Comparison of effects of obesity and non-alcoholic fatty liver disease on incidence of type 2 diabetes mellitus

Table 1 Study subjects’ general characteristics at baseline

Variable	Value
Gender (male/female)	3149/1587
Age (yr)	52.70 ± 14.98
Body mass index (kg/m2)	24.04 ± 3.13
Fasting plasma glucose (mmol/L)	5.29 ± 0.62
Systolic blood pressure (mmHg)	127.65 ± 17.28
Diastolic blood pressure (mmHg)	81.87 ± 10.46
Cholesterol (mmol/L)	4.94 ± 0.95
Triglycerides (mmol/L)	1.56 ± 1.10
Alanine aminotransferase (U/L)	26.42 ± 17.16
Creatinine (μmol/L)	76.77 ± 21.71
Uric acid (μmol/L)	328.26 ± 82.35
Non-alcoholic fatty liver disease, n (%)	1412 (29.81)

Table 2 Incidence of type 2 diabetes mellitus and Cox hazards regression analysis in subjects with different baseline non-alcoholic fatty liver disease and body mass index levels

Group	n	T2DM	Incidence rate (%)1	RR (95%CI)	RR2 (95%CI)
Non-alcoholic fatty liver disease
No	3379	135	4.1	1	1
Yes	1412	245	17.4	4.492 (3.640-5.542)	3.367 (2.367-4.266)
Body mass index (kg/m2)
< 24	2999	166	5.5	1	1
About 24	1249	137	11	2.023 (1.614-2.537)	1.274 (0.997-1.629)
About 28	488	77	15.8	2.954 (2.254-3.870)	1.554 (1.140-2.091)
Age (yr)
< 30	291	5	1.7	1	1
About 30	722	17	2.4	1.350 (0.498-3.658)	1.044 (0.379-2.875)
About 40	1033	54	5.2	3.043 (1.217-7.607)	1.853 (0.736-4.665)
About 50	1135	114	10	6.021 (2.459-14.743)	3.136 (1.270-7.747)
About 60	1555	190	12.2	7.469 (3.074-18.152)	4.344 (1.772-10.651)
Gender
F	3149	86	5.4	1	1
M	1587	294	9.3	1.748 (1.374-2.222)	1.327 (1.025-1.720)
SBp
< 140	3672	237	6.5	1	1
≥ 140	1064	143	13.4	2.164 (1.759-2.664)	1.462 (1.139-1.877)
Alanine aminotransferase
< 40	4094	303	7.4	1	1
≥ 40	642	77	12	1.628 (1.268-2.091)	1.522 (1.165-1.988)
Total	4736	380	8

¹P < 0.001 by Log Rank (Mantel-Cox) test, showing differences in the incidence rate between the groups;

²RR adjusted for age, sex, blood pressure, lipids, alanine aminotransferase, uric acid, and creatinine. T2DM: Type 2 diabetes mellitus.

Table 3 Cox regression analysis of the relationship between non-alcoholic fatty liver disease and type 2 diabetes mellitus at different body mass index levels

BMI	NAFLD	n	T2DM	Incidence rate1 (%)	RR (95%CI)	RR2 (95%CI)
< 24	Control	2383	85	3.6	1.0	1.0
	NAFLD	616	81	13.1	3.860 (2.847-5.233)	3.407 (2.461-4.717)
About 24	Control	712	35	4.9	1.0	1.0
	NAFLD	537	102	19.0	4.049 (2.758-5.944)	3.455 (2.269-5.262)
About 28	Control	229	15	6.6	1.0	1.0
	NAFLD	259	62	23.9	3.823 (2.175-6.719)	3.438 (1.841-6.420)

¹P < 0.001 by Log Rank (Mantel-Cox) test, indicating a significant difference in T2DM incidence between the two groups;

²RR adjusted for age, sex, blood pressure, lipids, alanine aminotransferase, uric acid, and creatinine. NAFLD: Non-alcoholic fatty liver disease; T2DM: Type 2 diabetes mellitus.