Center of Bone Diseases, Rheumatology Unit, Bone and Joint Department, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.
Service of Endocrinology, Diabetes and Metabolism, Department of Medicine, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.
J Clin Endocrinol Metab. 2020 Jan 1;105(1). doi: 10.1210/clinem/dgz058.
Both thyroid dysfunction and levothyroxine (LT4) therapy have been associated with bone loss, but studies on the effect of LT4 for subclinical hypothyroidism (SHypo) on bone yielded conflicting results.
To assess the effect of LT4 treatment on bone mineral density (BMD), Trabecular Bone Score (TBS), and bone turnover markers (BTMs) in older adults with SHypo.
Planned nested substudy of the double-blind placebo-controlled TRUST trial. Participants with SHypo were randomized to LT4 with dose titration versus placebo with computerized mock titration.
196 community-dwelling adults over 65 years enrolled at the Swiss TRUST sites had baseline and 1-year follow-up bone examinations; 4 participants withdrew due to adverse events not related to treatment.
One-year percentage changes of BMD, TBS, and 2 serum BTMs (serum CTX-1 [sCTX] and procollagen type 1 N-terminal polypeptide [P1NP]). Student's t-test for unadjusted analyses and linear regression adjusted for clinical center and sex were performed.
Mean age was 74.3 years ± 5.7, 45.4% were women, and 19.6% were osteoporotic. The unadjusted 1-year change in lumbar spine BMD was similar between LT4 (+0.8%) and placebo-treated groups (-0.6%; between-groups difference +1.4%: 95% confidence interval [CI] -0.1 to 2.9, P = .059). Likewise, there were no between-group differences in 1-year change in TBS (-1.3%: 95% CI -3.1 to 0.6, P = .19), total hip BMD (-0.2%: 95% CI -1.1 to 0.1, P = .61), or BTMs levels (sCTX +24.1%: 95% CI -7.9 to 56.2, P = .14), or after adjustment for clinical centers and sex.
Over 1-year levothyroxine had no effect on bone health in older adults with SHypo.
ClinicalTrial.gov NCT01660126 and NCT02491008.
甲状腺功能障碍和左甲状腺素（LT4）治疗均与骨丢失有关，但亚临床甲状腺功能减退症（SHypo）的 LT4 治疗对骨的影响的研究结果存在矛盾。
评估 LT4 治疗对老年亚临床甲状腺功能减退症（SHypo）患者骨密度（BMD）、骨小梁评分（TBS）和骨转换标志物（BTMs）的影响。
双盲安慰剂对照 TRUST 试验的计划嵌套子研究。SHypo 患者被随机分配至 LT4 加剂量滴定组或安慰剂加计算机模拟滴定组。
196 名居住在社区的 65 岁以上成年人在瑞士 TRUST 站点进行了基线和 1 年随访骨检查；4 名参与者因与治疗无关的不良事件而退出。
BMD、TBS 和 2 种血清 BTMs（血清 CTX-1[sCTX]和前胶原 1N 端多肽[P1NP]）的 1 年百分比变化。未调整分析采用学生 t 检验，线性回归调整临床中心和性别。
平均年龄为 74.3 岁±5.7，45.4%为女性，19.6%为骨质疏松症患者。LT4（+0.8%）和安慰剂治疗组的 1 年腰椎 BMD 未调整变化相似（-0.6%；组间差异+1.4%：95%置信区间[CI]0.1 至 2.9，P=0.059）。同样，1 年 TBS 变化（-1.3%：95%CI-3.1 至 0.6，P=0.19）、全髋关节 BMD 变化（-0.2%：95%CI-1.1 至 0.1，P=0.61）或 BTMs 水平（sCTX+24.1%：95%CI-7.9 至 56.2，P=0.14）也无差异，调整临床中心和性别后亦如此。
1 年内左甲状腺素对老年亚临床甲状腺功能减退症患者的骨健康没有影响。
ClinicalTrial.gov NCT01660126 和 NCT02491008。
