Association Between Uric Acid and Insulin-Like Growth Factor-1 in Type 2 Diabetes Mellitus

Figures & data

Table 1 Baseline Characteristics of Patients with Type 2 Diabetes Mellitus

Variables	All
Number	1230
Sex (male, n, %)	575 (46.75%)
Age (years)	54.18± 11.89
Duration of disease(years)	8.47 ± 6.90
Diabetes family history (n,%)	651 (52.93%)
BMI (kg/m^2)	26.16 ± 3.50
WHR	0.93 ± 0.26
TC (mmol/L)	4.45 ± 1.18
TG (mmol/L)	1.32 (0.95–1.80)
HDL-C (mmol/L)	1.11 ± 0.28
LDL-C (mmol/L)	2.82 ± 0.58
BUN (μmol/L)	5.73 ± 4.15
Cr (μmol/L)	57.82 ± 15.43
UA (mg/dl)	4.71 ± 1.36
IGF-1 (ng/mL)	158.76 ± 63.14
IGF-1 SDS	0.26 ± 1.42
FPG (mmol/L)	9.49 ± 4.03
HbA1c (%)	8.88 ± 1.91
HOMA-IR	2.37 (1.52–3.94)
Hypoglycaemic drugs
Sulfonylurea (n,%)	481 (39.11%)
Glinide (n,%)	81 (6.59%)
Biguanide (n,%)	571 (46.42%)
Thiazolidinedione (n,%)	40 (3.25%)
Alpha glucosidase inhibitor (n,%)	409 (33.25%)
DPP-4 inhibitors (n,%)	93 (7.56%)
SGTL2 inhibitors (n,%)	3 (0.24%)
Insulin (n,%)	408 (33.17%)

Note: Data was presented as mean ± standard deviation, median (interquartile range) and number (percentage).

Abbreviations: BMI, body mass index; WHR, waist-to-hip ratio; IGF-1, insulin-like growth factor-1; IGF-1 SDS, insulin-like growth factor-1 standard deviation score; TC, total cholesterol; TG, triglyceride; HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol; BUN, blood urea nitrogen; Cr, creatinine; UA, uric acid; FPG, fasting plasma glucose; HbA1c, glycated hemoglobin; HOMA-IR, homeostasis model assessment for insulin resistance.

Table 2 Univariate Analysis of Factors Affecting IGF-1 SDS

Covariate	β (95% CI)	P-value
UA (mg/dl)	0.01 (−0.02, 0.03)	<0.001
Sex
Male	Reference
Female	0.42 (−0.37, 1.21)	0.294
Age (years)	−0.04 (−0.07, −0.01)	0.031
Duration of disease(years)	−1.6 (−2.3, −1.0)	<0.001
Diabetes family history
Yes	Reference
No	−0.68 (−1.47, 0.10)	0.089
BMI (kg/m^2)	0.08 (−0.03, 0.19)	0.147
WHR	−0.01 (−1.54, 1.52)	0.991
TC (mmol/L)	−0.01 (−0.09, 0.07)	0.867
TG (mmol/L)	−0.03 (−0.07, 0.01)	0.086
HDL-C (mmol/L)	0.10 (0.06, 0.14)	<0.001
LDL-C (mmol/L)	−0.01 (−0.07, 0.05)	0.822
BUN (μmol/L)	0.05 (−0.04, 0.15)	0.286
Cr (μmol/L)	0.01 (−0.02, 0.03)	0.551
FBG (mmol/L)	0.37 (0.27, 0.46)	<0.001
HbA1c (%)	−0.08 (−0.13, −0.02)	<0.001
HOMA-IR	−0.13 (−0.19, −0.07)	<0.001

Note: Significant results (P <0.05) are indicated in bold.

Abbreviations: CI, confidence interval; BMI, body mass index; WHR, waist-to-hip ratio; IGF-1, insulin-like growth factor-1; IGF-1 SDS, insulin-like growth factor-1 standard deviation score; TC, total cholesterol; TG, triglyceride; HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol; BUN, blood urea nitrogen; Cr, creatinine; UA, uric acid; FPG, fasting plasma glucose; HbA1c, glycated hemoglobin; HOMA-IR, homeostasis model assessment for insulin resistance.

Table 3 The Independent Association Between UA and IGF-1 SDS by Multivariate Piecewise Linear Regression

Inflection Point of UA(mg/dl)	Effect Size (β)	95% CI	P-value
<4.17	0.12	(−0.04, 0.28)	0.121
≥4.17	−0.38	(−0.64, −0.12)	0.004

Notes: Significant results (P <0.05) are indicated in bold. Adjusted: sex, age, duration of disease, BMI, TC, TG, HDL-C, LDL-C, Cr, FPG, HbA1c, HOMA-IR, hypoglycemic drugs.

Figure 1 The relationship between UA and IGF-1 SDS. A threshold, nonlinear association between UA and IGF-1 SDS was found in a generalized additive model (GAM). Solid red line represents the smooth curve fit between variables. Dotted line represents the 95% of confidence interval from the fit. All adjusted for sex, age, duration of disease, BMI, TC, TG, HDL-C, LDL-C, Cr, FPG, HbA1c, HOMA-IR, hypoglycemic drugs.