Adverse social factors predict early ageing in middle-aged men and women: the Ebeltoft Health Study, Denmark

Abstract

This study examined whether adverse social factors are associated with an increased rate of biological ageing in middle-aged subjects. The authors investigated five markers of biological ageing in 690 subjects followed for five years in Ebeltoft, Denmark. Mean age at baseline was 40 years (range 30-50 years). These markers included repeated measures of pulse pressure, lung function, hearing, physical work capacity and a cardiovascular risk score. A zeta-score was calculated based on a factor analysis of the five markers used. The relative biological age was finally calculated in relation to chronological age in subgroups of different social class (occupation, educational level) and marital status, at baseline and after follow-up. Men and women from a higher social class appeared to be biologically younger than corresponding subjects from a lower social class (p < 0.001). This difference was still evident after 5 years of follow-up (p < 0.01) for men and women of different occupations and for women of different educational levels (p < 0.01). Married/cohabiting men were biologically younger than single men and this difference increased during the follow-up period in that the difference between groups at five-year follow-up was significant (p < 0.05). Middle-aged men and women from a higher social class showed signs of being biologically younger than their corresponding chronological age, while the opposite was found for men and women of lower social class. This discrepancy was still evident after five years of follow-up, and even tended to increase for single men. Differential ageing may thus be an important biological aspect of differences in health according to social class.