Table 1.

Baseline characteristics of patients with multiple sclerosis (MS) and healthy controls investigated in the case–control studies that were included in the present meta-analysis.

Study	Patients with MS										Healthy controls
	Total	CIS		RRMS		SPMS/PPMS		Mean age, years	Women		Total	Mean age, years	Women
		n	%	n	%	n	%		n	%			n	%
Zamboni et al. [2009c]	109	0	0	69	63	40	37	40	64	59	132	37/58*	75	57
Zamboni et al. [2009d]	16	0	0	16	100	0	0	35	10	63	8	32	6	75
Al-Omari and Rousan [2010]	25	0	0	21	84	4	16	35	13	52	25	34	13	52
Doepp et al. [2010]	56	0	0	41	73	15	27	42	36	64	20	41	12	60
Krogias et al. [2010]	10	0	0	2	20	8	80	42	3	30	2	38	1	50
Baracchini et al. [2011a]	50	50	100	0	0	0	0	33	35	70	110	33/63$	67	61
Centonze et al. [2011]	84	0	0	69	82	15	18	39	52	62	56	42	36	64
Zivadinov et al. [2011]	304	21	7	191	63	92	30	48	230	76	163	46	88	54
Mayer et al. [2011]	20	0	0	17	85	3	15	42	13	65	20	34	10	50
Tsivgoulis et al. [2011]	42	0	0	38	90	4	10	39	25	60	43	38	27	63
Auriel et al. [2011]	27	0	0	21	78	6	22	42	17	63	32	36	23	72
Baracchini et al. [2011a]	60	0	0	0	0	60	100	46	33	55	60	46	33	55
Marder et al. [2011]	18	1	6	6	33	11	61	55	3	17	11	55	4	36
Blinkenberg et al. [2012]	24	0	0	24	100	0	0	37	16	67	15	37	11	73
Zamboni et al. [2012b]	44	NA	NA	NA	NA	NA	NA	41	25	57	40	41	18	45
Kantarci et al. [2012]	62	0	0	32	52	30	48	37	40	65	54	37	27	50
Amato et al. [2012]	15	0	0	15	100	0	0	18	9	60	16	18	7	44
Mancini et al. [2012]	103	0	0	41	40	62	60	42	62	60	42	38	23	55
Zaniewski et al. [2013]	181	0	0	98	54	83	46	41	110	61	50	40	31	62

CIS, clinically isolated syndrome; NA, not available; PPMS, primary progressive multiple sclerosis; RRMS, relapsing–remitting multiple sclerosis; SPMS, secondary progressive multiple sclerosis.

^*Two control groups were used in the study. The mean age was 37 and 58 years in the first (n = 60) and second (n = 72) control group, respectively.

^$Two control groups were used in the study. The mean age was 33 and 63 years in the first (n = 50) and second (n = 60) control group, respectively.