Association Between Serum Albumin Levels and Diabetic Peripheral Neuropathy Among Patients with Type 2 Diabetes: Effect Modification of Body Mass Index

Figures & data

Table 1 Characteristics of the Study Participants Without and with Diabetic Peripheral Neuropathy*

Characteristics	Total	Without DPN	With DPN	P value*
No. of participants	523	120	403
Age, year	59.3 (10.7)	56.2 (11.0)	60.2 (10.4)	<0.001
Male, No. (%)	274 (52.4)	69 (57.5)	205 (50.9)	0.202
BMI, kg/m^2	24.1 (3.8)	24.1 (4.4)	24.1 (3.6)	0.915
Current smoker, No. (%)	67 (13.6)	13 (11.4)	54 (14.3)	0.432
Blood pressure, mmHg
Systolic BP at baseline	134.7 (19.0)	131.4 (17.7)	135.8 (19.2)	0.029
Diastolic BP at baseline	83.2 (11.5)	82.8 (10.9)	83.3 (11.7)	0.694
NRF2 polymorphisms				0.090
CC	228 (43.6)	46 (38.3)	182 (45.2)
AC	246 (47.0)	57 (47.5)	189 (46.9)
AA	49 (9.4)	17 (14.2)	32 (7.9)
Laboratory results
Fasting glucose, mmol/L	8.4 (4.3)	7.4 (3.6)	8.5 (4.4)	0.010
HbA1c (%)	8.6 (2.3)	8.3 (2.3)	8.7 (2.4)	0.091
Total cholesterol, mmol/L	4.3 (1.2)	4.2 (1.4)	4.4 (1.1)	0.083
Triglycerides, mmol/L	1.6 (1.5)	1.6 (1.7)	1.5 (1.4)	0.494
LDL-C, mmol/L	2.6 (0.9)	2.5 (0.8)	2.7 (0.9)	0.039
HDL-C, mmol/L	1.3 (4.7)	1.2 (0.5)	1.4 (5.3)	0.663
Serum albumin, g/L	39.9 (7.2)	42.1 (7.5)	39.3 (7.0)	<0.001

Note: *Continuous variables are presented as mean (standard deviation), categorical variables are presented as numbers (percentages).

Abbreviations: DPN, diabetic peripheral neuropathy; BP, blood pressure; BMI, body mass index; LDL-C, low-density lipoprotein cholesterol; HDL-C, high-density lipoprotein cholesterol.

Table 2 Characteristics of the Study Participants Stratified by Quintiles of Serum Albumin*

Characteristics	Q1	Q2	Q3	Q4	P value*
No. of participants	128	133	131	131
Age, year	59.6 (10.7)	62.6 (9.9)	58.6 (10.5)	57.0 (11.1)	<0.001
Male, No. (%)	71 (50.4)	70 (50.7)	76 (48.7)	88 (60.3)	0.181
BMI, kg/m^2	23.9 (3.1)	23.5 (4.8)	24.7 (4.1)	24.6 (3.7)	0.134
Current smoker, No. (%)	23 (17.4)	11 (8.1)	16 (11.0)	12 (16.1)	0.081
NRF2 polymorphisms
CC	66 (46.8)	51 (37.0)	71 (45.5)	66 (45.2)	0.560
AC	63 (44.7)	76 (55.1)	69 (44.2)	66 (45.2)
AA	12 (8.5)	11 (8.0)	16 (10.3)	14 (9.6)
Blood pressure, mmHg
Systolic BP at baseline	134.6 (22.2)	135.2 (19.1)	134.6 (18.9)	135.7 (15.9)	0.962
Diastolic BP at baseline	81.2 (13.9)	82.9 (11.0)	82.6 (10.7)	85.1 (11.8)	0.052
Laboratory results
Fasting glucose, mmol/L	9.6 (5.9)	8.5 (3.5)	8.0 (4.0)	7.4 (3.2)	<0.001
HbA1c (%)	9.5 (3.0)	8.8 (2.3)	8.5 (2.3)	7.9 (1.8)	<0.001
Total cholesterol, mmol/L	3.9 (1.1)	4.2 (0.9)	4.5 (1.4)	4.7 (1.4)	<0.001
Triglycerides, mmol/L	1.3 (0.8)	1.4 (1.2)	2.2 (4.1)	1.6 (1.2)	0.009
LDL-C, mmol/L	2.4 (1.0)	2.5 (0.8)	2.5 (0.9)	2.8 (1.0)	<0.001
HDL-C, mmol/L	1.0 (0.4)	1.1 (0.4)	1.2 (0.4)	1.9 (8.8)	0.298
Serum albumin, g/L	31.2 (6.2)	38.3 (1.0)	41.6 (1.0)	47.3 (5.8)	<0.001

Note: *Continuous variables are presented as mean (standard deviation), categorical variables are presented as numbers (percentages).

Abbreviations: BP, blood pressure; BMI, body mass index; LDL-C, low-density lipoprotein cholesterol; HDL-C, high-density lipoprotein cholesterol.

Table 3 Association of Serum Albumin Levels and Diabetic Peripheral Neuropathy

Albumin, g/L	No.	OR (95% CI)
		Unadjusted	Adjusted	P value*
Continuous	523	0.94 (0.91, 0.97)	0.95 (0.92, 0.98)	<0.001
Quartiles
Q1 (<36.9)	128	1.00	1.00
Q2 (36.9–40.4)	133	0.65 (0.34, 1.24)	0.61 (0.31, 1.17)	0.137
Q3 (40.4–43.5)	131	0.48 (0.26, 0.89)	0.53 (0.28, 1.00)	0.051
Q4 (≥43.5)	131	0.43 (0.23, 0.79)	0.49 (0.25, 0.95)	0.035
P for trend		0.004	0.036
Clinical cutoff
<35	87	1.00	1.00
≥35	436	0.34 (0.16, 0.70)	0.36 (0.17, 0.74)	0.006

Note: *Adjusted for age, sex, body mass index, fasting plasma glucose, glycated hemoglobin, total cholesterol, as well as low-density lipoprotein cholesterol.

Figure 1 Association between serum albumin levels with diabetic peripheral neuropathy in patients with type 2 diabetes mellitus*.

Note: *Adjusted for age, sex, body mass index, fasting plasma glucose, glycated hemoglobin, total cholesterol, as well as low-density lipoprotein cholesterol.

Figure 2 Association between serum albumin and diabetic peripheral neuropathy in various subgroups*.

Note: *Adjusted for age, sex, body mass index, fasting plasma glucose, glycated hemoglobin, total cholesterol, as well as low-density lipoprotein cholesterol, if not stratified.