Childhood migration and cardiovascular risk.

Background: Childhood living conditions have been hypothesized to be associated with the development of cardiovascular diseases and diabetes mellitus in adult life.
Methods: We analysed, using logistic regression, the risk of self-reported diabetes, hypertension, hyperlipidaemia, and ischaemic heart disease in a population-based sample of 3643 Chinese men and 3778 Chinese women some of whom had experienced a change to more favourable economic conditions at different life stages through migration from mainland China to Hong Kong.
Results: Adjusting for socio-economic status, risk behaviours, and family history, the development of diabetes was associated with migration from China to Hong Kong in the first two decades of life, albeit with a decreasing intensity of effect (OR = 2.02, 95% CI: 1.18, 3.45, OR = 1.84, 95% CI: 1.27, 2.66, and OR = 1.72, 95% CI: 1.21, 2.45 for migration at ages 0-7, 8-17, and 18-24, respectively). The development of hypertension was mostly susceptible to environmental change during the growth spurt and puberty (migration at ages 8-17 OR = 1.56, 95% CI: 1.22, 1.99). The development of heart disease was associated with a sex-specific critical period in early childhood for men (migration at ages 0-7 OR = 3.17, 95% CI: 1.70, 5.91).
Conclusion: Environmental change by migration throughout the first two decades of life can affect the development of diabetes, hypertension, hyperlipidaemia, and ischaemic heart disease, although adverse childhood conditions alone may not be a risk factor. Our results suggest that specific life course pathways may pre-dispose to these conditions and could be relevant to their aetiology in populations undergoing rapid development.