Prakash C. Gupta

Association between Body-Mass Index and Risk of Death in More Than 1 Million Asians

BACKGROUND Most studies that have evaluated the association between the body-mass index (BMI) and the risks of death from any cause and from specific causes have been conducted in populations of European origin. METHODS We performed pooled analyses to evaluate the association between BMI and the risk of death among more than 1.1 million persons recruited in 19 cohorts in Asia. The analyses included approximately 120,700 deaths that occurred during a mean follow-up period of 9.2 years. Cox regression models were used to adjust for confounding factors. RESULTS In the cohorts of East Asians, including Chinese, Japanese, and Koreans, the lowest risk of death was seen among persons with a BMI (the weight in kilograms divided by the square of the height in meters) in the range of 22.6 to 27.5. The risk was elevated among persons with BMI levels either higher or lower than that range--by a factor of up to 1.5 among those with a BMI of more than 35.0 and by a factor of 2.8 among those with a BMI of 15.0 or less. A similar U-shaped association was seen between BMI and the risks of death from cancer, from cardiovascular diseases, and from other causes. In the cohorts comprising Indians and Bangladeshis, the risks of death from any cause and from causes other than cancer or cardiovascular disease were increased among persons with a BMI of 20.0 or less, as compared with those with a BMI of 22.6 to 25.0, whereas there was no excess risk of either death from any cause or cause-specific death associated with a high BMI. CONCLUSIONS Underweight was associated with a substantially increased risk of death in all Asian populations. The excess risk of death associated with a high BMI, however, was seen among East Asians but not among Indians and Bangladeshis.

Suicide mortality in India: a nationally representative survey

BACKGROUND WHO estimates that about 170,000 deaths by suicide occur in India every year, but few epidemiological studies of suicide have been done in the country. We aimed to quantify suicide mortality in India in 2010. METHODS The Registrar General of India implemented a nationally representative mortality survey to determine the cause of deaths occurring between 2001 and 2003 in 1·1 million homes in 6671 small areas chosen randomly from all parts of India. As part of this survey, fieldworkers obtained information about cause of death and risk factors for suicide from close associates or relatives of the deceased individual. Two of 140 trained physicians were randomly allocated (stratified only by their ability to read the local language in which each survey was done) to independently and anonymously assign a cause to each death on the basis of electronic field reports. We then applied the age-specific and sex-specific proportion of suicide deaths in this survey to the 2010 UN estimates of absolute numbers of deaths in India to estimate the number of suicide deaths in India in 2010. FINDINGS About 3% of the surveyed deaths (2684 of 95,335) in individuals aged 15 years or older were due to suicide, corresponding to about 187,000 suicide deaths in India in 2010 at these ages (115,000 men and 72,000 women; age-standardised rates per 100,000 people aged 15 years or older of 26·3 for men and 17·5 for women). For suicide deaths at ages 15 years or older, 40% of suicide deaths in men (45,100 of 114,800) and 56% of suicide deaths in women (40,500 of 72,100) occurred at ages 15-29 years. A 15-year-old individual in India had a cumulative risk of about 1·3% of dying before the age of 80 years by suicide; men had a higher risk (1·7%) than did women (1·0%), with especially high risks in south India (3·5% in men and 1·8% in women). About half of suicide deaths were due to poisoning (mainly ingestions of pesticides). INTERPRETATION Suicide death rates in India are among the highest in the world. A large proportion of adult suicide deaths occur between the ages of 15 years and 29 years, especially in women. Public health interventions such as restrictions in access to pesticides might prevent many suicide deaths in India. FUNDING US National Institutes of Health.

Smokeless tobacco and cancer

Use of smokeless tobacco products is common worldwide, with increasing consumption in many countries. Although epidemiological data from the USA and Asia show a raised risk of oral cancer (overall relative risk 2.6 [95% CI 1.3-5.2]), these are not confirmed in northern European studies (1.0 [0.7-1.3]). Risks of oesophageal cancer (1.6 [1.1-2.3]) and pancreatic cancer (1.6 [1.1-2.2]) have also increased, as shown in northern European studies. Results on lung cancer have been inconsistent, with northern European studies suggesting no excess risk. In India and Sudan, more than 50% of oral cancers are attributable to smokeless tobacco products used in those countries, as are about 4% of oral cancers in US men and 20% of oesophageal and pancreatic cancers in Swedish men. Smokeless tobacco products are a major source of carcinogenic nitrosamines; biomarkers of exposure have been developed to quantify exposure as a framework for a carcinogenesis model in people. Animal carcinogenicity studies strongly support clinical results. Cancer risk of smokeless tobacco users is probably lower than that of smokers, but higher than that of non-tobacco users.

A nationally representative case-control study of smoking and death in India.

