Table 7.

Meta-regression analysis of variables predicting serum and plasma levels of inteleukin-6 comparing obstructive sleep apnea syndrome with controls.

Year of publication	R	Adjusted R2	P	Mean age of OSAS patients	R	Adjusted R2	P	Mean age of controls	R	Adjusted R2	P
Serum	0.001	−0.029	0.995	Serum	0.479	0.207	0.03	Serum	0.385	0.123	0.022
Plasma	0.124	−0.034	0.582	Plasma	0.377	0.092	0.112	Plasma	0.204	−0.018	0.417
Mean BMI of OSAS patients	R	Adjusted R2	P	Mean BMI of controls	R	Adjusted R2	P	Mean AHI of OSAS patients	R	Adjusted R2	P
Serum	0.119	−0.017	0.504	Serum	0.089	−0.023	0.615	Serum	0.188	−0.011	0.391
Plasma	0.143	−0.031	0.538	Plasma	0.168	−0.032	0.504	Plasma	0.169	−0.036	0.517
Number of participants	R	Adjusted R2	P
Serum	0.062	−0.025	0.717
Plasma	0.159	−0.029	0.504

R, correlation coefficient. Bold numbers for statistically significant values (P < 0.05).