Diabetic nephropathy is associated with an increased familial risk of stroke

OBJECTIVE - To test the hypothesis that genetic susceptibility to diabetic nephropathy is associated with an increased familial risk of vascular disea se, we have examined the causes and rates of death of parents of individual s with type 1 diabetes complicated by diabetic nephropathy compared with th e causes and rates of death of parents of control subjects with diabetes un complicated by nephropathy RESEARCH DESIGN AND METHODS - Individuals with at least a 14-year duration of type I diabetes complicated by diabetic nephropathy were identified and matched for age, sex, and duration of diabetes to control subjects. A total of 118 patients and 118 matched control subjects Here identified and appro ached to obtain information on parental age and cause of death. For parents who had died, the cause of death was ascertained from the death certificat e. RESULTS - Kaplan-Meier curves showed that parents of subjects with nephropa thy (PN) had reduced survival compared with parents of diabetic subjects wi thout nephropathy (PC) (log rank test P < 0.05). There nas an excess of ail vascular deaths and, in particular, strokes in the parents of subjects wit h nephropathy (PN: 20 of 103 deaths, 19% vs. PC: 3 of 66 deaths, 4%: Fisher 's exact test P < 0.01). CONCLUSIONS - Parents of diabetic patients with nephropathy have reduced su rvival. This seems to be largely explained by an increase in vascular death s and, in particular, a fourfold increase in the number of strokes. This su pports the hypothesis that a common hereditary risk factor predisposes to b oth vascular death and diabetic renal disease.