Table 3. Linear regression analysis of factors associated with TSH, free T3, and free T4 levels.

Variable	TSH			Free T3			Free T4
	Coefficient	SE	P-value	Coefficient	SE	P-value	Coefficient	SE	P-value
Age	−0.028	0.027	0.297	−0.010	0.006	0.099	0.003	0.003	0.342
Body mass index	−0.014	0.025	0.577	0.000	0.006	0.889	0.000	0.003	0.815
Hemoglobin	−0.020	0.192	0.916	−0.011	0.048	0.820	−0.042	0.023	0.073
PCOS	−0.124	0.270	0.646	0.151	0.065	0.023	0.008	0.033	0.812
FSH	0.024	0.031	0.449	0.004	0.008	0.646	0.002	0.004	0.620
LH	−0.051	0.035	0.152	0.002	0.009	0.848	0.000	0.002	0.754
Prolactin	−0.006	0.018	0.745	−0.002	0.004	0.623	0.000	0.001	0.913
Cholesterol	0.009	0.008	0.236	0.001	0.001	0.598	0.000	0.000	0.430
Triglycerides	−0.004	0.003	0.202	0.000	0.001	0.788	−0.002	0.003	0.413
HDL	0.013	0.021	0.543	−0.006	0.005	0.221	0.001	0.001	0.465
LDL	−0.004	0.009	0.671	0.000	0.001	0.914	0.002	0.013	0.896
Testosterone	−0.023	0.193	0.918	−0.012	0.049	0.821	−0.043	0.024	0.074
TSH				0.026	0.025	0.305	0.002	0.013	0.896
Free T3	0.576	0.413	0.166				0.123	0.050	0.015
Free T4	0.108	0.823	0.896	0.438	0.198	0.029
Anti-TPO	0.156	0.155	0.318	−0.078	0.036	0.031	0.034	0.019	0.073
Anti-TG	0.396	0.534	0.461	−0.171	0.133	0.200	−0.055	0.066	0.407

TSH, thyroid-stimulating hormone; T3, tri-iodothyronine; T4, thyroxine; SE, standard error; PCOS, polycystic ovary syndrome; FSH, follicle stimulating hormone; LH, luteinizing hormone; HDL, high-density lipoprotein cholesterol; LDL, low-density lipoprotein cholesterol; TPO, thyroid peroxidase; TG, thyroglobulin.