Prevalence of hypertension and associated risk factors among diabetic individuals. The Three-City Study.

A cross-sectional study was conducted from 1979 through 1982 in three rural Minnesota cities to describe the natural history of diabetes mellitus. Detailed abstracts of the medical records of physician-defined diabetic individuals were used to construct medical profiles. As part of the effort, the date of physician-defined hypertension was identified and used to calculate hypertension prevalence. The crude hypertension prevalence was 56.8% for women and 33.99% for men, with an overall crude prevalence of 47.2%. No hypertensive patients were identified among diabetic patients less than 15 yr old, and most hypertensive diabetic patients were greater than 70 yr old. Hypertension prevalence in diabetic individuals demonstrated a highly significant trend with age (P less than .01). Compared with the general population, diabetic individuals had a significantly higher prevalence of hypertension (P less than .01), largely explained by the higher prevalence in women. Variables known to be associated with hypertension risk in the general population were also significantly associated with hypertension among diabetic individuals. Older age, being female, and increased body mass index were strongly associated with hypertension in this study population. Diabetic individuals with hypertension were six times more likely to have renal disease than those without hypertension. The level of blood glucose control, diabetes treatment (i.e., insulin or oral hypoglycemics versus diet), and diabetes duration were not associated with hypertension.