Serum hepcidin concentrations and type 2 diabetes

Table 1 Studies linking hepcidin/prohepcidin and type 2 diabetes (n = 6)

Ref.	Subject/study design	Measurement of hepcidin/prohepcidin	Assessment of T2D	Results
Sam et al[15]	British men and women/case-control	Active serum hepcidin-25 and serum hepcidin-ferritin ratio measured using RIA	HbA1c = 73.17 ± 4.12, mean ± SEM	Student's t-test/Mann-Whitney U-test to compare hepcidin (ng/mL) and hepcidin-ferritin ratio in T2D vs control showed: 20.00 (10.00-41.00) vs 33.00 (18.05-54.00), P < 0.05 and 0.22 (0.15-0.32) vs 0.45 (0.26-0.58), P < 0.01
Guo et al[16]	Chinese men and women/case-control	Serum hepcidin measured using ELISA	Fasting plasma glucose > 7 mmol/L	Wilcoxon rank test to compare hepcidin (ng/mL) in T2D vs control showed: 34.44 ± 26.98 vs 32.34 ± 22.75, P = 0.72. Logistic regression analysis showed no significant association between serum hepcidin concentrations and onset of T2D: OR = 1.03, 95%CI: 0.87-1.22, P = 0.75
Gan et al[30]	Chinese men and women/prospective cohort	Two TMPRSS6 SNPs [rs855791 (V736A) and rs4820268 (D521D)] of hepcidin by DNA genotyping	WHO 1999 criteria or previous history of T2D. Fasting plasma glucose < 5.6 mmol/L = normoglycemia	Logistic regression analysis showed both 2 TMPRSS6 SNPs to be significantly associated with decreased risk of T2D:ORrs855791 (v736A) = 0.801, 95%CI: 0.654-0.98, P = 0.0314 and ORrs4820268(D521D) = 0.802, 95%CI: 0.656-0.98, P = 0.0311
Jiang et al[14]	Chinese men and women/case-control	Serum hepcidin measured using ELISA	Fasting glucose ≥ 7.0 mmol/L, non-fasting glucose ≥ 11.1 mmol/L, use of diabetes medication, or a self-reported physician diagnosis	Kruskal-Wallis test/student's t-test to compare hepcidin (μg/L) in T2D vs control showed: 778.91 ± 175.22 vs 513.44 ± 281.73, P < 0.001
Aso et al[29]	Japanese men and women/case-control	Serum prohepcidin measured using ELIA	Not reported	Mann-Whitney U test to compare prohepcidin (ng/mL) in T2D vs control showed: 141 ± 42.6 vs 198.1 ± 36.7, P < 0.0001
Fernández-Real et al[28]	Spanish men/cross-sectional and intervention	Serum prohepcidin measured using ELISA	Oral glucose tolerance test	Pearson's test showed significant correlation between circulating prohepcidin and fasting glucose (r = 0.27; P = 0.002) and HbA1c (r = 0.31; P < 0.0001). After phlebotomy, prohepcidin decreased significantly in T2D (P = 0.04) and in HFE gene mutation carrier (0.03) with a negative correlation between serum prohepcidin and insulin sensitivity (r = -0.50, P = 0.04)

HbA1c: Glycated hemoglobin; T2D: Type 2 diabetes; RIA: Radioimmunoassay; ELISA: Enzyme linked immunosorbent assay; TMPRSS6: Transmembrane protease serine 6; SNPs: Single nucleotide polymorphisms; WHO: World Health Organization.