Clinical study of different prediction models in predicting diabetic nephropathy in patients with type 2 diabetes mellitus

Table 1 Results of univariate analysis of diabetic nephropathy in patients with type 2 diabetes [n (%)/mean ± SD]

Indicators	DN group (n = 74)	Non-DN group (n = 136)	t/χ²	P value
Age	56.01 ± 9.41	57.42 ± 8.15	-1.129	0.260
Sex			1.150	0.284
Male	27 (36.49)	60 (44.12)
Female	47 (63.51)	76 (55.88)
BMI (kg/m2)	24.60 ± 3.92	23.73 ± 2.94	1.673	0.097
Duration of diabetes (yr)	5.28 ± 1.34	4.86 ± 0.76	2.507	0.014
History of hypertension			0.465	0.495
Yes	24 (32.43)	38 (27.94)
No	50 (67.57)	98 (72.06)
DR			8.761	0.003
Yes	34 (45.95)	24 (17.65)
No	40 (54.05)	112 (82.35)
Coronary heart disease			0.350	0.554
Yes	19 (25.68)	30 (22.06)
No	55 (74.32)	106 (77.94)
FBG (mmol/L)	8.18 ± 1.67	7.71 ± 1.14	2.160	0.033
Scr (μmol/L)	91.25 ± 14.72	84.61 ± 9.80	3.485	0.001
HbAlc (%)	7.04 ± 1.33	6.29 ± 1.05	4.239	< 0.001
BUN (mmol/L)	7.10 ± 0.96	6.78 ± 1.13	2.111	0.036
TC (mmol/L)	4.81 ± 0.89	4.83 ± 0.97	–0.189	0.851
TG (mmol/L)	1.78 ± 0.4	1.72 ± 0.38	1.090	0.277
HDL-C (mmol/L)	1.41 ± 0.31	1.45 ± 0.32	−0.972	0.332
LDL-C (mmol/L)	3.31 ± 0.57	3.33 ± 0.86	−0.185	0.853

BMI: Body mass index; FBG: Fasting blood glucose; Scr: Serum creatinine; HbAlc: Glycosylated hemoglobin; BUN: Blood urea nitrogen; DR: Diabetic retinopathy; TC: Total cholesterol; TG: Triglyceride; HDL-C: High-density lipoprotein cholesterol; LDL-C: Low-density lipoprotein cholesterol.

Table 2 Variable assignment

Factors	Variables of interest	Assignment of value
Concurrent DN or not	Y	Yes = 1, No = 0
Duration of diabetes (yr)	× 1	Numerical value
FBG (mmol/L)	× 2	Numerical value
Scr (μmol/L)	× 3	Numerical value
HbAlc (%)	× 4	Numerical value
BUN (mmol/L)	× 5	Numerical value
DR	× 6	Yes = 1, No = 0

FBG: Fasting blood glucose; Scr: Serum creatinine; HbAlc: Glycosylated hemoglobin; BUN: Blood urea nitrogen; DR: Diabetic retinopathy.

Table 3 Results of multivariate analysis of diabetic nephropathy in patients with type 2 diabetes

Factors	B	SE	Wald	P value	OR	95%CI
Duration of diabetes (yr)	0.352	0.164	4.619	0.032	1.421	1.031-1.959
FBG (mmol/L)	0.272	0.128	4.518	0.034	1.312	1.021-1.685
Scr (μmol/L)	0.063	0.015	16.745	< 0.001	1.065	1.033-1.097
HbAlc (%)	0.707	0.161	19.31	< 0.001	2.029	1.480-2.781
BUN (mmol/L)	0.250	0.158	2.507	0.113	1.283	0.942-1.748
DR	0.883	0.360	6.035	0.014	2.419	1.196-4.894

FBG: Fasting blood glucose; Scr: Serum creatinine; HbAlc: Glycosylated hemoglobin; BUN: Blood urea nitrogen; DR: Diabetic retinopathy; OR: Odds ratio; CI: Confidence interval.

Table 4 Efficacy of three model validation sets in predicting concurrent diabetic nephropathy in patients with type 2 diabetes

Model	Accuracy	Sensitivity	Specificity	Rate of recall	Rate of precision	AUC (95%CI)
Nomogram	0.746	0.710	0.844	0.906	0.690	0.811 (0.700-0.923)
Decision tree	0.714	0.710	0.875	0.906	0.659	0.735 (0.602-0.869)
Random forest	0.730	0.806	0.844	0.906	0.674	0.850 (0.750-0.950)

AUC: Area under the receiver operating characteristic curve; 95%CI: 95% confidence interval.