Male age and sperm necrosis in assisted reproductive technologies.
BACKGROUND
Sperm apoptosis is well characterized but studies on the effect of male age and necrozoospermia are lacking. The objectives were: (a) to analyze percentages of apoptotic and necrotic sperm in ejaculates, and (b) to compare the results between younger and older age groups.


METHODS
Routine semen analyses were carried out (n = 189 males) and sperm cells were analyzed by dual fluorescence assay Hoechst 33342 and propidium iodide, and the acridine orange test.


RESULTS
The percentage of necrotic sperm in the ejaculate increased by 22% for males aged over 35. There was a positive correlation between age and necrosis (R = 0.30). Sperm apoptosis increased by 17% in males aged 45 and older. The population of DNA intact sperm declined in males aged 40 and over (R = -0.21). There were no age-related changes in strict normal morphology, sperm concentration and semen volume. A decrease in rapid progressive motility was correlated (R = -0.24) with male age and was significant after age 35.


CONCLUSIONS
The study demonstrated increased necrosis, DNA damage and apoptosis while rapid progression and total motility declined with advancing age in the male beginning as early as age 35. The order of the observed changes was sequential, suggesting the involvement of different pathways in sperm necrosis after age 40.
Siddighi
Sam
S
Department of Gynecology and Obstetrics, Loma Linda University School of Medicine, Loma Linda, Calif, USA.
Chan
Christopher A
CA
Patton
William C
WC
Jacobson
John D
JD
Chan
Philip J
PJ
D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D000375:Aging / Q000473:pathology*; D017209:Apoptosis; D004249:DNA Damage; D006801:Humans; D008297:Male; D008856:Microscopy, Fluorescence; D008875:Middle Aged; D009336:Necrosis; D027724:Reproductive Techniques, Assisted; D013076:Sperm Count; D013081:Sperm Motility; D013094:Spermatozoa / Q000473:pathology*; D013194:Staining and Labeling