Lack of isoprene overproduction during peritoneal dialysis.

OBJECTIVE Isoprene is the constitutive unit of isoprenoid lipids and sterols. However, it is also a potential toxic and carcinogenic agent. Recent findings of a marked and prolonged isoprene overproduction induced by hemodialysis sessions raises the question of isoprene behavior in patients on peritoneal dialysis. DESIGN A study with repeated measures per patient and healthy control. SETTING Nephrology and Dialysis Unit and Perugia University Medical School. PATIENTS Sixteen consecutive patients on regular continuous ambulatory peritoneal dialysis (CAPD) were evaluated. Endogenous isoprene was analyzed using gas chromatographic assay of breath isoprene, collected at set times before and after dialysis fluid exchange. RESULTS No significant variations were found in breath isoprene concentrations in the different samples from each patient, and levels were almost stable within the normal range of healthy controls. CONCLUSION These results show that CAPD, unlike hemodialysis, has little or no effect on isoprene and isoprenoid-related lipid turnover. This lack of increased endogenous isoprene synthesis, in addition to being a distinctive metabolic feature of CAPD, could have important pathophysiological and clinical implications.