Santosh K. Bhargava

Birth weight and risk of type 2 diabetes: A systematic review

CONTEXTnLow birth weight is implicated as a risk factor for type 2 diabetes. However, the strength, consistency, independence, and shape of the association have not been systematically examined.nnnOBJECTIVEnTo conduct a quantitative systematic review examining published evidence on the association of birth weight and type 2 diabetes in adults.nnnDATA SOURCES AND STUDY SELECTIONnRelevant studies published by June 2008 were identified through literature searches using EMBASE (from 1980), MEDLINE (from 1950), and Web of Science (from 1980), with a combination of text words and Medical Subject Headings. Studies with either quantitative or qualitative estimates of the association between birth weight and type 2 diabetes were included.nnnDATA EXTRACTIONnEstimates of association (odds ratio [OR] per kilogram of increase in birth weight) were obtained from authors or from published reports in models that allowed the effects of adjustment (for body mass index and socioeconomic status) and the effects of exclusion (for macrosomia and maternal diabetes) to be examined. Estimates were pooled using random-effects models, allowing for the possibility that true associations differed between populations.nnnDATA SYNTHESISnOf 327 reports identified, 31 were found to be relevant. Data were obtained from 30 of these reports (31 populations; 6090 diabetes cases; 152 084 individuals). Inverse birth weight-type 2 diabetes associations were observed in 23 populations (9 of which were statistically significant) and positive associations were found in 8 (2 of which were statistically significant). Appreciable heterogeneity between populations (I(2) = 66%; 95% confidence interval [CI], 51%-77%) was largely explained by positive associations in 2 native North American populations with high prevalences of maternal diabetes and in 1 other population of young adults. In the remaining 28 populations, the pooled OR of type 2 diabetes, adjusted for age and sex, was 0.75 (95% CI, 0.70-0.81) per kilogram. The shape of the birth weight-type 2 diabetes association was strongly graded, particularly at birth weights of 3 kg or less. Adjustment for current body mass index slightly strengthened the association (OR, 0.76 [95% CI, 0.70-0.82] before adjustment and 0.70 [95% CI, 0.65-0.76] after adjustment). Adjustment for socioeconomic status did not materially affect the association (OR, 0.77 [95% CI, 0.70-0.84] before adjustment and 0.78 [95% CI, 0.72-0.84] after adjustment). There was no strong evidence of publication or small study bias.nnnCONCLUSIONnIn most populations studied, birth weight was inversely related to type 2 diabetes risk.

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

BACKGROUNDnSouth 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.nnnOBJECTIVEnAnthropometric indexes of adult body composition were examined in relation to birth size and body mass index (BMI) during childhood.nnnDESIGNnA 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.nnnRESULTSnMean 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.nnnCONCLUSIONSnBirth 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.

A century of trends in adult human height

Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.5–22.7) and 16.5 cm (13.3–19.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8–144.8). The height differential between the tallest and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries. DOI: http://dx.doi.org/10.7554/eLife.13410.001

Weight Gain in the First Two Years of Life Is an Important Predictor of Schooling Outcomes in Pooled Analyses from Five Birth Cohorts from Low- and Middle-Income Countries

Schooling predicts better reproductive outcomes, better long-term health, and increased lifetime earnings. We used data from 5 cohorts (Brazil, Guatemala, India, the Philippines, and South Africa) to explore the relative importance of birthweight and postnatal weight gain for schooling in pooled analyses (n = 7945) that used appropriate statistical methods [conditional weight (CW) gain measures that are uncorrelated with prior weights] and controlled for confounding. One SD increase in birthweight, ∼0.5 kg, was associated with 0.21 y more schooling and 8% decreased risk of grade failure. One SD increase in CW gain between 0 and 2 y, ∼0.7 kg, was associated with higher estimates, 0.43 y more schooling, and 12% decreased risk of failure. One SD increase of CW gain between 2 and 4 y, ∼0.9 kg, was associated with only 0.07 y more schooling but not with failure. Also, in children born in the lowest tertile of birthweight, 1 SD increase of CW between 0 and 2 y was associated with 0.52 y more schooling compared with 0.30 y in those in the upper tertile. Relationships with age at school entry were inconsistent. In conclusion, weight gain during the first 2 y of life had the strongest associations with schooling followed by birthweight; weight gain between 2 and 4 y had little relationship to schooling. Catch-up growth in smaller babies benefited schooling. Nutrition interventions aimed at women and children under 2 y are among the key strategies for achieving the millennium development goal of universal primary education by 2015.

Growth Patterns in Early Childhood and Final Attained Stature: Data from Five Birth Cohorts from Low- and Middle-Income Countries

Growth failure is cumulative, and short stature is associated with multiple indices of reduced human capital. Few studies have been able to address in a single analysis both consideration of the timing of growth failure and comparison across populations. We analyzed data from birth cohorts in Brazil, Guatemala, India, the Philippines, and South Africa (n = 4,659). We used data on length at birth (available for three of the five cohorts), 12 mo, 24 mo, and mid‐childhood to construct cohort‐ and sex‐ specific conditional length measures. We modeled adult height as a function of conditional length in childhood. The five cohorts experienced varying degrees of growth failure. As adults, the Brazil sample was 0.35 ± 0.89 standard deviations (SD) below the World Health Organization reference, while adult Guatemalans were 1.91 ± 0.87 SD below the reference. All five cohorts experienced a nadir in height for age Z‐score at 24 mo. Birth length (in the three cohorts with this variable), and conditional length at 12 mo (in all five cohorts) were the most strongly associated with adult height. Growth in the periods 12–24 mo and 24 mo to mid‐childhood showed inconsistent patterns across tertiles of adult height. Despite variation in the magnitude of cumulative growth failure across cohorts, the five cohorts show highly consistent age‐specific associations with adult stature. Growth failure prior to age 12 mo was most strongly associated with adult stature. These consistencies speak to the importance of interventions to address intrauterine growth failure and growth failure in the first 12 mo of life. Am. J. Hum. Biol. 2010.

