Association of blood pressure and cardiovascular mortality in India: Mumbai cohort study

Long-term exposure to particulate matter and all-cause and cause-specific mortality in an analysis of multiple Asian cohorts

BACKGROUND

Exposure to ambient air pollution is associated with a significant number of deaths. Much of the evidence associating air pollution with adverse effects is from North American and Europe, partially due to incomplete data in other regions limiting location specific examinations. The aim of the current paper is to leverage satellite derived air quality data to examine the relationship between ambient particulate matter and all-cause and cause-specific mortality in Asia.

METHODS

Six cohorts from the Asia Cohort Consortium provided residential information for participants, recruited between 1991 and 2008, across six countries (Bangladesh, India, Iran, Japan, South Korea, and Taiwan). Ambient particulate material (PM2·5) levels for the year of enrolment (or 1998 if enrolled earlier) were assigned utilizing satellite and sensor-based maps. Cox proportional models were used to examine the association between ambient air pollution and all-cause and cause-specific mortality (all cancer, lung cancer, cardiovascular and lung disease). Models were additionally adjusted for urbanicity (representing urban and built characteristics) and stratified by smoking status in secondary analyses. Country-specific findings were pooled via random-effects meta-analysis.

FINDINGS

More than 300,000 participants across six cohorts were included, representing more than 4-million-person years. A positive relationship was observed between a 5 µg/m (Dockery et al., 1993) increase in PM2·5 and cardiovascular mortality (HR: 1·06, 95 % CI: 0.99, 1·13). The additional adjustment for urbanicity resulted in increased associations between PM2.5 and mortality outcomes, including all-cause mortality (1·04, 95 % CI: 0·97, 1·11). Results were generally similar regardless of whether one was a current, never, or ex-smoker.

INTERPRETATION

Using satellite and remote sensing technology we showed that associations between PM2.5 and all-cause and cause-specific Hazard Ratios estimated are similar to those reported for U.S. and European cohorts.

FUNDING

This project was supported by the Health Effects Institute. Grant number #4963-RFA/18-5. Specific funding support for individual cohorts is described in the Acknowledgements.

Recent studies on hypertension prevalence and control in India 2023

Hypertension is the most important chronic disease risk factor in India. Recent epidemiological studies have reported that hypertension is increasing in India with a more rapid increase in rural and young populations. Fifth National Family Health Survey (NFHS-5) and Indian Council of Medical Research-INDIAB surveys have reported that there are substantial geographic variations in hypertension prevalence with greater prevalence in more developed states and districts of the country. There is a high prevalence of young-age hypertension, especially in the less developed states. The incidence of adverse events from hypertension-related cardiovascular disease is significantly greater in India than in more developed countries. A low level of hypertension awareness, treatment, and control, especially in rural and underserved urban populations is an important finding. In this narrative review, we highlight recent nationwide studies and unique features of hypertension in India and suggest strategies for better hypertension management and control.

Obesity is associated with biliary tract cancer mortality and incidence: A pooled analysis of 21 cohort studies in the Asia Cohort Consortium

Body fatness is considered a probable risk factor for biliary tract cancer (BTC), whereas cholelithiasis is an established factor. Nevertheless, although obesity is an established risk factor for cholelithiasis, previous studies of the association of body mass index (BMI) and BTC did not take the effect of cholelithiasis fully into account. To better understand the effect of BMI on BTC, we conducted a pooled analysis using population-based cohort studies in Asians. In total, 905 530 subjects from 21 cohort studies participating in the Asia Cohort Consortium were included. BMI was categorized into four groups: underweight (<18.5 kg/m2 ); normal (18.5-22.9 kg/m2 ); overweight (23-24.9 kg/m2 ); and obese (25+ kg/m2 ). The association between BMI and BTC incidence and mortality was assessed using hazard ratios (HR) and 95% confidence intervals (CIs) by Cox regression models with shared frailty. Mediation analysis was used to decompose the association into a direct and an indirect (mediated) effect. Compared to normal BMI, high BMI was associated with BTC mortality (HR 1.19 [CI 1.02-1.38] for males, HR 1.30 [1.14-1.49] for females). Cholelithiasis had significant interaction with BMI on BTC risk. BMI was associated with BTC risk directly and through cholelithiasis in females, whereas the association was unclear in males. When cholelithiasis was present, BMI was not associated with BTC death in either males or females. BMI was associated with BTC death among females without cholelithiasis. This study suggests BMI is associated with BTC mortality in Asians. Cholelithiasis appears to contribute to the association; and moreover, obesity appears to increase BTC risk without cholelithiasis.

Health Status and Nutritional Habits in Maldives Pediatric Population: A Cross-Sectional Study

Chronic noncommunicable diseases (NCDs) have become the major cause of morbidity and mortality in the Maldives, triggered by the nutrition transition to a "Western diet" that dramatically increases the prevalence of excess weight and hypertension. Our study aimed to evaluate dietary habits, blood pressure (BP) and body mass index in Maghoodoo Public School's students. A sample of 145 students (72 males and 73 females, age 9.37 ± 2.97 years) was enrolled. Factors causing excess weight were investigated through descriptive statistics. The relationship between blood pressure percentiles and possible influencing factors was investigated by a linear regression model.. Excess weight was present in 15.07% and 12.5% females and males, respectively. 15.18% of the subjects had elevated BP, with a significant difference according to gender detected only in the PAS z-score. Eating habits were investigated through a parent-filled questionnaire; 70.15% of the students consumed less than two portions of fruit per day, with a significant difference between gender (84.06% and 55.38% for boys and girls, respectively, p < 0.0001) and 71.64% ate less than two servings of vegetables per day. An alarming finding emerged for sweet snacks (30.6% of the students consumed 2-3 servings per day) and sugary drinks (2-3 servings per day for 32.84% of students) consumption. Our findings suggest that excess weight and hypertension in this population could be due to energy-rich, packaged-foods consumption. A nutrition education approach might thus help to reduce cardiovascular risk.

Relationship of resting heart rate and blood pressure with all-cause and cardiovascular disease mortality

OBJECTIVES

This study aimed to investigate associations of resting heart rate (RHR) and blood pressure (BP) with all-cause and cardiovascular disease (CVD) mortality.

