Association of subclinical thyroid dysfunction with bone mineral density and fracture: a meta-analysis of prospective cohort studies

Purpose To comprehensively investigate the associations of subclinical thyroid dysfunction with BMD and fractures at various sites. Methods Comprehensive electronic and manual searches of databases were systematically conducted to identify prospective cohort studies from the inception of the databases to May 2019. The summary results for fractures and BMDs at various sites were calculated by relative risks (RRs) and weighted mean differences (WMDs) with corresponding 95% confidence intervals (CIs) using the random-effects model. Results Seventeen prospective cohorts from 24 studies were identified and 313,557 individuals were recruited in a final analysis. The summary RR indicated that subclinical hyperthyroidism was associated with an increased risk of any fracture (RR, 1.17; 95% CI, 1.08–1.26; P