A Nomogram for Predicting the Risk of CKD Based on Cardiometabolic Risk Factors

Figures & data

Table 1 Clinical Features of the Participants

	Overall (n=5499)
Socio-demographic factors
Age (year)	60.87±9.46
Sex (male)	1873 (34.1%)
BMI (kg/m^2)	23.60±3.22
WHtR	0.51±0.06
Lifestyle behaviours
Current smoker	733 (13.3%)
Current drinker	670 (12.2%)
Biomarker
Fasting plasma glucose (mmol/L)	5.54±1.31
2hPG (mmol/L)	6.99±5.97
HbA1c (%)	5.82±0.90
Total cholesterol (mmol/L)	5.08±0.95
Triglyceride (mmol/L)	1.23 (0.89–1.75)
High-density lipoprotein (mmol/L)	1.51±0.36
Low-density lipoprotein (mmol/L)	2.89±0.79
Creatinine (mg/dL)	62.77±9.56
eGFR (mL/min/1.73m^2)	94.94±9.97
SBP (mmHg)	151.27±23.58
DBP (mmHg)	81.80±12.55
History of disease
Hypertension	3835 (69.7%)
Diabetes	718 (13.1%)
CVD	400 (7.3%)
Medication
Anti-hypertensive drug use	1048 (19.1%)
Anti-diabetic drug use	162 (2.9%)

Note: Data are presented as the mean±standard deviation or as number (%).

Abbreviations: BMI, body mass index; WHtR, waist-to-Height Ratio; FPG, fasting plasma glucose; 2hPG, OGTT 2-hour blood glucose; TC, total cholesterol; TG, total triglyceride; HDL-C, high density lipoprotein cholesterol; LDL-C, low density lipoprotein cholesterol; Cr, creatinine; eGFR, estimated glomerular filtration rate; SBP, systolic pressure; DBP, diastolic blood pressure.

Table 2 Univariable and Multivariate Analysis of Variables Associated with CKD Risk

Variables	Univariate Analysis			Multivariate Analysis
	RR	95% CI	P	RR	95% CI	P
Age (year)	1.09	1.07–1.11	<0.001	1.03	1.01–1.06	0.001
Sex (male vs female)	1.68	1.24–2.30	0.001	2.03	1.44–2.85	<0.001
WHtR (per 0.1 increase)	1.05	0.82–1.36	0.683
Current smoker (yes vs no)	1.09	0.71–1.70	0.688
Current drinker (yes vs no)	0.98	0.61–1.58	0.933
HbA1c (%)			<0.001			<0.001
<6.5	1			1
6.5–7.4	1.87	1.04–3.34	0.036	1.55	0.81–2.98	0.186
≥7.5	3.68	2.17–6.23	<0.001	3.89	2.10–7.21	<0.001
Total cholesterol≥ 6.22 mmol/L	1.74	1.16–2.61	0.007	1.68	1.07–2.66	0.025
Triglyceride≥ 2.26 mmol/L	1.37	0.92–2.05	0.555
High-density lipoprotein≥ 4.14 mmol/L	1.71	1.01–2.90	0.046
Low-density lipoprotein<1.04 mmol/L	2.26	1.40–3.65	0.001	1.99	1.14–3.46	0.015
eGFR (mL/min/1.73m^2)			<0.001			<0.001
≥90	1			1
75–89	7.09	4.75–10.59	<0.001	5.07	3.24–7.94	<0.001
60–74	37.2	24.07–57.50	<0.001	26.5	16.41–42.78	<0.001
SBP (mmHg)	1.02	1.01–1.02	<0.001	1.01	1.00–1.02	0.002
DBP (mmHg)	1.01	0.99–1.02	0.156
CVD history (yes vs no)	1.99	1.26–3.15	0.003

Note: All variables with a value of p < 0.1 in the univariate analysis were included in the multivariate analysis.

Abbreviations: WHtR, waist-to-Height Ratio; TC, total cholesterol; TG, total triglyceride; HDL-C, high density lipoprotein cholesterol; LDL-C, low density lipoprotein cholesterol; eGFR, estimated glomerular filtration rate; SBP, systolic pressure; DBP, diastolic blood pressure; RR, risk ratio; 95% CI, 95% confidence interval.

Figure 1 The nomogram developed in this study to calculate the predicted 3-year CKD risk.

Figure 2 A case of using the nomogram to calculate the predicted 3-year CKD risk.

Figure 3 Receiver operating characteristic curve (ROC) for predicting the 3-year risk of CKD. AUCs (areas under the curve) with 95% confidence intervals (red area) were calculated by 1000 bootstrap resamples.

Figure 4 Calibration plots for observed and predicted 3-year risks of CKD. The black dashed line indicates the reference line that represents where a perfect calibration would lie, the solid red line indicates the result for our risk prediction model, and the solid green line indicates optimism-corrected calibration plots derived from 1000 bootstrap resamples.

Table 3 Values of Sensitivity, Specificity, PPV and NPV for the Nomogram Scores at Different Cut-off Values

Predicted Probability	Specificity (%)	Sensitivity (%)	Accuracy (%)	PPV (%)	NPV (%)
≥0.05	0.86	0.65	0.86	0.13	0.99
≥0.10	0.95	0.45	0.93	0.20	0.98
≥0.15	0.97	0.38	0.95	0.28	0.98
≥0.20	0.98	0.30	0.96	0.32	0.98
≥0.25	0.99	0.23	0.96	0.37	0.98
≥0.30	0.99	0.19	0.97	0.43	0.98
≥0.35	0.99	0.16	0.97	0.53	0.97
≥0.40	0.99	0.10	0.97	0.63	0.97
≥0.45	0.99	0.07	0.97	0.73	0.97
≥0.50	0.99	0.04	0.97	0.70	0.97

Abbreviations: PPV, Positive predictive value; NPV, Negative predictive value.