STUDY DESIGN

A retrospective cohort study.

METHODS

A total of 67,028 Chinese participants aged ≥60 years were included in the analysis. RHR, systolic blood pressure (SBP), and diastolic blood pressure (DBP) were evaluated according to quartiles ([41-69, 70-74, 75-79, 80-127 beats/min], [80-119, 120-129, 130-139, 140-238 mm Hg], and [40-70, 71-79, 80-84, 85-133 mm Hg]). Cox proportional hazard models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) of all-cause and CVD mortality with RHR, SBP, and DBP. Restricted cubic splines were used to evaluate the dose-response association.

RESULTS

During the 361,975 person-year follow-up, 9326 deaths were recorded, of which 5039 deaths were due to CVD. The risk of all-cause mortality was increased by 25% with the quartiles four vs quartile one of RHR (HR [95% CI]:1.25 [1.17-1.33]), and CVD mortality was increased by 32% (HR [95% CI]: 1.32 [1.22-1.44]). Similar results were observed when comparing the quartiles four vs quartile one of SBP with the risk of all-cause and CVD mortality (HRs [95% CIs]: 1.14 [1.07, 1.22] and 1.23 [1.12. 1.34]) and DBP with the risk of all-cause and CVD mortality (HRs [95% CIs]: 1.17 [1.11. 1.24] and 1.36 [1.26. 1.47]). We found linear associations of RHR, SBP, and DBP with all-cause and CVD mortality (P_{non-linearity} >0.05), except for the approximately J-shaped association between DBP and all-cause mortality (P_{non-linearity} = 0.008). There was a significant interaction of RHR and SBP with all-cause and CVD mortality (P_interaction <0.05).

CONCLUSIONS

RHR and BP increased the risk of all-cause and CVD mortality, especially fast RHR combined with high SBP.

Incidence and Risk Factors of Hypertension Following Partial Nephrectomy in Patients With Renal Tumors: A Cross-sectional Study of Postoperative Home Blood Pressure and Antihypertensive Medications

INTRODUCTION

We aimed to evaluate the incidence and risk factors for nephrectomy-related hypertension (NR-HT) in patients with renal tumors who underwent partial nephrectomy (PN) or radical nephrectomy (RN).

PATIENTS AND METHODS

A retrospective cross-sectional follow-up survey of postoperative home blood pressure (BP) and defined daily dose (DDD) of antihypertensive medications was conducted in patients with renal tumors who underwent PN (210 patients) or RN (120 patients), and they were compared. We evaluated the incidence and risk factors for NR-HT, defined as the addition of antihypertensive medications in doses of 1 DDD or more after surgery, or postoperative BP of 140/90 mmHg with an increase of 20 mmHg from preoperative BP with no reduction in dose of antihypertensive medications.

RESULTS

Both systolic (mean, 124 vs. 129 mmHg; P < .001) and diastolic BP (mean, 74 vs. 79 mmHg; P < .001) significantly increased after PN compared with RN. Systolic (P < .001) and diastolic (P = .003) BP increased significantly more after PN than after RN, and NR-HT was more frequent after PN than after RN (16% vs. 5%; P = .002). PN (odds ratio [OR], 2.93; P = .022) and higher postoperative peak C-reactive protein (OR, 2.34; P = .017) were independently associated with NR-HT. When limited to only the patients who underwent PN, acute kidney injury (OR, 2.65; P = .036) and higher postoperative peak C-reactive protein (OR, 2.54; P = .016) were independent risk factors for NR-HT.

CONCLUSION

PN may cause postoperative progression of hypertension possibly through renal parenchymal damage.

Risk factors for cardiovascular disease in rural South India: cohort study

BACKGROUND AND OBJECTIVES

Cardiovascular diseases (CVD) accounted for one-third of the deaths in India. We conducted a cohort study to estimate the incidence of CVD and the association of established risk factors with the incident CVD in a rural population in South India.

DESIGN, SETTING AND PARTICIPANTS

We conducted a community-based cohort study among 6026 adults aged 25-64 years in five villages in Tiruvallur, Tamil Nadu. We did baseline (2005-2007) and two follow-up surveys in 2008-2009 and 2013-2015. Risk factors studied were tobacco, alcohol, hypertension, self-reported diabetes and central obesity.

OUTCOME MEASURES

Outcome measures were fatal or non-fatal ischaemic heart disease or cerebrovascular event. We estimated HRs for the risk factors and population attributable fraction (PAF).

RESULTS

We followed up 5641 (94.4%) subjects, and follow-up duration was 33 371 person years. The overall incidence of cardiovascular event or death was 4.6 per 1000 person years. Current smoking (HR 1.6, 95% CI 1.1 to 2.6) and hypertension (HR 2.2, 95% CI 1.5 to 3.4) were the risk factors among men and accounted for 47% of the PAF. Among women, hypertension (HR 1.8, 95% CI 1.0 to 3.4), self-reported diabetes (HR 4.3, 95% CI 2.2 to 8.1) and central obesity (HR 2.2, 95% CI 1.2 to 4.0) were associated with CVD and accounted for more than half of the PAF.

CONCLUSIONS

We described the high burden of fatal CVD and identified the role of CVD risk factors such as hypertension, self-reported diabetes, smoking and central obesity. There is an urgent need to implement low-cost interventions such as smoking cessation and treat hypertension and diabetes in primary care settings.

Usefulness of color Doppler imaging of orbital arteries in young hypertensive patients

Color Doppler imaging (CDI) is an established method for investigating ocular blood flow characteristics, and several blood flow parameters can be obtained from the velocity wave. This study evaluated CDI parameters in hypertensive subjects by measuring flow velocities, resistive index, and the pulsatility index of ocular arteries. One hundred young hypertensive patients and 50 age- and gender-matched healthy controls were recruited for the study. CDI parameters of the ophthalmic artery, central retinal artery, and posterior ciliary artery were measured in all subjects. Doppler index cutoff points were calculated using area under the curve with 95% confidence intervals. Results showed that Doppler parameters were significantly higher in subjects diagnosed with hypertension in the young compared to controls.

Prevalence and risks of hypertension among Indian tribes and its status among the lean and underweight individuals

OBJECTIVE

With the increased worldwide prevalence of hypertension among the underprivileged populations, fewerstudies have reported such risks among Indian tribes. In the context of high prevalence of undernutrition, no such study has examined hypertension among lean and underweight Indian tribal individuals separately.

METHODS

We selected total samples of 1066 adult males and 1090 adult females in 20-60 years age-group cross-sectionally to examine the status of hypertension and its risks among nine major tribes in three Indian states; separate analyses for lean and underweight tribal individuals were done.

RESULTS

Increased prevalence of hypertension (females, 14.2%; males, 9.3%) was observed among the tribes with the overall percentage of individuals at adversity (hypertensive + isolated hypertensive) at more than 20% (males 20.1%; females 26.5%). Age-group-wise prevalence showed a sharp rise in the prevalence of hypertension in the 40 + year individuals; additionally, this rise was alarming among females. Undernutrition was observed to be a potential risk factor as a remarkable prevalence of hypertension was observed among the undernourished (approximately 9%) and lean tribal participants (12%). Underweight females were observed to be at higher risk. Tribal statuses were observed to be alarming than the national trends due to their very low average BMI along with high average SBP. A curvilinear prevalence of hypertension was observed while comparing through both the nutritional extremes.

CONCLUSION

The increased prevalence and risks of hypertension in the background of lean and underweight status of Indian tribes indicates their epidemiological transition burdened with alarming cardio-metabolic health risks that warrant an early and consistent surveillance.

Managing hypertension in 2018: which guideline to follow?

Hypertension is a global public health issue and a major cause of morbidity and mortality. Its prevalence is increasing in many Asian countries, with a number of countries with blood pressure above the global average. Although the average systolic blood pressure is decreasing worldwide since the 1980s at the rate of about 1 mm Hg systolic blood pressure per decade, it is increasing in low-income and middle-income countries, especially in the East and South Asian population. Of note, the much larger base Asian population results in a considerably larger absolute number of individuals affected. When compared with Western countries, hypertension among Asian populations has unique features in terms of its onset, clustering of associated cardiovascular risk factors, complications and outcomes. Moreover, only a minority of hypertensive individuals are receiving treatment and achieving control. Projected number of deaths related to hypertension dramatically increased in the last 25 years in some Asian regions with a disproportionately high mortality and morbidity from stroke compared with Western countries. The relation between blood pressure and the risk of stroke is stronger in Asia than in Western regions. Although new Guidelines for hypertension diagnosis and management have been recently released from Europe and North America, the unique features of Asian hypertensive patients raise concerns on the clinical applicability of Western Guidelines to Asian populations. To this purpose, we critically reviewed key elements from the most updated Guidelines. We also discussed their core concepts to verify the impact on hypertension prevention and management in Asian countries.

Comparing the ability of anthropometric indicators in determining the prevalence of hypertension among Indian tribes

OBJECTIVE

We compared the ability of the selected anthropometric indicators to best predict the prevalence of hypertension among the Indian tribes.

METHODS

A cross-sectional study was undertaken among 1431 adult participants (705 males and 726 females) between the ages of 20 and 60 years from six major tribes in India. Selected anthropometric indicators such as body mass index (BMI), waist-hip-ratio (WHR), waist-height-ratio (WHtR), percentage body fat (PBF), visceral fat (VF), minimum-waist-circumference (MWC) and sum-of-the-four skinfold thickness (SF4), along with the physiological parameters such as blood pressure were recorded. Discriminant analysis (DA) was performed to examine and compare the ability of the selected anthropometric indicators towards classifying hypertension among males, females and the total population.

RESULTS

Significant independent association was observed for hypertension and similar conditions within gender and selected age-group categories. The overall hypertension prevalence among the studied tribes was observed at 12.6%. Standardized function coefficients (SFCs) in discriminant analysis revealed PBF(0.89, 0.36, and 0.76 for overall, males, and females respectively) as the most powerful discriminator of hypertension. In addition, visceral fat (0.74, 1.46, and 0.58 for overall, males and females respectively) was observed to be the other significant indicator of hypertensive blood pressure. These exploratory findings for the first time indicate fat deposition, rather than body density alone, as an emerging physiological and metabolic risk among Indian tribes.

CONCLUSION

In the context of the highly prevalent chronic undernutrition, internal fat deposition is a major classifying factor of physiological and metabolic intolerance. It also indicates the increasing trend in lifestyle changes and the associated adversities among the Indian tribes.

Emerging trends in hypertension epidemiology in India

Hypertension is the most important risk factor for chronic disease burden in India. Studies from various parts of India have reported high prevalence of hypertension. These studies have also reported that hypertension is increasing and there is low awareness and control. Two recent studies have been conducted with uniform tools and nationwide sampling to determine the true prevalence of hypertension in the country. Fourth National Family Health Survey evaluated hypertension in a large population based sample (n = 799,228) and reported hypertension in 13.8% men vs. 8.8% women (overall 11.3%) aged 15-49 and 15-54 respectively. More representative data (age > 18 years, n = 1,320,555) in Fourth District Level Household Survey reported hypertension in 25.3% with greater prevalence in men (27.4%) than women (20.0%). This translates into 207 million persons (men 112 million, women 95 million) with hypertension in India. Prevalence would be much higher using 2017 American guidelines. Global Burden of Diseases study reported that hypertension led to 1.63 million deaths in India in 2016 as compared to 0.78 million in 1990 (+108%). The disease burden (DALYs) attributable to hypertension increased from 21 million in 1990 to 39 million in 2016 (+89%). Social determinants of hypertension are important and Indian states with greater urbanization, human development and social development have more hypertension. There is poor association of hypertension prevalence with healthcare availability although there is positive association with healthcare access and quality. The health system in India should focus on better hypertension screening and control to reduce cardiovascular morbidity and mortality.

Baseline and longitudinal change in blood pressure and mortality in a Chinese cohort

Background

A J-curve association has been demonstrated for blood pressure (BP) and all-cause mortality, but data on longitudinal change of BP and mortality in Chinese population are limited.

