Annual and 5-year incidence rate of hypertension in type 2 diabetic patients

Hypertension in one of the aggravating factors for cardiovascular complications among diabetics, which in turn leads to increased mortality among these patients. This study investigated the annual and 5-year incidence rate of hypertension in type 2 diabetic patients referring to Isfahan Endocrine and Metabolism Research Center (IEMRC).

In a prospective study, all type 2 diabetic patients with normal blood pressure, who were referred to IEMRC in 1995, underwent investigation. Age, sex, weight, height, serum cholesterol, triglycerides and HbA1c and urine protein were measured and the results recorded in addition to the history of smoking and the duration of diabetes. All measurements (including blood pressure, ophthalmologic exam) were repeated every 6 months for 5 years.

Of 770 patients, 174 (23%) were excluded because of high blood pressure at their first visit. The 5-year incidence rate was 41.5%. The mean±SD of BMI and age in hypertensive vs normotensive patients were 27.8±3.8 vs 26.2±3.8 kg/m2 (p<0.05), 52.6±10 vs 45.6±10 years (p<0.05), respectively. Differences observed among other variables were not significant. Presence of retinopathy and proteinuria at base line causes significant increase in the 5-year incidence of hypertension.

The incidence of hypertension in type 2 diabetic patients is higher in our society as compared with that seen in other studies. Age, duration of the diabetes and BMI affect the incidence of hypertension. Retinopathy and proteinuria are important risk factors of hypertension among our patients.