Association of decreased muscle mass with reduced bone mineral density in patients with Graves’ disease

Abstract

BackgroundThe bone mineral density (BMD) did not increase signi cantly after the normalization of serum thyroid hormone levels. Studies on the effect of muscle mass on BMD in patients with Graves' disease are scarce. This study aimed to determine the association of decreased muscle mass with reduced bone mineral density in patients with Graves' disease. MethodsA total of 758 patients with Graves' at diagnosis (mean age 41.2 years) were enrolled for a cross-sectional study; of these, 287 patients were enrolled for a cohort study with a median follow-up of 24 months. Meanwhile, 1164 age-and sex-matched healthy controls participants were recruited. All participants underwent dual-energy x-ray absorptiometry and muscle mass index (ASMI) measurements. The changes in ASMI and BMD were calculated from the measurements made at a gap of 2 years. ResultsCompared with healthy controls participants, the BMD was still signi cantly lower after normalizing serum thyroid hormone levels (1.131 ± 0.268 vs. 1.07 ± 0.133, p < 0.05). ASMI was positively related to BMD in patients with Graves' disease(lumbar BMD, r = 0.210; femoral neck BMD, r = 0.259;hip BMD, r = 0.235;P < 0.001) and this relationship still existed after successful anti-thyroid therapy(lumbar BMD, r = 0.169; femoral neck BMD, r = 0.281;hip BMD, r = 0.394;P < 0.001). Low muscle mass was associated with low BMD (OR, 1.426; 95% CI, 1.019-1.994). Moreover, improving the muscle mass led to changes in the bone mass of the femoral neck (OR, 0.420; 95% CI, 0.194-0.911) and hip (OR, 0.217; 95% CI, 0.092-0.511) during the follow-up period. However, this phenomenon was not observed in lumbar, and bone turnover markers. ConclusionsThe recovery of bone mass might be related to the recovery of muscle mass. Improving muscle mass might bring about changes in the bone mass of the femoral neck and hip. A site-related discrepancy was also observed. Patients with Graves' disease should be helped in recovering muscle mass while administering antithyroid therapy.