Association between xanthinoxidase activity andparameters of glucose homeostasis in patients with type 2 diabetes mellitus

Abstract

Background. The purpose of the study is to determine the associations between clinical and anthropometric parameters, glucose homeostasis and serum xanthinoxidase (XO) activity in patients with type 2 diabetes mellitus (T2DM) taking into account gender, glycemic control and serum XO activity. Materials and methods. One hundred and twenty-five T2DM patients aged 34 to 81 years were examined, with an average age of 58.9±9.4 years, disease duration from 1 month to 29 years (average of 8.9±6.6 years). The age of patients at the time of the disease manifestation in the general sample was from 29 to 71 years, on average 50.6±9.1 years. Results. The authors have found a nonlinear dependence of serum XO activity on fasting insulin concentration in patients with T2DM in the total sample, described by the multiplicative model (r=0.45; p=0.001). Serum XO activity in patients with T2DM in the general sample increases with adaptive increase in secretory activity of β-cells on an empty stomach according to the HOMA_β%. Serum ХO activity was highest in T2DM patients with low fasting insulin sensitivity (HOMA_S% < 50%). In addition, it has been determined that the serum ХО activity in the subjects is nonlinearly associated with the QUICKI (r=–0.35; p=0.016) and Caro indices (r=–0.40; p=0.007). We have found a nonlinear dependence of serum XO activity on fasting insulin (r=0.50; p=0.08), HOMA_β% (r=–0.53; p=0.06), HOMA_S% (r=–0.48; p=0.09), HOMA-IR (r=–0.48; p=0.09) in men with optimal glycemic control (HbA1c < 7.5%) at the trend level and Caro (r=–0.64; p=0.02). In women of this group, there was a nonlinear dependence of serum XO activity on fasting insulin (r=0.56; p=0.004), HOMA_β% (r=0.56; p=0.003), HOMA_S% (r=–0.54; p=0.005), HOMA-IR (r=0.54; p=0.005), QUICKI (r=–0.50; p=0.01) and Caro (r=–0.61; p=0.003). Conclusions. In patients with T2DM, the serum uric acid is linearly associated with the level of serum XO activity, which determines 34% of its variability. In patients with T2DM, regardless of the state of glycemic control, serum XO activity is nonlinearly associated with parameters characterizing the state of glucose homeostasis (fasting insulin, HOMA_S%, HOMA_β%, QUICKI and Caro indices). Predictors of high serum XO activity in patients with T2DM are the level of postprandial blood glucose (t=–3.53; p=0.004) and serum uric acid (t=4.73; p=0.0005).