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Body mass index (BMI) has been demonstrated to affect female fertility; however, little information is available on the impact of BMI on male fertility or semen parameters. Therefore, the study objective was to determine the relationship between BMI and semen parameters, including sperm chromatin integrity. We analyzed data on semen samples from 520 men who were grouped based upon calculated BMI values (normal, 20-24 kg/m(2); overweight, 25-30 kg/m(2); obese, >30 kg/m(2)). The data collected included patient height and weight, semen volume, sperm concentration, percent sperm motility, percent sperm morphology (normal forms), and sperm chromatin integrity (DNA fragmentation index [DFI]). Data were analyzed by regression analysis and analysis of variance (ANOVA) with Tukey's test for multiple pairwise comparisons. The overall BMI mean (+/-SEM) was 27.5 (+/-0.49) kg/m(2). Linear regression revealed a significant (P < .05) and negative relationship between BMI and the total number of normal-motile sperm cells. ANOVA revealed a significant difference (P < .05) in the total number of normal-motile sperm cells among the different BMI groups. The number of normal-motile sperm cells per BMI group was as follows: normal, 18.6 x 10(6); overweight, 3.6 x 10(6); and obese, (0.7) x 10(6). All multiple pairwise comparisons were found to be significantly (P < .05) different. The overall DFI mean (+/-SEM) was 24.7 (+/-2.57). Linear regression revealed a significant (P < .05) and positive relation between BMI and DFI. Men presenting with a BMI greater than 25 kg/m(2) have fewer chromatin-intact normal-motile sperm cells per ejaculate. Therefore, to ensure maximum fertility potential, patients may be advised to reduce body weight.

Objective: To determine the relationship between platelet-activating factor acetylhydrolase (PAFah) content in semen and sperm motility., Design: The PAFah levels in semen were measured and correlated with sperm motility., Setting: Clinical laboratory in a private assistant reproductive technology clinic., Patient(s): Three hundred and twelve men seeking diagnosis and treatment of infertility., Intervention(s): Semen samples were collected from 312 healthy mature men seeking infertility treatment. Sperm motility and PAFah activity were measured in seminal plasma. Data was analyzed by Student's t test and regression analysis., Main Outcome Measure(s): PAFah activity and sperm motility., Result(s): Seminal PAFah content ranged from a low of 179 IU/L to a high of 2,457 IU/L. The overall mean PAFah content in semen was 780.59 IU/L. Linear regression analysis revealed a significant (R2 = 0.655) and negative relationship between PAFah content in semen and sperm motility. Semen specimens with high percent motility (> or = 50%) had significantly lower PAFah concentrations (442.03 +/- 14.37 IU/L) than those with the lower percent sperm motility (< 50%) (882.16 +/- 18.45 IU/L)., Conclusion(s): The data confirm the presence of PAFah in human semen and that activity is significantly and negatively correlated with sperm motility. The PAFah is proven to be a candidate for sperm decapacitation factors, whereas PAF is qualified to be a candidate for sperm capacitation factors.

Since its discovery nearly 30 years ago platelet-activating factor (PAF) has emerged as one of the more important lipid mediators known. PAF (1-O-alkyl-2-O-acetyl-sn-glycero-3-phosphorylcholine) exists endogenously as a mixture of molecular species with structural variants of the alkyl moiety. PAF is a novel potent signaling phospholipid that has unique pleiotropic biological properties in addition to platelet activation. PAF also plays a significant role in reproduction and is present in the sperm of a number of primate species. PAF content in squirrel monkey sperm is significantly higher during the breeding season than the non-breeding season. PAF content in rhesus sperm has a significant relationship with sperm motility. PAF content in human sperm has a positive correlation with seminal parameters and pregnancy outcomes. The enzymes (lyso-PAF-acetyltransferase and PAF-acetylhydrolase) necessary for PAF activation and deactivation are present in primate sperm. PAF-acetylhydrolase may act as a "decapacitation factor". Removal of this enzyme during capacitation promotes PAF synthesis increasing primate motility and fertilization. PAF also plays a significant role in the fertilization process, enhancing the fertilization rates of oocytes. Enhanced embryo development has also been reported in oocytes fertilized with PAF-treated sperm. Exogenous PAF will also significantly improve primate artificial insemination pregnancy outcomes. PAF antagonists inhibit sperm motility, acrosome reaction, and fertilization thus suggesting the presence of receptors for PAF. The PAF-receptor is present on primate sperm, with altered transcript levels and distribution patterns on abnormal cells. Whereas, the exact mechanism of PAF in sperm function and reproduction is uncertain, its importance in normal primate fertility is substantial.

Introduction: Previous studies have demonstrated the presence of ribonucleic acid (RNA) in mature, ejaculated sperm and that sperm with poor motility have significantly more RNA than good motility sperm. However, no studies have investigated the relationship between RNA content and sperm morphology. Therefore, the study objective was to determine the relationship between total RNA content and sperm morphology. Methods: Sperm samples were separated by density centrifugation (Promotor, CERES Fertility, San Diego, CA) into morphologically normal and abnormal populations. Sperm morphology scores were determined by strict criteria. Total RNA was extracted from sperm via the Roche (Indianapolis, IN, USA) RNA isolation kit. Total RNA (μg of RNA per million sperm cells) recovered per sperm population from each ejaculate was determined by spectrophotometer and calculated as follows: (absorbance at 260 nm)×(conversion factor)×(dilution factor). The conversion factor for RNA is 0.04 μg/μl per optical density unit at 260 nm. Total RNA purity was calculated as the absorbance at 260 nm divided by the absorbance at 280 nm. Data were analyzed by Student''s t-test. Results: A total of 179 semen specimens from different men underwent RNA extraction and analysis as described. All samples had absorbance readings between 0.1 and 1.0 at 260 nm and were determined to be accurate. Total RNA purity estimates for all samples were within the acceptable ratio of 1.7 and 1.9. RNA content in morphologically normal sperm (2.83±0.14 μg/106 cells) was significantly higher (P<0.05) than the amount found in morphologically abnormal sperm (2.26±0.23 μg/106 cells). Conclusions: Ribonucleic acid content is significantly lower in morphologically abnormal sperm. Morphologically abnormal sperm may have impaired transcriptional and, or translational pathways thus negatively impacting cell function. [Copyright &y& Elsevier]