Diurnal coupling between testosterone and cortisol from adolescence to older adulthood

Effects of social environments on male primate HPG and HPA axis developmental programming

Developmental plasticity is particularly important for humans and other primates because of our extended period of growth and maturation, during which our phenotypes adaptively respond to environmental cues. The hypothalamus-pituitary-gonadal (HPG) and hypothalamus-pituitary-adrenal (HPA) axes are likely to be principal targets of developmental "programming" given their roles in coordinating fitness-relevant aspects of the phenotype, including sexual development, adult reproductive and social strategies, and internal responses to the external environment. In social animals, including humans, the social environment is believed to be an important source of cues to which these axes may adaptively respond. The effects of early social environments on the HPA axis have been widely studied in humans, and to some extent, in other primates, but there are still major gaps in knowledge specifically relating to males. There has also been relatively little research examining the role that social environments play in developmental programming of the HPG axis or the HPA/HPG interface, and what does exist disproportionately focuses on females. These topics are likely understudied in males in part due to the difficulty of identifying developmental milestones in males relative to females and the general quiescence of the HPG axis prior to maturation. However, there are clear indicators that early life social environments matter for both sexes. In this review, we examine what is known about the impact of social environments on HPG and HPA axis programming during male development in humans and nonhuman primates, including the role that epigenetic mechanisms may play in this programming. We conclude by highlighting important next steps in this research area.

Intersection of Aging and Particulate Matter 2.5 Exposure in Real World: Effects on Inflammation and Endocrine Axis Activities in Rats

Exposure to particulate matter 2.5 (PM2.5) is detrimental to multiple organ systems. Given the factor that aging also alters the cellularity and response of immune system and dysfunction of hypothalamic-pituitary-adrenal, -gonad and -thyroid axes, it is imperative to investigate whether chronic exposure to PM2.5 interacts with aging in these aspects. In this study, two-months-old Sprague-Dawley rats were exposed to real world PM2.5 for 16 months. PM2.5 exposure diminished the relative numbers of CD4+ T cells and CD8+ T cells and increased the relative number of B cells in the peripheral blood of male rats. Conversely, only reduced relative number of CD4+ T cells was seen in the blood of female rats. These shifts resulted in elevated levels of proinflammatory factors interleukin-6 and tumor necrosis factor-α in the circulatory systems of both sex, with females also evidencing a rise in interleukin-1β levels. Moreover, heightened interleukin-6 was solely discernible in the hippocampus of female subjects, while increased tumor necrosis factor-α concentrations were widespread in female brain regions but confined to the male hypothalamus. Notable hormonal decreases were observed following PM2.5 exposure in both sex. These comprised declines in biomolecules such as corticotrophin-releasing hormone and cortisol, generated by the hypothalamic-pituitary-adrenal axis, and thyroid-releasing hormone and triiodothyronine, produced by the hypothalamic-pituitary-thyroid axis. Hormonal elements such as gonadotropin-releasing hormone, luteinizing hormone, and follicle-stimulating hormone, derived from the hypothalamic-pituitary-gonad axis, were also diminished. Exclusive to male rats was a reduction in adrenocorticotropic hormone levels, whereas a fall in thyroid-stimulating hormone was unique to female rats. Decreases in sex-specific hormones, including testosterone, estradiol, and progesterone, were also noted. These findings significantly enrich our comprehension of the potential long-term health repercussions associated with PM2.5 interaction particularly among the aging populace.

Gender minority stress and diurnal cortisol profiles among transgender and gender diverse people in the United States

The field of behavioral neuroendocrinology has only begun to explore the lived experiences of transgender and gender diverse (TGD) people exposed to stigma. In light of escalating attacks and legislation targeting TGD people in the United States, it is crucial to examine the physiological pathways through which gender minority stressors become embodied, impact health, and contribute to health inequities. The Trans Resilience and Health Study included baseline data collection from fall 2019 to spring 2020 from a sample of 124 TGD people, reflecting a diversity of gender identities (e.g., trans masculine, trans feminine, and nonbinary) and ages (range = 19-70 years old; M = 34.10), living in Michigan, Nebraska, Oregon, and Tennessee. These analyses examine experiences of gender-related enacted stigma in association with hypothalamic-pituitary-adrenal (HPA)-axis functioning. Among those experiencing the highest levels of enacted stigma, findings show a blunted cortisol awakening response and sluggish daily decline that resulted in elevated concentrations at bedtime compared to those experiencing less enacted stigma. These results of flattened diurnal activity are consistent with an emergent literature on discrimination as a social determinant of potential stress pathophysiology. In contrast, community connectedness was associated with a larger, more dynamic cortisol awakening response. These findings emphasize the importance of incorporating gender-minority stress and resilience measures when studying HPA-axis functioning among TGD people.

