Kolli Srinath Reddy

Anthropometric indicators of body composition in young adults: relation to size at birth and serial measurements of body mass index in childhood in the New Delhi birth cohort

BACKGROUND South Asians have a muscle-thin but adipose body phenotype and high rates of obesity-related disease. Adult body composition may be predictable in early life. OBJECTIVE Anthropometric indexes of adult body composition were examined in relation to birth size and body mass index (BMI) during childhood. DESIGN A population-based cohort of 1526 men and women aged 26-32 y in Delhi, India, who were measured sequentially from birth until 21 y of age were followed up. Adult weight, height, skinfold thicknesses, and waist and hip circumferences were measured. BMI and indexes of adiposity (sum of skinfold thicknesses), central adiposity (waist-hip ratio), and lean mass (residual values after adjustment of BMI for skinfold thicknesses and height) were derived. RESULTS Mean birth weight was 2851 g. As children, many subjects were underweight-for-age (>2 SDs below the National Center for Health Statistics mean; 53% at 2 y), but as adults, 47% were overweight, 11% were obese, and 51% were centrally obese (according to World Health Organization criteria). Birth weight was positively related to adult lean mass (P < 0.001) and, in women only, to adiposity (P = 0.006) but was unrelated to central adiposity. BMI from birth to age 21 y was increasingly strongly positively correlated with all outcomes. BMI and BMI gain in infancy and early childhood were correlated more strongly with adult lean mass than with adiposity or central adiposity. Higher BMI and greater BMI gain in late childhood and adolescence were associated with increased adult adiposity and central adiposity. CONCLUSIONS Birth weight and BMI gain during infancy and early childhood predict adult lean mass more strongly than adult adiposity. Greater BMI gain in late childhood and adolescence predicts increased adult adiposity.

Methods for establishing a surveillance system for cardiovascular diseases in Indian industrial populations

OBJECTIVE To establish a surveillance network for cardiovascular diseases (CVD) risk factors in industrial settings and estimate the risk factor burden using standardized tools. METHODS We conducted a baseline cross-sectional survey (as part of a CVD surveillance programme) of industrial populations from 10 companies across India, situated in close proximity to medical colleges that served as study centres. The study subjects were employees (selected by age and sex stratified random sampling) and their family members. Information on behavioural, clinical and biochemical determinants was obtained through standardized methods (questionnaires, clinical measurements and biochemical analysis). Data collation and analyses were done at the national coordinating centre. FINDINGS We report the prevalence of CVD risk factors among individuals aged 20-69 years (n = 19 973 for the questionnaire survey, n = 10 442 for biochemical investigations); mean age was 40 years. The overall prevalence of most risk factors was high, with 50.9% of men and 51.9% of women being overweight, central obesity was observed among 30.9% of men and 32.8% of women, and 40.2% of men and 14.9% of women reported current tobacco use. Self-reported prevalence of diabetes (5.3%) and hypertension (10.9%) was lower than when measured clinically and biochemically (10.1% and 27.7%, respectively). There was marked heterogeneity in the prevalence of risk factors among the study centres. CONCLUSION There is a high burden of CVD risk factors among industrial populations across India. The surveillance system can be used as a model for replication in India as well as other developing countries.

Sociodemographic patterning of non-communicable disease risk factors in rural India: a cross sectional study.

Objectives To investigate the sociodemographic patterning of non-communicable disease risk factors in rural India. Design Cross sectional study. Setting About 1600 villages from 18 states in India. Most were from four large states due to a convenience sampling strategy. Participants 1983 (31% women) people aged 20–69 years (49% response rate). Main outcome measures Prevalence of tobacco use, alcohol use, low fruit and vegetable intake, low physical activity, obesity, central adiposity, hypertension, dyslipidaemia, diabetes, and underweight. Results Prevalence of most risk factors increased with age. Tobacco and alcohol use, low intake of fruit and vegetables, and underweight were more common in lower socioeconomic positions; whereas obesity, dyslipidaemia, and diabetes (men only) and hypertension (women only) were more prevalent in higher socioeconomic positions. For example, 37% (95% CI 30% to 44%) of men smoked tobacco in the lowest socioeconomic group compared with 15% (12% to 17%) in the highest, while 35% (30% to 40%) of women in the highest socioeconomic group were obese compared with 13% (7% to 19%) in the lowest. The age standardised prevalence of some risk factors was: tobacco use (40% (37% to 42%) men, 4% (3% to 6%) women); low fruit and vegetable intake (69% (66% to 71%) men, 75% (71% to 78%) women); obesity (19% (17% to 21%) men, 28% (24% to 31%) women); dyslipidaemia (33% (31% to 36%) men, 35% (31% to 38%) women); hypertension (20% (18% to 22%) men, 22% (19% to 25%) women); diabetes (6% (5% to 7%) men, 5% (4% to 7%) women); and underweight (21% (19% to 23%) men, 18% (15% to 21%) women). Risk factors were generally more prevalent in south Indians compared with north Indians. For example, the prevalence of dyslipidaemia was 21% (17% to 33%) in north Indian men compared with 33% (29% to 38%) in south Indian men, while the prevalence of obesity was 13% (9% to 17%) in north Indian women compared with 24% (19% to 30%) in south Indian women. Conclusions The prevalence of most risk factors was generally high across a range of sociodemographic groups in this sample of rural villagers in India; in particular, the prevalence of tobacco use in men and obesity in women was striking. However, given the limitations of the study (convenience sampling design and low response rate), cautious interpretation of the results is warranted. These data highlight the need for careful monitoring and control of non-communicable disease risk factors in rural areas of India.

