A test of biological and behavioral explanations for gender differences in telomere length: the multi-ethnic study of atherosclerosis - PubMed (original) (raw)

A test of biological and behavioral explanations for gender differences in telomere length: the multi-ethnic study of atherosclerosis

Belinda L Needham et al. Biodemography Soc Biol. 2014.

Abstract

The purpose of this study was to examine biological and behavioral explanations for gender differences in leukocyte telomere length (LTL), a biomarker of cell aging that has been hypothesized to contribute to women's greater longevity. Data are from a subsample (n = 851) of the Multi-Ethnic Study of Atherosclerosis, a population-based study of women and men aged 45 to 84. Mediation models were used to examine study hypotheses. We found that women had longer LTL than men, but the gender difference was smaller at older ages. Gender differences in smoking and processed meat consumption partially mediated gender differences in telomere length, whereas gender differences in estradiol, total testosterone, oxidative stress, and body mass index did not. Neither behavioral nor biological factors explained why the gender difference in LTL was smaller at older ages. Longitudinal studies are needed to assess gender differences in the rate of change in LTL over time; to identify the biological, behavioral, and psychosocial factors that contribute to these differences throughout the life course; and to determine whether gender differences in LTL explain the gender gap in longevity.

PubMed Disclaimer

Figures

Figure 1

Conceptual models. Panel A shows the total effect model; Panel B shows the mediation model; Panel C shows the total conditional effect model; Panel D shows the mediated moderation model; X is gender; Y is LTL; M1–Mj are estradiol, total testosterone, oxidative stress (GGT), pack-years smoking, processed meat consumption, and BMI; W is age; c = total effect of X on _Y; c_′ = direct effect of X on _Y; a_1_b_1 = indirect effect of X on Y through _M_1; _a_2_b_2 = indirect effect of X on Y through _M_2; _aj_–1_bj_–1 = indirect effect on X on Y through _Mj_–1; ajbj = indirect effect of X on Y through _Mj; a_1_b_1+ _a_2_b_2+ … + _aj_–1_bj_–1 + ajbj = total indirect effect of X on Y through _M_1, _M_2, … _Mj_–1, Mj; d = total effect of X on Y conditional on _W; d_′ = direct effect of X on Y conditional on W; (_a_1+e_1_W)_b_1 = indirect effect of X on Y through _M_1 conditional on W; (_a_2 + e_2_W)_b_2 = indirect effect of X on Y through _M_2 conditional on W; (_aj_–1 + ej_1_W)_bj_–1 = indirect effect of X on Y through _Mj_–1 conditional on W; (aj + ejW)bj = indirect effect of X on Y through Mj conditional on _W; e_1_b_1 = indirect effect of XW on Y through _M_1; _e_2_b_2 = indirect effect of XW on Y through _M_2; _ej_–1_bj_–1 = indirect effect of XW on Y through _Mj_–1; ejbj = indirect effect of XW on Y through Mj.

Figure 2

LTL (T/S ratio) by gender and age (n = 851).

References

1. Alex L, Hammarstrom A, Norberg A, Lundman B. Construction of masculinities among men aged 85 and older in the north of Sweden. J Clin Nurs. 2008;17(4):451–459. -PubMed
1. Andrew T, Aviv A, Falchi M, Surdulescu GL, Gardner JP, Lu X, Kimura M, Kato BS, Valdes AM, Spector TD. Mapping genetic loci that determine leukocyte telomere length in a large sample of unselected female sibling pairs. Am J Hum Genet. 2006;78(3):480–486. -PMC -PubMed
1. Armanios M, Blackburn EH. The telomere syndromes. Nat Rev Genet. 2012;13(10):693–704. -PMC -PubMed
1. Astrup AS, Tarnow L, Jorsal A, Lajer M, Nzietchueng R, Benetos A, Rossing P, Parving HH. Telomere length predicts all-cause mortality in patients with type 1 diabetes. Diabetologia. 2010;53(1):45–48. -PubMed
1. Aubert G, Lansdorp PM. Telomeres and aging. Physiol Rev. 2008;88(2):557–579. -PubMed

A test of biological and behavioral explanations for gender differences in telomere length: the multi-ethnic study of atherosclerosis - PubMed (original) (raw)