Adult Metabolic Syndrome and Impaired Glucose Tolerance Are Associated With Different Patterns of BMI Gain During Infancy: Data from the New Delhi birth cohort

OBJECTIVE—The purpose of this study was to describe patterns of infant, childhood, and adolescent BMI and weight associated with adult metabolic risk factors for cardiovascular disease. RESEARCH DESIGN AND METHODS—We measured waist circumference, blood pressure, glucose, insulin and lipid concentrations, and the prevalence of metabolic syndrome (National Cholesterol Education Program Adult Treatment Panel III definition) in 1,492 men and women aged 26–32 years in Delhi, India, whose weight and height were recorded every 6 months throughout infancy (0–2 years), childhood (2–11 years), and adolescence (11 years–adult). RESULTS—Men and women with metabolic syndrome (29% overall), any of its component features, or higher (greater than upper quartile) insulin resistance (homeostasis model assessment) had more rapid BMI or weight gain than the rest of the cohort throughout infancy, childhood, and adolescence. Glucose intolerance (impaired glucose tolerance or diabetes) was, like metabolic syndrome, associated with rapid BMI gain in childhood and adolescence but with lower BMI in infancy. CONCLUSIONS—In this Indian population, patterns of infant BMI and weight gain differed for individuals who developed metabolic syndrome (rapid gain) compared with those who developed glucose intolerance (low infant BMI). Rapid BMI gain during childhood and adolescence was a risk factor for both disorders.

Infant-feeding patterns and cardiovascular risk factors in young adulthood: data from five cohorts in low- and middle-income countries

Background Infant-feeding patterns may influence lifelong health. This study tested the hypothesis that longer duration of breastfeeding and later introduction of complementary foods in infancy are associated with reduced adult cardiovascular risk. Methods Data were pooled from 10u2009912 subjects in the age range of 15–41u2009years from five prospective birth-cohort studies in low-/middle-income countries (Brazil, Guatemala, India, Philippines and South Africa). Associations were examined between infant feeding (duration of breastfeeding and age at introduction of complementary foods) and adult blood pressure (BP), plasma glucose concentration and adiposity (skinfolds, waist circumference, percentage body fat and overweight/obesity). Analyses were adjusted for maternal socio-economic status, education, age, smoking, race and urban/rural residence and infant birth weight. Results There were no differences in outcomes between adults who were ever breastfed compared with those who were never breastfed. Duration of breastfeeding was not associated with adult diabetes prevalence or adiposity. There were U-shaped associations between duration of breastfeeding and systolic BP and hypertension; however, these were weak and inconsistent among the cohorts. Later introduction of complementary foods was associated with lower adult adiposity. Body mass index changed by −0.19u2009kg/m2 [95% confidence interval (CI) −0.37 to −0.01] and waist circumference by −0.45u2009cm (95% CI −0.88 to −0.02) per 3-month increase in age at introduction of complementary foods. Conclusions There was no evidence that longer duration of breastfeeding is protective against adult hypertension, diabetes or overweight/adiposity in these low-/middle-income populations. Further research is required to determine whether ‘exclusive’ breastfeeding may be protective. Delaying complementary foods until 6 months, as recommended by the World Health Organization, may reduce the risk of adult overweight/adiposity, but the effect is likely to be small.

Adult metabolic syndrome abd impaired glucose tolerance are associated with different patterns of BMI from the New Delhi birth cohort

OBJECTIVE—The purpose of this study was to describe patterns of infant, childhood, and adolescent BMI and weight associated with adult metabolic risk factors for cardiovascular disease. RESEARCH DESIGN AND METHODS—We measured waist circumference, blood pressure, glucose, insulin and lipid concentrations, and the prevalence of metabolic syndrome (National Cholesterol Education Program Adult Treatment Panel III definition) in 1,492 men and women aged 26–32 years in Delhi, India, whose weight and height were recorded every 6 months throughout infancy (0–2 years), childhood (2–11 years), and adolescence (11 years–adult). RESULTS—Men and women with metabolic syndrome (29% overall), any of its component features, or higher (greater than upper quartile) insulin resistance (homeostasis model assessment) had more rapid BMI or weight gain than the rest of the cohort throughout infancy, childhood, and adolescence. Glucose intolerance (impaired glucose tolerance or diabetes) was, like metabolic syndrome, associated with rapid BMI gain in childhood and adolescence but with lower BMI in infancy. CONCLUSIONS—In this Indian population, patterns of infant BMI and weight gain differed for individuals who developed metabolic syndrome (rapid gain) compared with those who developed glucose intolerance (low infant BMI). Rapid BMI gain during childhood and adolescence was a risk factor for both disorders.

Birth weight, postnatal weight gain, and adult body composition in five low and middle income countries.

To evaluate the associations between birth weight (BW), infancy, and childhood weight gain and adult body composition.

Cohort Profile: The Consortium of Health-Orientated Research in Transitioning Societies

Human Sciences Research Council and the Birth to Twenty Research Programme, University of the Witwatersrand, South Africa, Universidade Federal de Pelotas, Pelotas, Brazil, Department of Nutrition, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA, S.L. Jain Hospital, New Delhi, India, MRC Lifecourse Epidemiology Unit, University of Southampton, UK, Office of Population Studies, University of San Carlos, Cebu City, Philippines, Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA, Birth to Twenty Research Programme and the Department of Paediatrics, University of the Witwatersrand, South Africa, Sitaram Bhartia Institute of Science and Research, New Delhi, India and Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA