Associations of childhood socioeconomic status and adulthood height with functional limitations among Japanese older people: results from the JAGES 2010 Project

Background: We examined the associations between childhood socioeconomic status and adulthood height with functional limitations in old age.

Methods: Data were obtained from the baseline survey of the Japan Gerontological Evaluation Study 2010, a population-based cohort of people aged ≥65 years enrolled from 27 municipalities across Japan (N = 15,499). People aged 65-69, 70-74, 75-79, and ≥80 years experienced the end of World War II when they were aged 0-4, 5-9, 10-14, and ≥15 years, respectively. Subjective socioeconomic status during childhood and current height were obtained by self-report through questionnaire in 2010. Higher-level functional capacity was assessed using a validated questionnaire scale. Poisson regression with robust variance estimator was employed to determine the association between childhood subjective socioeconomic status, height, and functional limitations.

Results: Lower childhood subjective socioeconomic status was consistently associated with higher prevalence rate ratio of limitations in higher-level functional capacity, regardless of age cohort. Height was associated with functional limitation only among the group aged 70-74 years: taller (≥170cm for men and ≥160cm for women) people were 16% less likely to report functional limitation in comparison with shorter (<155 cm for men and <145 cm for women) individuals in the fully adjusted model (prevalence rate ratio: 0.84, 95% confidence interval: 0.74-0.96).

Conclusions: Low childhood subjective socioeconomic status had a robust association with functional limitation regardless of age cohort. In addition, those who lived through World War II before they reached puberty and attained shorter height were more likely to report functional limitations in old age.