Lower birthweight and left‐/mixed‐handedness are associated with intensified age‐related sex steroid decline in men. Findings from the Men's Health 40+ Study

Abstract

In males, age-related decline in free testosterone (T) and dehydroepiandrosterone (DHEA) by 2-3% per year has been reported. Estradiol (E2) and progesterone (P) seem to decrease as well, but to a lesser extent. Lower sex steroid levels in men have been related to physical and mental symptoms. Low birthweight and left-/mixed-handedness (L/MH) are indicators of an adverse fetal environment during pregnancy, and both have been linked to morbidity in later life. The aim of this study is to examine the relationship between lower birthweight as well as L/MH and age-related sex steroid decline. In a cross-sectional study design, saliva samples were collected under standardized conditions from healthy men for subsequent steroid hormone analysis using standard luminescence immunoassays. T (M = 67.57 pg/mL), DHEA (M = 247.91 pg/mL), E2 (M = 1.29 pg/mL), and P (M = 28.20 pg/mL) have been quantified leading to a final sample of 256 men providing complete data on sex hormones (M =57.8; SD = 10.8). Information on participants' birthweight was obtained from birth reports (N = 134), and participants were asked about their handedness (right-handed, left-handed, mixed-handed) (N = 256). Multivariate-adjusted linear regression models relating each sex hormone individually and the principal component of declining steroid hormones (DSH)-an integrated hormonal parameter-with handedness and birthweight did not identify significant associations except for handedness and E2. Moderation analysis using robust regression accounting for bias due to influential data points detected a significant association between age and DSH for handedness (β = -0.0314, p = 0.040) but only a trend for birthweight (β = 0.0309, p = 0.073). For lower birthweight, a trend toward intensified age-related sex steroid decline in men was observed, while for L/MH, a significant association with intensified age-related sex steroid decline was identified. These results indicate that L/MH and potentially also lower birthweight might be considered as early risk factors for endocrine health in later life.

No association between adult sex steroids and hand preference in humans

“…Participants self-reported only the direction of their hand preference. While this is not the only study to have used such a measure (e.g., Hoppler et al, 2018;Vuoksimaa et al, 2010) it does not capture the full diversity of handedness phenotypes present in the population, as well as individual differences in strength of handedness. It is not clear to what extent participants interpreted "use both hands equally" to refer to using their left hand for some tasks and their right hand for others, or whether it was asking if they use both hands equally within each given task.…”

“…This imbalance of group sizes reduces statistical power further. For example, while Hoppler et al (2018) included data from 256 men, only 36 of these men were not right-handed (22 left-handers, 14 mixedhanders), so their power to detect group differences may be low. The small sample size of previous studies is due in part to the use of time-consuming and expensive (though rigorous) brain imaging (Papadatou-Pastou et al, 2017) as well as detailed and/or behavioral measures of handedness and laterality, such as the peg moving task (Beaton et al, 2011).…”

Inter-Day Variation in the Fasting Plasma Lipopolysaccharide Concentration in the Morning Is Associated with Inter-Day Variation in Appetite in Japanese Males: A Short-Term Cohort Study

“…We chose males as participants (condition 1) because it has been reported that the menstrual period affects appetite in females [ 30 ], and we were concerned that this would affect the evaluation of the relationship between the fasting plasma LPS concentration and appetite. We chose individuals younger than 40 years as participants (condition 2) to control for the influence of aging-related changes, based on the fact that males (in addition to females) have been reported to undergo changes in hormone balance in their forties and onward [ 31 ]. We chose individuals with a BMI exceeding the 22 kg/m 2 level (condition 3), that the Ministry of Health, Labor, and Welfare defines as appropriate for Japanese people, because blood LPS concentration positively correlates with BMI [ 32 , 33 ] thus individuals with a low BMI were concerned to exhibit a plasma LPS level below the detectable limit.…”