Incident hypertension in urban slums of central India: a prospective cohort study

Abstract

BackgroundNumerous studies have highlighted the burden of hypertension by estimating its prevalence. However, information regarding quantum and characteristics of persons whose blood pressure converts to hypertension range from their previous state of prehypertension or normal blood pressure is crucial for any public health programme. We aimed to estimate incidence rate of hypertension and to identify risk factors for the same, so that it is useful for programme implementation.MethodsWe established a cohort of adults residing in urban slums of Bhopal, who were registered in a baseline cardiovascular risk assessment survey, which was performed between November 2017 and March 2018. Blood pressure assessment was done at least three times at baseline for diagnosis of hypertension, which was defined as systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg on two occasions. Participants who did not have a diagnosis of hypertension were followed up during April–June 2019.ResultsOf the 5673 participants assessed at baseline, 4185 did not have hypertension of which 3199 (76.4%) were followed up after a median on 1.25 years (IQR 1.08–1.60) and a total of 170 (5.31%) individuals were detected with incident hypertension. Overall incidence rate of hypertension was 4.1 (95% CI 3.54 to 4.75) per 100 person-years of follow-up. On multivariate analysis, age (relative risk/RR 1.98; 95% CI 1.19 to 3.3, for age >60 years), being in first and second wealth tertile (T-1 RR 1.85; 95% CI 1.17 to 2.91) and being illiterate (RR 1.94; 95% CI 1.31 to 2.86) were significant predictors of incident hypertension. Individuals who had prehypertension at baseline also had a significantly increased risk of developing hypertension (RR 2.72; 95% CI 1.83 to 4.03).ConclusionsWe found that incidence of hypertension in urban slums of central India is higher with increasing age and in men. Illiteracy, lower Wealth Index and prehypertension are other determinants. We also demonstrate feasibility of establishing a cohort within the public health delivery system, driven by efforts of community health workers.

Trends in hypertension prevalence, awareness, treatment, and control: an 8-year follow-up study from rural North India

“…However, these studies estimated hypertension prevalence using cross-sectional study design thus, limiting the establishment of its temporal change within each cohort. Moreover, there are limited studies from India investigating the incidence of hypertension among community cohorts 16 – 20 . Thus, follow-up study designs will be more precise and reliable to estimate changing trend within the same cohort over time.…”

Evidence for lower threshold for diagnosis of hypertension: inferences from an urban-slum cohort in India

“…The current study is a secondary data analysis from a community based cohort that was established in year 2017, and is being followed up thereafter. 23 Primary study design was approved by institutional ethics committee, and participants who provided a written informed consent were included in the study.…”

“…If AHA/ACC 2017 guidelines are applied, individuals with BP below this threshold would get re-classified as having elevated blood-pressure (SBP between 120 and 130mm Hg) or hypertension (SBP between 130 and 140mm Hg). We completed a two-year follow up of cohort in 2019, 23 and a secondary data analysis will enable us to evaluate blood-pressure outcomes in re-classified cohort members. Our key research question is, among cohort members with at least two out-of-office BP assessments at baseline, do individuals with SBP values between 130 and 140, (as compared to those with SBP between 120 and 130mm Hg) have a significantly higher proportion of incident hypertension or mean SBP at the end of two years.…”