Increased familial history of arterial hypertension, coronary heart disease, and renal disease in Brazilian type 2 diabetic patients with diabetic nephropathy

OBJECTIVE - To evaluate whether there is a familial association of arterial hypertension, coronary heart disease, renal disease, and stroke with diabetic nephropathy. RESEARCH DESIGN AND METHODS - There were 115 outpatients and 34 patients with end-stage renal disease treated by hemodialysis (61 men, age range 41-81 years) and having at least one sibling with type 2 diabetes studied. The positive or negative history of siblings (n = 765) was assessed by a standard questionnaire. The urinary albumin excretion rate (UAER) was measured by radioimmunoassay in 24-h sterile urine (three samples). The subjects were grouped as normoalbuminuric (UAER <20 mu g/min, n = 59), microalbuminuric (UAER 20-200 mu g/min, n = 35), macroalbuminuric (UAER >200 mu g/min, n = 21), and end-stage renal disease (n = 34). RESULTS - Patients with microalbuminuria, macroalbuminuria, or end-stage renal disease had an increased prevalence of sibling history of arterial hypertension (33.2, 37.3, and 33.8 vs. 23.4%, P < 0.001) and coronary heart disease (15.2, 17.0, and 19.4 vs. 10.2%, P = 0.044) compared with the normoalbuminuric group. The renal disease history was increased only in the siblings of patients with macroalbuminuria or end-stage renal disease (12.8 and 15.6 vs. 7.6 and 6.1%, P = 0.005). The presence of sibling arterial hypertension strongly increases the prevalence of sibling renal and coronary heart disease independent of patient renal status. CONCLUSIONS - There is an association of diabetic nephropathy and sibling history of arterial hypertension and renal and coronary heart disease in type 2 diabetic patients. These associations are not independent, and arterial hypertension may be their main determining factor.