Significant association of sensitivity to thyroid hormones with liver fibrosis: Analysis based on NHANES data.

BACKGROUND AND STUDY AIMS: To explore the association between thyroid function and liver fibrosis using the data from the NHANES database.

PATIENTS AND

METHODS

The data of 5959 participants and 34 variables were obtained. Fibrosis-4 (FIB-4) score was used to assess the liver fibrosis level. LASSO regression analysis was conducted to identify the important thyroid function related indicators and other variables. Logistic and linear regression analyses were used to explore the association between key indicators and FIB-4 score, and their association was then verified by RCS and GAM analyses. The stability of their association was evaluated by trend regression and interaction effect analyses.

RESULTS

There were 4652 and 1307 participants in low and high FIB-4 score groups, respectively. LASSO analysis initially identified 17 important variables, of which 4 thyroid indicators were contained including total T3, FT4, TSH, and TT4RI (an index for reflecting sensitivity to thyroid hormones). Of them, TSH and TT4RI showed significant association with liver fibrosis level when FIB-4 was set as categorical (fully adjusted ORTSH = 1.048 [95 %CI: 1.026, 1.077], P < 0.001; OR TT4RI = 1.007 [95 %CI: 1.004, 1.011], P < 0.001) or continuous variable (fully adjusted βTSH = 0.010 [95 %CI: 0.004, 0.015], P = 0.001; βTT4RI = 0.002 [95 %CI: 0.001, 0.003], P < 0.001). RCS and GAM analyses further supported their association (all fully adjusted P < 0.05). However, fully adjusted trend regression analysis indicated the more stable association of TT4RI with liver fibrosis in a positive relationship (ORTT4RI = 1.079 [95 %CI: 1.013, 1.150], P = 0.018; βTT4RI = 0.019 [95 %CI: 0.004, 0.034], P = 0.011). We further found that age, sleep disorder, sodium level, and lymphocyte number had interaction effect with TT4RI (all P for interaction effect < 0.05).

CONCLUSIONS

The sensitivity to thyroid hormones was significantly related to the liver fibrosis, which was more valuable than the common thyroid profile.