Associations between body shape across the life course and adulthood concentrations of sex hormones in men and pre- and postmenopausal women: a multicohort study.

The objective was to investigate associations between life-course adiposity and sex hormone concentrations: trajectory of adiposity from age 5 to 40 (premenopausal)/60 (postmenopausal women and men) in relation to levels of oestrone (E1), oestradiol (E2), sex hormone-binding globulins (SHBG), testosterone in 4801 premenopausal and 6019 postmenopausal women in the Nurses' Health Study (NHS) and NHS II, and 2431 men in the Health Professionals Follow-up Study. We used group-based trajectory models to identify groups within each cohort based on recalled somatotypes and reported BMI. Multivariate linear regression models were used to compare sex hormone concentration across different trajectory groups. The mean age at blood draw was 64·1 ± 8·1 years for men, 59·4 ± 6·0 for postmenopausal and 44·1 ± 4·6 for premenopausal women. In men, compared with the medium-stable group, lean-marked increase and medium increase groups had lower levels of SHBG (percentage difference: -17 and -9 %) and testosterone (-15 and -13 %). In postmenopausal women, compared with the medium-stable group, lean-marked increase and medium increase groups had higher levels of E1 (21 and 34 %) and E2 (45 and 68 %) but lower level of SHBG (-29 and -35 %). In premenopausal women, compared with the lean-moderate increase group, medium-stable/increase and heavy-stable/increase groups had lower levels of SHBG (-6 and -28 %). Attained adulthood adiposity and middle-life weight gain were associated with lower SHBG and testosterone in men, higher E1 and E2 and lower SHBG in postmenopausal women, and lower SHBG in premenopausal women. The study indicates the importance of maintaining a healthy body weight throughout life course for homoeostasis of sex hormones.