Race- and sex-specific associations of parental education with insulin resistance in middle-aged participants: the CARDIA study

Low childhood socioeconomic status (SES) has been linked with insulin resistance (HOMA-IR) in adulthood. Our aim was to examine if maternal and paternal education, as indicators of childhood SES, equally contributed to increased HOMA-IR in later life. Of 5,115 adults from the Coronary Artery Disease Risk Development in Young Adults (CARDIA) Study aged 18–30 years in 1985–1986, data on 1,370 females and 1,060 males with baseline and 20 year follow-up data were used to estimate associations of maternal and paternal education with HOMA-IR, adjusting for personal education, BMI, lipids, blood pressure, and lifestyle factors. Parental education was determined as high with ≥12 years of schooling and classified as both high, only mother high, only father high, both low education. Distinct combinations of maternal and paternal education were associated with HOMA-IR across race and sex groups. Lowest year 20 HOMA-IR in European American (EA) females occurred when both parents were better educated, but was highest when only the father had better education. HOMA-IR was lowest in African American (AA) participants when the mother was better educated but the father had less education, but was highest when both parents were better educated. Parental education was unrelated to HOMA-IR in EA males. Associations of parental education with HOMA-IR are seen in AA females, AA males, and EA females but not in EA males. The distinct combinations of parental education and their associations with HOMA-IR especially in AA participants need to be addressed in further research on health disparities.