Semen quality, infertility and mortality in the USA

STUDY QUESTION

What is the relationship between semen parameters and mortality in men evaluated for infertility?

SUMMARY ANSWER

Among men undergoing an infertility evaluation, those with abnormal semen parameters have a higher risk of death, suggesting a possible common etiology between infertility and mortality.

WHAT IS KNOWN ALREADY

Conflicting data exist that suggest either an inverse relationship or no relationship between semen quality and mortality.

STUDY DESIGN, SIZE, DURATION

A study cohort was identified from two centers, each specializing in infertility care. In California, we identified men with data from 1994 to 2011 in the Stanford Reproductive Endocrinology and Infertility semen database. In Texas, we identified men with data from 1989 to 2009 contained in the andrology database at the Baylor College of Medicine Special Procedures Laboratory who were evaluated for infertility. Mortality was determined by data linkage to the National Death Index or Social Security Death Index. Comorbidity was estimated based on calculation of the Charlson Comorbidity Index or Centers for Medicare & Medicaid Services-Hierarchical Condition Categories Model.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In all, 11,935 men were evaluated for infertility from 1989 to 2011. During 92 104 person years of follow-up, 69 of 11,935 men died (0.58%). The mean age at infertility evaluation was 36.6 years with a mean follow-up of 7.7 years.

MAIN RESULTS AND THE ROLE OF CHANCE

Compared with the general population, men evaluated for infertility had a lower risk of death with 69 deaths observed compared with 176.7 expected (Standardized mortality rate 0.39, 95% CI 0.30-0.49). When stratified by semen parameters, however, men with impaired semen parameters (i.e. male factor infertility) had significantly higher mortality rates compared with men with normal parameters (i.e. no male factor infertility). Low semen volume, sperm concentration, sperm motility, total sperm count and total motile sperm count were all associated with higher risk of death. In contrast, abnormal sperm morphology was not associated with mortality. While adjusting for current health status attenuated the association between semen parameters and mortality, men with two or more abnormal semen parameters still had a 2.3-fold higher risk of death compared with men with normal semen (95% CI 1.12-4.65).

LIMITATIONS, REASONS FOR CAUTION

Our cohort represents infertile men, which may limit generalizability. As comorbidity relied on administrative data, granular information on each man regarding infertility diagnosis and lifestyle factors was unavailable.

WIDER IMPLICATIONS OF THE FINDINGS

Men with impaired semen parameters have an increased mortality rate in the years following an infertility evaluation suggesting semen quality may provide a marker of health.

STUDY FUNDING/COMPETING INTEREST(S)

This study is supported in part by P01HD36289 from the Eunice Kennedy Shriver National Institute for Child Health and Human Development, National Institutes of Health (to D.J.L. and L.I.L.). The project was also partially supported by an NIH CTSA award number UL1 RR025744. None of the authors has any conflict of interest to declare.

Good semen quality and life expectancy: a cohort study of 43,277 men

Fertility status may predict later mortality, but no studies have examined the effect of semen quality on subsequent mortality. Men referred to the Copenhagen Sperm Analysis Laboratory by general practitioners and urologists from 1963 to 2001 were, through a unique personal identification number, linked to the Danish central registers that hold information on all cases of cancer, causes of death, and number of children in the Danish population. The men were followed until December 31, 2001, death, or censoring, whichever occurred first, and the total mortality and cause-specific mortality of the cohort were compared with those of all age-standardized Danish men or according to semen characteristics. Among 43,277 men without azospermia referred for infertility problems, mortality decreased as the sperm concentration increased up to a threshold of 40 million/mL. As the percentages of motile and morphologically normal spermatozoa and semen volume increased, mortality decreased in a dose-response manner (P(trend) < 0.05). The decrease in mortality among men with good semen quality was due to a decrease in a wide range of diseases and was found among men both with and without children; therefore, the decrease in mortality could not be attributed solely to lifestyle and/or social factors. Semen quality may therefore be a fundamental biomarker of overall male health.

PROGNOSTIC PARAMETERS IN ADULT IMPALPABLE ULTRASONOGRAPHIC LESIONS OF THE TESTICLE

PURPOSE

Through an analysis of individual published data we assessed whether prognostic criteria exist for adult impalpable testicular sonographic lesions.

MATERIALS AND METHODS

We performed a bibliographic search on PubMed, MEDLINE, EMBASE online databases from 1990 to May 2004 using search words such as sonographic lesions of the testicle, impalpable tumors of the testicle and impalpable testicular lesions. Six articles were found that presented a description of the histological characteristics, patient age, lesion dimensions, presence of cryptorchidism and association with tumors in other parts of the body. A multivariate analysis was performed comparing the characteristics that appeared more interesting from a univariate analysis.

RESULTS

The characteristics of the 48 impalpable sonographic lesions were examined. Histologically 15 of the lesions were Leydig cell tumors (31%), 12 (25%) seminomas, 7 (14.5%) nonseminomatous germ cell tumors, 2 (4.5%) Sertoli cell tumors, 12 (25%) benign forms (fibrosis, infarct, lipoma, mesothelial hyperplasia, adenomatoid tumor). The average age was 37.5, average dimension was 10.11 mm. The lesions were hypoechoic in 85% of the cases. Of the patients 31% were infertile. Multivariate analysis showed that histological data were correlated with lesion dimensions and presence of infertility. Dimension was particularly related to germ cell tumors (for dimensions between 16 and 32 mm relative risk ratio [RRR] = 13.97, p=0.0449). Infertility proved significant in defining stromal tumors (RRR = 9,681, p=0.022)

CONCLUSIONS

Although with the limits of a retrospective study consisting in an analysis of individual data, interesting correlations between malignant pathologies and the initial characteristics of impalpable sonographic lesions were revealed. In particular an interesting correlation was found between the dimensions of the lesion and the malignant pathology and between Leydig cell tumor and infertility.

Autocrine deactivation of macrophages in transgenic mice constitutively overexpressing IL-10 under control of the human CD68 promoter

IL-10 plays an essential role in blocking cytokine production by activated macrophages. To analyze the consequences of enforced expression of IL-10 by macrophages on innate and adaptive immune responses, we generated transgenic mice (macIL-10tg mice) expressing an epitope-tagged IL-10 (Flag-IL-10) under control of the human CD68 promoter. Expression of Flag-IL-10 was constitutive and restricted to macrophages, as shown by sorting splenocyte cell populations and intracellular staining for IL-10. Transgenic macrophages displayed suppressed production of TNF-alpha and IL-12 upon stimulation with LPS. When macIL-10tg mice were challenged with LPS, serum levels of proinflammatory cytokines were attenuated compared with controls. Infection with Mycobacterium bovis bacille Calmette-Guérin resulted in approximately 10-fold-higher bacterial loads than in wild-type mice. Normal T and B cell responses were observed in macIL-10tg mice, suggesting that macrophage-specific overexpression of IL-10 predominantly acts in an autocrine/paracrine manner, resulting in chronically deactivated macrophages that manifest an impaired ability to control pathogens.