Epigenetic mechanisms underlying sex differences in the brain and behavior

Sex differences are found across brain regions, behaviors, and brain diseases. Sexual differentiation of the brain is initiated prenatally but it continues throughout life, as a result of the interaction of three major factors: gonadal hormones, sex chromosomes, and the environment. These factors are thought to act, in part, via epigenetic mechanisms which control chromatin and transcriptional states in brain cells. In this review, we discuss evidence that epigenetic mechanisms underlie sex-specific neurobehavioral changes during critical organizational periods, across the estrous cycle, and in response to diverse environments throughout life. We further identify future directions for the field that will provide novel mechanistic insights into brain sex differences, inform brain disease treatments and women's brain health in particular, and apply to people across genders.

Sex Differences in Stress Response: Classical Mechanisms and Beyond

Neuropsychiatric disorders, which are associated with stress hormone dysregulation, occur at different rates in men and women. Moreover, nowadays, preclinical and clinical evidence demonstrates that sex and gender can lead to differences in stress responses that predispose males and females to different expressions of similar pathologies. In this curated review, we focus on what is known about sex differences in classic mechanisms of stress response, such as glucocorticoid hormones and corticotrophin-releasing factor (CRF), which are components of the hypothalamicpituitary- adrenal (HPA) axis. Then, we present sex differences in neurotransmitter levels, such as serotonin, dopamine, glutamate and GABA, as well as indices of neurodegeneration, such as amyloid β and Tau. Gonadal hormone effects, such as estrogens and testosterone, are also discussed throughout the review. We also review in detail preclinical data investigating sex differences caused by recentlyrecognized regulators of stress and disease, such as the immune system, genetic and epigenetic mechanisms, as well neurosteroids. Finally, we discuss how understanding sex differences in stress responses, as well as in pharmacology, can be leveraged into novel, more efficacious therapeutics for all. Based on the supporting evidence, it is obvious that incorporating sex as a biological variable into preclinical research is imperative for the understanding and treatment of stress-related neuropsychiatric disorders, such as depression, anxiety and Alzheimer's disease.

Salivary androgens in adolescence and their value as a marker of puberty: results from the SCAMP cohort

Context

Salivary androgens represent non-invasive biomarkers of puberty that may have utility in clinical and population studies.

Objective

To understand normal age-related variation in salivary sex steroids and demonstrate their correlation to pubertal development in young adolescents.

Design, setting and participants

School-based cohort study of 1495 adolescents at two time points for collecting saliva samples approximately 2 years apart.

Outcome measures

The saliva samples were analyzed for five androgens (testosterone, androstenedione (A4), 17-hydroxyprogesterone, 11-ketotestosterone and 11β-hydroxyandrostenedione) using liquid chromatography-mass spectrometry; in addition, salivary dehydroepiandrosterone (DHEA) and oestradiol (OE2) were analysed by ELISA. The pubertal staging was self-reported using the Pubertal Development Scale (PDS).

Results

In 1236 saliva samples from 903 boys aged between 11 and 16 years, salivary androgens except DHEA exhibited an increasing trend with an advancing age (ANOVA, P < 0.001), with salivary testosterone and A4 concentration showing the strongest correlation (r = 0.55, P < 0.001 and r = 0.48, P < 0.001, respectively). In a subgroup analysis of 155 and 63 saliva samples in boys and girls, respectively, morning salivary testosterone concentrations showed the highest correlation with composite PDS scores and voice-breaking category from PDS self-report in boys (r = 0.75, r = 0.67, respectively). In girls, salivary DHEA and OE2 had negligible correlations with age or composite PDS scores.

Conclusion

In boys aged 11-16 years, an increase in salivary testosterone and A4 is associated with self-reported pubertal progress and represents valid non-invasive biomarkers of puberty in boys.

Hormone physiology and sleep dynamics among BaYaka foragers of the Congo Basin: Gendered associations between nighttime activity, testosterone, and cortisol

Sleep quality is an important contributor to health disparities and affects the physiological function of the immune and endocrine systems, shaping how resources are allocated to life history demands. Past work in industrial and post-industrial societies has shown that lower total sleep time (TST) or more disrupted nighttime sleep are linked to flatter diurnal slopes for cortisol and lower testosterone production. There has been little focus on these physiological links in other socio-ecological settings where routine sleep conditions and nighttime activity demands differ. We collected salivary hormone (testosterone, cortisol) and actigraphy-based sleep data from Congolese BaYaka foragers (N = 39), who have relatively short and fragmented nighttime sleep, on average, in part due to their typical social sleep conditions and nighttime activity. The hormone and sleep data collections were separated by an average of 11.23 days (testosterone) and 2.84 days (cortisol). We found gendered links between nighttime activity and adults' hormone profiles. Contrary to past findings in Euro-American contexts, BaYaka men who were more active at night, on average, had higher evening testosterone than those with lower nighttime activity, with a relatively flat slope relating nighttime activity and evening testosterone in women. Women had steeper diurnal cortisol curves with less disrupted sleep. Men had steeper cortisol diurnal curves if they were more active at night. BaYaka men often hunt and socialize when active at night, which may help explain these patterns. Overall, our findings indicate that the nature of nighttime activities, including their possible social and subsistence contexts, are potentially important modifiers of sleep quality-physiology links, meriting further research across contexts.

