Table 4.

Multiple linear regression model for the Epworth Sleepiness Scale (ESS) and serum irisin and BDNF levels

Panel A	Coefficient (95% CI)	p
Age in years	0.02 (−0.091; 0.095)	0.970
Gender (f/m)	3.955 (1.761; 6.149)	0.001
Irisin (ng/mL)	1.530 (0.355; 2.705)	0.012
BDNF (ng/mL)	0.014 (0.005; 0.023)	0.002
(log) PSQI	2.972 (1.506; 4.437)	< 0.001
Panel B	Coefficient (95% CI)	p
Age in years	0.001 (−0.092; 0.095)	0.974
Gender (f/m)	3.992 (1.768; 6.216)	0.001
Irisin (ng/mL)	0.973 (−2.898; 4.844)	0.006
BDNF (ng/mL)	0.003 (−0.069; 0.075)
Irisin-BDNF interaction term	0.002 (−0.009; 0.012)
(log) PSQI	2.965 (1.487; 4.442)	< 0.001

Regression coefficient values are presented with their 95% confidence intervals (CI). The initial model for the multiple linear regression analysis consisted of the significant parameters provided by the simple linear regression and the relevant a priori identified parameters (age, gender) (statistical significance is indicated in bold)