Low Normal TSH Levels and Thyroid Autoimmunity are Associated with an Increased Risk of Osteoporosis in Euthyroid Postmenopausal Women

EMAS position statement: Thyroid disease and menopause

INTRODUCTION

Thyroid diseases are common in women in their late reproductive years; therefore, thyroid disease and menopause may co-exist. Both conditions may present with a wide range of symptoms, leading to diagnostic challenges and delayed diagnosis. Aim To construct the first European Menopause and Andropause Society (EMAS) statement on thyroid diseases and menopause.

MATERIALS AND METHODS

Literature review and consensus of expert opinion (EMAS executive board members/experts on menopause and thyroid disease).

SUMMARY RECOMMENDATIONS

This position paper highlights the diagnostic and therapeutic dilemmas in managing women with thyroid disease during the menopausal transition, aiming to increase healthcare professionals' awareness of thyroid disorders and menopause-related symptoms. Clinical decisions regarding the treatment of both conditions should be made with caution and attention to the specific characteristics of this age group while adopting a personalized patient approach. The latter must include the family history, involvement of the woman in the decision-making, and respect for her preferences, to achieve overall well-being.

Association between thyroid autoimmunity and bone mineral density in patients with type 2 diabetes mellitus: a cross-sectional study

PURPOSE

The purpose of this study was to analyze the relationship between thyroid autoimmunity and bone mineral density (BMD) in patients with type 2 diabetes mellitus (T2DM), and to further explore the influence of thyroid autoimmunity on diabetic osteoporosis.

METHODS

A total of 601 T2DM patients were included and divided into two groups according to thyroid autoantibodies, namely thyroid autoimmunity positive group (TPOAb+ or TGAb + ) and thyroid autoimmunity negative group (TPOAb- and TGAb-). Clinical data were collected and BMD was determined by dual-energy X-ray absorptiometry (DXA). SPSS26.0 software was used to data analysis. Model regression was used to analyze the influencing factors of BMD, and ROC curve was used to analyze the optimal cut-off point of thyroid peroxidase antibody (TPOAb) for screening osteoporosis.

RESULTS

TPOAb and thyroglobulin antibody (TGAb) were negatively correlated with BMD and T-score (LS, FN and WB) (P < 0.01), and TGAb was negatively correlated with 25(OH)D (P < 0.05). Multiple linear regression analysis showed that TPOAb was an independent influence factor on LS, FN and WB BMD. ROC curve analysis showed that the optimal threshold of TPOAb for predicting osteoporosis was 12.35.

CONCLUSIONS

In T2DM patients, TPOAb and TGAb levels are negatively correlated with LS, FN and WB BMD, and TPOAb is an independent influencing factor for diabetic osteoporosis, and TPOAb has a certain predictive value for the occurrence and development of diabetic osteoporosis clinically.

Assessment for bone health in patients with differentiated thyroid carcinoma after postoperative thyroid-stimulating hormone suppression therapy: a new fracture risk assessment algorithm

Purpose

The fracture risk assessment tool (FRAX) is used to assess the 10-year risk of major site and hip fractures; however, whether this tool can be applied to patients receiving levothyroxine-based thyroid-stimulating hormone (TSH) suppressive therapy for postoperative differentiated thyroid cancer (DTC) patients is yet to be clarified.

Methods and design

A total of 64 patients with DTC following thyroidectomy and oral levothyroxine for TSH suppression therapy and 30 gender- and age-matched controls were collected. The fracture risk was compared between the affected groups with different TSH levels. FRAX was used to calculate the fracture risk with and without bone mineral density (BMD). The TSH level was converted to an age-weighted score to estimate the fracture risk of postoperatively differentiated thyroid cancer patients. The sensitivity, specificity, and area under the AUC curve of the traditional FRAX and the new algorithm for osteoporosis diagnosis were compared. The dual-energy X-ray bone mineral density measurement T score was used as the gold standard to diagnose osteoporosis.

Results

There were 24 patients in the T ≥ -1-2.5 group, 23 in the -2.5 < T < -1 group, and 17 in the T ≤ -2.5 group. The T score of BMD in the disease group was significantly lower than that in the control group (p < 0.05). The risk of MOF and hip fracture without a T score were significantly different under various TSH levels (p < 0.05). The area under the curve (AUC) of FRAX without BMD for predicting major osteoporotic fractures (PMOF) and major hip fractures (PHF) was 0.694 and 0.683, respectively. The cutoff values were 2.15% and 0.25%, respectively. The AUC of FRAX with BMD for PMOF and PHF was 0.976 and 0.989, respectively, and the cutoff values were 4.15% and 1.1%, respectively. The AUC of FRAX without BMD for PMOF and PHF was 0.708 and 0.72, respectively, and the cutoff values were 5.5% and 1.55%, respectively.

