Incidence of hypertension among Asian Indians: 10 year follow up of the Chennai Urban Rural Epidemiology Study (CURES-153)

Hypertension in India: a gender-based study of prevalence and associated risk factors

BACKGROUND

Hypertension, a major non-communicable disease, is responsible for a significant number of global deaths, including approximately 17.9 million yearly. The Global Burden of Disease 2019 (GBD 2019) estimates that 19% of global deaths are attributed to elevated blood pressure. India, with a population of over 1.4 billion, is facing a serious challenge in combating this silent killer. This study aims to analyze the gender-based prevalence of hypertension in India and explore its associated risk factors using data from the fifth National Family Health Survey (NFHS-5).

METHODS

NFHS-5 collected data from 636,699 households across all states and union territories. The study includes standardized blood pressure measurements for 17,08,241 individuals aged 15 and above. The data were analyzed using Stata, employing descriptive statistics for the assessment of the prevalence and binary logistic regression to identify predictors of hypertension.

RESULTS

The study found the overall prevalence of hypertension in India to be 22.6%, with men (24.1%) having a higher prevalence than women (21.2%). Prevalence increased with age, reaching 48.4% in individuals aged 60 and above. Urban residents had a slightly higher prevalence (25%) than rural residents (21.4%), indicating the rapid spread of hypertension across all populations. Regional variations were observed, with the highest prevalence in Sikkim (37.9%) and the lowest in Rajasthan (16.5%). Increasing age, urban residence, belonging to certain religions (Muslim and other than Hindu or Muslim), and being classified as Scheduled Tribes (ST) were associated with a higher likelihood of hypertension. Conversely, belonging to Scheduled Castes (SC) or Other Backward Classes (OBC), being currently unmarried, and having higher education were associated with a lower likelihood of hypertension. Wealth index analysis revealed that those in the richest quintile were more likely to have hypertension. Behavioural risk factors, such as alcohol consumption, overweight, obesity, increased waist circumference, and high blood glucose levels, are positively associated with hypertension.

CONCLUSION

Hypertension is a significant health burden in India, affecting both men and women. Age is the strongest non-modifiable predictor for both men and women. However, ageing women have higher odds of hypertension than ageing men, and this distinction becomes much more evident in their older ages. Obese women, based on BMI, have higher odds of hypertension than men. However, hypertension prevalence is slightly higher among men who are overweight or obese compared to women. BMI, waist circumference, random glucose level, alcohol use, and education level emerged as major predictors. Health education and awareness campaigns are critical to control the growing burden of hypertension in India. Policymakers must focus on preventive measures, targeting lifestyle changes and improved healthcare access for both men and women. By addressing these risk factors, India can make significant progress in controlling hypertension and reducing its impact on public health.

District-Wise Heterogeneity in Blood Pressure Measurements, Prehypertension, Raised Blood Pressure, and Their Determinants Among Indians: National Family Health Survey-5

Objective: The objective of the study was to determine the prevalence and determinants of ever-measured blood pressure, prehypertension, and raised blood pressure at national, state and district levels in India. Methods: We analysed data from the National Family Health Survey (NFHS-5), on 743,067 adults aged 18-54 years. The sample consisted of 87.6% females and 12.4% males. We estimated prevalence rates and determined adjusted odds ratios for various dependent variables related to blood pressure. Geographical variations were visualized on the map of India, and multivariate logistic regression was employed at state and district levels, with significance set at p < 0.05. Results: The prevalence of ever-measured blood pressure varied widely, from 30.3% to 98.5% across districts, with southern and northern regions showing higher rates. Prehypertension affected 33.7% of the population, with varying prevalence across districts. Raised blood pressure was there in 15.9%, with notably higher rates in southern region (16.8%). Determinants included age, gender, education, wealth, lifestyle, obesity, and blood glucose levels. Conclusion: These findings demonstrate the subnational variations in blood pressure, can guide evidence-based interventions at the state and district level, towards reducing the burden of raised blood pressure and enhancing overall population health.

