Abstract: | The aim of this study was to investigate the association between smoking behavior and hypoxanthine guanine phosphoribosyltransferase (HGPRT) activity. A cross-sectional study was performed of 82 men, including 38 non-smokers and 44 smokers. Inosine monophosphate (IMP), the product of HGPRT (used as the index of activity), was measured in peripheral blood mononuclear cells using high-performance liquid chromatography. The factors potentially associated with HGPRT activity included age, glutamyl oxaloacetic transaminase, glutamyl pyruvic transaminase, cholesterol, uric acid, triglycerides, creatinine, body mass index, gout, systolic blood pressure, diastolic blood pressure, alcohol consumption, and cigarette smoking. Mean HGPRT activity was 7.05 ? 3.44 nmol/10<sup>6</sup> viable cells/hour for all participants, and was significantly lower for smokers than for non-smokers (6.24 ? 3.40 vs 7.98 ? 3.28 nmol/10<sup>6</sup> viable cells/hour; p = 0.02). In addition, as the number of smoked cigarettes increased, the HGPRT activity decreased (p < 0.05). The age at onset of cigarette smoking showed a positive correlation with HGPRT activity after adjusting for smoking duration, serum uric acid, and cigarettes smoked per year using a multiple regression model (p < 0.001). We concluded that the greater the number of cigarettes smoked, the lower the HGPRT activity, and that HGPRT activity was higher in smokers who had started smoking later. |