Overview: The New Delhi Birth Cohort (NDBC) is led by Dr Santosh Bhargava, (Insert images C) Sunderlal Jain Hospital, New Delhi and Dr Harshpal Singh Sachdev (Insert image D), Sitaram Bhartia Institute of Science and Research. New Delhi. Other key investigators are Dr Lakshmi Ramakrishnan and Dr Nikhil Tandon (All India Institute of Medical Sciences, New Delhi) and Dr Dorairaj Prabhakaran (Centre for Chronic Disease Control, New Delhi). The cohort was set up prospectively in 1969 in order to study rates of low birth weight and pre-term birth and infant mortality. The babies were followed up throughout childhood and adolescence with measurements of height, weight and head circumference every 6-12 months, measurements which provide an exceptional record of their growth. The first study in adult life was in 1998-2002 at the age of ~30 years looked at the relationship between childhood growth and adult cardiometabolic risk markers. The cohort is now aged ~50 years and is currently involved in a study of cardiac structure and function, measured using echocardiography (the “INDECHO” study). The New Delhi Birth Cohort is a member of the COHORTS collaboration of 5 birth cohort studies from Brazil, Guatemala, India, The Philippines and South Africa. It also contributes to the NCDRisC collaboration, which monitors global trends in NCDs in >19 million people in >180 countries.

Objectives: The objective of the original cohort study was to describe birth weight and pre-term birth patterns and infant mortality. The collaboration between the MRC LEC and Drs Bhargava and Sachdev, started in 1995, and the cohort was re-traced to study the relationship of birth weight and patterns of post-natal growth with the later development of type 2 diabetes, hypertension, other cardiovascular risk markers (lipids and pro-inflammatory factors), in order to identify interventions and interventional windows in childhood to prevent later cardiovascular disease and diabetes. Further rounds of follow-up have repeated these risk markers, and have also examined other cardiovascular and NCD outcomes. Anthropometry has been measured in the children of the cohort, to study inter-generational changes in height and adiposity.

Methods: In the initial study, women’s pre-pregnancy height and socio-economic factors were recorded. Women were followed up through pregnancy, and newborn gestational age was recorded and weight, length and head circumference were measured. Weight, height and head circumference were then measured every 6-12 months through infancy, childhood and adolescence. In 1998-2002, measurements included anthropometry, blood pressure, an oral glucose tolerance test, fasting insulin, lipids, pro-inflammatory markers and homocysteine, and an electrocardiogram (ECG). Data were collected by questionnaire on socio-economic circumstances, diet and lifestyle habits such as smoking and physical activity. In 2006-2009, many of these measurements were repeated, and additionally, endothelial function, carotid intima media thickness [cIMT] and body composition and bone health [using DXA] were assessed in a sub-sample. In the current study (“INDECHO”, 2016-2019) echocardiographic indices of left ventricular structure and function are being measured, along with repeat cardiometabolic risk markers and SES and lifestyle data.

Findings from the New Delhi Birth Cohort study:

  1. Lower birth weight, lower weight in infancy, and more rapid gain in weight or body mass index in childhood and adolescence are associated with an increased risk of adult type 2 diabetes
  2. More rapid weight gain after infancy is also associated with higher adult blood pressure, plasma lipids and pro-inflammatory factors, poorer endothelial function and greater cIMT
  3. There have been large (approximately 1 SD) increases in height, weight and BMI between the original cohort and their children at equivalent ages. The increase in height was present at all ages from birth, while higher BMI was present only after age 5 years
  4. Maternal birth weight, height growth from birth to age 2 years, and weight gain in childhood and adolescence, are positively associated with next generation birth weight
  5. Young maternal age at childbirth (<19 years) is associated with a higher prevalence of a range of adverse outcomes in the next generation, including low birth weight, pre-term birth, infant underweight and stunting, under five mortality, impaired educational attainment, reduced adult height, and elevated adult glucose concentrations
  6. Cardiometabolic risk factors (BMI, blood pressure and diabetes) are rising more rapidly in LMICs than in Europe, the USA and Australasia; relationships with socio-demographic factors suggest worsening epidemics of disease as these countries continue to progress economically

Selected recent publications from the New Delhi Birth Cohort:

  • Huffman MD, Khalil A, Osmond C, Fall CHD, Tandon N, Ramakrishnan L, Ramji S, Gera T, Prabhakaran P, Dey Biswas K, Reddy KS, Bhargava SK, Sachdev HPS, Prabhakaran D. Association between anthropometry, cardiometabolic risk factors, and early life factors and adult measures of endothelial function: results from the New Delhi Birth Cohort. Ind J Med Res 2015;142:690-8 PMID: 26831418
  • Fall CHD, Sachdev HPS, Osmond C, Restrepo-Mendez M-C, Victora C, Martorell R, Stein AD, Sinha S, Tandon N, Adair L, Bas I, Norris S, Richter L and the COHORTS group. Associations between maternal age at childbirth and child and adult outcomes in the offspring; a prospective study in five low-income and middle-income countries. Lancet Global Health 2015; 3: e366-377. PMID: 25999096
  • Fall CH, Osmond C, Haazen DS, Sachdev HS, Victora C, Martorell R, Stein AD, Adair L, Norris S, Richter LM; COHORTS investigators. Disadvantages of having an adolescent mother. Lancet Glob Health. 2016; 4: e787-e788. PMID: 27765286
  • NCD Risk Factor Collaboration (NCD-RisC). Worldwide trends in diabetes since 1980: pooled analysis of 751 population-based measurement studies with over 4.4 million participants. Lancet 2016; 387: 1513-30. PMID: 27061677
  • NCD Risk Factor Collaboration (NCD-RisC). A century of trends in adult human height. E-life 2016; 5. pii: e13410. doi: 10.7554/eLife.13410. PMID: 27458798
  • Sinha S, Aggarwal AR, Osmond C, Fall CHD, Bhargava SK, Sachdev HPS. Intergenerational change in anthropometric indices of children and their predictors in New Delhi Birth Cohort. Indian Pediatrics 2017; 54: 185-192. PMID: 28031545
  • NCD Risk Factor Collaboration (NCD-RisC). Worldwide trends in blood pressure from 1975 to 2015: a pooled analysis of 1,479 population-based measurement studies with 19.1 million participants. Lancet 2017;7;389:37-55. PMID: 27863813
  • NCD Risk Factor Collaboration (NCD-RisC). Worldwide trends in body mass index, underweight, overweight and obesity from 1975 to 2016: a pooled analysis of 2,416 population-based measurement studies with 128.9 million children, adolescents and adults. Lancet 2017; 390: 2627-42. PMID: 29029897
  • Vasan SK, Roy A, Samuel VT, Antonisamy B, Bhargava SK, Alex AG, Singh B, Osmond C, Geethanjali FS, Karpe F, Sachdev HPS, Agrawal K, Ramakrishnan L, Tandon N, Thomas NJ, Premkumar PS, Asaithambi P, Princy SFX, Sinha S, Paul TV, Prabhakaran D, Fall CHD. IndEcho study: Cohort study investigating birth size, childhood growth and young adult cardiovascular risk factors as predictors of mid-life myocardial structure and function in South Asians. BMJ Open 2018:8:e019675. doi:10.1136/bmjopen-2017-019675. PMID: 29643156