Methods

We performed a retrospective cohort study to examine the association between BP (at baseline and longitudinal change) and risk of mortality in Yinzhou District, Ningbo, China, based on the Yinzhou Health Information System. At baseline, a total of 181 352 subjects aged over 18 years with at least one BP examination record were recruited through the Yinzhou Health Information System. The final analysis was restricted to 168 061 participants after exclusion of outliers of BP.

Results

A U-shaped association was observed for BP at baseline and risk of total and cardiovascular mortality. When compared with normotensive participants, patients with hypotension (HRs=1.51, 95% CI 1.21 to 1.88) and stage 3 hypertension (1.28, 95% CI 1.09 to 1.50) had an increased risk of all-cause mortality. Relative to stable BP of normotension, having a rise in BP from normotension to hypertension or from prehypertension to hypertension both conferred an increased risk of total and cardiovascular mortality (total: 1.39 (95% 1.10 to 1.75) and 1.40 (95% 1.15 to 1.69); cardiovascular: 2.22 (95% CI 1.35 to 3.65) and 1.89 (95% CI 1.20 to 2.96), respectively).

Conclusions

Our findings emphasise that hypotension and stage 3 hypertension were associated with an increased risk of all-cause mortality. Longitudinal change from normotensive or prehypertensive levels to 140/90 mm Hg or higher could increase the risk of total and cardiovascular mortality.

Comparative associations between anthropometric and bioelectric impedance analysis derived adiposity measures with blood pressure and hypertension in India: a cross-sectional analysis

Background

The utility of bioelectrical impedance analysis (BIA) derived adiposity measures as compared to anthropometric measures for the assessment of adiposity-related health risk is not clear. We aimed to clarify the relationships of BIA and anthropometric derived adipose measures with blood pressure and hypertension, and to compare the discriminative ability of the respective measures for hypertension.

Methods

We used baseline data collected between 2015 and 2016 from the Indian Study on Health of Adults (ISHA), an ongoing population based cohort study in India (N = 5990; age 30–69 years). We examined and compared the associations and discriminative ability between anthropometric (body mass index, waist circumference, hip circumference, waist-hip ratio, waist-height ratio) and BIA (whole body and trunk fat percentage) derived adiposity measures with blood pressure components (systolic pressure, diastolic pressure, pulse pressure, mean arterial pressure, mid-blood pressure) and hypertension.

Results

Regardless of whether the adiposity measure was derived from BIA or anthropometry, all were strongly and positively associated with blood pressure and hypertension. For both men and women, the magnitude of association of BIA measures with blood pressure and hypertension were comparable to those of anthropometric measures. Further, the ability of BIA derived adiposity measures to distinguish between those with and without hypertension was similar to the discriminative ability of anthropometric measures.

Conclusions

As compared to simple anthropometric measures, BIA derived estimates of adiposity provide no apparent advantage in the assessment of blood pressure and hypertension. The observed similarities between adiposity measures suggest that simple anthropometrics may be sufficient to assess adiposity and adiposity-related risks.

Age and sex-specific associations of anthropometric measures of adiposity with blood pressure and hypertension in India: a cross-sectional study

BACKGROUND

A determinant of blood pressure is adiposity; however, there are uncertainties surrounding whether general or central adiposity is the more important determinant of blood pressure. Further, inconsistent results exist for the relationships of anthropometric measures with blood pressure and hypertension, and whether these relationships differ substantially by age and sex is unclear. We aimed to elucidate the associations of anthropometric measures of general and central adiposity with blood pressure and hypertension, and determine the effect of age and sex on these relationships.

METHODS

We used cross-sectional data from the Centre for Global Health Research health check-up survey conducted during 2006-2007 of the general population in India (n = 7 601; age 18-59 years). We examined the associations of anthropometric measures (body mass index, waist circumference, hip circumference, waist-hip ratio, waist-height ratio) with blood pressure components (systolic pressure, diastolic pressure, pulse pressure, mean arterial pressure, mid-blood pressure) and hypertension within four (18-29 years, 30-39 years, 40-49 years, 50-59 years) age groups, by sex. We adjusted all analyses for education and location, with further adjustments, variously, for either a measure of central (waist circumference) or general (body mass index) adiposity.

RESULTS

On average, every 5 kg/m² greater body mass index or 10 cm wider waist circumference was associated with a 5 and 4 mmHg higher systolic blood pressure, respectively. When considered separately, each anthropometric measure was strongly and positively associated with most blood pressure components in all age groups, and for both sexes. However, with few exceptions, when considered jointly (body mass index adjusted for waist circumference), the associations of body mass index with blood pressure components and hypertension were greatly diminished for both sexes, and particularly in the ≥30 years age groups. By contrast, further adjustment of waist circumference for body mass index did not materially alter the associations of waist circumference with blood pressure components and hypertension.

CONCLUSIONS

Our findings indicate that central adiposity, as assessed with anthropometric measures, may be a more important determinant of blood pressure and hypertension than general adiposity for adults in India.

Prevalence of Hypertension in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis

We aimed to obtain overall and regional estimates of hypertension prevalence, and to examine the pattern of this disease condition across different socio-demographic characteristics in low-and middle-income countries. We searched electronic databases from inception to August 2015. We included population-based studies that reported hypertension prevalence using the current definition of blood pressure ≥140/90 mm Hg or self-reported use of antihypertensive medication. We used random-effects meta-analyses to pool prevalence estimates of hypertension, overall, by World Bank region and country income group. Meta-regression analyses were performed to explore sources of heterogeneity across the included studies. A total of 242 studies, comprising data on 1,494,609 adults from 45 countries, met our inclusion criteria. The overall prevalence of hypertension was 32.3% (95% confidence interval [CI] 29.4-35.3), with the Latin America and Caribbean region reporting the highest estimates (39.1%, 95% CI 33.1-45.2). Pooled prevalence estimate was also highest across upper middle income countries (37.8%, 95% CI 35.0-40.6) and lowest across low-income countries (23.1%, 95% CI 20.1-26.2). Prevalence estimates were significantly higher in the elderly (≥65 years) compared with younger adults (<65 years) overall and across the geographical regions; however, there was no significant sex-difference in hypertension prevalence (31.9% vs 30.8%, P = 0.6). Persons without formal education (49.0% vs 24.9%, P < 0.00001), overweight/obese (46.4% vs 26.3%, P < 0.00001), and urban settlers (32.7% vs 25.2%, P = 0.0005) were also more likely to be hypertensive, compared with those who were educated, normal weight, and rural settlers respectively. This study provides contemporary and up-to-date estimates that reflect the significant burden of hypertension in low- and middle-income countries, as well as evidence that hypertension remains a major public health issue across the various socio-demographic subgroups. On average, about 1 in 3 adults in the developing world is hypertensive. The findings of this study will be useful for the design of hypertension screening and treatment programmes in low- and middle-income countries.

