The Effect of 17β-Estradiol Plus Norethisterone Acetate on Estradiol, Testosterone, IGF-1 and SHBG in Postmenopausal Women: A Meta-Analysis of Randomized Controlled Trials.

We conducted this meta-analysis of randomized controlled trials (RCTs) with the aim of assessing the effect of 17β-estradiol plus norethisterone acetate on estradiol, testosterone, IGF-1, and SHBG in postmenopausal women. To our knowledge, this is the first meta-analysis of RCTs to assess these effects. Databases including the Web of Science, PubMed/Medline, Scopus, and EMBASE were searched to identify publications up to July 2024. The results were reported as weighted mean difference (WMD) and 95% confidence intervals (CI) generated by using a random-effects model according to the Der-Simonian-Laird model. Fifteen publications were included in current meta-analysis. Overall results from the random-effects model manifested a significant increase in estradiol (WMD: 55.30 pg/ml, 95% CI: 39.32, 7128, p<0.001) and SHBG (WMD: 18.48 nmol/l, 95% CI: 3.64, 33.33, p=0.015) levels, a significant decrease in FSH (WMD: -41.55 IU/l, 95% CI: -53.17, -29.92, p<0.001) and testosterone (WMD: -4.29 ng/dl, 95% CI: -5.38, -3.21, p=0.000) levels, and a non-significant decrease in IGF-1 levels (WMD: -9.70 μg/l, 95% CI: -34.21, 14.80, p=0.438) after treatment with 17β-estradiol plus norethisterone acetate on postmenopausal women. In conclusion, 17β-estradiol plus norethisterone acetate in postmenopausal women increases estradiol and SHBG concentrations and decreases FSH and testosterone concentrations, with no statistically significant effect on IGF-1.