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.

Validation and reproducibility of a food frequency questionnaire to assess energy and fat intake in affluent north Indians.

BACKGROUND: India is currently witnessing a sharp rise in noncommunicable disorders such as obesity, diabetes, hypertension and cardiovascular diseases. This rise can be related in part to dietary changes such as increased intake of calories, fat (especially saturated fat) and cholesterol. A simple, accurate and reproducible method to measure these nutrients is essential to study the role of diet in these diseases in epidemiological studies. We aimed to develop and validate a food frequency questionnaire that could be used for this purpose. METHODS: Thirty urban north Indian subjects (age 23-64 years, 16 men) belonging to a high socioeconomic group were studied. The subjects were selected consecutively over a period of 3 weeks from among those participating in an epidemiological survey on cardiovascular risk factors in an affluent population. A 102-item food frequency questionnaire was developed to capture the intake of calories, fat, saturated fat and cholesterol. The results obtained by the food frequency questionnaire were compared with a 5-day diet record. To assess the reproducibility of the food frequency questionnaire, it was re-administered after 3 months to the 23 subjects available. RESULTS: It took the dietician 20 minutes or less to administer the questionnaire. There was good correlation between the nutrient values as calculated by the food frequency questionnaire and 5-day diet record. The correlation for energy intake was 0.80, and varied between 0.55 and 0.69 for unadjusted intake of other nutrients. After adjusting for calories, the correlation varied between 0.45 and 0.68. In general, the food frequency questionnaire overestimated the energy-adjusted nutrient intake by 6%-17%. When intake was classified into quartiles, there was good agreement between the two methods: 43%-100% for calories; 29%-86% for other nutrients for unadjusted intake; 29%-71% for nutrients after energy adjustment. On calculation of intake after re-administration of the food frequency questionnaire, there was a moderate to strong correlation (energy adjusted r=0.49-0.90) between the two evaluations for various nutrients. CONCLUSION: The food frequency questionnaire developed for the assessment of nutrient intake in a north Indian population was easy to administer, showed moderate to good correlation with the 5-day diet record and was reproducible.