Conclusions

FRAX is suitable for postoperative DTC patients after TSH suppressive therapy. In the absence of BMD, TSH weighted by age can improve the specificity of FRAX in the diagnosis of osteoporosis in this population.

A clinical prediction model for 10-year risk of self-reported osteoporosis diagnosis in pre- and perimenopausal women

A machine learning model using clinical, laboratory, and imaging data was developed to predict 10-year risk of menopause-related osteoporosis. The resulting predictions, which are sensitive and specific, highlight distinct clinical risk profiles that can be used to identify patients most likely to be diagnosed with osteoporosis.

PURPOSE

The aim of this study was to incorporate demographic, metabolic, and imaging risk factors into a model for long-term prediction of self-reported osteoporosis diagnosis.

METHODS

This was a secondary analysis of 1685 patients from the longitudinal Study of Women's Health Across the Nation using data collected between 1996 and 2008. Participants were pre- or perimenopausal women between 42 and 52 years of age. A machine learning model was trained using 14 baseline risk factors-age, height, weight, body mass index, waist circumference, race, menopausal status, maternal osteoporosis history, maternal spine fracture history, serum estradiol level, serum dehydroepiandrosterone level, serum thyroid-stimulating hormone level, total spine bone mineral density, and total hip bone mineral density. The self-reported outcome was whether a doctor or other provider had told participants they have osteoporosis or treated them for osteoporosis.

RESULTS

At 10-year follow-up, a clinical osteoporosis diagnosis was reported by 113 (6.7%) women. Area under the receiver operating characteristic curve of the model was 0.83 (95% confidence interval, 0.73-0.91) and Brier score was 0.054 (95% confidence interval, 0.035-0.074). Total spine bone mineral density, total hip bone mineral density, and age had the largest contributions to predicted risk. Using two discrimination thresholds, stratification into low, medium, and high risk, respectively, was associated with likelihood ratios of 0.23, 3.2, and 6.8. At the lower threshold, sensitivity was 0.81, and specificity was 0.82.

CONCLUSION

The model developed in this analysis integrates clinical data, serum biomarker levels, and bone mineral densities to predict 10-year risk of osteoporosis with good performance.

Independent Skeletal Actions of Pituitary Hormones

Over the past years, pituitary hormones and their receptors have been shown to have non-traditional actions that allow them to bypass the hypothalamus-pituitary-effector glands axis. Bone cells-osteoblasts and osteoclasts-express receptors for growth hormone, follicle stimulating hormone (FSH), thyroid stimulating hormone (TSH), adrenocorticotrophic hormone (ACTH), prolactin, oxytocin, and vasopressin. Independent skeletal actions of pituitary hormones on bone have been studied using genetically modified mice with haploinsufficiency and by activating or inactivating the receptors pharmacologically, without altering systemic effector hormone levels. On another front, the discovery of a TSH variant (TSH-βv) in immune cells in the bone marrow and skeletal action of FSHβ through tumor necrosis factor α provides new insights underscoring the integrated physiology of bone-immune-endocrine axis. Here we discuss the interaction of each pituitary hormone with bone and the potential it holds in understanding bone physiology and as a therapeutic target.

Thyrotropin, Hyperthyroidism, and Bone Mass

Thyrotropin (TSH), traditionally seen as a pituitary hormone that regulates thyroid glands, has additional roles in physiology including skeletal remodeling. Population-based observations in people with euthyroidism or subclinical hyperthyroidism indicated a negative association between bone mass and low-normal TSH. The findings of correlative studies were supported by small intervention trials using recombinant human TSH (rhTSH) injection, and genetic and case-based evidence. Genetically modified mouse models, which disrupt the reciprocal relationship between TSH and thyroid hormone, have allowed us to examine an independent role of TSH. Since the first description of osteoporotic phenotype in haploinsufficient Tshr +/- mice with normal thyroid hormone levels, the antiosteoclastic effect of TSH has been documented in both in vitro and in vivo studies. Further studies showed that increased osteoclastogenesis in Tshr-deficient mice was mediated by tumor necrosis factor α. Low TSH not only increased osteoclastogenesis, but also decreased osteoblastogenesis in bone marrow-derived primary osteoblast cultures. However, later in vivo studies using small and intermittent doses of rhTSH showed a proanabolic effect, which suggests that its action might be dose and frequency dependent. TSHR was shown to interact with insulin-like growth factor 1 receptor, and vascular endothelial growth factor and Wnt pathway might play a role in TSH's effect on osteoblasts. The expression and direct skeletal effect of a biologically active splice variant of the TSHβ subunit (TSHβv) in bone marrow-derived macrophage and other immune cells suggest a local skeletal effect of TSHR. Further studies of how locally secreted TSHβv and systemic TSHβ interact in skeletal remodeling through the endocrine, immune, and skeletal systems will help us better understand the hyperthyroidism-induced bone disease.