Implications of Cardiovascular Disease Risk Assessment Using the WHO/ISH Risk Prediction Charts in Rural India

Cardiovascular disease (CVD) risk in India is currently assessed using the World Health Organization/International Society for Hypertension (WHO/ISH) risk prediction charts since no population-specific models exist. The WHO/ISH risk prediction charts have two versions-one with total cholesterol as a predictor (the high information (HI) model) and the other without (the low information (LI) model). However, information on the WHO/ISH risk prediction charts including guidance on which version to use and when, as well as relative performance of the LI and HI models, is limited. This article aims to, firstly, quantify the relative performance of the LI and HI WHO/ISH risk prediction (for WHO-South East Asian Region D) using data from rural India. Secondly, we propose a pre-screening (simplified) point-of-care (POC) test to identify patients who are likely to benefit from a total cholesterol (TC) test, and subsequently when the LI model is preferential to HI model. Analysis was performed using cross-sectional data from rural Andhra Pradesh collected in 2005 with recorded blood cholesterol measurements (N = 1066). CVD risk was computed using both LI and HI models, and high risk individuals who needed treatment(THR) were subsequently identified based on clinical guidelines. Model development for the POC assessment of a TC test was performed through three machine learning techniques: Support Vector Machine (SVM), Regularised Logistic Regression (RLR), and Random Forests (RF) along with a feature selection process. Disagreement in CVD risk predicted by LI and HI WHO/ISH models was 14.5% (n = 155; p<0.01) overall and comprised 36 clinically relevant THR patients (31% of patients identified as THR by using either model). Using two patient-specific parameters (age, systolic blood pressure), our POC assessment can pre-determine the benefit of TC testing and choose the appropriate risk model (out-of-sample AUCs:RF-0.85,SVM-0.84,RLR:0.82 and maximum sensitivity-98%). The identification of patients benefitting from a TC test for CVD risk stratification can aid planning for resource-allocation and save costs for large-scale screening programmes.

Prehypertension and the risk of coronary heart disease in Asian and Western populations: a meta-analysis

BACKGROUND

The results of studies on the association between prehypertension (blood pressure 120 to 139/80 to 89 mm Hg) and coronary heart disease (CHD) remain controversial. Furthermore, it is unclear whether prehypertension affects the risk of CHD in Asian and Western populations differently. This meta-analysis evaluated the risk of CHD associated with prehypertension and its different subgroups.

METHODS AND RESULTS

The PubMed and Embase databases were searched for prospective cohort studies with data on prehypertension and the risk of CHD. Studies were included if they reported multivariate-adjusted relative risks (RRs) with 95% CIs of CHD from prehypertension. A total of 591 664 participants from 17 prospective cohort studies were included. Prehypertension increased the risk of CHD (RR 1.43, 95% CI 1.26 to 1.63, P<0.001) compared with optimal blood pressure (<120/80 mm Hg). The risk of CHD was higher in Western than in Asian participants (Western: RR 1.70, 95% CI 1.49 to 1.94; Asian: RR 1.25, 95% CI 1.12 to 1.38; ratio of RRs 1.36, 95% CI 1.15 to 1.61). The population-attributable risk indicated that 8.4% of CHD in Asian participants was attributed to prehypertension, whereas this proportion was 24.1% in Western participants.

CONCLUSIONS

Prehypertension, even at the low range, is associated with an increased risk of CHD. This risk is more pronounced in Western than in Asian populations. These results supported the heterogeneity of target-organ damage caused by prehypertension and hypertension among different ethnicities and underscore the importance of prevention of CHD in Western patients with prehypertension.

Hypertension in India: a systematic review and meta-analysis of prevalence, awareness, and control of hypertension

Background:

A region-specific (urban and rural parts of north, east, west, and south India) systematic review and meta-analysis of the prevalence, awareness, and control of hypertension among Indian patients have not been done before.

Methods:

Medline, Web of Science, and Scopus databases from 1950 to 30 April 2013 were searched for ‘prevalence, burden, awareness, and control of blood pressure (BP) or hypertension (≥140 SBP and or ≥90 DBP) among Indian adults’ (≥18 years). Of the total 3047 articles, 142 were included.

Results:

Overall prevalence for hypertension in India was 29.8% (95% confidence interval: 26.7–33.0). Significant differences in hypertension prevalence were noted between rural and urban parts [27.6% (23.2–32.0) and 33.8% (29.7–37.8); P = 0.05]. Regional estimates for the prevalence of hypertension were as follows: 14.5% (13.3–15.7), 31.7% (30.2–33.3), 18.1% (16.9–19.2), and 21.1% (20.1–22.0) for rural north, east, west, and south India; and 28.8% (26.9–30.8), 34.5% (32.6–36.5), 35.8% (35.2–36.5), and 31.8% (30.4–33.1) for urban north, east, west, and south India, respectively. Overall estimates for the prevalence of awareness, treatment, and control of BP were 25.3% (21.4–29.3), 25.1% (17.0–33.1), and 10.7% (6.5–15.0) for rural Indians; and 42.0% (35.2–48.9), 37.6% (24.0–51.2), and 20.2% (11.6–28.7) for urban Indians.

