Participation rates in epidemiologic studies on semen quality are generally very low, raising concerns as to the potential for selection bias. Since hormones both initiate and maintain spermatogenesis, they may serve as surrogates of semen quality in epidemiologic studies. For this reason, in the present study, we explored the influence and predictive ability of reproductive and thyroid hormones on semen quality among men who were partners in an infertile couple. Between 1999 and 2003, 388 men were recruited from Massachusetts General Hospital Andrology Laboratory for clinical evaluation of fertility status. Fresh semen samples were assessed for quality (concentration, motility and morphology) and the serum levels of hormones, including follicle-stimulating hormone (FSH), luteinizing hormone (LH), inhibin B, sex hormone-binding globulin (SHBG), testosterone, free androgen index, free T4, total T3, and thyroid-stimulating hormone (TSH), were measured. Multiple logistic regression revealed increased odds for below-reference sperm concentration and morphology in men with increased FSH, and decreased odds for below-reference sperm concentration and motility in men with increased inhibin B. When FSH and inhibin B were divided into quintiles, the relationships with sperm concentration showed evidence of a threshold value. However, the ability of specific FSH (10 IU/L) and/or inhibin B (80 pg/mL) cutoff values to predict semen quality was lower than in previous reports. In multiple linear regression analysis, FSH and LH were inversely associated with sperm concentration, motility, and morphology. Inhibin B and free T4 were positively associated with sperm concentration, while there was a suggestive positive association between testosterone and sperm motility. In conclusion, we have found that FSH, LH, inhibin B, testosterone and free T4 levels are associated with human semen parameters. Additional consideration should be given to the utility of serum hormone levels as a surrogate for semen quality in epidemiologic studies in which the collection of semen is difficult due to logistical and/or volunteer rate constraints.
Phthalates are a group of multifunctional chemicals used in consumer and personal care products, plastics, and medical devices. Laboratory studies show that some phthalates are reproductive and developmental toxicants. Recently, human studies have shown measurable levels of several phthalates in most of the U.S. general population. Despite their widespread use and the consistent toxicologic data on phthalates, information is limited on sources and pathways of human exposure to phthalates. One potential source of exposure is medications. The need for site-specific dosage medications has led to the use of enteric coatings that allow the release of the active ingredients into the small intestine or in the colon. The enteric coatings generally consist of various polymers that contain plasticizers, including triethyl citrate, dibutyl sebacate, and phthalates such as diethyl phthalate (DEP) and dibutyl phthalate (DBP). In this article we report on medications as a potential source of exposure to DBP in a man who took Asacol [active ingredient mesalamine (mesalazine)] for the treatment of ulcerative colitis. In a spot urine sample from this man collected 3 months after he started taking Asacol, the concentration of monobutyl phthalate, a DBP metabolite, was 16,868 ng/mL (6,180 micro g/g creatinine). This concentration was more than two orders of magnitude higher than the 95th percentile for males reported in the 1999-2000 National Health and Nutrition Examination Survey (NHANES). The patient's urinary concentrations of monoethyl phthalate (443.7 ng/mL, 162.6 micro g/g creatinine), mono-2-ethylhexyl phthalate (3.0 ng/mL, 1.1 micro g/g creatinine), and monobenzyl phthalate (9.3 ng/mL, 3.4 micro g/g creatinine) were unremarkable compared with the NHANES 1999-2000 values. Before this report, the highest estimated human exposure to DBP was more than two orders of magnitude lower than the no observable adverse effect level from animal studies. Further research is necessary to determine the proportional contribution of medications, as well as personal care and consumer products, to a person's total phthalate burden.
Although semen quality has been discussed extensively with regard to age and season in the andrology literature, the results vary and firm conclusions are still outstanding. To investigate seasonal and age-related variations in human semen parameters, we analyzed data that were collected from an andrology clinic population. We performed a retrospective review of 551 semen analysis records collected from 1989 to 2000 from the Vincent Memorial Andrology Laboratory at Massachusetts General Hospital. Semen volume, sperm concentration, total sperm count, motility, total motile sperm, and morphology significantly decreased as age increased. In addition, as age increased, the percentage of sperm with tail defects increased. Sperm concentration was significantly higher in winter (mean 157.9 million /mL) than in fall (mean 119.1 million /mL) (P Ͻ .05). The mean percentage of sperm with normal morphology was significantly higher in winter (9.2%) than in summer and spring (7.0% and 7.5%, respectively; P Ͻ .05). The mean percentage of sperm with head defects was significantly higher in fall and summer (74.0% and 72.3%, respectively) than in winter (68.6%; P Ͻ .05). Seasonal variations were found in sperm concentration and morphology, with higher sperm concentrations in winter than in fall, and a greater percentage of sperm with normal morphology in winter than in spring and summer. Sperm concentration was lowest in the fall, whereas the percentage of sperm with normal morphology was lowest in summer. Semen volume, sperm concentration, total sperm count, motility, total motile sperm, and morphology decreased as age increased.
Background: To investigate the relationship of human semen parameters with season, age and smoking status.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.