Differences in body mass index and waist : hip ratios in North Indian rural and urban populations

Overweight could be a major factor in determining the increasing rates of coronary heart disease in the Indian population, by its influence on blood pressure, diabetes and insulin resistance. We studied the prevalence of overweight in north Indian urban and rural population samples. The urban sample population (n = 3050) was selected using a multistage sampling with stratification for geographical zone and the type of residential colony and cluster sampling of urban blocks in each stratum. The rural sample (n = 2487) was selected by random sampling of villages stratified for population size followed by coverage of all eligible persons in the village. All participating individuals were 35–64 years of age. Women constituted 52.2% (n = 1594) and 57% (n = 1417) of urban and rural samples, respectively. The study reveals that overweight is widely prevalent in the adult urban Delhi population, whereas underweight is a significant problem in the rural population. This was noted across all the age groups in both men and women. We estimated ‘comprehensive coronary risk estimates’ based on the New Zealand Heart foundation guidelines and noted that the proportion of high and very high risk subjects increased in a continuous manner even within the ‘normal’ ranges of BMI. This difference in prevalence in the urban population could represent the demographic transition in the Indian population.

Social determinants of cardiovascular disease outcomes in Indians

Cardiovascular diseases (CVD) are the leading cause of death and disability in both developed and developing countries. In developed countries socio-economic mortality differentials have been studied extensively showing that the low socio-economic group suffers the highest mortality. As the epidemiological transition is taking place against a background of economic globalization, CVD risk factors among the urban poor and middle class are rapidly increasing in India. Recent evidences from India also suggest reversal of social gradient with excess burden of CVD morbidity in the low socio-economic group. Understanding the social determinants of environmental and behavioural exposures, in determining the risk factors for cardiovascular disease is an important challenge for public health professionals as well as communities. Socio-economic disadvantage is not simply a proxy for poor cardiovascular risk factor status, but also an indication of the likely trajectory that an individual or a community may follow in the course of their life. The paucity of intervention research seeking to address the role of social determinants in shaping lifestyle practices among individuals in culturally and socially diverse population groups within India is definitely a measure of inadequacy in public health research. This review article provides an overview of the role of social determinants of CVD and its possible conceptual pathways with special focus on acute coronary syndrome (ACS) outcomes among Indians.

Prevalence and determinants of diabetes mellitus in the Indian industrial population

Aim   To highlight the regional difference in the prevalence of diabetes mellitus (DM) and to explore determinants in variability in the Indian industrial population.

Socio-Demographic Patterning of Physical Activity across Migrant Groups in India: Results from the Indian Migration Study

Objective To investigate the relationship between rural to urban migration and physical activity (PA) in India. Methods 6,447 (42% women) participants comprising 2077 rural, 2,094 migrants and 2,276 urban were recruited. Total activity (MET hr/day), activity intensity (min/day), PA Level (PAL) television viewing and sleeping (min/day) were estimated and associations with migrant status examined, adjusting for the sib-pair design, age, site, occupation, education, and socio-economic position (SEP). Results Total activity was highest in rural men whereas migrant and urban men had broadly similar activity levels (p<0.001). Women showed similar patterns, but slightly lower levels of total activity. Sedentary behaviour and television viewing were lower in rural residents and similar in migrant and urban groups. Sleep duration was highest in the rural group and lowest in urban non-migrants. Migrant men had considerably lower odds of being in the highest quartile of total activity than rural men, a finding that persisted after adjustment for age, SEP and education (OR 0.53, 95% CI 0.37, 0.74). For women, odds ratios attenuated and associations were removed after adjusting for age, SEP and education. Conclusion Our findings suggest that migrants have already acquired PA levels that closely resemble long-term urban residents. Effective public health interventions to increase PA are needed.

