Table 2.

Subgroup analysis in adults with obstructive sleep apnea compared to controls.

Variable, N	SMD	95% CI		p-Value	I2, %	P heterogeneity
		Min	Max
Ethnicity
Asian (8)	1.10	0.69	1.52	<0.00001	79	<0.0001
Caucasian (2)	0.03	–0.47	0.54	0.89	0	0.98
Mixed (1)	–0.18	–0.34	–0.01	0.04	-	-
Sample size
<100 (9)	0.95	0.47	1.43	<0.0001	81	<0.00001
≥100 (2)	0.24	–0.59	1.07	0.58	95	<0.00001
Sampling
Serum (9)	0.95	0.47	1.43	<0.0001	81	<0.00001
Plasma (4)	0.24	−0.59	1.07	0.58	95	<0.00001

N: Number of studies. SMD: Standardized mean difference. CI: Confidence interval.