Objective
We examined the relationship between childhood socioeconomic status (SES) and glucoregulation in later life and used a life-course framework to examine critical periods and underlying pathways.
Methods
Data came from the MIDUS (Midlife in the U.S.) national study (n=895). Childhood SES indicators retrospectively reported at MIDUS I were used to create a childhood SES disadvantage index. Adult SES disadvantage and potential pathways were measured at MIDUS I and included waist circumference, depressive symptoms, and physical activity. Glucose and HbA1c, measured approximately 9-10 years later at MIDUS II, were used to create the ordinal outcome measure (no diabetes/prediabetes/diabetes).
Results
Childhood SES disadvantage predicted increased odds of prediabetes and diabetes net of age, gender, race, and smoking (OR=1.11, 95% CI: 1.01-1.22). Childhood SES disadvantage predicted adult SES disadvantage (β=.26, p=.001) and the three key mediators: higher waist circumference (β=.10, p=.002), lower physical activity (β=−.11, p=.001), and marginally higher depressive symptoms (β=.07, p=.072). When childhood and adult SES disadvantage were in the same model, only adult SES predicted glucoregulation (OR=1.07, 95% CI: 1.01-1.13). The SES disadvantage measures were no longer significantly associated with glucoregulation after including waist circumference, physical activity, and depressive symptoms, all of which were significant predictors of glucoregulation.
Conclusions
The consequences of childhood SES disadvantage are complex and include both critical period and pathway effects. The lack of a direct effect of childhood SES on glucoregulation does not negate the importance of early environment but suggests that early-life socioeconomic factors propel unequal life-course trajectories that ultimately influence health.