Association between Serum Homocysteine Level and Obstructive Sleep Apnea: A Meta-Analysis

Table 1

Characteristics of included studies.

Author	Year	Country	(OG/CG)	NOS
Murat	2006	Turkey	30/30	8
Ma Hm	2007	China	34/57	7
Yeşim	2008	Turkey	34/15	8
Wang et al. (young)	2010	China	51/23	8
Wang et al. (old)	2010	China	32/29	8
Leticia	2013	Brazil	14/13	8
Li et al. (mild)	2014	China	41/33	7
Li et al. (moderate)	2014	China	40/33	7
Li et al. (severe)	2014	China	36/33	7
Kumor et al.	2006	Poland	32/12	8
Ryan et al. (mild-moderate)	2007	Ireland	35/30	8
Ryan et al. (severe)	2007	Ireland	31/30	8
Basoglu et al.	2011	Turkey	36/34	8
Andaku et al.	2015	Brazil	11/10	8

OG: OSA group; CG: control group; NOS: Newcastle-Ottawa Scale; : sample size.