Supplementary Material for: Kidney Disease in Women is Associated with Disadvantaged Childhood Socioeconomic Position

<b><i>Background:</i></b> Socioeconomic position (SEP) is an important determinant of health and it is dynamic across the entire lifespan. We sought to investigate the relationship between life-course SEP and chronic kidney disease (CKD) using 3 conceptual models: critical period, pathway and accumulation. <b><i>Methods:</i></b> Cross-sectional analysis of 4,996 participants from The Irish Longitudinal Study on Ageing, a nationally representative cohort of community-dwelling adults aged ≥50 years. We defined childhood and adulthood SEP according to father’s and respondent’s occupation respectively. SEP was categorised as high (reference), intermediate, low and never worked. CKD was defined as a glomerular filtration rate < 60 mL/min/1.73 m² estimated from the combination of creatinine and cystatin C. We used logistic regression to estimate the age-adjusted association between SEP and CKD separately in men and women. <b><i>Results:</i></b> Low childhood SEP was strongly associated with CKD in women, after adjusting for adulthood SEP (OR 1.90 [95% CI 1.24–2.92]), supporting the critical period hypothesis. This association was not explained by traditional CKD risk factors. Women who experienced low childhood SEP and whose circumstances improved in adulthood also had increased odds of CKD, further supporting a critical period effect in childhood. There was comparatively less evidence in support of the pathway or accumulation models. We did not observe a statistically significant association between SEP and CKD in men. <b><i>Conclusions:</i></b> Our findings suggest that women exposed to disadvantaged SEP in childhood represent an at-risk group in whom there may be opportunities for identification of CKD and facilitation of health-promoting behaviours from an early age