Hypertension in Rural India: The Contribution of Socioeconomic Position

Risk factors for incident cardiovascular events and their population attributable fractions in rural India: The Rishi Valley Prospective Cohort Study

OBJECTIVE

We prospectively determined incident cardiovascular events and their association with risk factors in rural India.

METHODS

We followed up with 7935 adults from the Rishi Valley Prospective Cohort Study to identify incident cardiovascular events. Using Cox proportional hazards regression, we estimated hazard ratios (HRs) with 95% confidence intervals (95% CI) for associations between potential risk factors and cardiovascular events. Population attributable fractions (PAFs) for risk factors were estimated using R ('averisk' package).

RESULTS

Of the 4809 participants without prior cardiovascular disease, 57.7% were women and baseline mean age was 45.3 years. At follow-up (median of 4.9 years, 23,180 person-years [PYs]), 202 participants developed cardiovascular events, equating to an incidence of 8.7 cardiovascular events/1000 PYs. Incidence was greater in those with hypertension (hazard ratio [HR] [95% CI] 1.73 [1.21-2.49], adjusted PAF 18%), diabetes (1.96 [1.15-3.36], 4%) or central obesity (1.77 [1.23, 2.54], 9%) which together accounted for 31% of the PAF. Non-traditional risk factors such as night sleeping hours and number of children accounted for 16% of the PAF.

CONCLUSIONS

Both traditional and non-traditional cardiovascular risk factors are important contributors to incident cardiovascular events in rural India. Interventions targeted to these factors could assist in reducing the incidence of cardiovascular events.

Comparison of the performance of cardiovascular risk prediction tools in rural India: the Rishi Valley Prospective Cohort Study

AIMS

We compared the performance of cardiovascular risk prediction tools in rural India.

METHODS AND RESULTS

We applied the World Health Organization Risk Score (WHO-RS) tools, Australian Risk Score (ARS), and Global risk (Globorisk) prediction tools to participants aged 40-74 years, without prior cardiovascular disease, in the Rishi Valley Prospective Cohort Study, Andhra Pradesh, India. Cardiovascular events during the 5-year follow-up period were identified by verbal autopsy (fatal events) or self-report (non-fatal events). The predictive performance of each tool was assessed by discrimination and calibration. Sensitivity and specificity of each tool for identifying high-risk individuals were assessed using a risk score cut-off of 10% alone or this 10% cut-off plus clinical risk criteria of diabetes in those aged >60 years, high blood pressure, or high cholesterol. Among 2333 participants (10 731 person-years of follow-up), 102 participants developed a cardiovascular event. The 5-year observed risk was 4.4% (95% confidence interval: 3.6-5.3). The WHO-RS tools underestimated cardiovascular risk but the ARS overestimated risk, particularly in men. Both the laboratory-based (C-statistic: 0.68 and χ2: 26.5, P = 0.003) and non-laboratory-based (C-statistic: 0.69 and χ2: 20.29, P = 0.003) Globorisk tools showed relatively good discrimination and agreement. Addition of clinical criteria to a 10% risk score cut-off improved the diagnostic accuracy of all tools.

CONCLUSION

Cardiovascular risk prediction tools performed disparately in a setting of disadvantage in rural India, with the Globorisk performing best. Addition of clinical criteria to a 10% risk score cut-off aids assessment of risk of a cardiovascular event in rural India.

LAY SUMMARY

In a cohort of people without prior cardiovascular disease, tools used to predict the risk of cardiovascular events varied widely in their ability to accurately predict who would develop a cardiovascular event.The Globorisk, and to a lesser extent the ARS, tools could be appropriate for this setting in rural India.Adding clinical criteria, such as sustained high blood pressure, to a cut-off of 10% risk of a cardiovascular event within 5 years could improve identification of individuals who should be monitored closely and provided with appropriate preventive medications.

Morbidity and utilisation of healthcare services among people with cardiometabolic disease in three diverse regions of rural India

OBJECTIVES

To assess the prevalence and determinants of cardiometabolic disease (CMD), and the factors associated with healthcare utilisation, among people with CMD.

METHODS

Using a cross-sectional design, 11,657 participants were recruited from randomly selected villages in 3 regions located in Kerala and Andhra Pradesh from 2014 to 2016. Multivariable logistic regression was used to identify factors independently associated with CMD and healthcare utilisation (public or private).

RESULTS

Thirty-four per cent (n = 3629) of participants reported having ≥1 CMD, including hypertension (21.6%), diabetes (11.6%), heart disease (5.0%) or chronic kidney disease (CKD) (1.6%). The prevalence of CMD was progressively greater in regions of greater socio-economic position (SEP), ranging from 19.1% to 40.9%. Among those with CMD 41% had sought any medical advice in the last month, with only 19% utilising public health facilities. Among people with CMD, those with health insurance utilised more healthcare (age-gender adjusted odds ratio (AOR) (95% confidence interval (CI)): 1.31 (1.13, 1.51)) as did those who reported accessing private rather than public health services (1.43 (1.23, 1.66)).

