The characteristics of the study participants (n = 5,517) and prevalence of risk variables are shown in Table 1. Mean age was higher in rural populations. The village dwellers had lower values for anthropometry, biochemical variables and blood pressure than urban participants (city or town). The prevalence of hypertension was higher in the city than in other areas (Table 1). There was a low prevalence of dyslipidaemia in the villages. Although the concentration of HDL-cholesterol was lower in the villages, the total cholesterol:HDL-cholesterol ratio was normal in a larger percentage of participants in this group than in the other two groups. Participants from the city were most likely to be in the sedentary and light physical activity categories (67%), followed by the town (63%) and the villages (51%) (city vs town z = 2.4, p = 0.017; city vs villages z = 9.6, p < 0.0001). Cigarette smoking was more common in the town and villages than in the city (city 11.9%, town 22.8%, villages 23.9%); there were very few female smokers (data not shown). A positive family history of cardiovascular disease was reported by 7.2%, 2.5% and 1.0% of participants from the city, town and villages, respectively.
The prevalence of risk factors was higher in the city (67.5%) than in the other two areas (city vs town z = 2.33, p = 0.02; city vs villages z = 12.27, p < 0.0001) (Fig. 1), and was higher in the town (63.6%) than in the villages (47%) (z = 10.48, p < 0.0001). Multiple abnormalities, particularly combinations of three or more variables, were more common in urban areas, with a prevalence of 23.3%, 17.6% and 10.4% in the city, town and villages, respectively (villages vs town z = 6.55, town vs city z = 4.06, villages vs city z = 10.52, p < 0.001).
Age, male sex, BMI, waist circumference, being in the sedentary physical activity category and living in an urban environment were independently associated with hypertension. After adjusting for these variables, fasting and 2 h glucose values showed no association with hypertension. Dyslipidaemia showed an independent association with fasting glucose between the levels of 5.0 and 5.3 mmol/l (OR 1.162, 95% CI 1.023–1.321, p = 0.021).