Association of serum uric acid with 2-hour postload glucose in Chinese with impaired fasting plasma glucose and/or HbA1c

Abstract

Objective: To examine whether serum uric acid (SUA) is associated with 2-hour postload glucose (2-h PG) in Chinese with impaired fasting plasma glucose (IFG) and/or HbA1c (IA1C).

Research design and methods: Anthropometric and biochemical examinations, such as SUA concentration, were performed in 3763 individuals from all the villages in Baqiao County, China. A 75-g oral glucose tolerance test (OGTT) was conducted in 1197 Chinese with prediabetes as having IFG (110 ≤ fasting plasma glucose [FPG] <126 mg/dl and HbA1c <6.5%), IA1C (5.7% ≤ HbA1c <6.5% and FPG <126 mg/dl), or both.

Results: The present study included 1197 participants with IFG and/or IA1C (mean age 56.5 ± 10.3 years; 50.6% men). In multivariate linear regression, after adjustment for gender, age, smoking and drinking, body mass index (BMI), systolic and diastolic blood pressure (SBP, DBP), lipid profiles, logarithmic transformed C-reactive protein (log-CRP), estimated glomerular filtration rate (e-GFR), FPG and HbA1c, with a 1-mg/dl increment of SUA, 2-h PG increased by 5.04 ± 0.72 (P<0.001), 3.06 ± 1.08 (P = 0.001), 5.40 ± 1.26 (P<0.001), and 2.34 ± 2.16 mg/dl (P = 0.056) in all participants, in participants with normal glucose tolerance (NGT), with impaired glucose tolerance (IGT), and with 2-h newly diagnosed diabetes (2-h NDM, with 2-h PG ≥ 200 mg/dl), respectively. In both men and women, 2-h PG increased progressively and significantly from the lower to the upper SUA tertiles (P<0.001). Moreover, in multivariate logistic regression, 1-standard deviation (SD; 1.53 mg/dl) increment of SUA was significantly associated with a 36% higher risk for 2-h NDM (Odds ratio [CI 95%]: 1.36 [1.09-1.99]; P = 0.03).

Conclusions: SUA is significantly associated with 2-h PG in Chinese with IFG and/or IA1C.

Figure 1. 2-h PG levels across the gender-specific tertiles of SUA in men (▪) and women (▴).

Mean 2-h PG levels across gender-specific tertiles of SUA resulting from a general linear model were present, with adjustment for age, smoking and drinking, BMI, SBP, DBP, total cholesterol, HDL and LDL, triglycerides, log-CRP, FPG, HbA1c and e-GFR. Vertical lines denoted standard error (SE). Reference values of 2-h PG were111.78 mg/dl in men and 125.10 mg/dl in women. 2-h PG, 2 hour postload glucose; SUA, serum uric acid; BMI, body mass index; SBP, systolic blood pressure; DBP, diastolic blood pressure; HDL, high density lipoprotein; LDL, low density lipoprotein; log-CRP, logarithmic transformed C-reactive protein; FPG, fasting plasma glucose; e-GFR, estimated glomerular filtration rate. International system of units (SI) conversion: plasma glucose 1 mg/dl = 1/18 mmol/l; SUA 1 mg/dl = 59.5 µmol/l.

Figure 2. Relation between SUA and log-CRP and insulin sensitivity.

Insulin sensitivity was calculated by Matsuda index. SUA, serum uric acid; log-CRP, logarithmic transformed C-reactive protein. International system of units (SI) conversion: plasma glucose 1 mg/dl = 1/18 mmol/l; SUA 1 mg/dl = 59.5 µmol/l.