The Serum Uric Acid to Serum Creatinine Ratio is an Independent Risk Factor for Diabetic Kidney Disease

Figures & data

Figure 1 Flow chart of the study.

Abbreviations: DM, diabetes mellitus; UA, uric acid.

Table 1 Characteristics of T2DM Patients According to the SUA/SCr Tertiles

	Tertile 1 (SUA/SCr < 3.934)	Tertile 2 (3.934≤ SUA/SCr <4.947)	Tertile 3 (SUA/SCr ≥ 4.947)	P-value
N	150	148	152
Characteristics
Age(year)	60.30±11.64	55.59±11.91*	54.64±12.85*	0.000
Male, N (%)	101(67.3)	106(71.6)	73(48.0)*^▲	0.000
Duration of DM(year)	8.00(3.75,13.00)	7.50(2.25,12.00)	6.00(2.00,11.00)	0.127
BMI(kg/m²)	23.69(21.86,25.42)	24.16(22.10,26.13)	24.80(22.83,27.18)*	0.002
DM family History, N (%)	65(43.3)	67(45.3)	73(48.0)	0.713
HBP history, N (%)	79(52.7)	59(39.9)	54(35.5)*	0.008
Smoking history, N (%)	65(43.3)	59(39.9)	48(31.6)	0.097
Parameters
FBG(mmol/L)	7.63(6.36,9.33)	7.80(6.64,10.05)	7.56(6.37,9.49)	0.345
HbA1C(%)	8.20(6.87,9.97)	8.60(7.30,10.20)	8.15(6.90,10.00)	0.378
C-P(nmol/L)	0.56(0.38,0.70)	0.57(0.39,0.75)	0.59(0.44,0.79)	0.165
Renal function
SCr(umol/L)	80.30(67.93,95.93)	70.35(61.05,79.00)*	56.30(48.00,67.07)*^▲	0.000
BUN(mmol/L)	5.25(4.40,6.48)	5.20(4.40,6.20)	4.40(3.80,5.10)*^▲	0.000
Cysc(mg/L)	0.87(0.75,1.06)	0.79(0.68,0.90)*	0.74(0.66,0.89)*	0.000
SUA(umol/L)	268.82±61.21	307.54±62.65*	351.86±78.04*^▲	0.000
Hepatic function
GGT(IU/L)	18.00(12.00,27.00)	20.00(14.25,31.00)	22.00(14.00,34.00)*	0.028
ALT(U/L)	19.00(14.00,28.00)	21.00(16.00,29.00)	22.00(17.00,31.00)*	0.026
AST(U/L)	19.00(15.00,24.00)	18.50(15.25,23.00)	20.00(17.00,23.00)	0.217
Fatty liver, N (%)	71(48)	84(57.9)	110(73.8)*^▲	0.000
Serum lipid
Triglycerides(mmol/L)	1.37(1.05,2.08)	1.62(1.13,2.48)	1.81(1.18,2.49)*	0.010
TCH(mmol/L)	4.35±1.00	4.33±0.94	4.55±1.02^▲	0.093
LDL-C(mmol/L)	2.42±0.89	2.36±0.82	2.50±0.88	0.398
HDL-C(mmol/L)	1.14(0.95,1.33)	1.02(0.88,1.23)	1.04(0.90,1.29)*	0.009

Notes: *Compared with Tertile 1 group, P < 0.05; ^▲Compared with Tertile 2 group, P < 0. 05.

Abbreviations: T2DM, type 2 diabetes mellitus; SUA/SCr, serum uric acid to serum creatinine ratio; eGFR, estimated glomerular filtration rate; UACR, urinary albumin creatinine ratio; DM, diabetes mellitus; BMI, body mass index; HBP, hypertension; FBG, fasting Blood Glucose; HbA1C, glycosylated hemoglobin A1c; BUN, blood urea nitrogen; Cysc, cystatin-c; ALT, alanine transaminase; AST, aspartate transaminase; GGT, gamma-glutamyl transpeptidase; C-P, C-peptide; TCH, total cholesterol, LDL-C, low-density lipoprotein cholesterol; HDL-C, high-density lipoprotein cholesterol.

Figure 2 Prevalence of eGFR and UACR among three groups categorized by tertile of SUA/SCr. (A) Comparison of eGFR among the three groups; (B) Comparison of UACR among the three groups.

Abbreviations: SUA/SCr, serum uric acid to serum creatinine ratio; eGFR, estimated glomerular filtration rate; UACR, urinary albumin creatinine ratio.

Figure 3 Prevalence of carotid lesions and LLAL among three groups categorized by tertile of SUA/SCr. (A) Comparison of the prevalence of carotid lesions among the three groups; (B) Comparison of the prevalence of LLAL among the three groups.

Abbreviations: SUA/SCr, serum uric acid to serum creatinine ratio; LLAL, lower limb atherosclerotic lesion.

