The effect of long-term, non-suppressive levothyroxine treatment on quantitative ultrasonometry of bone in women

Abstract

Objective: To evaluate the impact of long-term, non-suppressive levothyroxine (L-T 4 ) treatment on quantitative ultrasonometry in women.Design: This was a case-control study. Subjects and methods: Altogether 667 women (mean age Ϯ S.D., 49.5 Ϯ 13.1 years) were studied. Of these, 156 (23%) had non-toxic goitre or hypothyroidism and had been taking L-T 4 (75-100 mg/day) for at least 5 years (mean Ϯ S.D., 12.5 Ϯ 7.5 years); the remaining 511 (77%) women were not receiving L-T 4 . All women had completed a questionnaire on risk factors for thyroid dysfunction and osteoporosis, and those with diseases or treatments known to effect bone metabolism -other than thyroxine or hormone replacement therapy (HRT) -were excluded. Women underwent quantitative ultrasonometry (QUS) at the heel. Speed of sound (SOS), broadband ultrasound attenuation (BUA) and the stiffness index (SI) were compared, first, in all women taking L-T 4 and controls and, secondly, in women taking L-T 4 and controls pair-matched for age, weight, body mass index (BMI), menopausal status and HRT use. Results: Even after matching for age, weight, BMI, menopausal and HRT status, women taking L-T 4 had significantly lower values for SOS and SI (P < 0.05), but not for BUA. However, absolute T-and Z-scores for SI were not low in either the study or control groups. Lower values were associated, but not significantly so, with years since the menopause and duration of L-T 4 treatment. Conclusions: Long-term, non-suppressive L-T 4 treatment in women with goitre or hypothyroidism was associated with a slight reduction in QUS values, which was more pronounced in postmenopausal women. This group could be at higher risk for osteoporotic fracture.

Utility of C-terminal Telopeptide in Evaluating Levothyroxine Replacement Therapy-Induced Bone Loss

“…The longest trial where patients were followed for one year after the initiation of therapy supports the finding in the current study. Many other studies have shown significant bone loss after a minimum of 7.5 years of LT4 replacement therapy as evidenced by a significant attenuation in speed of sound and stiffness index of the ultrasound measurements at the heel region 34,35. The technique used to measure BMD in these studies was similar to our study as were the findings.…”

Effects on Bone Mineral Density by Treatment of Benign Nodular Goiter with Mildly Suppressive Doses of <i>L</i>-Thyroxine in a Cohort Women Study

“…The lack of ultrasensitive thyroid-stimulating hormone (TSH) assay and densitometers with adequate precision and the heterogeneity of study protocols and analyzed series could explain these discordant results [1,2,3,4,5,6,7]. …”

Quantitative Ultrasound in Diagnosis of Metabolic Bone Diseases

“…Among other methods also QUS was successfully used in order to assess bone side effects [85][86][87][88][89]. QUS values were decreased in patients with Cushing syndrome [85].…”

“…QUS values were decreased in patients with Cushing syndrome [85]. QUS was used to evaluate bone status in girls treated by growth hormone [89], and in women on long-term therapy using non-supressive doses of thyroid hormones QUS values at calcaneus were decreased in comparison to controls [88]. The latter observation seems of clinical importance because the number of females taking thyroid hormones is high and bone-side effects in this group of patients usually is not adequately estimated.…”