Carnitine for the treatment of idiopathic asthenospermia: a randomized, double-blind, placebo-controlled trial.

OBJECTIVE: To determine the effect of oral carnitine supplementation on the semen parameters of men with idiopathic asthenospermia. DESIGN: Prospective, randomized, double-blind placebo-controlled study. SETTING: Academic tertiary referral centers. PATIENT(S): Male patients presenting with infertility and with sperm motility of 10%-50% were selected. INTERVENTION(S): Patients were randomized to 24-week treatment arms of oral carnitine (2,000 mg L-carnitine and 1,000 mg L-acetyl-carnitine per day) or placebo. MAIN OUTCOME MEASURE(S): Sperm motility and total motile sperm counts at baseline, 12 weeks, and 24 weeks. Seminal plasma and sperm free, acetyl, and total L-carnitine levels at baseline and at week 24. RESULT(S): Twenty-one patients entered the study, with 12 patients in the carnitine arm and 9 in the placebo arm. There were no significant differences in baseline semen parameters between the carnitine and placebo arms. There was no statistically significant or clinically significant increase in motility or total motile sperm counts between baseline, 12 week, or 24 weeks in the carnitine or placebo arms. CONCLUSION(S): Carnitine supplementation demonstrated no clinically or statistically significant effect on sperm motility or total motile sperm counts in men with idiopathic asthenospermia.

The diagnosis of azoospermia depends on the force of centrifugation.

OBJECTIVE: To determine the centrifugal force required to pellet sperm. DESIGN: Prospective, in vitro study. SETTING: Tertiary referral center. PATIENT(S): Men undergoing semen processing or postvasectomy semen analyses. INTERVENTION(S): In Phase I, postvasectomy semen samples were centrifuged at 600 x g, and the pellets were examined. Supernatants from samples with no visible sperm underwent repeat centrifugation at 1,000 x g; the supernatants were removed and centrifuged at 3,000 x g. Pellets from both centrifugations were examined. Phase II examined nonazoospermic semen that was divided into 3 aliquots and centrifuged at 500, 1,000, and 3,000 x g. The supernatants were examined for the presence of sperm. MAIN OUTCOME MEASURE(S): Sperm presence in centrifuged pellets or seminal supernatant. RESULT(S): Phase I: After centrifugation at 1,000 x g and 3,000 x g, sperm were noted in 12% and 0% of samples, respectively. Phase II: Sperm were noted in the supernatant in 100% of samples subjected to 500 x g and 1,000 x g, and in 92% of samples subjected to 3,000 x g centrifugation. CONCLUSION(S): If sperm are in the seminal plasma, they will also be present in the pellet following centrifugation at a force of 1,000 x g or greater. Semen samples that appear azoospermic upon initial wet mount microscopy should be centrifuged at a minimum of 1,000 x g for 15 minutes.