Abstracts

A recent study of semen quality in men with epilepsy on long-term VPA or CBZ treatment, showed that both treatment groups differed from the controls regarding sperm motility, and sperm neck and head abnormalities. Men on VPA also had significantly more sperm tail abnormalities than the controls. Carnitin levels have been found to be lower in patients taking valproate. Both human and animal studies have pointed out carnitin as a marker of epididymal function, and the Sertoli cells has been considered a possible target for a widespread metabolic action of carnitin. We wanted to investigate whether carnitin deficiency is measurable in these otherwise healthy men on long-term VPA or CBZ treatment, and to compare the results with the previous semen findings in the same patients. Men with epilepsy, 20-40 years old, having used either VPA (n=16) or CBZ (n=19) for [gt] 2 years were included and compared with 38 closely age-matched controls. Total and free carnitin were analyzed by an enzymatic method. In principle, carnitin and tritiated acetyl-CoA are converted CoASH and [³H] acetylcarnitin which is separated and measured in a scintillation counter. The ratio of free carnitin/total carnitin was significantly lower in the men on long-term VPA treatment compared to controls (ratio: 0.8 vs. 0.9; p[lt] 0.001), as opposed to the CBZ treated (ratio 0.9). A comparison of the two treatment groups also showed significantly lower levels of free carnitin/total carnitin ratio in the VPA treated patients than in the CBZ treated (ratio: 0.8 vs. 0.9; p[lt] 0.001). Reduced ratio of free carnitin/total carnitin were found in the VPA treated men. CBZ treated men, however, did not differ from healthy controls. As carnitin has been found to be of importance for sperm motility, the reduced ratio may be related to our findings in VPA treated men. These findings may have implications for fertility in men.