원저 : 장기간의 갑상선 호르몬 치료가 골밀도에 미치는 영향

Both spontaneous and exogenous hyperthyroidism result in osteoporosis by increased bone-remodeling. We studied the effect of long-term suppressive thyroxine therapy on axial bone density in 59 female patients (28 premenopausal, 31 postmenopausal). Bone densities of the lumber spine, femoral neck, femoral trochanter and Wards triangle were measured by dual photon absoptiometry and compared with those of age, sex, menopause-matched normal controls. The levels of serum osteocalcin, alkaline phosphatase, calcium, phosphorus were measured in patients and their correlations with bone densities were analyzed. The degree of change in bone density was quantified with Z transformation. Bone densities of lumbar spine and femur were decreased significantly in postmenoausal patients when compared with controls (lumbar spine: 0.8696±0.116 vs. 0.9264±0.043(g/cm²), femoral neck: 0.7246±0.096vs. 0.8020±0.037(g/cm²), femoral trochanter: 0.6021±0.088 vs 0.6489±0.032(g/cm²), Ward's triangle: 0.6216±0.128 vs. 0.6900±0.048(g/cm²), p<0.05) but in premenopausal women, there were no differences in bone densities between patients and controls. Bone densities were negatively correlated with serum ostocalcin (lumbar spine r=-0.572, femoral neck r=-0.561, femoral trochanter r=0.646, Ward's triangle r =-0.581, p<0.001), and alkaline phosphatase (lumbar spine r= -0.615, femoral neck r =-0.610 femoral trochanter r=-0.452, Ward's triangle r=-0.573, p<0.01) and Z value were negatively correlated with osteocalcin (lumber spine r=-0.427 femoral neck r=-0.473 femoral trochanter r=-0,567 Ward's triangle r=-0.464, p<0.01), and patients age (lumbar spine r=-0.464 femeral neck r=-0. 350, femoral trochanter r=-0.425, Ward. triangle r=-0.310, p<0.05). These results suggest that sucblinical hyperthyroidism induced by suppressive thyroxine therapy can cause osteoporosis by high bone turnover which is severer in older postmenoausal women. Therefore regular evaluation of bone mineral density and warning for osteoporosis will be necessary.