Development and Validation of a Risk Nomogram Model for Predicting Constipation in Patients with Type 2 Diabetes Mellitus

Figures & data

Figure 1 Screening process for patients with type 2 diabetes mellitus required for this study.

Abbreviations: ZU, Zhejiang University; NU, Nanchang University.

Table 1 Base Characteristics of Patients in the Primary and Validation Cohorts

Features	Primary Set (n=545)	Independent-Validation Set (n=201)	P
Constipation [n (%)]			0.314
Yes	111(20.4)	48(23.9)
No	434(79.6)	153(76.1)
Gender [n (%)]			0.458
Male	281(51.6)	97(48.3)
Female	264(48.4)	104(51.7)
Age [n (%)]			0.110
< 60	412(75.6)	140(69.7)
≥60	133(24.4)	61(30.3)
BMI (kg²/m) [n (%)]			0.211
<18.5	131(24.0)	45(22.4)
18.5~24.0	268(49.2)	89(44.3)
>24.0	146(26.8)	67(33.3)
ALT (mean±SD, U/L)	24.3±26.7	24.8±34.1	0.834
Scr (mean±SD, μmol/L)	80.0±11.8	80.2±11.4	0.836
TP (mean±SD, g/L)	65.0±6.4	64.6±6.2	0.445
HDL (mean±SD, mmol/L)	1.0±0.3	1.1±0.4	<0.001
LDL (mean±SD, mmol/L)	3.2±1.1	3.0±0.9	0.021
History of smoking [n (%)]			0.732
Yes	198(36.3)	76(37.8)
No	347(63.7)	125(62.2)
History of drinking [n (%)]			0.674
Yes	213(39.1)	82(40.8)
No	332(60.9)	119(59.2)
Hyperlipemia [n (%)]			0.959
Yes	186(34.1)	69(34.3)
No	359(65.9)	132(65.7)
HbA1c[n (%)]			<0.001
< 7.0	423(77.6)	105(52.2)
≥7.0	122(22.4)	96(47.8)
Calcium[n (%)]			0.872
Yes	136(25.0)	49(24.4)
No	409(75.0)	152(75.6)
Family history of type 2 diabetes [n (%)]			0.367
Yes	192(35.2)	78(38.8)
No	353(64.8)	123(61.2)
Anxiety [n (%)]			<0.001
Yes	71(13.0)	56(27.9)
No	474(87.0)	145(72.1)
Regular exercise [n (%)]			0.105
Yes	141(25.9)	64(31.8)
No	404(74.1)	137(68.2)

Notes: P value is derived from the univariate association analyses between primary set and independent-validation set.

Abbreviations: SD, Standard deviation; BMI, Body Mass Index; ALT, alanine aminotransferase; Scr, serum creatinine; TP, total protein;HDL, high-density lipoprotein; LDL, low-density lipoprotein; HbA1c, glycated haemoglobin.

Table 2 Results of Univariate and Multivariable Analysis for Prediction of Incidence of Constipation

	Univariate			Multivariable
	β	P-value	OR (95% CI)	β	P-value	OR (95% CI)
Gender	0.653	0.016	1.922(1.129–3.27)
Age	1.561	<0.001	4.765(2.731–8.316)	2.247	<0.001	9.462(3.712–24.117)
BMI	−0.178	0.330	0.837(0 0.585–1.197)
Family history of diabetes	0.258	0.357	1.295(0.747–2.243)
ALT	−0.07	0.363	0.993(0.979–1.008)
Scr	−0.014	0.220	0.986(0.965–1.008)
TP	−0.019	0.384	0.982(0.942–1.023)
HDL	−0.706	0.135	0.494(0 0.196–1.246)
LDL	−0.022	0.869	0.978(0.754–1.270)
History of smoking	0.554	0.056	1.740(0.988–3.067)
History of drinking	0.291	0.286	1.338(0.783–2.286)
HbA1c	3.035	<0.001	20.793(11.042–39.152)	3.092	<0.001	22.015(10.352–46.819)
Calcium	1.103	<0.001	3.014(1.756–5.172)	0.681	0.016	1.976(0.865–4.513)
Hyperlipemia	0.751	0.065	1.770(0.966–3.243)
Anxiety	2.079	<0.001	7.998(4.168–15.349)	1.618	0.001	5.042(2.027–12.543)
Regular exercise	−0.071	0.048	0.932(0.515–1.684)	−1.135	0.02	0.321(0.123–0.837)

Abbreviations: BMI, Body Mass Index; ALT, alanine aminotransferase; Scr, serum creatinine; TP, total protein; HDL, high-density lipoprotein; LDL, low-density lipoprotein; HbA1c, glycated haemoglobin; OR, odds ratio; CI, confidence interval.

Figure 2 The nomogram model for quantifying individual risk of constipation in patients with type 2 diabetes mellitus.

Figure 3 Prediction performance of the model. Receiver operating characteristic (ROC) curve plot in the training set (A); ROC curve plot in the internal‑validation set (B); ROC curve plot in the independent‑validation set (C);AUC, the area under the receiver operating characteristic.

Figure 4 Calibration curve plot in each set. (A) the training set; (B) the internal‑validation set; (C) the independent–validation set.

Figure 5 Decision curve analysis for classification of different risk population.