DISCUSSION

The prevalence of CMD is high in these regions of rural India and is positively associated with indices of SEP. The utilisation of outpatient health services, particularly public services, among those with CMD is low.

Overweight (BMI of 25-30) Is Independently Associated With Significantly Higher Prevalence of Systolic and Diastolic Hypertension in Adults

OBJECTIVE

Hypertension (HTN) is a major risk factor for cardiovascular disease. Obesity has been found to be associated with HTN. However, there are not many studies available to evaluate any association between overweight alone and HTN.

METHODS

A database from the Anthony Bates Foundation that performs preventive cardiovascular examinations including measurement of body mass index (BMI) and blood pressure across the United States was used for our study. Using recorded measurements, we evaluated any association between being overweight defined as a BMI of 25 to 30 and the occurrence of systolic and diastolic HTN in adults over the age of 18 years.

RESULTS

A total of 1558 participants with documented BMI and blood pressure over the age of 18 years were studied. Among them, 758 participants had a normal BMI, and 800 had a BMI in overweight category. The prevalence of systolic and diastolic HTN was significantly higher in participants in the overweight versus normal weight cohort. Systolic HTN was present in 36% of participants in the overweight versus 14% of the normal weight group ( P < 0.00.1). Diastolic HTN was present in 43% of participants with overweight versus 21% of normal weight cohort ( P < 0.001). After adjusting for age and gender, high systolic blood pressure (SBP) and diastolic blood pressure (DBP) remained independently associated with overweight (SBP prevalence OR, 2.8; CI, 2.1-3.6; P < 0.001; DBP prevalence OR, 2.1; CI, 1.7-2.7; P < 0.001).

CONCLUSIONS

Our study found that increased BMI in the overweight category alone is independently associated with SBP and DBP in adults undergoing screening warranting further investigation.

Combining general and central measures of adiposity to identify risk of hypertension: a cross-sectional survey in rural India

AIM

In three socioeconomically diverse regions of rural India, we determined the optimal cut-offs for definition of overweight, the prevalence of overweight, and the relationships between measures of overweight and risk of hypertension.

SUBJECTS AND METHODS

Villages were randomly sampled within rural Trivandrum, West Godavari, and Rishi Valley. Sampling of individuals was stratified by age group and sex. Cut-offs for measures of adiposity were compared using area under the receiver operating characteristic curve. Associations between hypertension and definitions of overweight were assessed by logistic regression.

RESULTS

Of 11 657 participants (50 % male; median age 45 years), 29.8 % had hypertension. Large proportions were overweight as defined by body mass index (BMI) ≥ 23 kg/m2 (47.7 %), waist circumference (WC) ≥ 90 cm for men or ≥ 80 cm for women (39.6 %), waist-hip ratio (WHR) ≥ 0.9 for men or ≥ 0.8 for women (65.6 %), waist-height ratio (WHtR) ≥ 0.5 (62.5 %), or by BMI plus either WHR, WC or WHtR (45.0 %). All definitions of overweight were associated with hypertension, with optimal cut-offs being at, or close to, the World Health Organization (WHO) Asia-Pacific standards. Having overweight according to both BMI and a measure of central adiposity was associated with approximately twice the risk of hypertension than overweight defined by only one measure.

CONCLUSIONS

Overweight, as assessed by both general and central measures, is prevalent in rural southern India. WHO standard cut-offs are appropriate in this setting for assessing risk of hypertension. However, combining BMI with a measure of central adiposity identifies risk of hypertension better than any single measure. The risk of hypertension is significantly greater in those centrally and generally overweight than those overweight by a single measure.

Socioeconomic Inequalities in the Prevalence of Non-Communicable Diseases among Older Adults in India

Understanding socioeconomic inequalities in non-communicable disease prevalence and preventive care usage can help design effective action plans for health equality programs among India's aging population. Hypertension (HTN) and diabetes mellitus (DM) are frequently used as model non-communicable diseases for research and policy purposes as these two are the most prevalent NCDs in India and are the leading causes of mortality. For this investigation, data on 31,464 older persons (aged 60 years and above) who took part in the Longitudinal Ageing Survey of India (LASI: 2017-2018) were analyzed. The concentration index was used to assess socioeconomic inequality whereas relative inequalities indices were used to compare HTN, DM, and preventive care usage between the different groups of individuals based on socioeconomic status. The study reveals that wealthy older adults in India had a higher frequency of HTN and DM than the poor elderly. Significant differences in the usage of preventive care, such as blood pressure/blood glucose monitoring, were found among people with HTN or DM. Furthermore, economic position, education, type of work, and residential status were identified as important factors for monitoring inequalities in access to preventive care for HTN and DM. Disparities in non-communicable diseases can be both a cause and an effect of inequality across social strata in India.

