathological studies were performed in 40 patients with nephrosclerosis, with special attention to the relationship between hyperinsulinemia and glomerular hypertrophy. Forty patients with biopsy-proven nephrosclerosis were divided into two groups by the 75-g oral glucose tolerance test (OGTT): group A, 2-hr plasma glucose concentration > 140 mg/dL (n = 25); group B, 140 < or = 2-hr plasma glucose < 200 mg/dL (n = 15). Patients with diabetes mellitus or diabetic nephropathy were not included. Morphometric analysis of the glomeruli revealed a significantly larger mean glomerular volume in subjects with nephrosclerosis in both subgroups. In addition, the mean glomerular volume was significantly correlated with the fasting insulin level, while no significant correlation was observed between the mean glomerular volume and creatinine clearance or degree of global sclerosis. These results indicate that hyperinsulinemia may be intimately related to glomerular hypertrophy in patients with nephrosclerosis.