Predisposition to Hypertension and Susceptibility to Renal Disease in Insulin-Dependent Diabetes Mellitus

Only one third of patients with juvenile-onset insulin-dependent diabetes seem to be susceptible to diabetic nephropathy. To test whether this susceptibility is related to a predisposition to hypertension, we investigated the association of nephropathy with markers of risk for hypertension. We randomly selected 89 patients with insulin-dependent diabetes from a roster of children and adolescents who were seen between 1968 and 1972 at about the time the diagnosis was made. These 89 patients were recalled for examination, as young adults, in 1986 and 1987. Patients with nephropathy (cases, n = 33) were compared with controls without nephropathy (n = 56). Having a parent with hypertension tripled the risk of nephropathy (odds ratio, 3.7; 95 percent confidence interval, 1.4 to 10.1). Moreover, cases had significantly higher values for maximal velocity of lithium–sodium countertransport in red cells than controls (mean maximal velocity ±SE, 0.51 ±0.04 vs. 0.38±0.02 mmol per liter of cells per hour; P