Hypertension and its association with body mass index among the Indian population. Findings from a nationwide survey (NFHS-4), 2015-16

Background

Globally, hypertension (HTN) and obesity are two cardinal causes of morbidity and mortality. The Asian population shows comorbidities associated with obesity at a much lower body mass index (BMI) than the western population.

Aim

The primary objective of the present study was to evaluate the association between BMI and HTN among the adult population.

Material and Methods

We did a cross-sectional secondary data analysis of the NFHS-4 datasets, conducted during 2015-16. We included the adult population, that is, ≥19 years of age (93,040 men and 5,46,066 women), and excluded adolescents and pregnant women from our analysis. HTN was the primary dependent variable, while BMI was the primary predictor variable. Other covariates included age, education, place of residence, wealth index, use of alcohol and tobacco, and diabetes. Weighted analysis was done to depict our results.

Results

Around 18.7% of men and 13.5% of women were hypertensive, of which 53.86% of males and 38.7% females were either overweight or obese. The odds of living with HTN among obese men and women increased with age, wealth, use of alcohol and tobacco, and comorbidities such as diabetes. The prevalence of HTN was higher even among the underweight adults living with diabetes and those consuming alcohol and tobacco.

Conclusion

We reaffirm the significant association between BMI and HTN among adults. The use of the Asian classification of BMI for India and its neighboring countries to assess the burden of obesity would help in planning better interventions. A community-based targeted approach would help in controlling and reducing the prevalence of HTN.

Absolute cardiovascular risk scores and medication use in rural India: a cross-sectional study

OBJECTIVES

We compared the performance of laboratory-based cardiovascular risk prediction tools in a low-income and middle-income country setting, and estimated the use of antihypertensive and lipid-lowering medications in those deemed at high risk of a cardiovascular event.

DESIGN

A cross-sectional study.

SETTING

The study population comprised adult residents (aged ≥18 years) of the Rishi Valley region located in Chittoor District, south-western Andhra Pradesh, India.

PARTICIPANTS

7935 participants were surveyed between 2012 and 2015. We computed the 10-year cardiovascular risk and undertook pair-to-pair analyses between various risk tools used to predict a fatal or non-fatal cardiovascular event (Framingham Risk Score (FRS), World Health Organization Risk Score (WHO-RS) and Australian Risk Score (ARS)), or a fatal cardiovascular event (Systematic COronary Risk Evaluation (SCORE-high and SCORE-low)). Concordance was assessed by ordinary least-products (OLP) regression (for risk score) and quadratic weighted kappa (κ_w, for risk category).

RESULTS

Of participants aged 35-74 years, 3.5% had prior cardiovascular disease. The relationships between risk scores were quasi-linear with good agreement between the FRS and ARS (OLP slope=0.96, κ_w=0.89). However, the WHO-RS underestimated cardiovascular risk compared with all other tools. Twenty per cent of participants had ≥20% risk of an event using the ARS; 5% greater than the FRS and nearly threefold greater than the WHO-RS. Similarly, 16% of participants had a risk score ≥5% using SCORE-high which was 6% greater than for SCORE-low. Overall, absolute cardiovascular risk increased with age and was greater in men than women. Only 9%-12% of those deemed 'high risk' were taking lipid-lowering or antihypertensive medication.

CONCLUSIONS

Cardiovascular risk prediction tools perform disparately in this setting of disadvantage. Few deemed at high risk were receiving the recommended treatment.

Mixed Effect of Alcohol, Smoking, and Smokeless Tobacco Use on Hypertension among Adult Population in India: A Nationally Representative Cross-Sectional Study

Sporadic evidence is available on the association of consuming multiple substances with the risk of hypertension among adults in India where there is a substantial rise in cases. This study assesses the mutually exclusive and mixed consumption patterns of alcohol, tobacco smoking and smokeless tobacco use and their association with hypertension among the adult population in India. Nationally representative samples of men and women drawn from the National Family and Health Survey (2015-2016) were analyzed. A clinical blood pressure measurement above 140 mmHg (systolic blood pressure) and 90 mmHg (diastolic blood pressure) was considered in the study as hypertension. Association between mutually exclusive categories of alcohol, tobacco smoking and smokeless tobacco and hypertension were examined using multivariate binary logistic regression models. Daily consumption of alcohol among male smokeless tobacco users had the highest likelihood to be hypertensive (OR: 2.32, 95% CI: 1.99-2.71) compared to the no-substance-users. Women who smoked, and those who used any smokeless tobacco with a daily intake of alcohol had 71% (OR: 1.71, 95% CI: 1.14-2.56) and 51% (OR: 1.51, 95% CI: 1.25-1.82) higher probability of being hypertensive compared to the no-substance-users, respectively. In order to curb the burden of hypertension among the population, there is a need for an integrated and more focused intervention addressing the consumption behavior of alcohol and tobacco.