Conclusion:

About 33% urban and 25% rural Indians are hypertensive. Of these, 25% rural and 42% urban Indians are aware of their hypertensive status. Only 25% rural and 38% of urban Indians are being treated for hypertension. One-tenth of rural and one-fifth of urban Indian hypertensive population have their BP under control.

Association between pre-hypertension and cardiovascular outcomes: a systematic review and meta-analysis of prospective studies

BACKGROUND

The quantitative associations between prehypertension or its separate blood pressure (BP) ranges and the risk of main cardiovascular diseases (CVDs) have not been reliably documented.

METHODS

We performed a comprehensive search of PubMed (1966 to June 2012) and the Cochrane Library (1988 to June 2012) without language restrictions. Prospective studies were included if they reported multivariate-adjusted risk ratios (RRs) and corresponding 95 % confidence intervals (CIs) of desirable outcomes, including fatal or non-fatal incident stroke, coronary heart disease, myocardial infarction (MI) or total CVD events, with respect to prehypertension or its separate BP ranges (low range: 120–129/80–84 mmHg; high range: 130–139/85–89 mmHg) at baseline with normal BP (<120/80 mmHg) as reference. Pooled RRs were estimated using a random-effects model or a fixed-effects model.

RESULTS

Twenty-nine articles met our inclusion criteria, with 1,010,858 participants. Both low-range and high-range prehypertension were associated with a greater risk of developing or dying of total CVD (low-range: RR: 1.24; 95 % CI: 1.10 to 1.39; high range: RR: 1.56; 95 % CI: 1.36 to 1.78), stroke (low-range: RR: 1.35; 95 % CI: 1.10 to 1.66; high-range: RR: 1.95; 95 % CI: 1.69 to 2.24) and myocardial infarction (MI) (low range: RR: 1.43; 95 % CI: 1.10 to 1.86; high range: RR: 1.99; 95 % CI: 1.59 to 2.50). The whole range prehypertension had a 1.44-fold (95 % CI: 1.35 to 1.53), 1.73-fold (95 % CI: 1.61 to 1.85), and 1.79-fold (95 % CI: 1.45 to 2.22) risk of total CVD, stroke, and MI, respectively. There was no evidence of publication bias.

CONCLUSIONS

Prehypertensive patients have a greater risk of incident stroke, MI and total CVD events. The impact was markedly different between the low and high prehypertension ranges

Association of all-cause and cardiovascular mortality with prehypertension: a meta-analysis

BACKGROUND

Studies of prehypertension and mortality are controversial after adjusting for other cardiovascular risk factors. This meta-analysis sought to evaluate the association of prehypertension with all-cause and cardiovascular disease (CVD) mortality.

METHODS

The PubMed, EMBASE, Cochrane Library databases, and conference proceedings were searched for studies with data on prehypertension and mortality. The relative risks (RRs) of all-cause, CVD, coronary heart disease (CHD), and stroke mortality were calculated and presented with 95% CIs. Subgroup analyses were conducted according to blood pressure, age, gender, ethnicity, follow-up duration, participant number, and study characteristics.

RESULTS

Data from 1,129,098 participants were derived from 20 prospective cohort studies. Prehypertension significantly increased the risk of CVD, CHD, and stroke mortality (RR 1.28, 95% CI 1.16-1.40; RR 1.12, 95% CI 1.02-1.23; and RR 1.41, 95% CI 1.28-1.56, respectively), but did not increase the risk of all-cause mortality after multivariate adjustment (RR 1.03, 95% CI 0.97-1.10). The difference between CHD mortality and stroke mortality was significant (P < .001). Subgroup analyses showed that CVD mortality was significantly increased in high-range prehypertension (RR 1.28, 95% CI 1.16-1.41) but not in low-range prehypertension (RR 1.08, 95% CI 0.98-1.18).

CONCLUSION

Prehypertension is associated with CVD mortality, especially with stroke mortality, but not with all-cause mortality. The risk for CVD mortality is largely driven by high-range prehypertension.

Meta-analysis of cohort studies of baseline prehypertension and risk of coronary heart disease

Prehypertension is a common condition, but the extent to which it increases the risk for coronary heart disease (CHD) is unclear. The aim of this study was to determine the association between baseline prehypertension and risk for CHD by performing a meta-analysis of prospective cohort studies. A systematic search of published research was conducted through January 2013, using electronic databases and bibliographies of retrieved reports. Studies were included if they reported multivariate-adjusted relative risks (RRs) and corresponding 95% confidence intervals (CIs) of CHD with respect to prehypertension. A random-effects model was used to combine the study-specific risk estimates. Eighteen studies, consisting of 934,106 participants and 14,952 cases, with a median follow-up period of 8.8 years, were included. Prehypertension was associated with a significantly elevated risk for CHD (RR 1.36, 95% CI 1.22 to 1.53). Eight studies consisting of 12 cohorts further provided risk estimates for low-range prehypertension (120/80 to 129/84 mm Hg) and high-range prehypertension (130/85 to 139/89 mm Hg) separately. The risk for CHD increased significantly in high-range prehypertensive populations (RR 1.53, 95% CI 1.19 to 1.97) but not in low-range prehypertensive populations (RR 1.16, 95% CI 0.96 to 1.42). In conclusion, prehypertension is associated with a significantly increased risk for developing CHD, particularly high-range prehypertension. Further well-designed randomized controlled trials are needed to clarify the efficacy of blood pressure reduction in subjects with prehypertension.

Prehypertension is not associated with all-cause mortality: a systematic review and meta-analysis of prospective studies

OBJECTIVES

Quantitative associations between prehypertension or its two separate blood pressure (BP) ranges and cardiovascular disease (CVD) or all-cause mortality have not been reliably documented. In this study, we performed a comprehensive systematic review and meta-analysis to assess these relationships from prospective cohort studies.

METHODS

We conducted a comprehensive search of PubMed (1966-June 2012) and the Cochrane Library (1988-June 2012) without language restrictions. This was supplemented by review of the references in the included studies and relevant reviews identified in the search. Prospective studies were included if they reported multivariate-adjusted relative risks (RRs) and corresponding 95% confidence intervals (CIs) of CVD or all-cause mortality with respect to prehypertension or its two BP ranges (low range: 120-129/80-84 mmHg; high range: 130-139/85-89 mmHg) at baseline. Pooled RRs were estimated using a random-effects model or a fixed-effects model depending on the between-study heterogeneity.