Evaluating bias with loss to follow-up in a community-based cohort: empirical investigation from the CARRS Study

BACKGROUND

Retention of participants is a challenge in community-based longitudinal cohort studies. We aim to evaluate the factors associated with loss to follow-up and estimate attrition bias.

METHODS

Data are from an ongoing cohort study, Center for cArdiometabolic Risk Reduction in South Asia (CARRS) in India (Delhi and Chennai). Multinomial logistic regression analysis was used to identify sociodemographic factors associated with partial (at least one follow-up) or no follow-up (loss to follow-up). We also examined the impact of participant attrition on the magnitude of observed associations using relative ORs (RORs) of hypertension and diabetes (prevalent cases) with baseline sociodemographic factors.

RESULTS

There were 12 270 CARRS cohort members enrolled in Chennai and Delhi at baseline in 2010, and subsequently six follow-ups were conducted between 2011 and 2022. The median follow-up time was 9.5 years (IQR: 9.3-9.8) and 1048 deaths occurred. Approximately 3.1% of participants had no follow-up after the baseline visit. Younger (relative risk ratio (RRR): 1.14; 1.04 to 1.24), unmarried participants (RRR: 1.75; 1.45 to 2.11) and those with low household assets (RRR: 1.63; 1.44 to 1.85) had higher odds of being lost to follow-up. The RORs of sociodemographic factors with diabetes and hypertension did not statistically differ between baseline and sixth follow-up, suggesting minimal potential for bias in inference at follow-up.

CONCLUSION

In this representative cohort of urban Indians, we found low attrition and minimal bias due to the loss to follow-up. Our cohort's inconsistent participation bias shows our retention strategies like open communication, providing health profiles, etc have potential benefits.

Three-year change in glycemic state and the future risk of incident hypertension among Iranian adults: Tehran Lipid and Glucose Study

The impact of 3-year change in glycemic state on the risk of hypertension among Tehranian adults aged ≥20 years was assessed. The study population included 1679 men and 2348 women who were non-diabetic normotensive at enrollment. The following categories were defined both at baseline visit and three years later (second visit): normoglycemia [normal fasting glucose (NFG) and normal glucose tolerance (NGT)] and prediabetes [impaired fasting glucose (IFG) or impaired glucose tolerance (IGT)]. Changes in the categories, i.e., regression to normoglycemia, remaining in previous status, and progression to diabetes were assessed. Changes in fasting plasma glucose (FPG) and 2-hour plasma glucose (2hPG) categories were also considered separately. We used the Cox models adjusted for traditional hypertension risk factors to estimate hazard ratios (HRs) with 95% confidence intervals (CIs). During a median follow-up of 9.4 years, 485 men and 589 women developed hypertension. Among men, considering both FPG and 2hPG, compared to individuals remaining normoglycemic, changing from prediabetes to normoglycemia had a HR of 1.30 (95% CI: 0.98-1.71; P-value: 0.064). Defining changes by 2hPG showed that compared to remaining NGT, incident IGT (progression from NGT to IGT) had a significant association with increased risk of hypertension development by a HR of 1.61 (1.13-2.30). Among women, on the other hand, change in glycemic state generally didn't show a significant association with incident hypertension. To sum up, change in glycemic state hadn't a significant association with hypertension development among women; however, compared to remaining NGT, men with incident IGT had a significant higher risk.

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

Hypertension is a major contributor to global CVD burden. LMICs including India is challenged with rising hypertension prevalence, yet limited studies are available on temporal change and incidence among community-cohorts. This study aimed to describe trends in hypertension prevalence, awareness, treatment, and control over 8 years among a rural community-cohort from Haryana, India. The study also lends towards an analysis of incidence. Adults ≥ 30 years (N = 1542) recruited during baseline cross-sectional study between 2011 and 2014 were followed up after a median 8.1 years. At endline, demographic/lifestyle characteristics and blood pressure were re-examined. Overall median SBP significantly increased from 120 mmHg at baseline to 125.5 mmHg at endline (p < 0.001), while hypertension prevalence increased from 34.4% (95% CI 32.0-36.9) to 40.4% (95% CI 37.5-43.4) (p = 0.002). Age-standardized hypertension incidence was 30.2% (95% CI 26.7-35.2) over 8 years. Among hypertensive group, awareness, treatment, and control increased from 9.6, 8.8 and 5.0% to 31.8, 27.3 and 9.6% (p < 0.05), respectively. Increasing trend in SBP and hypertension prevalence was observed as the cohort ages. This increase is supported by the high incidence of hypertension. Nevertheless, our study highlights positive trends in hypertension care cascade but poor control, suggesting that this trend may not be adequately impactful to reduce hypertension burden.