New perspectives on sex differences in learning and memory

Females have historically been disregarded in memory research, including the thousands of studies examining roles for the hippocampus, medial prefrontal cortex, and amygdala in learning and memory. Even when included, females are often judged based on male-centric behavioral and neurobiological standards, generating and perpetuating scientific stereotypes that females exhibit worse memories compared with males in domains such as spatial navigation and fear. Recent research challenges these dogmas by identifying sex-specific strategies in common memory tasks. Here, we discuss rodent data illustrating sex differences in spatial and fear memory, as well as the neural mechanisms underlying memory formation. The influence of sex steroid hormones in both sexes is discussed, as is the importance to basic and translational neuroscience of studying sex differences.

Day-to-day coordination of the stress and reproductive axes: A continuous-time analysis of within-person testosterone and cortisol relationships in athletic and healthy men

Day-to-day coordination of the stress (i.e., hypothalamic-pituitary-adrenal [HPA]) and reproductive (i.e., hypothalamic-pituitary-gonadal [HPG]) axes is central to allostatic regulation, reproductive success, and survival. Reports of positive, within-person testosterone and cortisol relationships (or coupling) suggest cross-talk of a facilitative nature, but longitudinal evidence is scarce and has methodological and analytical limitations. To address this, we used a continuous-time (CT) model to investigate day-to-day, within-person coupling of testosterone and cortisol in two male cohorts. Salivary testosterone and cortisol fluctuations were monitored in 35 athletic men across two international tournaments (M = 19.3 tests) and in 41 healthy men during normal daily living (M = 27.9 tests). Bayesian CT analysis revealed a diminishing effect of each hormone on itself as time-interval length or lag increased. In both groups, cortisol had a negative lagged effect on testosterone that persisted for around three days. The cortisol effect on testosterone peaked after 0.71 and 0.51 days in athletic (standardized estimate = -0.13) and healthy men (standardized estimate = -0.11), respectively. Further estimates of non-lagged, contemporaneous correlations revealed positive testosterone and cortisol relationships (athlete r = 0.04, healthy r = 0.46). In summary, complex within-person HPA and HPG interplay emerged in two independent male cohorts. Specifically, a rising cortisol concentration was linked to a fall in testosterone concentration at later time points, but concurrently these hormones tended to rise and fall together. Our results suggest that inhibitory and facilitatory hormonal actions coexist on varying timescales, thereby expanding knowledge of HPG and HPA cross-talk in everyday life.

A Study of Diurnal Cortisol Adaptations in Sleep-Deprived Firefighters During a 72-Hour Work Shift: A Case Series

Seventy percent of US firefighters are overweight or obese. The combination of sleep deprivation and exposure to traumatic events during 72-hour work shifts, commonly employed in emergency responders, is thought to put firefighters at high risk for a variety of stress-related diseases and suicide. Previous studies suggest that the cortisol awakening response (CAR) may be increased in sleep-deprived emergency responders. This case series was designed to investigate the variations in CAR and associations with measurements of salivary cortisol and testosterone, blood glucose and triglyceride, and blood pressure during a 72-hour work shift. Measurements were made at 08:00 and 20:00 in five participants (one normal weight normotensive, three obese hypertensive, and one morbidly obese normotensive male). Data were characterized by the regression statistic R² computed from the relationship between diurnal measurement and concentration, with significance at R²≥0.4. The predominant AM CAR adaptation response consisted of no significant 72-h change (flat response) in salivary cortisol (R²<0.4), found in three of the five participants (60%). The normal-weight participant's 72-h AM CAR adaptation was characterized as incremental (R²=0.91), and markedly different than that of the four obese firefighters who exhibited either a flat response (R²<0.4, 60%) or, in one subject, a decremental response (R²=0.40, 20%). The predominant 72-h PM cortisol adaptation was found to be decremental (R²=0.78-0.97) in three of the five participants (60%), including the normal weight subject (R²=0.78). Diurnal salivary cortisol and testosterone exhibited normal physiological circadian variations (P=0.01, AM>PM and P=0.1, AM>PM, respectively). Blood glucose and triglyceride also showed physiological circadian variations (P=0.02 AM<PM and P=0.002 AM<PM, respectively). Diurnal variation of systolic BP was found to be not significant (P=0.2). The flat AM CAR adaptation exhibited in three of four obese hypertensive firefighters may represent a blunted adaptation response, akin to the responses reported for survivors of suicide. These findings suggest that diurnal variations in salivary cortisol and testosterone, blood glucose, and triglyceride may be useful biochemical markers for identifying stress-related adaptations to 72-hour work shifts. Future studies should be designed to correlate diurnal variations in biomarkers with the risk of developing stress-related diseases and suicide in firefighters.

