Prolonged hormone therapy may reduce muscle mass decline postmenopause

Use of hormone therapy (HT) for ≥13 months was associated with higher muscle mass and low prevalence of sarcopenia in postmenopausal women, a Korean study has shown.

Sarcopenia, a condition that is highly prevalent postmenopause, entails an increased risk of falls, fractures, disability, functional impairment, and mortality due to the attendant low muscle mass and strength. [Maturitas 2011;68:331-336; Age Ageing 2019;48:16-31; Osteoporos Int 2014;25:187-193; Age Ageing 2013;42:203-209]

Given evidence reflecting a link between age-related reductions in anabolic hormones and muscle loss, hormone supplementation might be beneficial in preventing or reducing muscle loss. [J Gerontol A Biol Sci Med Sci 2014;69:1186-1198; Menopause 2002;9:117-121; Clin Sci (Lond) 1999;97:79-84]

The team evaluated 4,233 women from the Korea National Health and Nutrition Examination Survey. Most women did not receive HT (86.4 percent). The remaining subjects had HT for either 12 months or >13 months (7.1 percent and 6.5 percent, respectively). Appendicular skeletal muscle mass divided by weight (ASM/Wt) and the prevalence of sarcopenia were assessed by duration of HT use. [Menopause 2020;doi:10.1097/GME.0000000000001509]

Women with prolonged HT use had a higher estimated mean ASM/Wt than those with shorter HT use (25.1 percent vs 24.8 percent; p<0.05).

After adjusting for reproductive and nutrient factors as well as medical and social history, prolonged HT use was significantly associated with a low prevalence of sarcopenia (odds ratio [OR], 0.60, 95 percent confidence interval [CI], 0.41–0.88; p=0.01).

Stratification by age and body mass index (BMI) sustained the significant association between prolonged HT use and low prevalence of sarcopenia among subjects aged <65 years (OR, 0.56, 95 percent CI, 0.36–0.86; p<0.01) and those with a BMI <25 kg/m² (OR, 0.65, 95 percent CI, 0.42–1.00; p<0.05).

“These results suggest that the beneficial effects of HT use on sarcopenia may be more prominent in younger and leaner postmenopausal women,” said the researchers. However, as the significance was only found in a younger subset, this suggests that current – and not previous – HT use may have factored in the low prevalence of sarcopenia.

Despite the inherent limitations (ie, retrospective nature, cross-sectional design, lack of variables such as type and timing of HT use), the large sample tendered an advantage, said the researchers. “Although not all studies examining an association between HT and muscle mass have shown positive results, this large study demonstrated a relationship between extended [HT] use and both greater muscle mass and lower risk of sarcopenia in women <65 years and with a BMI <25 kg/m²,” said Dr Stephanie Faubion from the North American Menopause Society in Pepper Pike, Ohio, US, in a press release.

The oestrogen factor

The role of oestrogen decline in the development of sarcopenia remains unclear, noted the researchers. Oestrogen may regulate carbohydrate and lipid metabolism by relieving muscle glycogen and inducing lipid oxidation, which may consequently influence skeletal muscle composition following menopause. [J Womens Health Gend Based Med 2002;11:225-237]

“Oestrogen may also be directly involved in muscle metabolism by binding to oestrogen receptors expressed on skeletal muscle, as well as indirectly by altering the secretion of growth hormone and insulin growth factor 1,” they added. [Med Sci Sports Exerc 2003;35:439-443; J Clin Endocrinol Metab 1996;81:2250-2256]

Larger studies are thus warranted to validate the impact of HT use on sarcopenia, especially among older and/or obese postmenopausal women in light of the subgroup findings. “[A]dditional study [may also shed light on] the mechanism by which oestrogen protects muscle mass,” added Faubion.