BACKGROUND The nationwide effects of smoking on mortality in India have not been assessed reliably. METHODS In a nationally representative sample of 1.1 million homes, we compared the prevalence of smoking among 33,000 deceased women and 41,000 deceased men (case subjects) with the prevalence of smoking among 35,000 living women and 43,000 living men (unmatched control subjects). Mortality risk ratios comparing smokers with nonsmokers were adjusted for age, educational level, and use of alcohol. RESULTS About 5% of female control subjects and 37% of male control subjects between the ages of 30 and 69 years were smokers. In this age group, smoking was associated with an increased risk of death from any medical cause among both women (risk ratio, 2.0; 99% confidence interval [CI], 1.8 to 2.3) and men (risk ratio, 1.7; 99% CI, 1.6 to 1.8). Daily smoking of even a small amount of tobacco was associated with increased mortality. Excess deaths among smokers, as compared with nonsmokers, were chiefly from tuberculosis among both women (risk ratio, 3.0; 99% CI, 2.4 to 3.9) and men (risk ratio, 2.3; 99% CI, 2.1 to 2.6) and from respiratory, vascular, or neoplastic disease. Smoking was associated with a reduction in median survival of 8 years for women (99% CI, 5 to 11) and 6 years for men (99% CI, 5 to 7). If these associations are mainly causal, smoking in persons between the ages of 30 and 69 years is responsible for about 1 in 20 deaths of women and 1 in 5 deaths of men. In 2010, smoking will cause about 930,000 adult deaths in India; of the dead, about 70% (90,000 women and 580,000 men) will be between the ages of 30 and 69 years. Because of population growth, the absolute number of deaths in this age group is rising by about 3% per year. CONCLUSIONS Smoking causes a large and growing number of premature deaths in India.

Global epidemiology of areca nut usage

Abstract A substantial proportion of the worlds population is engaged in chewing areca nut and the habit is endemic throughout the Indian subcontinent, large parts of south Asia and Melanesia. A large variety of ingredients, including tobacco, may be used along with areca nut constituting a betel quid. The composition and method of chewing can vary widely from country to country and these population variations are described in this review. Some populations are known to use areca nut without tobacco providing good opportunities to further research the carcinogenecity of areca nut. Some interesting trends on chewing patterns have emerged from recent data, suggesting a decline in the habit in some countries such as Thailand while the prevalence of areca nut use is rising in India and Taiwan.

Smokeless tobacco and health in India and South Asia

Abstract:  South Asia is a major producer and net exporter of tobacco. Over one‐third of tobacco consumed regionally is smokeless. Traditional forms like betel quid, tobacco with lime and tobacco tooth powder are commonly used and the use of new products is increasing, not only among men but also among children, teenagers, women of reproductive age, medical and dental students and in the South Asian diaspora. Smokeless tobacco users studied prospectively in India had age‐adjusted relative risks for premature mortality of 1.2–1.96 (men) and 1.3 (women). Current male chewers of betel quid with tobacco in case‐control studies in India had relative risks of oral cancer varying between 1.8–5.8 and relative risks for oesophageal cancer of 2.1–3.2. Oral submucous fibrosis is increasing due to the use of processed areca nut products, many containing tobacco. Pregnant women in India who used smokeless tobacco have a threefold increased risk of stillbirth and a two‐ to threefold increased risk of having a low birthweight infant. In recent years, several states in India have banned the sale, manufacture and storage of gutka, a smokeless tobacco product containing areca nut. In May 2003 in India, the Tobacco Products Bill 2001 was enacted to regulate the promotion and sale of all tobacco products. In two large‐scale educational interventions in India, sizable proportions of tobacco users quit during 5–10 years of follow‐up and incidence rates of oral leukoplakia measured in one study fell in the intervention cohort. Tobacco education must be imparted through schools, existing government health programmes and hospital outreach programmes.

Prospective Study of One Million Deaths in India: Rationale, Design, and Validation Results