Longitudinal patterns of neuroendocrine coupling from middle childhood to early adolescence

Recent scholarship has highlighted the importance of understanding relations between hormones, rather than studying hormones in isolation. Considering neuroendocrine coupling, or the coordination of hypothalamic-pituitary-adrenal axis and hypothalamic-pituitary-gonadal axis hormones over time, is one way to investigate how systems governing stress responsiveness and pubertal development covary during critical periods. To date, however, most work has considered hormone coupling cross-sectionally. The current study investigated neuroendocrine coupling in a longitudinal sample from the Northeastern United States. Youth (N = 437, 53% male, 90% White) provided saliva samples for analysis of diurnal hormone activity at ages 9 (three samples per day across 3 days) and 12 (one sample per day on the same weekday for 4 weeks). At both timepoints, samples collected 30-min after waking were assayed for cortisol, dehydroepiandrosterone (DHEA), and testosterone. Multilevel growth modeling was used to determine how levels of morning cortisol changed in tandem with DHEA and testosterone. Morning cortisol-DHEA coupling varied by child sex, as males' cortisol-DHEA diminished over time, especially among pubertally advanced males. Females, in contrast, demonstrated strengthening cortisol-DHEA coupling over time, especially more pubertally advanced females. Morning cortisol-testosterone coupling did not vary by sex or pubertal status, demonstrating strengthening associations between ages 9 and 12. The current findings contribute to the literature on hormone coupling across development and expand this work into an earlier developmental phase than previously investigated.

Cortisol and testosterone concentrations during the prenatal and postpartum period forecast later caregiving quality in mothers and fathers

Given that parental caregiving quality affects child development from birth onwards, it is important to detect parents who are at risk for low-quality caregiving as early as possible, preferably before or soon after birth. This study investigated whether cortisol (CORT) and testosterone (T) measured during the last trimester of pregnancy and six weeks postpartum were associated with observed caregiving quality at child age 3 in mothers (N = 63) and fathers (N = 45). CORT and T were measured during an interaction with a simulator infant (pregnancy) and their own infant (postpartum). In mothers, no associations were found with CORT and T during pregnancy, but higher postpartum CORT during a mother-infant interaction was related to higher caregiving quality during toddlerhood. In fathers, the association between T during pregnancy and caregiving quality in toddlerhood was more negative for fathers with low CORT. In contrast to mothers, higher postpartum CORT in fathers was associated with lower caregiving quality in toddlerhood. These findings proved robust after applying the Benjamini-Hochberg procedure to control for false discovery rate. Our findings indicate that CORT and T during the perinatal period can forecast caregiving quality in both mothers and fathers. Moreover, our results provided evidence for the dual-hormone hypothesis, but only in fathers. These findings contribute to our growing understanding on how endocrine measures explain individual differences in caregiving quality in mothers and fathers.

An analysis of neuroscience and psychiatry papers published from 2009 and 2019 outlines opportunities for increasing discovery of sex differences

Sex differences exist in many neurological and psychiatric diseases, but these have not always been addressed adequately in research. In order to address this, it is necessary to consider how sex is incorporated into the design (e.g. using a balanced design) and into the analyses (e.g. using sex as a covariate) in the published literature. We surveyed papers published in 2009 and 2019 across six journals in neuroscience and psychiatry. In this sample, we find a 30% increase in the percentage of papers reporting studies that included both sexes in 2019 compared with 2009. Despite this increase, in 2019 only 19% of papers in the sample reported using an optimal design for discovery of possible sex differences, and only 5% of the papers reported studies that analysed sex as a discovery variable. We conclude that progress to date has not been sufficient to address the importance of sex differences in research for discovery and therapeutic potential for neurological and psychiatric disease.

Sex differences occur in many neurological and psychiatric diseases, and yet research is not always designed optimally to identify these. Here the authors perform a study of how sex was incorporated into the design and analyses of papers published six journals in neuroscience and psychiatry in 2009 compared with 2019.

Hormone and enzyme reactivity before, during, and after a music performance: Cortisol, testosterone, and alpha-amylase

Performance anxiety is common in a wide range of settings. This study was designed to explore the hormonal correlates of a music performance recital – a setting commonly associated with extreme and often unsettling anxiety linked to the anticipation of performing. Thirty-nine college undergraduate participants (24 women and 15 men) were recruited from students enrolled in an undergraduate music performance course. Each gave a saliva sample on a neutral non-performance day and gave additional samples immediately before and 10 and 30-min after each of two solo music recitals. Samples were subsequently assayed for cortisol, alpha-amylase, and testosterone. For women, pre-performance salivary cortisol levels were significantly elevated relative to neutral-day baseline (presumably in anticipation of performing) and continued to rise in association with the performance phase of the recital. Pre-performance alpha-amylase was significantly higher than neutral-day baseline. Testosterone increased in connection with the performance phase of the recital, but not during the anticipation phase. For all three products, patterns for men were generally similar to those for women, though not as statistically robust, perhaps owing to the smaller sample size. Increases in cortisol and alpha-amylase, from neutral-day to immediately pre-performance on recital day, suggest an effect related to the psychological anticipation of the recital. Cortisol and testosterone (but not alpha-amylase) increased in association with the performance phase of the recital. Phase-related changes in these products appears to reflect a coordinated response to the stress of a music recital and perhaps, more generally, to social-evaluative threat.

