Thursday, March 2, 2023

Men working non-daytime/rotating shifts and those with physically demanding jobs have higher sperm concentration and total sperm count as well as higher estradiol and total testosterone concentrations

Occupational factors and markers of testicular function among men attending a fertility center. Lidia Mínguez-Alarcón, Paige L Williams, Irene Souter, Jennifer B Ford, Ramy Abou Ghayda, Russ Hauser, Jorge E Chavarro, for the Earth Study Team. Human Reproduction, dead027, Feb 11 2023.


Study Question: Are occupational factors associated with markers of testicular function among men attending a fertility center?

Summary Answer: Men working non-daytime/rotating shifts and those with physically demanding jobs have higher sperm concentration and total sperm count as well as higher estradiol and total testosterone concentrations.

What Is Known Already: Semen quality has declined during recent decades and has been negatively correlated with higher risks of common chronic diseases and mortality, highlighting its public health importance beyond fertility and reproduction. While most of the previous epidemiology literature on male fertility has focused on environmental exposures, dietary factors, and other related variables, little attention has been paid to occupational factors.

Study Design, Size, Duration: This observational study included 377 men who were male partners in couples seeking infertility treatment at a fertility center, who enrolled in the Environment and Reproductive Health (EARTH) study between 2005 and 2019.

Participants/Materials, Setting, Methods: Self-reported information on lifting/moving heavy objects, typical shift, and physical level of exertion at work was collected from a take-home questionnaire. Semen samples were analyzed following World Health Organization guidelines. Enzyme immunoassays were used to assess reproductive hormone concentrations. Linear regression models were used to evaluate the association between occupational factors and measures of testicular function, while adjusting for covariates such as age, BMI, education, race, smoking, and abstinence time, and accounting for multiple semen samples (mean = 2, min–max = 1–9) in analyses for semen parameters.

Main Results And The Role Of Chance: Men had a median (interquartile range) age of 36 (33, 39) years and were predominantly Caucasian (87%). Of the men who completed the survey, 12% reported often lifting or moving heavy objects at work, 6% reported heavy physical exertion at work, and 9% reported evening or rotating shifts. Men who reported often lifting or moving heavy objects at work had 46% higher sperm concentrations (P = 0.01) and 44% higher total counts (P = 0.01) compared with men who reported never lifting or moving heavy objects at work. Similar results were found for men working in rotating shifts compared to those in day shifts, as well as for men involved in heavy levels of physical exertion compared to those with light levels at work. We also found that men involved in heavy/moderate levels of physical exertion at work had higher circulating testosterone concentrations compared to those with lighter exertion (adjusted means of 515 and 427 ng/dl, respectively, P = 0.08), and men who often moved/lifted heavy objects at work had higher estradiol concentrations, compared to those who never did (adjusted means of 36.8 and 27.1 pg/ml, respectively, P = 0.07). Men working evening/rotating shifts had 24% higher testosterone (P = 0.04) and 45% higher estradiol concentrations (P = 0.01), compared to men working day shifts. No associations were observed for ejaculated volume, total motility, morphologically normal sperm, or serum FSH and LH concentrations.

Limitations, Reasons For Caution: Due to our study design which recruited men from couples seeking fertility treatment, it may not be possible to generalize our findings to men from the general population. Also, as is the case of all studies based on self-reported questionnaires, measurement error and misclassification of the exposure are potential concerns.

Wider Implications Of The Findings: Physically demanding jobs and rotating or evening shift occupations may be associated with higher testicular function in men measured as higher sperm concentrations and counts as well as higher serum testosterone and estradiol levels. Confirmation of these findings in other non-fertility clinic study populations is warranted.

Keywords: occupational, work shift, physical exertion, semen parameters, testosterone

This article argues that “open source intelligence (OSINT)” is a fundamentally incoherent concept that should be abandoned

There Is No Such Thing as Open Source Intelligence. Joseph M. Hatfield. International Journal of Intelligence and CounterIntelligence, Mar 1 2023.

Abstract: This article argues that “open source intelligence (OSINT)” is a fundamentally incoherent concept that should be abandoned. It does so in two steps. First, by challenging the underlying criteria used to demarcate it as a separate “INT” among its more traditional peers. Second, through a historical critique that argues that “OSINT” as a conceptual category served a transitionary stage that has long passed. That is, it helped intelligence practitioners and scholars appreciate the influx of valuable unclassified information made newly available by the World Wide Web in the 1990s, but the advantages gained from this notion have now declined, and the concept is now a liability. By discarding the term altogether, and recategorizing openly derived sources of information back into their traditional homes, significant conceptual and analytical benefits can be attained.

Happiness was associated with worse reasoning; happiness may not be predictive of the rate of cognitive decline over time

The association between happiness and cognitive function in the UK Biobank. Xianghe Zhu, Martina Luchetti, Damaris Aschwanden, Amanda A. Sesker, Yannick Stephan, Angelina R. Sutin & Antonio Terracciano. Current Psychology, Mar 01 2023.

Abstract: Feelings of happiness have been associated with better performance in creative and flexible thinking and processing. Less is known about whether happier individuals have better performance on basic cognitive functions and slower rate of cognitive decline. In a large sample from the UK Biobank (N = 17,885; Age 40–70 years), we examine the association between baseline happiness and cognitive function (speed of processing, visuospatial memory, reasoning) over four assessment waves spanning up to 10 years of follow-up. Greater happiness was associated with better speed and visuospatial memory performance across assessments independent of vascular or depression risk factors. Happiness was associated with worse reasoning. No association was found between happiness and the rate of change over time on any of the cognitive tasks. The cognitive benefits of happiness may extend to cognitive functions such as speed and memory but not more complex processes such as reasoning, and happiness may not be predictive of the rate of cognitive decline over time. More evidence on the association between psychological well-being and different cognitive functions is needed to shed light on potential interventional efforts.

Migrants at Sea: Search and Rescue Operations induced more crossings in dangerous conditions, offsetting their intended safety benefits; despite the increased mortality, these operations likely increased aggregate migrant welfare

Migrants at Sea: Unintended Consequences of Search and Rescue Operations. Claudio Deiana, Vikram Maheshri, Giovanni Mastrobuoni. American Economic Journal: Economic Policy, Feb 2023.

Abstract: Many developed countries currently both face and resist strong migratory pressure, fueling irregular migration. The Central Mediterranean Sea is among the most dangerous crossings for irregular migrants in the world. In response to mounting deaths, European nations intensified search and rescue operations in 2013. We develop a model of irregular migration to identify the effects of these operations. Leveraging exogenous variation from rapidly varying crossing conditions, we find that smugglers responded by sending boats in adverse weather and shifting from seaworthy boats to flimsy rafts. As a result, these operations induced more crossings in dangerous conditions, ultimately offsetting their intended safety benefits due to moral hazard and increasing the realized ex post crossing risk for migrants. Despite the increased risk, these operations likely increased aggregate migrant welfare; nevertheless, a more successful policy should instead restrict the supply of rafts and expand legal alternatives for migration.