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Hypothalamic-Pituitary-Gonadal Axis in Aging Men and Women: Increasing Total Testosterone in Aging Men

Xia F, Wang N, Han B, Li Q, Chen Y, Zhu C, Chen Y, Pu X et al.

Neuroendocrinology, 2017

6,825 participants

Abstract

BACKGROUND: Aging is associated with variations in hypothalamic-pituitary-gonadal (HPG) axis hormones. However, it is not clear how aging changes these hormones. This study examined the natural alterations in the HPG axis in aging men and women in China.

METHODS: Data were obtained from our cross-sectional study (SPECT-China) in 16 areas of three provinces in East China between February and June 2014. There were 6,825 subjects selected, including 2,908 men and 3,917 women aged 25-93 years who had no diseases affecting HPG hormones and did not take exogenous supplements. Total testosterone (TT), estradiol (E2), free testosterone, sex hormone-binding globulin (SHBG), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were measured.

RESULTS: In men, the ranges of the 10-90th percentiles for each hormone were as follows: TT, 9.9-23.4 nmol/l; SHBG, 20.6-79.54 nmol/l; E2, 34.84-187 pmol/l. TT values were higher in men aged 25-30 years than in those aged 31-35 years and began to increase progressively at the age of 41-50 years until men reached their eighties. The unadjusted annual age trend (β) was 0.079 nmol/l/year (p < 0.001). A linear regression analysis, after full adjustment for demographic variables, metabolic factors, other hormones, lifestyle and co-morbidities, showed that higher TT levels were still associated with aging (p < 0.05). However, the ratio of TT to LH decreased with age (β = -0.272/year, p < 0.001). E2 and SHBG increased with age (β = 1.774…

How strong is the evidence?

Evidence Hub reads this as a cross-sectional, done in people. Its evidence level is 4 of 5 (Low · observational). Observational designs can show an association but not prove cause. Reported size: 6,825 participants or records.

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