The Dose-Response Relationship between Gamma-Glutamyl Transferase and Risk of Diabetes Mellitus Using Publicly Available Data: A Longitudinal Study in Japan

Table 1

Baseline characteristics of participants in the NAGALA study by categories of serum GGT levels, 2004–2015.

Variable	All participants	Serum GGT quintiles					value
		Q1 (≤10 IU/L)	Q2 (11–12 IU/L)	Q3 (13–16 IU/L)	Q4 (17–24 IU/L)	Q5 (≥25 IU/L)
Participants (n)	15464	2885	2328	3674	3304	3273
Age (years)	43.71 ± 8.90	42.18 ± 8.49	42.60 ± 8.65	43.56 ± 9.18	44.36 ± 9.00	45.35 ± 8.66	<0.001
Female	7034 (45.49%)	2467 (85.51%)	1642 (70.53%)	1751 (47.66%)	743 (22.49%)	431 (13.17%)	<0.001
Smoking status							<0.001
Never	9031 (58.40%)	2340 (81.11%)	1707 (73.32%)	2246 (61.13%)	1475 (44.64%)	1263 (38.59%)
Past	2952 (19.09%)	277 (9.60%)	278 (11.94%)	632 (17.20%)	840 (25.42%)	925 (28.26%)
Current	3481 (22.51%)	268 (9.29%)	343 (14.73%)	796 (21.67%)	989 (29.93%)	1085 (33.15%)
Alcohol intake	1 (0–60.5)	1 (0–4.2)	1 (0–12)	1 (0–40)	12 (1–90)	60 (1–154)	<0.001
Habit of exercise							0.001
Never	12755 (82.48%)	2399 (83.15%)	1946 (83.59%)	2975 (80.97%)	2684 (81.23%)	2751 (84.05%)
≥1/week	2709 (17.52%)	486 (16.85%)	382 (16.41%)	699 (19.03%)	620 (18.77%)	522 (15.95%)
BMI (kg/m^2)	22.12 ± 3.13	20.67 ± 2.40	21.07 ± 2.66	21.66 ± 2.88	22.83 ± 3.12	23.93 ± 3.21	<0.001
WC (cm)	76.47 ± 9.11	70.54 ± 7.27	72.79 ± 7.53	75.37 ± 8.08	79.37 ± 8.35	82.63 ± 8.53	<0.001
SBP (mmHg)	114.50 ± 14.97	107.11 ± 12.95	109.68 ± 13.44	113.76 ± 14.31	117.66 ± 14.08	122.08 ± 14.84	<0.001
DBP (mmHg)	71.58 ± 10.50	66.29 ± 8.90	67.97 ± 9.32	70.96 ± 9.93	73.90 ± 9.98	77.18 ± 10.36	<0.001
Fatty liver	86 (2.98%)	130 (5.58%)	436 (11.87%)	828 (25.06%)	1261 (38.53%)	86 (2.98%)	<0.001
ALT (IU/L)	17 (13–23)	12 (10–15)	14 (11–17)	16 (13–20)	19 (15–25)	26 (20–37)	<0.001
AST (IU/L)	17 (14–21)	15 (12–17)	16 (13–19)	17 (14–20)	18 (15–22)	21 (18–26)	<0.001
GGT (IU/L)	15 (11–22)	9 (8–10)	12 (11–12)	14 (13–15)	20 (18–22)	35 (28–48)	<0.001
TC (mmol/L)	5.13 ± 0.86	4.90 ± 0.83	4.96 ± 0.82	5.06 ± 0.83	5.21 ± 0.87	5.43 ± 0.86	<0.001
HDL (mmol/L)	1.46 ± 0.40	1.59 ± 0.37	1.56 ± 0.39	1.49 ± 0.41	1.37 ± 0.40	1.33 ± 0.39	<0.001
TG (mmol/L)	0.73 (0.50–1.12)	0.54 (0.40–0.75)	0.59 (0.41–0.82)	0.69 (0.47–0.99)	0.88 (0.61–1.28)	1.12 (0.76–1.67)	<0.001
FPG (mmol/L)	5.16 ± 0.41	4.95 ± 0.38	5.02 ± 0.39	5.14 ± 0.39	5.27 ± 0.38	5.37 ± 0.38	<0.001
HbA1c (%)	5.17 ± 0.32	5.11 ± 0.32	5.15 ± 0.31	5.18 ± 0.31	5.20 ± 0.32	5.21 ± 0.34	<0.001

Notes: data presented are mean ± SD, median (Q1–Q3), or N (%). Abbreviations: BMI, body mass index; WC, waist circumference; SBP, systolic blood pressure; DBP, diastolic blood pressure; ALT, alanine aminotransferase; AST, aspartate aminotransferase; GGT, gamma-glutamyl transferase; TC, total cholesterol; HDL, high-density lipoprotein cholesterol; TG, triglyceride; FPG, fasting plasma glucose; HbA1c, haemoglobin A1c.