Abstract P050: Correlates of Serum Cortisol and its Prognostic Value in the Community

Abstract

Introduction: Community-based data on correlates of serum cortisol are scarce. We investigated the sources of variability in morning serum cortisol, and its relation to cardiometabolic outcomes in a large biracial sample. Hypothesis: Serum cortisol is monotonically associated with cardiometabolic outcomes, an effect that is potentiated by aldosterone. Methods: We included 2896 whites (Framingham Heart Study [Generation 3], 53% women, mean age 44 years) and 2479 blacks (Jackson Heart Study, 52% women, mean age 53 years). Cohort-and sex-specific linear regression was used to identify cortisol correlates. Heritability was derived using the variance-components method. Cohort- and sex-specific logistic regression was used to relate cortisol to progression in blood pressure (BP) or fasting blood glucose (FBG) categories, and incidence of hypertension (HTN), diabetes (DM) or metabolic syndrome (MetS). Results: Serum cortisol was higher in blacks compared to whites (age-adjusted mean: 13.1 vs 10.2 μg/dL in men [ P <0.001] and 12.7 vs. 8.1 μg/dL in women [ P <0.001]). Serum cortisol was positively related to age and smoking in blacks, DM, menopausal status and use of hormonal therapy (replacement or contraception) in both racial groups (P <0.005). Body mass index and glomerular filtration rate were inversely associated with cortisol in whites and blacks (P <0.01). The age- and sex-adjusted heritability of serum cortisol was 0.20 in whites and 0.11 in blacks ( P ≤0.005). Serum cortisol was not associated with outcomes ( Table ). In blacks, concomitantly high cortisol (>median) and high aldosterone (>median) was associated with incident HTN (odd ratio [OR]: 1.90 [95%CI: 1.14, 3.16]) and DM (1.75 [1.17, 2.62]) compared to normal aldosterone and cortisol; ORs in whites were 1.15 (0.81, 1.63) for HTN and 0.95 (0.52, 1.74) for DM. Conclusions: Serum cortisol is a heritable trait influenced by clinical factors. Conjointly high aldosterone and cortisol levels in blacks is associated with increased risk of HTN and DM in blacks, not in whites.