Women exposed to disadvantaged socioeconomic conditions during childhood have higher chances to develop chronic kidney disease later in life. This is the result of a study conducted by a group of researchers from the Trinity College Dublin, published on The American Journal of Nephrologyand supported by the LIFEPATH project, a project funded by the European Commission that investigates the biological pathways underlying social differences in healthy ageing.

Chronic kidney disease (CKD) is a strong independent risk factor for premature cardiovascular disease and mortality, even if only a minority of individuals suffering from it ultimately requires renal replacement therapy. Such a disease exhibits substantial regional variation that is not explained by geographical differences in traditional risk factors like diabetes or hypertension. This means that there should be other factors contributing to the risk of developing it.

The researchers analysed kidney function, and childhood and adulthood socioeconomic position – defined as father’s and respondent’s occupation respectively – of 5,000 participants from The Irish Longitudinal Study on Ageing, a nationally representative cohort of adults aged more than 50 years. The association between disadvantaged socioeconomic positions and CKD was significant only in women, even for those whose circumstances improved in adulthood. 

«Our observations support the so-called “critical period hypothesis”, according to which exposure to adverse socioeconomic conditions early in life results in physiological “scarring” that directly influences disease risk in adulthood», explains Mark Canney, leading author of the study.

Disadvantaged social and economic conditions during childhood likely capture a number of factors that could influence the predisposition to poorer health in later life, such as early-life nutrition, in utero tobacco smoke exposure, and social patterning of health behaviours such as diet and exercise. The strong evidence that the authors observed for this critical period could also reflect socioeconomic disparities in preterm birth or intrauterine growth restriction.

«We think that more attention should be paid to the potential contribution of early-life socioeconomic circumstances to the risk of developing kidney disease», concluded Cathal McCrory, coordinator of the research. «The results of our study can provide evidence for more focused public health efforts».