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Salivary cortisol, alpha-amylase, and testosterone increase in association with a music recital.

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Cortisol and alpha-amylase increase in anticipation of the performance phase.

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Cortisol and testosterone increase during the performance phase.

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Cortisol/Testosterone coupling increases testosterone reactivity in this setting.

Chronotype and time of day effects on verbal and facial emotional Stroop task performance in adolescents

This study investigated chronotype and time of day effects on lexical and facial emotion processing tasks and explored relationships with sleep quality and mental health outcomes. Participants were 351 Taiwanese adolescents (204 males) aged 13 to 16 years of age who completed both a Facial-Emotional Stroop and a Lexical-Emotional Stroop task at 08:00-10:00 am or at 14:00-16:00 pm. Chronotype was measured using the Morningness-Eveningness Questionnaire (MEQ) and grouped into Morning (n = 46), Intermediate (n = 248) or Evening types (n = 57). Participants completed validated measures of sleep quality (PSQI) and mental health difficulties (DASS-21). The study observed independent effects of time of day and chronotype on the Facial-Emotional Stroop task. Independent of chronotype group, delayed reaction times to anger stimuli were observed in adolescents tested in the morning. Younger adolescents with an Evening chronotype showed delayed responses to anger faces independent of the time of testing. Facial-Emotional Stroop task performance correlated with reported sleep quality and mental health only in Evening chronotypes, with attenuated responses to anger versus neutral stimuli associated with poorer sleep quality and worse mental health outcomes. An exploratory simple mediation analysis indicated that the relationship between attenuated responses to anger and greater mental health difficulties was fully mediated by poorer sleep quality. This study provides evidence of diurnal and chronotype-related variation in facial threat-related processing in typical adolescent development. It also indicates how social emotional processing is vulnerable to sleep disruptions and is linked to the greater mental health problems observed in adolescents with an eveningness profile.

Long-term residential exposure to air pollution is associated with hair cortisol concentration and differential leucocyte count in Flemish adolescent boys

BACKGROUND

Exposure to air pollution and traffic noise are associated with adverse health outcomes in adolescents. Chronic endocrine stress and systemic inflammation have been hypothesized to underlie the adverse health effects. Simultaneous assessment of inflammation and chronic endocrine stress in epidemiological studies is lacking. The aim of the study was to investigate biomarkers of chronic endocrine stress and inflammation in relation to long-term residential exposure to air pollution and traffic noise in adolescents.

METHODS

In Flemish adolescents (14-15 years), we determined hair cortisol concentration (HCC) as a chronic stress biomarker in 3-cm scalp-near hair sections (n = 395), and leucocyte and leucocyte subtype counts (neutrophils, monocytes, lymphocytes) as inflammatory biomarkers in peripheral blood (n = 385). Daily particulate matter (PM_2.5, PM₁₀), nitrogen dioxide (NO₂) and black carbon (BC) concentrations were modelled at the residential address and averaged over 3-month and 1-year periods prior to sampling. Residential traffic noise level was estimated and classified in 5 dB intervals. Sex-specific associations between residential exposures and effect biomarkers were studied using linear regression models, adjusted for a priori selected covariates.

RESULTS

In boys, HCC increased with a factor 1.30 (95% CI: 1.10, 1.54) for an increase in 1-year mean NO₂ from the 25th to 75th percentile (p75/p25), after adjustment for age, BMI, personal and neighborhood socioeconomic status. The corresponding estimate for PM₁₀ was 1.24 (95% CI: 1.02, 1.51). Total leucocyte count in boys, adjusted for the aforementioned covariates and recent health complaints, was positively associated with PM_2.5, PM₁₀, NO₂ and BC. In particular, the neutrophil count increased with a factor 1.11 (95% CI: 1.03, 1.19) for a (p75/p25)-factor increase in 1-year mean BC, corresponding estimates for PM_2.5, PM₁₀ and NO₂ were 1.10 (95% CI: 1.01, 1.19), 1.10 (95% CI: 1.01, 1.20) and 1.08 (95% CI: 1.00, 1.16). Lymphocyte count increased with a factor 1.05 (95% CI: 1.01, 1.10) for a (p75/p25)-factor increase in 1-year mean NO₂. Similar results were observed for 3-month mean exposures. Results were robust to adjustment for recent air pollution exposure. In girls, air pollutants were not associated with HCC or differential leucocyte count. Residential traffic noise level was not associated with HCC or leucocyte counts in boys nor girls.

CONCLUSIONS

Long-term residential exposure to air pollutants was positively associated with chronic endocrine stress and inflammation in adolescent boys, not in girls. This study may contribute to a better understanding of the early pathophysiological changes that may underlie adverse health effects of air pollution exposure in adolescents.

