TABLE 1.

Methodology of studies investigating the association between RBP4 and oxidative stress¹

Markers	Study design	Study population	Sex	Age,2 y	Study size, n	Cytokine measurement method	RBP4 measurement method	Analysis	Relation	RBP4 specimen	Authors, year (ref)
Uri-8-isoPGF2α	CC	101 Subjects with T2D; 22 controls	62 M; 39 F	61.6 ± 4.5	123	EIA kit	EIA	Correlation	None	Serum	Takebayashi et al., 2007 (20)
Urinary 8-isoprostane	CS	Healthy obese and overweight children	45 M; 38 F	8–15	83	ELISA	Immunononenephelometry	ANCOVA	+	Serum	Codoñer-Franch et al., 2013 (49)
Uri-8-isoPGF2α	CS	Chinese	910 M; 838 F	50–70	1748	ELISA	ELISA	Correlation	+	Plasma	Liu et al., 2014 (50)
13-HOD	CS	Chinese	910 M; 838 F	50–70	1748	Colorimetric EIA kit	ELISA	Correlation	+	Plasma	Liu et al., 2014 (50)
Glutathione	CS	Healthy obese and overweight children	45 M; 38 F	8–15	83	ELISA	Immunononenephelometry	Multivariate regression	−	Serum	Codoñer-Franch et al., 2013 (49)
MDA	CC	Normotensive subjects	111 M; 47 F	49	66	TBAR	ELISA validated by Western blot	Linear correlation	+	Plasma	Solini et al., 2012 (51)

¹CC, case-control; CS, cross-sectional; EIA, enzyme immunoassay; F, female; M, male; MDA, malondialdehyde; RBP4, retinol binding protein 4; ref, reference; T2D, type 2 diabetes; Uri-8-isoPGF2α, urinary 8-iso-prostaglandin F2α 13-HOD, 13-(S)-hydroxyoctadecadienoic acid; +, positive; −, negative.

²Values are ranges, means ± SDs, or the median.