The impact of thyroid function on total spine bone mineral density in postmenopausal women.

PURPOSE: Osteoporosis has been a widespread concern for older women, especially postmenopausal women. Thyroid function is crucial for bone metabolism. However, the relationship between thyroid function variation within thyroxine reference range and bone mineral density (BMD) remains ambiguous. The objective of this study was to evaluate the effect of subclinical hypothyroidism or hyperthyroidism on total spinal BMD in postmenopausal women. METHODS: Based on data from the National Health and Nutrition Examination Survey (NHANES) 2007-2010, multivariable weighted logistic regression was used to evaluate the relationships between total spine BMD and TSH among postmenopausal women aged ≥50. RESULTS: After accounting for a number of variables, this study discovered that the middle TSH tertile was associated with a decreased probability of osteoporosis. Additionally, the subgroup analysis revealed that postmenopausal women over the age of 65 or people with an overweight BMI had a clearer relationship between total spine BMD and TSH. CONCLUSION: The total spinal BMD had a positive relationship with thyroid stimulating hormone in postmenopausal women, and that appropriate TSH level (1.38-2.32 mIU/L) was accompanied by higher total spinal BMD.

Coffee and the risk of osteoarthritis: a two-sample, two-step multivariable Mendelian randomization study.

Purpose: To investigate the potential causal relationship between coffee consumption and osteoarthritis (OA), and to disentangle whether body mass index (BMI) and Bone mineral density (BMD) mediate this relationship. Methods: We performed two-sample and two-step Mendelian randomization (MR) analyses utilizing publicly available genome-wide association studies (GWAS) summary statistics to estimate the association between coffee intake and OA risk (including knee OA, hip OA, knee or hip OA, and total OA), as well as the possible mediating effects of BMI and BMD. In addition, data of different coffee types (decaffeinated coffee, instant coffee, ground coffee-including espresso, filter, etc., and other coffee types) were used to explore the effect of coffee type on the risk of OA. Results: In two-sample MR, coffee intake increased the risk of OA in various sites, with the most significant impact observed in knee osteoarthritis (KOA) (odds ratio [OR] 2.03, 95% confidence interval [CI] 1.57-2.61, p < 0.001). The effect on self-reported OA was minimal (OR 1.03, 95% CI 1.01-1.05, p = 0.006). Further analysis of different types of coffee revealed that only decaffeinated coffee was causally associated with both KOA (OR 4.40, 95% CI 1.71-11.33, p = 0.002) and self-reported OA (OR 1.13, 95% CI 1.02-1.26, p = 0.022). In two-step MR, BMI explained over half of the coffee intake-all OA risk association, while BMD accounted for less than 5% of the mediation effect. Conclusion: Our study suggests that coffee intake increase the risk of OA, with BMI playing a significant mediating role. Decaffeinated coffee appears to have the greatest impact on OA risk compared to other types of coffee. Therefore, managing BMI and selecting appropriate types of coffee should be included in the health management of individuals who frequently consume coffee.