Alarm of non-communicable disease in Iran: Kavar cohort profile, baseline and 18-month follow up results from a prospective population-based study in urban area

The PERSIAN Kavar cohort study (PKCS) aims to investigate the prevalence, trends, and relevant prognostic risk factors of non-communicable diseases in participants aged 35-70 years living in the urban area of Kavar County. Kavar County is located at the center of Fars province in the southwest of Iran. Overall, 5236 adults aged 35-70 years old were invited to participate in the PKCS. From whom, 4997 people comprising 2419 men and 2578 women met the inclusion criteria and were recruited in the study (participation rate: 95.4%). This study is aimed to follow participants for at least 10 years; it is designed to perform all procedures similar to the primary phase including biological sampling, laboratory tests, physical examinations, and collecting general, nutritional, and medical data at the 5th and 10th years of follow-up. In addition, participants are annually followed-up by phone to acquire data on the history of hospitalization, any major diagnosis or death. At the enrollment phase, trained interviewers were responsible for obtaining general, nutritional, and medical data utilizing a 482-item questionnaire. The results of the baseline phase of this study show that the overweight category was the most prevalent BMI category among the registered participants (n = 2005, 40.14%). Also, almost one-third of Kavar adult population suffered from metabolic syndrome at the baseline phase (n = 1664, 33.30%). The rate of eighteen-month follow-up response was 100% in the PKCS. Hypertension (n = 116, 2.32%), cardiovascular outcomes (n = 33, 0.66%), and diabetes (n = 32, 0.64%) were the most prevalent new-onset NCDs during eighteen months of follow-up in the participants.

Investigating the incidence and risk factors of hypertension: A multicentre retrospective cohort study in Tabuk, Saudi Arabia

Background

Hypertension is a major global health concern affecting approximately 1.13 billion people worldwide, with most of them residing in developing countries. The aim of this study was to determine the incidence of different stages of hypertension and its associated modifiable and non-modifiable risk factors among patients in military-setting hospitals in Tabuk, Saudi Arabia.

Methods

This retrospective cohort study was conducted at two hospitals in Tabuk, Saudi Arabia. The data were collected from hospital electronic records from 1 January 2019 to 31 December 2019. The blood pressure levels of patients from the last three separate medical visits were recorded. Descriptive statistics and multinomial logistic regression were used for the data analysis.

Results

The study included 884 hypertensive patients. The incidences of stage of elevated BP, stage 1, stage 2, and hypertension crisis were 60.0, 29.5, 7.0, and 3.5 cases per 1000 persons. Multivariate analysis indicated that progression from the stage of elevated blood pressure to hypertension crisis was significantly associated with advanced age (odds ratio [OR] = 3.62, 95% confidence interval [CI] = 1.99–8.42), male sex (OR = 2.84, 95% CI: 0.57–5.92), and a positive family history of hypertension (OR = 1.95, 95% CI: 1.23–3.09). Other key determinants of the development of stage of elevated blood pressure to hypertension crisis were current smoking status (OR = 1.74, 95% CI: 1.23–4.76), and physical inactivity (OR = 6.48, 95% CI: 2.46–9.14).

Conclusion

The incidence stage of elevated blood pressure was high among the patients investigated at armed forces hospitals in Tabuk, Saudi Arabia. The logistic regression model proposed in the present study can be used to predict the development of different stages of hypertension. Age, sex, marital status, family history, smoking status, and physical activity play an important role in the development of hypertension. Better strategies to improve awareness, screening, treatment, and management of hypertension are required in Saudi Arabia.

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

Background

Numerous 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.

Methods

We 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.

Results

Of 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).

Conclusions

We 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.