Table 1.

Characteristics of studies included in this review.

Study	Year	Region	Center number	Disease/severity	n (case)	n (control)	Hemodialysis	Peritoneal dialysis	Kidney transplant	No dialysis
Wang et al.	2012	Shaanxi, China	1	ESRD	30	10	0	0	0	30
Wang et al.	2012	Taiwan, China	1	ESRD	29	41	0	29	0	0
Vaziri et al.	2013	California, USA	1	ESRD	24	12	24	0	0	0
Jiang et al.	2017	Guangdong, China	1	ESRD	52	60	0	0	0	52
Vanessa et al.	2017	Graz, Austria	1	ESRD	30	21	15	15	0	0
Ye et al.	2018	Guangdong, China	1	ESRD	100	53	84	0	16	0
Li et al.	2019	Shandong, China	1	ESRD	53	69	29	24	0	0
Terpstra et al.	2019	Amsterdam, Netherlands	1	ESRD	35	15	31	0	4	0
Wang et al.	2020	Beijing, China	4	ESRD	223	69	223	0	0	0
Total			12		575	350	406	68	20	82
Barros et al.	2015	Niterói, RJ, Brazil	1	CKD stage 3–4	20	19	0	0	0	20
Margiotta et al.	2020	Milano, Italy	1	CKD stage 3b–4	64	15	0	0	0	64
Xu et al.	2017	Guangdong, China	1	CKD stage 4–5	32	32	0	0	0	32
Salguero et al.	2019	Texas, USA	1	CKD stage 4–5 & T2DM	20	20	0	0	0	20
Al-Obaide et al.	2017	Texas, USA	1	CKD stage 4–5 & T2DM	20	20	0	0	0	20
Li et al.	2019	Shanxi, China	1	CKD stage 3–5	50	22	0	0	0	50
Jiang et al.	2016	Guangdong, China	1	CKD stage 1–5	65	20	0	0	0	65
Lun et al.	2018	Shandong, China	1	CKD stage 1–5	49	24	13	0	0	36
Wang et al.	2019	Guangdong, China	1	CKD stage 1–5	128	63	0	0	0	128
Wu et al.	2020	Taiwan, China	1	CKD stage 1–5	92	30	–	–	0	–
Hu et al.	2020	Hunan, China	1	CKD stage 1–5	95	20	0	0	0	95
Ren et al.	2020	Zhengzhou, China	1	CKD stage 1–5	110	210	0	0	0	110
Total			12		635	285	13	0	0	530
De Angelis et al.	2014	Bari, Italy	1	IgAN	32	16	0	0	0	32
Hu et al.	2020	Hunan, China	1	IgAN	17	18				17
Zhong et al.	2020	Sichuan, China	1	IgAN	52	25	0	0	0	52
Tao et al.	2019	Chengdu, China	1	DN	14	14	0	0	0	14
Total			28		1436	918	419	68	20	837

ESRD: end-stage renal disease; CKD: chronic kidney disease; T2DM: type 2 diabetes mellitus; IgAN: IgA nephropathy; DN: diabetic nephropathy.

All studies were conducted in adults.