Anthropometrics of Estonian children in relation to family disruption: Thrifty phenotype and Trivers-Willard effects

Background and objectives

The thrifty phenotype hypothesis proposes that at resource limitation, the growth of some organs/tissues is selectively spared to preserve more critical ones, such as the brain or lungs. The Trivers–Willard hypothesis (TWH) predicts that boys are more vulnerable in the case of resource limitation than girls. Both hypotheses were tested in children from disrupted families, differing in the extent of deprivation/adversities imposed on them.

Methodology

In a retrospective cohort study in the mid-20th century Estonia (Juhan Aul’s database), different types of orphans and children of divorced parents (treatment groups; n = 106–1401) were compared with children from bi-parental families (control groups; n = 2548–8648) so that children from treatment groups were matched with control children on the basis of sex, age, year of birth, urban versus rural origin and socioeconomic position.

Results

Children in orphanages suffered strong growth suppression, best explained by psychosocial deprivation. Their feet were on average 0.5 SD shorter than the feet of the controls, followed by height, leg/torso ratio and cranial volume that differed from controls by ca 0.4 SD. Weight difference was 0.2 SD units, while body mass index did not differ from controls. The growth of boys and girls in orphanages was suppressed to the same extent. Boys whose mothers were dead were relatively smaller and less masculine than girls from such families. Fathers’ absence was unrelated to growth suppression. Sons of divorced parents had broader shoulders than boys whose fathers were dead.

Conclusions and implications

Prediction of TWH about the greater vulnerability of male growth may hold under some conditions but not universally. Predictions of the thrifty phenotype hypothesis were partly supported: trunk growth was spared at the expense of leg growth; however, no evidence for brain sparing was found. Comparison of children of divorced versus dead fathers may appear useful for indirect assessment of sexual selection on offspring quality.

Lay Summary: Boys and girls in orphanages suffered similarly strong growth suppression, best explained by psychosocial deprivation. Boys whose mothers were dead were relatively smaller and less masculine than girls from such families. The occurrence of sex-specific associations between family structure and children’s growth depends on the type of family disruption.

A meta-analysis of blood and salivary cortisol levels in first-episode psychosis and high-risk individuals

Dysregulated cortisol responses and glucose metabolism have been reported in psychosis. We performed a random-effects meta-analysis of cortisol responses in first-episode psychosis (FEP) and psychosis risk states, taking into consideration glucose metabolism. A total of 47 studies were included. Unstimulated blood cortisol levels were significantly higher (g = 0.48, 95 %CI: 0.25-0.70, p < 0.001) in FEP, but not in psychosis risk states (g = 0.39, 95 %CI: -0.42-1.21, p = 0.342), compared to controls. Cortisol awakening response (CAR) was attenuated in FEP (g = -0.40, 95 %CI: -0.68 - -0.12, p = 0.006), but not in psychosis risk states (p = 0.433). Glucose and insulin levels were positively correlated with unstimulated blood cortisol levels in FEP. Our meta-analysis supports previous findings of elevated blood cortisol levels and attenuated CAR in FEP. Future research should focus on identifying the common denominators for alterations in stress hormones and glucose metabolism.

Fathering behavior, attachment, and engagement in childcare predict testosterone and cortisol

The present study examined testosterone (T) and cortisol (Cort) in fathers engaged with caregiving. We collected saliva samples in the mornings and evenings of two consecutive days in 150 fathers of 1- to 5-year-old children. Fathers completed questionnaires on socioeconomic status, family structure and life, sleep characteristics and body mass index (BMI), and reported on their engagement in childcare. Fathers used smartphone-based experience sampling throughout 1 week to sample ongoing activities with their children, including times of supervision, joint play, rough-and-tumble play, and cuddling episodes. External observers rated father-child attachment during a home visit. We began by testing for widely characterized covariates of T and excluded seasonal variations and known predictors associated with lowered T, such as older fathers and those with multiple and young children, lower BMI, shorter sleep duration, and sexual activity before sampling. Most interestingly, however, fathers' engagement in childcare and attachment to the child appeared more pronounced the greater the diurnal decline in T. Cuddling predicted a similar negative association, whereas joint play and rough-and-tumble play (RTP) showed enhancing effects on declining T. Interestingly, all fathering behaviors (except RTP) were positively related to lower Cort. In contrast, supervision was ineffective on both Cort and T.

Exposure to artificial light at night accelerates but does not override latitude-dependent seasonal reproductive response in a North American songbird

