Prevalence and correlates of hypertension in a subarctic Indian population

In a cross-sectional survey of 704 Cree and Ojibwa Indians ages 20-64 in six northern Canadian communities, blood pressure was measured along with various anthropometric, dietary, biochemical, sociodemographic, and lifestyle data.

Two readings of systolic (SBP) and diastolic (DBP) pressures were obtained using a mercury sphygmomanometer in accordance with WHO protocol. In analyses where blood pressure (BP) was a continuous variable, the means of the two readings were used. Where "hypertension" as a dichotomous variable was used, a "normal" subject was one with no past history of known physician-treated hypertension and who currently had SBP less than or equal to 140 and DBP less than or equal to 90 mm Hg. All others were classified as "hypertensives."

Based on these criteria, the adjusted prevalence of hypertension in the sample was 27%, with an increased frequency among males and those in the older age group. Compared with data from the Canada Health Survey, the mean SBP among the Indians exceeded that of Canadians in the younger age groups but was lower beyond age 45. For DBP, Indians had higher mean levels than Canadians consistently across all age groups and in both sexes. On univariate comparisons, significantly higher BP levels were found among men, the old, those with little education, nondrinkers, the physically inactive, the obese, and the diabetic. Hypertensives also differed from nonhypertensives in terms of total cholesterol, triglycerides, high-density lipoprotein cholesterol/total cholesterol ratio, various indices of obesity and fat patterning, and fasting glucose levels. In a multiple logistic regression model, significant predictors of hypertensive status included male sex, age, body mass index, total cholesterol, unemployed and single marital status, and positive family history of hypertension.