Effect of stilboestrol on levels of uric acid in plasma and urine

Abstract

It is well known that plasma levels of urate in adult women under the age of the menopause are about 1.0 mg./100 ml. lower than those of men. Renal clearance of urate tends to be higher in women than in men. It is possible that this sex difference is mediated by hormonal influences and the present study examines the effect of long term administration of stilboestrol on plasma and urinary urate. The study was carried out on 22 adult trans sexual men who were to undergo psychotherapy and hormone therapy. Basal 24 hour urate and creatinine clearances were estimated with the subjects taking a low purine diet, after which treatment was started with stilboestrol in a daily dose of 10 to 30 mg. After treatment had continued for a mean of 10 weeks, the subjects again took a low purine diet and clearances were repeated. Plasma urate fell in fifteen of the 22 subjects, the mean overall fall being 0.7 mg./100 ml., a significant decrease (P < 0.01). Urinary urate rose in seventeen of twenty subjects, the mean rise being 115 mg./24 hrs, again significant (P < 0.01). Mean urate clearance rose correspondingly while the hormone was being taken, creatinine clearance remaining unchanged. The results show clearly that stilboestrol enhances the excretion of urate and lowers the plasma level. It is suggested that such a hormonal factor is the cause of the difference in plasma urate levels found between the sexes.