In the modern era of industrialization, illuminated nights have become a common defining feature of human-occupied environments, particularly cities. Artificial light at night (ALAN) imposes several known negative impacts on the neuroendocrine system, metabolism, and seasonal reproduction of species living in the wild. However, we know little about the impact of ALAN on populations of birds that either live year-round in the same location or move to different latitudes across seasons. To test whether ALAN has a differing impact on the reproductive timing of bird populations that winter in sympatry but breed at different latitudes, we monitored sedentary and migratory male dark-eyed juncos that were or were not exposed to low intensity (∼2.5 ± 0.5 lux) ALAN. All groups were held in common conditions and day length was gradually increased to mimic natural day length changes (NDL). We assessed seasonal reproductive response from initiation to termination of the breeding cycle. As expected based on earlier research, the sedentary birds exhibited earlier gonadal recrudescence and terminated breeding later than the migratory birds. In addition, resident and migrant birds exposed to ALAN initiated gonadal recrudescence earlier and terminated reproductive events sooner as compared to their conspecifics experiencing NDL. Importantly, the difference in the reproductive timing of sedentary and migratory populations was maintained even when exposed to ALAN. This variation in the seasonal reproductive timing may likely have a genetic basis or be the result of early developmental effects imposed due to different light regimes related to the latitude of origin. This study reveals first that ALAN accelerated reproductive development across both migrants and residents and second that latitude-dependent variation in reproductive timing is maintained despite exposure to ALAN. These results corroborate a relationship between latitude, population, and reproductive timing while also revealing ALAN's impact on seasonal reproductive timing. This study reveals that, ALAN accelerated reproductive development but maintained latitude-dependent variation in reproductive timing across both migrant and resident bird populations.

Longitudinal effects of family psychopathology and stress on pubertal maturation and hormone coupling in adolescent twins

Adolescents experience profound neuroendocrine changes, including hormone "coupling" between cortisol, testosterone, and dehydroepiandrosterone. Emerging research has only begun to elucidate the role of hormone coupling, its genetic and environmental etiology, and the extent to which coupling is impacted by gender, puberty, and family context. We included measures on parent and child mental health, parenting stress, and family conflict of 444 twin pairs and their parents across two timepoints, when youth were on average 8 and 13 years old, respectively. Structural equation models examined the impact of family context effects on coupling during adolescence. Biometric twin models were then used to probe additive genetic, shared, and non-shared environmental effects on hormone coupling. Hormones were more tightly coupled for females than males, and coupling was sensitive to parental depression and co-twin psychopathology symptoms and stress exposure in females. The association between family context and coupling varied across specific neuroendocrine measures and was largely distinct from pubertal maturation. Biometric models revealed robust shared and non-shared environmental influences on coupling. We found that family antecedents modify the strength of coupling. Environmental influences account for much of the variation on coupling during puberty. Gender differences were found in genetic influences on coupling.

Within-person coupling of estradiol, testosterone, and cortisol in women athletes

Purpose

In variety of settings cortisol and testosterone are positively “coupled.” That is, within-person fluctuations of cortisol and testosterone levels occur in parallel—increases and decreases in one hormone are associated with corresponding increases and decreases in the other. The present report explored hormone coupling in women athletes in two studies selected because they included measurements of salivary levels of cortisol, testosterone, and estradiol—a hormone that has been only infrequently studied in the context of competitive athletics.

Methods

Consenting members of Emory University’s varsity volleyball and soccer teams gave saliva samples on multiple occasions in the run-up to and over the course of two different intercollegiate contests.

Results

Volleyball and soccer players showed remarkably similar hormone-specific patterns of increase in relationship to the different stages of competition—before warm-up, after warm-up, and after competition. For both the volleyball and soccer team, Hierarchical Linear Model (HLM) analyses showed estradiol as being significantly coupled with testosterone which was also coupled with cortisol.

Conclusions

This is, apparently, the first report of significant within-person coupling between estradiol and testosterone in the context of competitive athletic stress. These two hormones may be coupled in a wide variety of circumstances not limited to ones involving sport competition, and results reported here should encourage exploration of the extent to which coordinated fluctuations in estradiol, testosterone, and cortisol levels are present in other, more neutral settings and the ways in which the coordination of these fluctuating hormone levels may benefit human performance.

The promises and pitfalls of sex difference research

Funding agencies in North America and Europe are recognizing the importance of the integration of sex differences into basic and clinical research. Although these mandates are in place to improve our knowledge of health for both men and women, there have been a number of implementation issues that require vigilance on the part of funders and the research community. Here we discuss issues on simple inclusion of both sexes in studies to specialisation of sex differences with attention paid to statistics and the need for sex-specific treatments. We suggest differing mandates need to be considered regarding simple integration versus the need for studies in the specialisation of sex differences and/or the need for research that recognises the importance of male-specific or female-specific factors that influence subsequent health such as menstruation, menopause or pregnancy.

Day-to-day friends' victimization, aggression perpetration, and morning cortisol activity in late adolescents

This study investigates bidirectional associations between adolescents' daily experiences of victimization and aggression perpetration within friendships. We investigated (a) across-day associations between victimization and aggression perpetration; (b) morning cortisol activity as a moderator of cross-day victimization and aggression links; and (c) potential sex differences in these patterns. For 4 consecutive days, 99 adolescents (Mage  = 18.06, SD = 1.09, 46 females) reported whether they were victimized by or aggressive toward their friends. On three of these days, adolescents provided three morning saliva samples. Multilevel path analyses showed that across days, victimization and aggression were bidirectionally linked, but only for male adolescents. Additionally, for male adolescents, morning cortisol output (but not morning cortisol increase) moderated the association between victimization and next-day aggression; victimization predicted greater next-day aggression for boys with low, but not high, morning cortisol output. Findings implicate a physiological factor that may modify daily links between victimization and aggression in male adolescent friendships.

