Prevalence and determinants of isolated systolic and isolated diastolic hypertension in India: Insights from the national family health survey (NFHS)- 4

Background: Isolated Systolic Hypertension (ISH) and Isolated Diastolic Hypertension (IDH) are often the ignored forms of hypertension and are determinants of future cardiac and neurological events and contribute to mortality. However, the nationally representative estimates of both these forms of hypertension remain unknown from India. Aim: To estimate the ISH and IDH from a nationally representative survey of India. Material and Methods: The present study used data from 7,23,181 people (15-54 years), recorded during the fourth round (2015-2016) of the National Family Health Survey (NFHS), India. The prevalence of ISH and IDH was calculated for state comparison, while multilevel logistic regression analysis was done to assess the correlates of both types of hypertension. Results: The prevalence of ISH and IDH was found to be 1.2% (95% CI 1.0-1.4) and 5.7% (95% CI 5.2-6.2), respectively. The prevalence of both ISH and IDH increased with age, with a more significant increase in systolic pressure towards the higher age. Northeastern states of India (Assam, Meghalaya, and Arunachal Pradesh) had the highest prevalence of both forms of hypertension. On multilevel logistic regression, male gender, increasing age groups (highest odds ratio (OR) being in 45-49 year age group), alcohol, and diabetes positively predicted both ISH and IDH. Urban residence, literacy, and tobacco were positive predictors of IDH, whereas urban residence, smoking, and literacy negatively predicted ISH. Conclusion: ISH and IDH have a significant presence among the population of India. This data provides insights to formulate strategies at the primary and primordial prevention levels.