Clinical Characteristics
All enrolled T2DM patients were categorized into three subgroups according to UACR. Demographic and laboratory features of the patients as well as the healthy subjects are reported in Table 1. Our results showed that there was significant difference among the subgroups of patients regarding to SBP, Known diabetes duration, UACR, sCr, BUN and eGFR. Meanwhile, there was no significant difference among the subgroups of patients regarding to gender, age, DBP, FBG, HbAlc, sUA, TC, TG, HDL-C and LDL-C. Compare the clinical and laboratory data among the subgroups of patients and the healthy subjects, there was no significant statistical difference only in gender, age, TC and LDL-C levels.
Table 1
Comparison of clinical and laboratory data among subgroups of patients with T2DM divided according to UACR and healthy subjects
|
Heathy
controls
(n = 45)
|
Normo
Albuminuria
(n = 121)
|
Micro
albuminuria
(n = 73)
|
Macro
albuminuria
(n = 25)
|
aP-value
|
bP-value
|
Male,n(%)
|
26(57.8%)
|
72(59.5%)
|
38(52.1%)
|
15(60.0%)
|
0.768
|
0.568
|
Age(years)
|
63.40 ± 10.38
|
62.51 ± 10.34
|
65.18 ± 13.52
|
64.48 ± 10.85
|
0.445
|
0.277
|
SBP(mmHg)
|
117.44 ± 7.04
|
129.50 ± 12.15&&
|
132.12 ± 14.41&&
|
141.60 ± 17.68&&**#
|
< 0.001
|
< 0.001
|
DBP(mmHg)
|
74.00 ± 6.79
|
79.41 ± 7.76&&
|
78.96 ± 9.47&
|
79.88 ± 6.70&
|
0.001
|
0.874
|
FBG(mmol/L)
|
4.81 ± 0.42
|
8.63 ± 4.14&&
|
8.79 ± 3.50&&
|
9.10 ± 2.76&&
|
< 0.001
|
0.850
|
HbAlc(%)
|
5.50 ± 0.37
|
9.41 ± 2.40&&
|
9.88 ± 3.19&&
|
9.45 ± 2.17&&
|
< 0.001
|
0.479
|
Known diabetes duration (years)
|
/
|
8.00(3.00,15.00)
|
10.00(6.00,20.00)**
|
18.00(13.00,20.00)**#
|
/
|
< 0.001
|
UACR(mg/g)
|
3.59(2.04,5.75)
|
8.55(5.30,14.07)&&
|
77.69(48.49,166.00)&&**
|
834.05(614.33,2103.99)&&**##
|
< 0.001
|
< 0.001
|
sCr(umol/L)
|
66.73 ± 12.19
|
65.07 ± 13.82
|
72.07 ± 18.48*
|
137.04 ± 49.66&&**##
|
< 0.001
|
< 0.001
|
BUN(mmol/L)
|
5.11 ± 0.96
|
5.58 ± 1.45
|
7.08 ± 2.81&&**
|
8.91 ± 4.33&&**#
|
< 0.001
|
< 0.001
|
sUA(ummol/L)
|
308.84 ± 71.81
|
325.74 ± 94.77
|
345.77 ± 101.29&
|
373.84 ± 103.01&*
|
0.022
|
0.060
|
eGFR(ml/min/1.73m2)
|
102.44 ± 21.80
|
106.44 ± 21.12
|
95.31 ± 28.75*
|
47.53 ± 12.50&&**##
|
< 0.001
|
< 0.001
|
TC(mmol/L)
|
4.67 ± 0.72
|
4.68 ± 1.59
|
4.38 ± 1.22
|
4.41 ± 1.38
|
0.421
|
0.335
|
TG(mmol/L)
|
0.94(0.75,1.33)
|
1.55(1.08,2.43)&
|
1.40(0.99,2.12)&
|
1.66(1.13,2.63)&
|
< 0.001
|
0.360
|
LDL-C(mmol/L)
|
2.97 ± 0.84
|
2.93 ± 1.15
|
2.69 ± 0.84
|
2.84 ± 1.00
|
0.373
|
0.319
|
HDL-C(mmol/L)
|
1.41 ± 0.28
|
1.13 ± 0.35&&
|
1.11 ± 0.31&&
|
