FSH Levels in Older Postmenopausal Women Affect Bone and Body Composition

Higher follicle-stimulating hormone (FSH) levels in older postmenopausal women are associated with higher bone marrow adiposity but lower fat, lean mass, and bone mineral density (BMD), according to a study in The Journal of Clinical Endocrinology and Metabolism.

A total of 483 older people, including 238 older postmenopausal women (mean age, 80.8 years), from the observational AGES-Reykjavik Study underwent densitometry measurements for areal BMD, total body fat, and lean mass. The investigators also measured lumbar vertebral BMA using proton magnetic resonance spectroscopy. Quantitative computed tomographic (QCT) scans were used to measure volumetric BMD and visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) areas.

Women in the lowest FSH quartile (Q1: 17.9-55.2 IU/L) had lower adjusted mean spine integral BMD compared with women in the highest FSH quartile (Q4: 85.2-180.0 IU/L;-8.6%).

Women in the highest FSH quartile had lower spine compressive strength index (-34.8%), higher BMA (+8.4%), lower weight (-8.4%), lower VAT (-17.6%), lower lean mass (-6.1%), and lower fat mass (-11.9%) compared with women in the lowest quartile (all P <.05). The FSH level was not associated with any outcome in men.

The serum FSH held inverse correlations with estradiol (r=-0.27; P <.0001) and testosterone (r=-0.35; P <.0001) in men. Both estradiol and testosterone were also highly correlated (r=0.66; P <.0001) in men.

In women and men, the serum FSH level held a positive correlation with age (r=0.11; P =.08 and r=0.20; P <.01, respectively).

Limitations of this study included its cross-sectional design as well as the lack of adjustment for potential confounders not identified in the study.

The investigators concluded that future “longitudinal studies are needed to better understand the mechanisms that underlie” the relationships between FSH level and bone mass, bone marrow adiposity, and fat and lean mass in older women.

Reference

Veldhuis-Vlug AG, Woods GN, Sigurdsson S, et al. Serum FSH is associated with BMD, bone marrow adiposity and body composition in the AGES-Reykjavik study of older adults. Published online December 16, 2020. J Clin Endocrinol Metab. doi:10.1210/clinem/dgaa922