Prevalence and predictors of prehypertension and hypertension in adult population of rural Southern India-An epidemiological study

Introduction:

Hypertension is considered as one of the major health problem worldwide and the most important risk factor for non-communicable diseases.

Aims:

To estimate the prevalence and the risk factors of prehypertension and hypertension.

Methods and Material:

A community-based cross-sectional study was conducted among adult population of rural area of Chittoor District. WHO STEPS was applied for data collection from 1,742 study participants aged 18 years and above. Chi-square test, Fisher exact, and ANOVA test applied to find out the intragroup and intergroup variable association with raised blood pressure.

Results:

The overall prevalence of hypertension and prehypertension in our study was 21.5% [95% CI: (19.6–23.5)] and 42.8% [95% CI: (39.5–46.3)], respectively. Males had higher prevalence when compared to females. The mean systolic and diastolic blood pressure was 118.7 ± 17.6 mmHg and 77.1 ± 9.7 mmHg, respectively. The odds of being hypertensive was higher among older age group (OR: 3.83), male study participants (OR: 1.83), either widowed or separated (OR: 2.03), unemployed (OR: 1.51), and those who belonged to upper socioeconomic status (OR: 2.01). Those who were overweight (OR: 3.15), obese (OR: 2.55) and having central obesity (OR: 1.74), and also tobacco smokers (OR: 1.53) were having higher odds of hypertension. Significant association was found between hypertension and age, gender, marital status, body mass index, abdominal obesity, tobacco smoking, and physical inactivity.

Conclusion:

The prevalence of prehypertension and hypertension in this study was found to be high in rural area of Andhra Pradesh. There is a need to develop a community-based program, which would aim at minimizing the risk factors of hypertension.

Additive association of knowledge and awareness on control of hypertension: a cross-sectional survey in rural India

OBJECTIVE

To determine whether there is an interaction between knowledge about hypertension and awareness of hypertension on the treatment and control of hypertension in three regions of South India at different stages of epidemiological transition (see Video, Supplemental Digital Content 1, http://links.lww.com/HJH/B426).

METHODS

Using a cross-sectional design, we randomly selected villages within each of rural Trivandrum, West Godavari, and Chittoor. Sampling was stratified by age group and sex. We measured blood pressure and administered a questionnaire to determine knowledge and awareness of hypertension. Logistic regression was used to assess associations of awareness and knowledge about hypertension with its treatment and control in participants with hypertension, while examining for statistical interaction.

RESULTS

Among a total of 11 657 participants (50% male; median age 45 years), 3455 had hypertension. In analyses adjusted for age and sex, both knowledge score [adjusted odds ratio (aOR) 1.14 [95% confidence interval (CI) 1.12--1.17)] and awareness [aOR 104 (95% CI 82--134)] were associated with treatment for hypertension. Similarly, both knowledge score [aOR 1.10; 95% CI (1.08--1.12)] and awareness [aOR 13.4; 95% CI (10.7--16.7)], were positively associated with control of blood pressure in those with hypertension, independent of age and sex. There was an interaction between knowledge and awareness on both treatment and control of hypertension (P of attributable proportion <0.001 for each).

CONCLUSION

Health education to improve knowledge about hypertension and screening programs to improve awareness of hypertension may act in an additive fashion to improve management of hypertension in rural Indian populations.

Hypertension in Rural India: The Contribution of Socioeconomic Position

Background

Various indicators of socioeconomic position (SEP) may have opposing effects on the risk of hypertension in disadvantaged settings. For example, high income may reflect sedentary employment, whereas greater education may promote healthy lifestyle choices. We assessed whether education modifies the association between income and hypertension in 3 regions of South India at different stages of epidemiological transition.

Methods and Results

Using a cross‐sectional design, we randomly selected villages within each of rural Trivandrum, West Godavari, and Rishi Valley. Sampling was stratified by age group and sex. We measured blood pressure and anthropometry and administered a questionnaire to identify lifestyle factors and SEP, including education, literacy, and income. Logistic regression was used to assess associations between various components of SEP and hypertension, and interaction analyses were used to determine whether educational attainment modified the association between income and hypertension. Trivandrum, the region of highest SEP, had the greatest prevalence of hypertension, whereas Rishi Valley, the lowest SEP region, had the least. Overall, greater income was associated with greater risk of hypertension. In interaction analyses, there was no evidence that educational attainment modified the association between income and hypertension.

Conclusions

Education is widely considered to ameliorate the risk of hypertension in high‐income countries. Why this effect is absent in rural India merits investigation.