Associations of FTO and MC4R Variants with Obesity Traits in Indians and the Role of Rural/Urban Environment as a Possible Effect Modifier.

Few studies have investigated the association between genetic variation and obesity traits in Indian populations or the role of environmental factors as modifiers of these relationships. In the context of rapid urbanisation, resulting in significant lifestyle changes, understanding the aetiology of obesity is important. We investigated associations of FTO and MC4R variants with obesity traits in 3390 sibling pairs from four Indian cities, most of whom were discordant for current dwelling (rural or urban). The FTO variant rs9939609 predicted increased weight (0.09 Z-scores, 95% CI: 0.03, 0.15) and BMI (0.08 Z-scores, 95% CI: 0.02, 0.14). The MC4R variant rs17782313 was weakly associated with weight and hip circumference (P < .05). There was some indication that the association between FTO and weight was stronger in urban than that in rural dwellers (P for interaction = .03), but no evidence for effect modification by diet or physical activity. Further studies are needed to investigate ways in which urban environment may modify genetic risk of obesity.

Association Between Urban Life-Years and Cardiometabolic Risk The Indian Migration Study

Urban living is associated with an increase in cardiometabolic risks, but the speed at which these risks are accrued over time is unknown. Using a cross-sectional sibling-pair design, the authors surveyed migrant factory workers and their spouses from 4 cities in India together with their rural-dwelling siblings and examined the associations between urban life-years and cardiometabolic risk factors. Data on 4,221 participants (39% women; mean age = 41 years) were available (2005–2007). In regression models, a 2-slope pattern for body fat (with a marked shift at 10 years) was found, whereas a common slope could be accepted for other risk factors. In men, the regression coefficients (per decade of urban life) were 2.5% in the first decade and 0.1% thereafter for body fat; 1.4 mm Hg for systolic blood pressure; and 7% for fasting insulin. Age, gender, marital status, household structure, and occupation did not influence the patterns appreciably; however, stronger gradients for adiposity were noted in migrants from lower socioeconomic positions. The findings suggest that body fat increases rapidly when one first moves to an urban environment, whereas other cardiometabolic risk factors evolve gradually. Public health interventions focused on the control of obesity in newer migrants to urban areas, particularly those from lower socioeconomic positions, may be beneficial.

Predicting adult metabolic syndrome from childhood body mass index: follow-up of the New Delhi birth cohort

Objectives: To assess whether serial measurements of childhood body mass index (BMI) give clinically useful predictions of the risk of developing adult metabolic syndrome and impaired glucose tolerance or type 2 diabetes. Design/setting: Follow-up of a community-based birth cohort in Delhi, India. Participants: 1492 men and women aged 26–32 years whose BMI was recorded 6-monthly throughout childhood. Main outcome measures: The predictive value of childhood BMI for adult metabolic syndrome and impaired glucose tolerance (IGT) and diabetes mellitus. Results: 25% of subjects had metabolic syndrome and 15% had IGT/diabetes mellitus. Both outcomes were associated with greater childhood BMI gain (metabolic syndrome: OR 1.63 (95% CI 1.44 to 1.85); IGT/diabetes mellitus: 1.39 (1.20 to 1.60) per unit increase in within-cohort BMI SD score between 5 and 14 years). The best predictions of adult disease were obtained using a combined test comprising (i) any increase in BMI SD score between 5 and 14 years and (ii) a BMI SD score >0 at 14 years (metabolic syndrome: sensitivity 45%, specificity 78%; IGT/diabetes mellitus: 37%, 73%). Likelihood ratios were low (metabolic syndrome: 1.4–2.0; IGT/diabetes mellitus: 1.2–1.4). A single high BMI measurement at 14 years (overweight or obese, according to International Obesity Task Force criteria) was highly specific but insensitive (metabolic syndrome: sensitivity 7%, specificity 97%; IGT/diabetes mellitus: 8%, 97%). Charts for plotting BMI SD scores through childhood were produced. Conclusions: Serial measurements of childhood BMI give useful predictions of adult risk and could guide advice to children and parents on preventing later disease.