Prevalence & risk factors of pre-hypertension & hypertension in an affluent north Indian population.

BACKGROUND & OBJECTIVES: Urban Indians have a high prevalence of insulin resistance, hypertension and cardiovascular disease. We studied the prevalence of pre-hypertension and hypertension, as well their association with cardiovascular risk factors, in a north Indian upper socio-economic population.

METHODS

A total of 1746 adults (age >or=30 yr) residing in an urban colony of high-income group residents in the city of Lucknow, north India, were invited to be enrolled for the study. The response rate was 64 per cent (n=1112). Blood pressure, anthropometry, plasma glucose in response to oral glucose tolerance test and lipids were measured. The variables contributing significantly to pre-hypertension and hypertension were analyzed by multiple logistic regression analysis.

RESULTS

The age and sex adjusted prevalence of hypertension was 32.2 per cent and pre-hypertension was 32.3 per cent. In contrast to hypertension, which was highest in the age group 60-69 yr (64%), prehypertension was highest (36%) in the group 30-39 yr. There was a high prevalence of cardiovascular risk factors in the general population [central obesity (86.7%), elevated LDL cholesterol (22.8%), abnormal glucose tolerance (41.6%) and smoking (20.3% of males)]. Two or more of the cardiovascular risk factors were present in a higher proportion of hypertensive [66%, odds ratio (OR) 3.0, P<0.0001] and pre-hypertensive, (56%, OR 2.0, P<0.0001) compared to normotensive subjects (39%). Subjects with pre-hypertension had body mass index, waist-hip ratio and frequency of glucose intolerance, which was intermediate between normotensive and hypertensive subjects. In multiple logistic regression analysis, increasing age, body mass index, waist hip ratio and impaired glucose tolerance/diabetes were independent risk factors for both hypertension and pre-hypertension.

INTERPRETATION & CONCLUSION: A high prevalence of pre-hypertension and hypertension were noted in affluent urban north Indians. Increasing age, body mass index, central obesity and impaired glucose tolerance/diabetes were significantly associated with both hypertension and pre-hypertension. Pre-hypertension was associated with an increased prevalence of cardiovascular risk factors.