Table 2 Correlation Between SUA/SCr and Other Parameters in T2DM Patients

Variables	r	P
eGFR(mL/min/1.73m²)	0.419	0.000
UACR(mg/g)	−0.048	0.311
Age(year)	−0.199	0.000
Male	−0.166	0.000
Duration of DM(year)	−0.119	0.012
BMI(kg/m²)	0.198	0.000
DM family history	0.043	0.365
HBP history	−0.153	0.001
Smoking history	−0.091	0.054
FBG(mmol/L)	0.021	0.662
HbA1C(%)	0.005	0.918
C-P(nmol/L)	0.111	0.019
SCr(umol/L)	−0.577	0.000
BUN(mmol/L)	−0.285	0.000
Cysc(mg/L)	−0.314	0.000
SUA(umol/L)	0.455	0.000
GGT(IU/L)	0.129	0.006
ALT(IU/L)	0.122	0.010
AST(IU/L)	0.065	0.168
Fatty liver	0.210	0.000
Triglycerides(mmol/L)	0.114	0.016
TCH(mmol/L)	0.035	0.461
LDL-C(mmol/L)	−0.020	0.677
HDL-C(mmol/L)	0.096	0.041
Carotid lesions	−0.139	0.004
LLAL	−0.155	0.001

Abbreviations: T2DM, type 2 diabetes mellitus; SUA/SCr, serum uric acid to serum creatinine ratio; eGFR, estimated glomerular filtration rate; UACR, urinary albumin creatinine ratio; DM, diabetes mellitus; BMI, body mass index; HBP, hypertension; FBG, fasting Blood Glucose; HbA1C, glycosylated hemoglobin A1c; BUN, blood urea nitrogen; Cysc, cystatin-c; ALT, alanine transaminase; AST, aspartate transaminase; GGT, gamma-glutamyl transpeptidase; C-P, C-peptide; TCH, total cholesterol, LDL-C, low-density lipoprotein cholesterol; HDL-C, high-density lipoprotein cholesterol; LLAL, Lower limb atherosclerotic lesion.

Table 3 Logistic Regression Analysis of SUA/SCr for DKD in T2DM Patients

	Regression Coefficient	SE	Wald -Value	P-value	OR(95% CI)
Model 1	1.827	0.300	36.993	0.000	6.214(3.449~11.195)
Model 2	1.713	0.327	27.361	0.000	5.544(2.918~10.532)
Model 3	2.341	0.473	24.445	0.000	10.389(4.107~26.275)
Model 4	2.456	0.497	24.467	0.000	11.66(4.406~30.856)

Notes: Model 1: no parameter was adjusted; Model 2: adjusted for age, sex; Model 3: Model 2 plus duration of DM, BMI, DM family history, HBP history, smoking history, FBG, HbA1C, C-P; Model 4: Model 3 plus hepatic function and serum lipids.

Abbreviations: T2DM, type 2 diabetes mellitus; SUA/SCr, serum uric acid to serum creatinine ratio; DM, diabetes mellitus.

Table 4 Logistic Regression Analysis of SUA/SCr for Macroangiopathy in T2DM Patients

	Regression Coefficient	SE	Wald -Value	P-value	OR(95% CI)
Carotid lesion
Model 1	−0.125	0.063	3.938	0.047	0.883(0.780~0.998)
Model 2	−0.009	0.074	0.014	0.906	0.991(0.858~1.145)
Model 3	−0.019	0.08	0.054	0.816	0.982(0.84~1.147)
Model 4	−0.02	0.083	0.059	0.807	0.98(0.833~1.153)
LLAL
Model 1	−0.184	0.065	7.873	0.005	0.832(0.732~0.946)
Model 2	−0.077	0.076	1.043	0.307	0.926(0.798~1.074)
Model 3	−0.069	0.082	0.708	0.400	0.933(0.794~1.096)
Model 4	−0.1	0.085	1.379	0.240	0.905(0.765~1.069)

Notes: Model 1: no parameter was adjusted; Model 2: adjusted for age, sex; Model 3: Model 2 plus duration of DM, BMI, DM family history, HBP history, smoking history, FBG, HbA1C, C-P; Model 4: Model 3 plus hepatic function and serum lipids.

Abbreviations: T2DM, type 2 diabetes mellitus; SUA/SCr, serum uric acid to serum creatinine ratio; DM, diabetes mellitus; LLAL, lower limb atherosclerotic lesion.

Figure 4 The ROC curves of SUA/SCr for DKD in T2DM.

Abbreviations: SUA/SCr, serum uric acid to serum creatinine ratio; T2DM, type 2 diabetes mellitus; DKD, diabetic kidney disease.

Figure 5 Comparison of SUA/SCr levels according to eGFR among patients with normal UACR.

Notes: Normal eGFR group, eGFR ≥ mL/min/1.73 m²; Low eGFR group, eGFR < 60 mL/min/1.73 m².

Abbreviations: SUA/SCr, serum uric acid to serum creatinine ratio; eGFR, estimated glomerular filtration rate; UACR, urinary albumin creatinine ratio.