Depression, telomeres and mitochondrial DNA: between- and within-person associations from a 10-year longitudinal study.

Alterations in cellular aging, indexed by leukocyte telomere length (LTL) and mitochondrial DNA copy number (mtDNAcn), might partly account for the increased health risks in persons with depression. Although some studies indeed found cross-sectional associations of depression with LTL and mtDNAcn, the longitudinal associations remain unclear. This 10-year longitudinal study examined between- and within-person associations of depressive symptoms with LTL and mtDNAcn in a large community sample. Data are from years 15, 20 and 25 follow-up evaluations in 977 subjects from the Coronary Artery Risk Development in Young Adults study. Depressive symptoms (years 15, 20, 25) were assessed with the Center for Epidemiologic Studies Depression (CES-D) scale; LTL (years 15, 20, 25) and mtDNAcn (years 15, 25) were measured in whole blood by quantitative PCR. With mixed-model analyses, we explored between- and within-person associations between CES-D scores and cellular aging markers. Results showed that high levels of depressive symptomatology throughout the 10-year time span was associated with shorter average LTL over 10 years (B=-4.2; P=0.014) after covarying for age, sex, race and education. However, no within-person association was found between depressive symptoms and LTL at each year (B=-0.8; P=0.548). Further, we found no between-person (B=-0.2; P=0.744) or within-person (B=0.4; P=0.497) associations between depressive symptomatology and mtDNAcn. Our results provide evidence for a long-term, between-person relationship of depressive symptoms with LTL, rather than a dynamic and direct within-person relationship. In this study, we found no evidence for an association between depressive symptoms and mtDNAcn.

Stress-induced cortisol, mood, and fat distribution in men.

OBJECTIVE: A previous study in our laboratory (Moyer et al., Obes Res. 1994;2:255-62 found that, in response to uncontrollable laboratory stress, women with a high waist-to-hip ratio (WHR) had higher cortisol reactivity, poorer coping skills, and lower anger responses than women with low WHR. We aimed to compare high WHR men's stress responses to these women. RESEARCH METHODS AND PROCEDURES: The current study examined cortisol reactivity and psychological data of 27 healthy high WHR men exposed to the same laboratory challenges as the women from our previous study. Men's data are discussed in relation to that of the high and low WHR women. RESULTS: Men responded to the stress with increases in both cortisol and blood pressure. In comparison with the high and low WHR women, men had significantly higher total cortisol on the stress day. However, when comparing a sub-sample of men and women matched in WHR's, differences in cortisol secretion were greatly diminished and no longer significant. In addition, men had higher desire for control than both high and low WHR women, and lower mood reactivity than low WHR women. Despite the lower mood reactivity of high WHR groups, the high mood reactors among the high WHR women, and to a lesser extent, men, tended to have higher cortisol reactivity. DISCUSSION: These results suggest that the psychological differences and greater exposure to cortisol observed among the high WHR men and women may have played a role in contributing to their greater abdominal fat depots.