Effects of levothyroxine therapy on bone mineral density and bone turnover markers in premenopausal women with thyroid cancer after thyroidectomy.

INTRODUCTION: We investigated the impact of long-term levothyroxine (LT4) treatment on bone mineral density (BMD) and bone turnover markers (BTMs) in premenopausal women with differentiated thyroid cancer (DTC) after thyroidectomy. MATERIAL AND METHODS: Sixty-five premenopausal women who received LT4 therapy at least one year (range, 1.5-9.0 years) after thyroidectomy for DTC and 50 premenopausal women without thyroid diseases were enrolled in this study. We measured the Z-scores of lumbar and hip BMD, serum free triiodothyronine (FT3), free thyroxine (FT4), thyroid-stimulating hormone (TSH), intact parathyroid hormone (iPTH), N-terminal propeptide of type 1 N procollagen (P1NP), C terminal telopeptide of type 1 collagen (CTX-1), calcium (Ca), phosphorus (P), vitamin D3, and alkaline phosphatase (ALP) in all participants. RESULTS: In DTC subjects, serum TSH levels were lower, and serum FT4, P1NP, CTX-1, and ALP levels were higher compared with controls. The prevalence of low BMD was higher in DTC subjects than in controls. Multivariate logistic regression analysis showed that serum TSH levels were negatively associated with CTX-1 and ALP. CONCLUSIONS: We found a high prevalence of low BMD among premenopausal women who received long-term LT4 therapy for DTC after thyroidectomy. Long-term TSH suppression therapy was a significant risk factor for decreased bone strength, mainly by increasing bone turnover.

Associations of oxytocin with metabolic parameters in obese women of childbearing age.

INTRODUCTION: The aim of this study was to compare plasma oxytocin levels in obese women of childbearing age with non-obese women of childbearing age, and to investigate the relationship between plasma oxytocin levels and metabolic parameters (including blood glucose, insulin resistance, blood lipid, and blood pressure). MATERIAL AND METHODS: A total of 151 obese women of childbearing age and 160 non-obese women of childbearing age were enrolled in this study. Plasma oxytocin levels were measured by electrochemiluminescence immunoassays. Height, body weight, body mass index (BMI), fasting blood glucose (FBG), fasting insulin (FI), homeostasis model assessment for insulin resistance (HOMA-IR), total triglycerides (TG), total cholesterol (TC), low-density lipoprotein-C (LDL-C), high-density lipoprotein-C (HDL-C), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were measured in all subjects. Quantile regression analysis was used to analyse the associations of plasma oxytocin levels with FBG, FI, HOMA-IR, TG, TC, LDL-C, HDL-C, SBP, and DBP. RESULTS: In obese women of childbearing age, plasma oxytocin levels were lower compared with non-obese controls. After adjusting for age, quantile regression analysis showed that the plasma oxytocin levels were inversely associated with HOMA-IR at the quantile level between 0.27 and 0.79 (i.e. the HOMA-IR level of 2.11 and 3.07, respectively), the plasma oxytocin levels were inversely associated with TC after the quantile level of 0.21 (i.e. the TC level of 3.78 ), and the plasma oxytocin levels were inversely associated with LDL-C at all quantile levels of LDL-C. In addition, the plasma oxytocin levels showed a positive association with HDL-C at all quantile levels of HDL-C. No significant associations were found between the plasma oxytocin levels and FBG, FI, TG, SBP, and DBP. CONCLUSIONS: Oxytocin deficiency was common in obese women of childbearing age. Oxytocin showed negative correlation with HOMA-IR, TC, and LDL-C, while it showed positive association with HDL-C. Our findings suggest that oxytocin played an important role in inhibiting metabolic disorders associated with obesity in women of childbearing age.