Effect of smoking on uric acid and other metabolic markers throughout normal pregnancy.

OBJECTIVES

Smoking, pregnancy, and preeclampsia are all associated with changes in markers of the metabolic syndrome. Several markers are increased in all three conditions. However, smoking is negatively associated with preeclampsia, and therefore some markers would be expected to behave differently in smokers during pregnancy. We compared several metabolic markers of the metabolic syndrome in healthy primigravid smokers and nonsmokers over normal pregnancy to explore mechanisms for the reduced risk of preeclampsia in smokers.

STUDY DESIGN

Plasma was obtained from 63 women throughout pregnancy who delivered at term. Smoking status was determined by urinary cotinine concentrations measured by HPLC. Uric acid, creatinine, free fatty acids, triglycerides, and total cholesterol were measured with diagnostic kits. Data were analyzed by repeated-measures ANOVA.

RESULTS

The smoking groups were not different by delivery gestational age, maternal age, body mass index, or race. Uric acid, cholesterol, and triglyceride concentrations increased during pregnancy (significant for time, P < 0.0001). Mean uric acid and creatinine concentrations were different by smoking status (P < 0.001 and P = 0.046). Nonsmokers had the lowest concentrations of uric acid, and women who quit smoking had the highest concentrations. Uric acid concentrations remained significantly different controlling for serum creatinine

CONCLUSIONS

Women have changes in markers of the metabolic syndrome during pregnancy, and uric acid is further influenced by smoking. The difference in uric acid concentrations by smoking status may be secondary to increased production through the xanthine oxidase pathway but is not simply a result of altered glomerular function because the association persists after controlling for creatinine.