Abstract
Globally there had been sustained increase in over-nutrition, adiposity, hypertension and morbidity and mortality due to cardiovascular diseases (CVD) in the last three decades. In India over-nutrition rates have doubled in two decades. Over-nutrition, and adiposity especially abdominal adiposity rank as major risk factors for high prevalence of hypertension and CVD in Indians. Age-standardized CVD death rate in Indians is higher than the global average. Some of the contributing factors for this higher CVD mortality in Indians include the earlier age of onset, low detection in the early asymptomatic phase of hypertension, poor coverage and high discontinuation of treatment for hypertension.
The present study was undertaken in adults from urban low middle-income families to explore:
- changes in blood pressure in relation to age, Body Mass Index (BMI), fat mass index (FMI), visceral fat grades, abdominal adiposity;
- whether prior screening of adults by age, BMI or abdominal adiposity and then undertaking blood pressure screening in identified high risk groups could reduce the number to be screened without missing those who had hypertension.
The profile of the study population was similar to the Indian urban low middle-income population documented in national surveys. One fourth of men and women below 30 years and over 2/3rd of women beyond 50 years were over-nourished. Nearly a third of women below 30 years and over 80% of women beyond 50 years of age had abdominal adiposity. There was progressive increase in fat mass index with increase in age and BMI both in men and women.
Among men below 30 years of age 10% had hypertension. There was a progressive increase in prevalence of hypertension with increase in age; one fourth of women and one third of men beyond 50 years had hypertension. Age ≥ 30 years, BMI ≥ 25, high adiposity as assessed by fat mass and fat mass index, high abdominal adiposity as assessed by waist circumference (WC), waist hip ratio (WHR), waist height ratio (WHtR) and high visceral fat were statistically significant risk factors for hypertension in men and women.
Screening only persons with BMI ≥ 25 reduced the work load by 50% but resulted in detection of only 76.7% of all hypertensive women and 54.1% of hypertensive men. Circumferential measurements take more time than blood pressure measurements. The paramedical persons are not well trained in taking circumferential measurements. Therefore, these parameters are not suitable for use as a preliminary screening procedure. Bioelectrical impedance analysis machines are not available in health care settings and so fat mass measurement cannot be used for preliminary screening.
Screening adults beyond 30 years for hypertension reduced the work load by about 30% and ensured that over 85% of all hypertensive persons are detected. Ascertainment of age can be done quickly in both hospital and community settings. The current guidelines under the National NCD control programme envisaging blood pressure screening of all adults beyond 30 years of age is the rational and feasible option for reducing the work load and providing effective screening for hypertension.