1.06 ± 0.27&&
|
< 0.001
|
0.660
|
CgA(ng/mL)
|
1.89(1.42,2.47)
|
2.26(1.38,4.12)&
|
4.83(2.63,6.46)&&**
|
6.35(4.91,7.54)&&**#
|
< 0.001
|
< 0.001
|
Notes: |
& P < 0.05. |
&& P < 0.001 vs. healthy controls. |
* P < 0.05. |
** P < 0.001 vs. normoalbuminuria group. |
# P < 0.05. |
## P < 0.001 vs. microalbuminuria group. |
aP-value: comparisons among the healthy controls group, the normoalbuminuria group, the microalbuminuria group and the macroalbuminuria group; |
bP-value: comparisons among the normoalbuminuria group, the microalbuminuria group and the macroalbuminuria group |
SBP, systolic blood pressure; DBP, diastolic blood pressure; FBG, fasting blood glucose; HbA1c, hemoglobin A1c; UACR, urine albumin to creatinine ratio; sCr, serum creatinine; BUN, blood urea nitrogen; sUA, serum uric acid; eGFR, estimated glomerular filtration rate; TC, total cholesterol; TG, triglyceride; LDL-C, low density lipoprotein cholesterol; HDL-C, high density lipoprotein cholesterol; CgA, Chromogranin A. |
Comparison of serum CgA levels among subgroups of patients with T2DM and healthy subjects
A comparison of serum CgA levels among subgroups of patients divided according to UACR and healthy subjects was performed using the Kruskal-Wallis test. The serum CgA levels were higher in patients with T2DM compared to healthy subjects and a statistically significant difference among studied subgroups regarding CgA was found (P < 0.05). A non-parametric Jonckheere-Terpstra test showed that CgA was increasing gradually with the degree of DN (Z = 6.567, P < 0.001). The results are shown in Fig. 1 and Table 1.
Correlation between serum CgA levels and clinical and laboratory data
Spearman rank correlation test demonstrated that there was moderate intensity positive correlation between serum CgA levels and Known diabetes duration, UACR in all subjects (P < 0.001). Weak correlation was found between serum CgA levels and FBG, HbAlc, sCr, BUN, eGFR, HDL-C (all P < 0.05), and there was no correlation between serum CgA levels and age, SBP, DBP, sUA, TC, TG, LDL-C in all subjects. There was moderate intensity positive correlation between serum CgA levels and UACR in patients with T2DM (P < 0.001). Weak correlation was found between serum CgA levels and Known diabetes duration, DBP, HbAlc, sCr, BUN, eGFR (all P < 0.05), and there was no correlation between serum CgA levels and age, SBP, FBG, sUA, TC, TG, LDL-C, HDL-C in patients with T2DM. The correlation coefficients between serum CgA levels and clinical and laboratory data are presented in Table 2.