RESULTS

Thirteen studies met our inclusion criteria, with 870,678 participants. Prehypertension was not associated with an increased risk of all-cause mortality either in the whole prehypertension group (RR: 1.03; 95% CI: 0.91 to 1.15, P = 0.667) or in its two separate BP ranges (low-range: RR: 0.91; 95% CI: 0.81 to 1.02, P = 0.107; high range: RR: 1.00; 95% CI: 0.95 to 1.06, P = 0.951). Prehypertension was significantly associated with a greater risk of CVD mortality (RR: 1.32; 95% CI: 1.16 to 1.50, P<0.001). When analyzed separately by two BP ranges, only high range prehypertension was related to an increased risk of CVD mortality (low-range: RR: 1.10; 95% CI: 0.92 to 1.30, P = 0.287; high range: RR: 1.26; 95% CI: 1.13 to 1.41, P<0.001).

CONCLUSIONS

From the best available prospective data, prehypertension was not associated with all-cause mortality. More high quality cohort studies stratified by BP range are needed.

Prevalence, risk factors and awareness of hypertension in India: a systematic review

Indians have high rates of cardiovascular disease. Hypertension (HTN) is an important modifiable risk factor. There are no comprehensive reviews or a nationally representative study of the burden, treatments and outcomes of HTN in India. A systematic review was conducted to study the trends in prevalence, risk factors and awareness of HTN in India. We searched MEDLINE from January 1969 to July 2011 using prespecified medical subject heading (MeSH) terms. Of 3372 studies, 206 were included for data extraction and 174 were observational studies. Prevalence was reported in 48 studies with sample size varying from 206 to 167 331. A significant positive trend (P<0.0001) was observed over time in prevalence of HTN by region and gender. Awareness and control of HTN (11 studies) ranged from 20 to 54% and 7.5 to 25%, respectively. Increasing age, body mass index, smoking, diabetes and extra salt intake were common risk factors. In conclusion, from this systematic review, we record an increasing trend in prevalence of HTN in India by region and gender. The awareness of HTN in India is low with suboptimal control rates. There are few long-term studies to assess outcomes. Good quality long-term studies will help to understand HTN better and implement effective prevention and management programs.

Association of alcohol, alcohol and tobacco with mortality: findings from a prospective cohort study in Mumbai (Bombay), India

The aim of the present study was to examine the association between alcohol, alcohol and tobacco, and mortality in a large adult population in the city of Mumbai. A total of 35,102 men aged 45 years and older were surveyed about their alcohol drinking as part of a cohort study. These respondents were followed up over time, and all deaths were recorded. Compared with those who never drank alcohol, alcohol drinkers had 1.22 times higher risk of mortality, with the highest risk observed for liver disease (hazard ratio [HR]=3.19). Among ever drinkers, risk of mortality varied according to types (country/desi), frequency (four or less times a week, HR=1.39), and quantity of alcohol consumed (>100 mL) per day. In addition, country/desi drinkers (HR=1.34) had the highest mortality risk compared with all other types of alcohol (HR=0.97). Alcohol drinkers had increased risk of mortality for tuberculosis (HR=2.53), cerebrovascular disease (HR=1.83), and liver disease (HR=3.19). Synergistic joint effect of tobacco and alcohol on mortality was also observed, with lowest risk in never tobacco user drinkers (HR=1.02) and highest in mixed tobacco user drinkers (HR=1.79). The results of this study show a direct association between greater consumption of alcohol and increased risk of mortality from alcohol-specific causes. In addition to individual effect, this study demonstrates the synergistic interaction between alcohol and tobacco use in various forms on mortality.

Presence of baseline prehypertension and risk of incident stroke: a meta-analysis

OBJECTIVE

To qualitatively and quantitatively assess the association of prehypertension with incident stroke through a meta-analysis of prospective cohort studies.

METHODS

We searched Medline, Embase, the Cochrane Library, and bibliographies of retrieved articles. Prospective cohort studies were included if they reported multivariate-adjusted relative risks (RRs) and corresponding 95%confidence intervals (CI) of stroke with respect to baseline prehypertension.

RESULTS

Twelve studies with 518,520 participants were included. Prehypertension was associated with risk of stroke (RR 1.55, 95% CI 1.35-1.79; p < 0.001). Seven studies further distinguished a low prehypertensive population (systolic blood pressure [SBP] 120-129 mm Hg or diastolic blood pressure [DBP] 80-84 mm Hg) and a high prehypertensive population (SBP 130-139 mm Hg or DBP 85-89 mm Hg). Among persons with lower-range prehypertension, stroke risk was not significantly increased (RR 1.22, 0.95-1.57). However, for persons with higher values within the prehypertensive range, stroke risk was substantially increased (RR 1.79, 95% CI 1.49-2.16).

CONCLUSIONS

Prehypertension is associated with a higher risk of incident stroke. This risk is largely driven by higher values within the prehypertensive range and is especially relevant in nonelderly persons. Randomized trials to evaluate the efficacy of blood pressure reduction in persons with this designation are warranted.

Availability of data for monitoring noncommunicable disease risk factors in India

OBJECTIVE

To examine the availability of data measuring noncommunicable disease (NCD) risk factor indicators from household surveys conducted in India from 2000 to 2009.

METHODS

Questionnaires and publications used in household surveys were identified through internet and PubMed searches and examined to determine which core NCD risk factor indicators recommended by the World Health Organization (WHO) for NCD monitoring were being measured. Surveys with a sample size of 5000 or more were included to ensure a certain level of precision. The completeness of core indicator measurement and the geographical representativeness of the surveys were assessed.

FINDINGS

Twenty six surveys met the inclusion criteria. Among the WHO-recommended core behavioural risk factor indicators, those monitoring tobacco use were measured completely in national and subnational surveys; those assessing dietary intake and physical inactivity were measured only in subnational surveys, and those assessing alcohol use were not measured at all. Among WHO-recommended core biological risk factors, only body mass index was measured in national and subnational surveys, whereas blood pressure, fasting blood glucose and blood cholesterol were measured only in subnational surveys. Due to the use of non-standard indicator definitions, measurement of core indicators in some of the national and subnational surveys was incomplete.

