Higher blood pressure in normoalbuminuric type 1 diabetic patients with a familial history of type 2 diabetes.

Background: To address whether type 1 diabetic patients with type 2 diabetic first degree relatives are different from others in terms of cardiovascular risk factors, insulin resistance and daily insulin dosage.
Methods: We studied 18 type 1 diabetic patients with type 2 diabetic first degree relatives and 36 type 1 diabetic patients without such relatives. Patients with diabetic complications (including microalbuminuria) were excluded. The groups were similar in terms of baseline characteristics. We measured systolic and diastolic blood pressures, body mass index, waist circumference, total cholesterol, triglycerides, LDL, VLDL, HDL, daily insulin dosage and insulin sensitivity. Insulin sensitivity was tested using insulin tolerance test.
Results: Type 1 diabetic patients having first degree relatives with type 2 diabetes had significantly higher systolic and diastolic blood pressures (although within the normal range) than others (p < 0.001). They were more insulin resistant according to insulin tolerance test and were using higher daily insulin dosages. In this group, waist circumference, triglyceride and VLDL levels also tended to be higher, but differences were not significant statistically. Total cholesterol, LDL and HDL levels were similar in both groups.
Conclusion: Family history of type 2 diabetes increases blood pressure and decreases insulin sensitivity in type 1 diabetic patients. Thus such patients should be treated more aggressively in terms of both cardiovascular risk factors and glucose control.