Purine metabolism state in patients with type 1 diabetes mellitus

Abstract

The aim of the study. To carry out a comprehensive analysis of the purine metabolism (PM) state and assess its features in patients with type 1 diabetes mellitus (DM). Materials and methods. 181 patients with type 1 DM were examined (94 women and 87 men) aged 42.5 ± 12.1 years. Indicators of the carbohydrate metabolism state, creatinine (Cr) concentration by the method of Popper, purine bases (PBs) and the activity of xanthine oxidase (XO) by a photometric method, uric acid (UA) by a colorimetric method were determined in fasting venous blood. UA excretion was detected by the colorimetric method, Cr by an enzymatic method. Renal UA clearance (RCUA), fractional UA clearance (FCUA), total UA tubular reabsorption (TTRUA) and hypoxanthine-guanine-phosphoribosyltransferase (HGPRT) activity were calculated. The comparison group, representative in terms of age and sex, included 25 healthy volunteers. Results. PM changes in patients with type 1 DM were orientated towards an excessively increased catabolism and insufficient reutilization of PBs. The structure of the detected disorders was as follows: hyperuricemia (HU) (13.8 %), enhanced RCUA (42.8 %), increased XO activity (35.6 %) and inhibition of HGPRT activity (53.3 %). In about 56 % of the subjects, high concentrations of PBs were found, and HU was diagnosed only in every seventh subject. It was identified that PB concentrations were negatively correlated with the level of XO activity. RCUA and XO activity levels were revealed to be of the greatest informational value for assessing the PM state in patients with type 1 DM. RCUA was significantly associated with the level of UA excretion and HGPRT activity. Relationships of RCUA and FCUA with HbAc1 levels were established. The higher the level of HbAc1, the greater the clearance of RCUA was, especially FCUA, which led to a significant decrease in TTRUA. Conclusions. PM in type 1 DM is characterized by a high intensity, which is realized due to a decrease in anabolism, increased oxidation and suppression of PB reutilization. Uricemia inadequately reflects the level of UA production in patients with type 1 DM. The severity of PM disorders in type 1 DM patients is associated with the carbohydrate metabolism compensation state.

Keywords

• type 1 diabetes mellitus
• purine metabolism
• purine bases
• xanthine oxidase
• hypoxanthineguanine phosphoribosyltransferase