Background Over 75% of the annual estimated 9.5 million deaths in India occur in the home, and the large majority of these do not have a certified cause. India and other developing countries urgently need reliable quantification of the causes of death. They also need better epidemiological evidence about the relevance of physical (such as blood pressure and obesity), behavioral (such as smoking, alcohol, HIV-1 risk taking, and immunization history), and biological (such as blood lipids and gene polymorphisms) measurements to the development of disease in individuals or disease rates in populations. We report here on the rationale, design, and implementation of the worlds largest prospective study of the causes and correlates of mortality. Methods and Findings We will monitor nearly 14 million people in 2.4 million nationally representative Indian households (6.3 million people in 1.1 million households in the 1998–2003 sample frame and 7.6 million people in 1.3 million households in the 2004–2014 sample frame) for vital status and, if dead, the causes of death through a well-validated verbal autopsy (VA) instrument. About 300,000 deaths from 1998–2003 and some 700,000 deaths from 2004–2014 are expected; of these about 850,000 will be coded by two physicians to provide causes of death by gender, age, socioeconomic status, and geographical region. Pilot studies will evaluate the addition of physical and biological measurements, specifically dried blood spots. Preliminary results from over 35,000 deaths suggest that VA can ascertain the leading causes of death, reduce the misclassification of causes, and derive the probable underlying cause of death when it has not been reported. VA yields broad classification of the underlying causes in about 90% of deaths before age 70. In old age, however, the proportion of classifiable deaths is lower. By tracking underlying demographic denominators, the study permits quantification of absolute mortality rates. Household case-control, proportional mortality, and nested case-control methods permit quantification of risk factors. Conclusions This study will reliably document not only the underlying cause of child and adult deaths but also key risk factors (behavioral, physical, environmental, and eventually, genetic). It offers a globally replicable model for reliably estimating cause-specific mortality using VA and strengthens Indias flagship mortality monitoring system. Despite the misclassification that is still expected, the new cause-of-death data will be substantially better than that available previously.

Survey of sociodemographic characteristics of tobacco use among 99,598 individuals in Bombay, India using handheld computers.

OBJECTIVES: To study the diversity and sociodemographic characteristics of tobacco use in Bombay, India. DESIGN: Population-based, cross-sectional, house-to-house survey with face-to-face interviews in the city of Bombay during 1992-94. Data was input directly into a programmed, handheld computer (electronic diary). PARTICIPANTS: Permanent residents of the city of Bombay aged 35 years and older. MAIN OUTCOME MEASURES: Tobacco use in various smoking and smokeless forms. RESULTS: 99598 individuals were interviewed (60% women, 40% men). Among women, prevalence of tobacco use was high (57.5%) but almost solely in the smokeless form. Among men, 69.3% reported current tobacco use and 23.6% were smokers. The most common smokeless tobacco practice among women was mishri use (44.5% of smokeless users) and among men betel quid with tobacco (27.1%). About half of smokers used bidi and half smoked cigarettes. Chewing areca nut without tobacco was rare (< 0.5% of smokeless users). Educational level was inversely associated with tobacco use of all kinds except cigarette smoking. CONCLUSIONS: The pattern of tobacco use varies across India and, in Bombay, is very different from other areas. Using handheld computers to collect data in the field was successful.

Epidemiologic and histologic study of oral cancer and leukoplakia among 50,915 villagers in India

The paper presents the results of an epidemiologic house‐to‐house survey of oral cancer and lcukoplakia among 50,915 adult villagers in 4 states of India which were selected according to various types of chewing and smoking habits. Twenty‐six oral cancer cases were found in the survey. The prevalence of leukoplakia ranged from 0.2 to 4.9%. There was a predominance of men. Leukoplakias were already observed in the 15‐ to 24‐year age group, and a considerable number were in the 25‐ to 34‐year age group. Intra‐oral locations of the leukoplakias were found to vary within the 4 states depending upon the chewing and smoking habits prevailing. The leukoplakias were analyzed with regard to intra‐oral locatios and correlation with habits. Special habits like hookli smoking and reverse smoking are associated with leukoplakias on the labial mucosa and on the palate, respectively. The histologic analysis of biopsies from 723 leukoplakias showed variations in the type of hyperkeratosis which may depend upon habits. The prevalence of epithelial atypia ranged from 3.0% to 12.4% in the 4 states. Epithelial atypia was seen in 8.4% of homogeneous leukoplakias but in 59.1% of speckled leukoplakias.

An epidemiologic assessment of cancer risk in oral precancerous lesions in India with special reference to nodular leukoplakia.

A cohort of 12,212 tobacco users was followed up annually to assess malignant potential of oral precancerous lesions in the Ernakulam district in Kerala, India. A total of 19 new oral cancers were diagnosed over a period of 8 years, and 15 (79%) of these arose from some preexisting precancerous lesion or condition. Nodular leukoplakia showed highest rate of malignant transformation (16% per year) as six of 13 nodular leukoplakia underwent malignant transformation over a mean follow‐up period of 2.8 years. The relative risk (3243.2) compared with individuals with tobacco habits but without any precancerous oral lesion was also the highest for nodular leukoplakia. In addition, nodular leukoplakia was associated with submucous fibrosis in two patients, which progressed to oral cancer and was the clinical diagnosis for four lesions that turned out to be malignant on histopathologic examination. Nodular appearance was noted in two other precursor lesions as well. Thus, 14 of 19 oral cancers (74%) were either preceded by nodular leukoplakia and with lesions showing a distinct nodular appearance, or had the clinical appearance of nodular leukoplakia.