Sex differences in major cardiovascular outcomes and fractures in patients with subclinical thyroid dysfunction: a systematic review and meta-analysis.

Abstract

To evaluate whether sex differences in the associations of subclinical hypothyroidism (SH) and subclinical hyperthyroidism (SCH) with the risks of major adverse cardiovascular events (MACE) and fractures. The PubMed, EmBase, and Cochrane Library databases were searched for eligible studies from inception until November 2021. The relative risk (RR) ratio with the 95% confidence interval (CI) was used to identify sex differences in the associations of SH and SCH with the risks of MACE and fractures. All analyses were performed using a random-effects model. Twenty-four cohort studies (in 3,480,682 patients) were selected for meta-analysis. There were no sex differences in the associations of SH and SCH with the risks of atrial fibrillation, all-cause mortality, cardiac death, coronary heart disease, heart failure, MACE, stroke, fracture. Subgroup analyses indicated a greater risk of MACE in men than in women with SH if follow-up was ≥10.0 years (RR ratio 2.44; 95% CI 1.17-5.10; P = 0.017). The risk of any fracture was greater in men than in women with SH if follow-up was <10.0 years (RR ratio 1.17; 95% CI 1.03-1.34; P = 0.017) and in studies with a high level of adjustment (RR ratio 1.16; 95% CI 1.02-1.32; P = 0.022). However, the risk of hip fracture was lower in men than in women with SH on pooling of studies with low adjustment (RR ratio 0.53; 95% CI 0.29-0.97; P = 0.039). There may be sex-related differences in the risks of MACE, any fracture, and hip fracture in patients with SH.