Table 2
Correlation between serum CgA and clinical and laboratory data of subjects
clinical and laboratory data
|
CgA (in all subjects)
(n = 264)
|
CgA (in patients with T2DM)
(n = 219)
|
r
|
P
|
r
|
P
|
Known diabetes duration (years)
|
0.302
|
< 0.001
|
0.171
|
0.011
|
Age(years)
|
0.066
|
0.286
|
0.053
|
0.434
|
SBP(mmHg)
|
0.099
|
0.110
|
-0.029
|
0.673
|
DBP(mmHg)
|
-0.084
|
0.172
|
-0.170
|
0.012
|
FBG(mmol/L)
|
0.240
|
< 0.001
|
0.128
|
0.060
|
HbAlc(%)
|
0.285
|
< 0.001
|
0.144
|
0.033
|
UACR(mg/g)
|
0.441
|
< 0.001
|
0.408
|
< 0.001
|
sCr(umol/L)
|
0.163
|
0.008
|
0.188
|
0.005
|
BUN(mmol/L)
|
0.229
|
< 0.001
|
0.202
|
0.003
|
sUA(ummol/L)
|
0.061
|
0.322
|
0.049
|
0.470
|
eGFR(ml/min/1.73m2)
|
-0.227
|
< 0.001
|
-0.252
|
< 0.001
|
TC(mmol/L)
|
-0.118
|
0.056
|
-0.109
|
0.107
|
TG(mmol/L)
|
0.035
|
0.572
|
-0.049
|
0.473
|
LDL-C(mmol/L)
|
-0.109
|
0.076
|
-0.105
|
0.120
|
HDL-C(mmol/L)
|
-0.124
|
0.044
|
-0.027
|
0.689
|
SBP, systolic blood pressure; DBP, diastolic blood pressure; FBG, fasting blood glucose; HbA1c, hemoglobin A1c; UACR, urine albumin to creatinine ratio; sCr, serum creatinine; BUN, blood urea nitrogen; sUA, serum uric acid; eGFR, estimated glomerular filtration rate; TC, total cholesterol; TG, triglyceride; LDL-C, low density lipoprotein cholesterol; HDL-C, high density lipoprotein cholesterol; CgA, Chromogranin A. |
Serum CgA level was associated with the occurrence of early DN
We performed multivariate logistic regression analyses in patients with T2DM between the normoalbuminuria group and the microalbuminuria group. As shown in Table 3, multivariable logistic regression analysis revealed that serum CgA (OR 1.403, 95%CI 1.202–1.637, P < 0.001) and BUN (OR 1.299, 95%CI 1.045–1.616, P = 0.019) were independently associated with the occurrence of early DN, when adjusted for age, gender, Known diabetes duration, SBP, DBP, FBG, HbAlc, TC, TG, HDL-C, LDL-C, sUA, BUN, sCr and CgA. (Enter)
Table 3
Multivariate logistic regression analysis of factors independently associated with early DN in patients with T2DM between the normoalbuminuria group and the microalbuminuria group.
Variables
|
P-value
|
EXP(B)
|
95% CI
|
Male
|
0.252
|
0.603
|
0.254–1.434
|
Age
|
0.375
|
0.983
|
0.946–1.021
|
Known diabetes duration
|
0.164
|
1.039
|
0.985–1.096
|
SBP
|
0.468
|
1.013
|
0.978–1.049
|
DBP
|
0.538
|
1.017
|
0.963–1.074
|
FBG
|
0.564
|
0.971
|
0.877–1.074
|
HbAlc
|
0.519
|
1.050
|
0.905–1.219
|
TC
|
0.686
|
0.850
|
0.386–1.871
|
TG
|
0.637
|
1.052
|
0.851–1.302
|
HDL-C
|
0.315
|
2.176
|
0.478–9.917
|
LDL-C
|
0.927
|
0.958
|
0.385–2.384
|
sUA
|
0.816
|
0.999
|
0.994–1.004
|
BUN
|
0.019
|
1.299
|
1.045–1.616
|
sCr
|
0.097
|
1.029
|
0.995–1.064
|
CgA
|
< 0.001
|
1.403
|
1.202–1.637
|
adjusting for age, gender, Known diabetes duration, SBP, DBP, FBG, HbAlc, TC, TG, HDL-C, LDL-C, sUA, BUN, sCr and CgA. (Enter) |
Significance level was set at P < 0.05. |
CI, confidence interval; SBP, systolic blood pressure; DBP, diastolic blood pressure; FBG, fasting blood glucose; HbA1c, hemoglobin A1c; sCr, serum creatinine; BUN, blood urea nitrogen; sUA, serum uric acid; TC, total cholesterol; TG, triglyceride; LDL-C, low density lipoprotein cholesterol; HDL-C, high density lipoprotein cholesterol; CgA, Chromogranin A. |
ROC analysis
ROC analysis was performed to assess the sensitivity and specificity of serum CgA as the potential biomarkers in prediction of early DN. The ROC analysis of serum CgA yielded an AUC of 0.714 (95% CI, 0.639–0.788; P < 0.001) in the differentiation of T2DM patients with early DN (Table 4 and Fig. 2). The diagnostic sensitivity and specificity of serum CgA for early DN was 69.86% and 66.12% when the cut off value was 3.46 ng/mL.