SAT-395 Differences in the correlation coefficient between TSH levels and lipid parameters for ten-year age groups and basal thyroid function status

Abstract Disclosure: N. Edo: None. T. Sawa: None. H. Tachimori: None. H. Tomomitsu: None. C. Ishiwata: None. R. Nakajima: None. A. Terakawa: None. T. Suzuki: None. H. Yamazaki: None. K. Uno: None. K. Morita: None. T. Ishikawa: None. T. Teramoto: None. K. Tsukamoto: None. Objective: There have been many basic and clinical studies on the relationship between thyroid function and lipid metabolism. In this present study, we hypothesized and evaluated that this relationship might be influenced by age and/or basal thyroid function status, such as hyper/hypothyroidism or euthyroidism.[Subjects and methods]We analyzed the results of TSH, TC, HDL-C, and TG simultaneous measurements (25,911 samples: Group 1) and the results of TSH, HDL-C, LDL-C, and TG simultaneous measurements (17,811 samples: Group 2) from April 2016 to February 2021 in all patients above 18-year-old at our hospital. In Group 1, non-HDL-C and LDL-C were calculated. Because our series contained limited numbers of central hyper/hypothyroidism, we divided our subjects into three groups based on TSH levels: groups with exceeding, within, and below the normal range (NR). In each group, the correlation coefficient between TSH levels and lipid parameters was determined for each age group (seven ten-year age groups from 20s including 10s to 80s embracing over 90s) by sex using the Spearman test. The bootstrap method was adopted to obtain 95% confidence intervals. R 4.4.2 and RStudio 2024.12.0+467 were used in the analysis.[Results]An age-related change was observed in which the positive correlation values at younger ages declined to zero in the male exceeding-the-NR group and the female below-the-NR group. There were no significant changes in the other groups, considering the confidence intervals and reproducibility among Groups 1 and 2.[Discussion]In this study, the relationship between TSH and LDL-C is influenced more clearly by age, which might be profound, especially in the male hyperthyroid and female hypothyroid states. Previous studies have reported this relationship is affected by gonadal function, insulin resistance, and medical treatment, such as statin prescription for LDL-C level control. Our results indicated that a basal thyroidal state also has some influence on this relationship. As our limitation, our analysis used the results independent of mealtime as a first. Secondly, we divided our subjects based only on TSH levels, not using other thyroid parameters like free T3 and free T4. Therefore, further research is needed about the effects of age and basal thyroidal state on the relationship between thyroid function and lipid parameters. Presentation: Saturday, July 12, 2025