Introduction South Asians have high rates of cardiovascular disease (CVD) and its risk factors (hypertension, diabetes, dyslipidaemia and central obesity). Left ventricular (LV) hypertrophy and dysfunction are features of these disorders and important predictors of CVD mortality. Lower birth and infant weight and greater childhood weight gain are associated with increased adult CVD mortality, but there are few data on their relationship to LV function. The IndEcho study will examine associations of birth size, growth during infancy, childhood and adolescence and CVD risk factors in young adulthood with midlife cardiac structure and function in South Asian Indians.
Methods and analysis We propose to study approximately 3000 men and women aged 43–50 years from two birth cohorts established in 1969–1973: the New Delhi Birth Cohort (n=1508) and Vellore Birth Cohort (n=2156). They had serial measurements of weight and height from birth to early adulthood. CVD risk markers (body composition, blood pressure, glucose tolerance and lipids) and lifestyle characteristics (tobacco and alcohol consumption, physical activity, socioeconomic status) were assessed at age ~30 years. Clinical measurements in IndEcho will include anthropometry, blood pressure, biochemistry (glucose, fasting insulin and lipids, urinary albumin/creatinine ratio) and body composition by dual energy X-ray absorptiometry and bioelectrical impedance. Outcomes are LV mass and indices of LV systolic and diastolic function assessed by two-dimensional and Doppler echocardiography, carotid intimal-media thickness and ECG indicators of ischaemia. Regression and conditional growth models, adjusted for potential confounders, will be used to study associations of childhood and young adult exposures with these cardiovascular outcomes.
Ethics and dissemination The study has been approved by the Health Ministry Steering Committee, Government of India and institutional ethics committees of participating centres in India and the University of Southampton, UK. Results will be disseminated through scientific meetings and peer-reviewed journals.
Trial registration number ISRCTN13432279; Pre-results.
- South Asians
- left ventricular mass and function
- birth weight and early growth
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Contributors SKV, AR, VTS, BA, SKB, AAG, CO, FSK, HS, LR, NT, NJT, TVP, DP and CHDF conceived the study and wrote the study protocol. BS, FSG, KA, PSP, PA, SFXP and SS will contribute significantly to the acquisition of the data. CO, SKV, FK, DP, SKB, HS, AR, VTS, AGA, BA, PSP, SFXP and CHDF significantly contributed to the planning of analyses of the data. SKV and CHDF drafted the first version of the manuscript and all authors revised the manuscript critically for important intellectual content. All authors reviewed and approved the final manuscript and agreed to be accountable for all aspects of the work.
Funding The original cohort studies were supported by the National Center for Health Statistics, USA and the Indian Council of Medical Research. The two earlier follow-up studies in young adult life were supported by the British Heart Foundation. The IndEcho study is supported by British Heart Foundation Clinical Research Grant, no. CRM: 0022324. Professor Fall’s work on the study is supported by the UK Medical Research Council (MRC) and the UK Department for International Development (DFID) under the MRC/DFID Concordat.
Competing interests None declared.
Patient consent Obtained.
Ethics approval The study has been approved by the research ethics committees of Sunder Lal JainHospital, New Delhi (13th August 2015; SLJ/IEC/1); Sitaram Bhartia Institute of Science and Research, New Delhi (23 October 2015; IEC/SBSR/2015/1); Centre for Chronic Disease Control, New Delhi (no.50/7/TF-CVD/15-NCD-II); All-India Institute of Medical Sciences, New Delhi (21 October 2015, IEC/NP-410/09.10.2015); Christian Medical College, Vellore (22 July 2015; IRB 9548 (OBSERV)) and the Faculty of Medicine, University of Southampton, UK (11 April 2016; RE 18694).
Provenance and peer review Not commissioned; externally peer reviewed.
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