The association between serum soluble α-Klotho and thyroid profile among adults from NHANES 2007-2012.

Background: Thyroid hormone is the key endocrine regulator of growth, development, metabolism, and other bodily functions. α-Klotho has been involved in the aging process and acts as an endocrine factor involved in the regulation of various metabolic processes in humans. However, the relationship between α-Klotho and thyroid profile has not been uniformly recognize.

Objective: To determine the relationship between α-Klotho and thyroid profile in adult individuals.

Methods: Population data of 4614 adult individuals were obtained from the NHANES database during the period of 2007-2012. Weighted multivariable regression analysis was performed using a general linear model with serum α-Klotho as the independent variable and thyroid profile as the dependent variables, respectively. The generalized additive model was used for smoothing curve fitting and threshold effect analysis.

Results: α-Klotho was associated with a slightly higher FT3, TT3 and TT4 level in unadjusted and adjusted regression models. However, a higher α-Klotho level was associated with a lower TSH level. After α-Klotho was grouped as quantiles with reference (Q1), α-Klotho still showed a statistically significant positive correlation with FT3 and TT3 levels in Q2, Q3 and Q4. In addition, α-Klotho was positively corrected with TT4, but negatively associated with TSH in Q4.

Conclusions: Serum soluble α-Klotho was positively associated with FT3, TT3 and TT4, but negatively correlated with TSH. The significant effect of α-Klotho on thyroid profile suggests its potential as a predictive marker of thyroid functions, indicating its possible involvement in the regulation of thyroid hormone secretion.