Serum Gamma-Glutamyl Transferase and Ferritin Synergistically Associated with the Rate of Chronic Kidney Disease

Table 3

General characteristics of individuals in groups stratified by different combinations of GGT and SF levels^a.

	Group 1	Group 2	Group 3
n	614	304	106
Age, years (S. E.)	41.9 (0.6)	48.4 (0.7)^†	49.3 (1.2)^†
Male, % (n)	56.4 (346)	38.2 (116)	49.1 (52)
BMI, kg/m^2	21.4 (0.1)	23.3 (0.2)^†	24.3 (0.4)^†‡
Drinking, % (n)	31.3 (192)	36.5 (111)	48.1 (51)
Heavy drinking^b, % (n)	23.1 (142)	26.6 (81)	42.5 (45)
Diabetes mellitus^c, % (n)	4.9 (30)	7.2 (22)	15.1 (16)
Hypertension^d, % (n)	14.2 (87)	22.7 (69)	34.9 (37)
TG, mmol/L	1.26 (0.0)	1.98 (0.1)^†	2.81 (0.3)^†‡
Metabolic syndrome^e, % (n)	8.1 (50)	29.3 (89)	36.8 (39)
SF, μmol/L	72.5 (35.9, 131.0)	164.6 (96.2, 269.3)^†	300.8 (211.2, 359.2)^†‡
GGT, U/L	16 (12, 23.3)	34 (20, 63.5)^†	75 (49.8, 127.3)^†‡
MDA, mmol/L	4.0 (0.1)	4.2 (0.1)^†	4.5 (0.1)^†
eGFR, mL/min per 1.73 m^2	92.2 (0.8)	86.1 (0.9)^†	86.1 (1.7)^†
ACR, mg/g creatinine	10.3 (4.0, 19.2)	12.2 (5.8, 24.2)^†	14.4 (5.4, 35.0)^†

^† compared with group 1; ^‡ compared with group 2; compared across groups. ^aGroup 1: both GGT and SF were not in the fourth quartile; group 2: only GGT or SF was in the fourth quartile; group 3: both GGT and SF were in the fourth quartile. ^bDrinking more than 60 mL of alcohol per day. ^cDiabetes mellitus was defined according to the criteria of the American Diabetes Association (1999). ^dHypertension was defined as systolic blood pressure ≥ 140 mmHg and/or diastolic blood pressure ≥ 90 mmHg. ^eMetabolic syndrome was defined according to the criteria of the IDF (2005).