CONCLUSION

The availability of data on core risk factor indicators to monitor the increasing burden of NCDs is inadequate in India. These indicators using standardized definitions should be included in the periodic national household health surveys to provide data at the national and disaggregated levels.

High prevalence and low awareness, treatment and control of hypertension in Asian Indian women

Hypertension is an important public health problem in India. To determine its prevalence, awareness, treatment and control among women, we performed a nationwide study. Population-based studies among women aged 35-70 years were performed in four urban and five rural locations. Stratified sampling was performed and we enrolled 4608 (rural 2604 and urban 2004) of the targeted 8000 (57%). Demographic details, medical history, diet, physical activity, anthropometry and blood pressure (BP) were recorded. Descriptive statistics are reported. Logistic regression was performed to determine the association of hypertension and its awareness, treatment and control with socioeconomic factors. Age-adjusted prevalence of hypertension (known or BP≥140/≥90 mm Hg) was observed in 1672 women (39.2%) (rural 746, 31.5%; urban 926, 48.2%). Significant determinants of hypertension were urban location, greater literacy, high dietary fat, low fibre intake, obesity and truncal obesity (P<0.01). Hypertension awareness was noted in 727 women (42.8%), more in urban (529, 56.8%) than in rural (198, 24.6%). Of these, 38.6% of the women were on treatment (urban 35.7, rural 46.5) and of those treated, controlled blood pressure (<140 and <90 mm Hg) was observed in 21.5% (urban 28.3 vs 10.2). Among hypertensive subjects, treatment was noted in 18.3% (rural 13.1, urban 22.5) and control in 3.9% (rural 1.3, urban 5.9). A significant determinant of low awareness, treatment and control was rural location (multivariate-adjusted P<0.05). There is a high prevalence of hypertension in middle-aged Asian Indian women. Very low awareness, treatment and control status are observed.

Illiteracy, low educational status, and cardiovascular mortality in India

BACKGROUND

Influence of education, a marker of SES, on cardiovascular disease (CVD) mortality has not been evaluated in low-income countries. To determine influence of education on CVD mortality a cohort study was performed in India.

METHODS

148,173 individuals aged ≥ 35 years were recruited in Mumbai during 1991-1997 and followed to ascertain vital status during 1997-2003. Subjects were divided according to educational status into one of the five groups: illiterate, primary school (≦ 5 years of formal education), middle school (6-8 years), secondary school (9-10 years) and college (> 10 years). Multivariate analyses using Cox proportional hazard model was performed and hazard ratios (HRs) and 95% confidence intervals (CIs) determined.

RESULTS

At average follow-up of 5.5 years (774,129 person-years) 13,261 deaths were observed. CVD was the major cause of death in all the five educational groups. Age adjusted all-cause mortality per 100,000 in illiterate to college going men respectively was 2154, 2149, 1793, 1543 and 1187 and CVD mortality was 471, 654, 618, 518 and 450; and in women all-cause mortality was 1444, 949, 896, 981 and 962 and CVD mortality was 429, 301, 267, 426 and 317 (ptrend < 0.01). Compared with illiterate, age-adjusted HRs for CVD mortality in primary school to college going men were 1.36, 1.27, 1.01 and 0.88 (ptrend < 0.05) and in women 0.69, 0.55, 1.04 and 0.74, respectively (ptrend > 0.05).

CONCLUSIONS

Inverse association of literacy status with all-cause mortality was observed in Indian men and women, while, for CVD mortality it was observed only in men.

Assessment of follow-up, and the completeness and accuracy of cancer case ascertainment in three areas of India

BACKGROUND

A prospective study of diet and cancer has not been conducted in India; consequently, little is known regarding follow-up rates or the completeness and accuracy of cancer case ascertainment.

METHODS

We assessed follow-up in the India Health Study (IHS; 4671 participants aged 35-69 residing in New Delhi, Mumbai, or Trivandrum). We evaluated the impact of medical care access and relocation, re-contacted the IHS participants to estimate follow-up rates, and conducted separate studies of cancer cases to evaluate registry coverage (604 cases in Trivandrum) and the accuracy of self- and proxy-reporting (1600 cases in New Delhi and Trivandrum).

RESULTS

Over 97% of people reported seeing a doctor and 85% had lived in their current residence for over six years. The 2-year follow-up rate was 91% for Trivandrum and 53% for New Delhi. No cancer cases were missed among public institutions participating in the surveillance program in Trivandrum during 2003-2004; but there are likely to be unmatched cases (ranging from 5 to 13% of total cases) from private hospitals in the Trivandrum registry, as there are no mandatory reporting requirements. Vital status was obtained for 36% of cancer cases in New Delhi as compared to 78% in Trivandrum after a period of 4 years.

CONCLUSIONS

A prospective cohort study of cancer may be feasible in some centers in India with active follow-up to supplement registry data. Inclusion of cancers diagnosed at private institutions, unique identifiers for individuals, and computerized medical information would likely improve cancer registries.

Treating prehypertension: medically sound and economically viable

The 7th Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure provided new guide-lines for the definition and management of hypertension. Notably, a new category-"prehypertension"-was created for intermediate systolic pressures exceeding 120 mmHg, the upper limit of normal, but less than 139 mmHg, the threshold for stage 1 hypertension. The therapeutic consequences of this new classification are not yet clear, but research indicates that prehypertension is an independent risk factor for cardiovascular, cognitive, and renal morbidities as well as diabetes, and statistical data indicate that prehypertension is present in over 30% of US, European, and Asian adults. However, while pharmacotherapy is recommended for hypertension, the use of drugs to control prehypertension is under question. Given the serious health consequences linked with prehypertension, such debates seem misplaced if patient well-being is our priority. While acknowledging the lack of specific randomized controlled trial data on this topic, we suggest that anti-hypertensive therapy be recommended for everyone with prehypertension and address resulting cost-benefit issues.