Developmental Adaptation to Stress: An Evolutionary Perspective

The assumption that early stress leads to dysregulation and impairment is widespread in developmental science and informs prevailing models (e.g., toxic stress). An alternative evolutionary–developmental approach, which complements the standard emphasis on dysregulation, proposes that early stress may prompt the development of costly but adaptive strategies that promote survival and reproduction under adverse conditions. In this review, we survey this growing theoretical and empirical literature, highlighting recent developments and outstanding questions. We review concepts of adaptive plasticity and conditional adaptation, introduce the life history framework and the adaptive calibration model, and consider how physiological stress response systems and related neuroendocrine processes may function as plasticity mechanisms. We then address the evolution of individual differences in susceptibility to the environment, which engenders systematic person–environment interactions in the effects of stress on development. Finally, we discuss stress-mediated regulation of pubertal development as a case study of how an evolutionary–developmental approach can foster theoretical integration.

Genetic and environmental influences on pubertal hormones in human hair across development

Puberty is a complex biopsychosocial process that can affect an array of psychiatric and medical disorders emerging in adolescence. Although the pubertal process is driven by neuroendocrine changes, few quantitative genetic studies have directly measured puberty-relevant hormones. Hair samples can now be assayed for accumulation of hormones over several months. In contrast to more conventional salivary measures, hair measures are not confounded by diurnal variation or hormonal reactivity. In an ethnically and socioeconomically diverse sample of 1286 child and adolescent twins and multiples from 672 unique families, we estimated genetic and environmental influences on hair concentrations of testosterone, DHEA, and progesterone across the period of 8-18 years of age. On average, male DHEA and testosterone were highly heritable, whereas female DHEA, progesterone, and puberty were largely influenced by environmental components. We identified sex-specific developmental windows of maximal heritability in each hormone. Peak heritability for DHEA occurred at approximately 10 years of age for males and females. Peak heritability for testosterone occurred at age 12.5 and 15.2 years for males and females, respectively. Peak heritability for male progesterone occurred at 11.2 years, while the heritability of female progesterone remained uniformly low. The identification of specific developmental windows when genetic signals for hormones are maximized has critical implications for well-informed models of hormone-behavior associations in childhood and adolescence.

Hair and Salivary Testosterone, Hair Cortisol, and Externalizing Behaviors in Adolescents

Although testosterone is associated with aggression in the popular imagination, previous research on the links between testosterone and human aggression has been inconsistent. This inconsistency might be because testosterone's effects on aggression depend on other moderators. In a large adolescent sample ( N = 984, of whom 460 provided hair samples), we examined associations between aggression and salivary testosterone, hair testosterone, and hair cortisol. Callous-unemotional traits, parental monitoring, and peer environment were examined as potential moderators of hormone-behavior associations. Salivary testosterone was not associated with aggression. Hair testosterone significantly predicted increased aggression, particularly at low levels of hair cortisol (i.e., Testosterone × Cortisol interaction). This study is the first to examine the relationship between hair hormones and externalizing behaviors and adds to the growing literature that indicates that androgenic effects on human behavior are contingent on aspects of the broader endocrine environment-in particular, levels of cortisol.

Social evaluative threat with verbal performance feedback alters neuroendocrine response to stress

Laboratory stress tasks such as the Trier Social Stress Test (TSST) have provided a key piece to the puzzle for how psychosocial stress impacts the hypothalamic-pituitary-adrenal axis, other stress-responsive biomarkers, and ultimately wellbeing. These tasks are thought to work through biopsychosocial processes, specifically social evaluative threat and the uncontrollability heighten situational demands. The present study integrated an experimental modification to the design of the TSST to probe whether additional social evaluative threat, via negative verbal feedback about speech performance, can further alter stress reactivity in 63 men and women. This TSST study confirmed previous findings related to stress reactivity and stress recovery but extended this literature in several ways. First, we showed that additional social evaluative threat components, mid-task following the speech portion of the TSST, were still capable of enhancing the psychosocial stressor. Second, we considered stress-reactive hormones beyond cortisol to include dehydroepiandrosterone (DHEA) and testosterone, and found these hormones were also stress-responsive, and their release was coupled with one another. Third, we explored whether gain- and loss-framing incentive instructions, meant to influence performance motivation by enhancing the personal relevance of task performance, impacted hormonal reactivity. Results showed that each hormone was stress reactive and further had different responses to the modified TSST compared to the original TSST. Beyond the utility of showing how the TSST can be modified with heightened social evaluative threat and incentive-framing instructions, this study informs about how these three stress-responsive hormones have differential responses to the demands of a challenge and a stressor.

Effects of Mindfulness-Based Interventions on Salivary Cortisol in Healthy Adults: A Meta-Analytical Review

Objective: The aim of the present study was to elucidate the effects of Mindfulness-based interventions (MBIs) on salivary cortisol levels in healthy adult populations.

Method: We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs), published between January 1980 and June 2015 in PubMed, EMBASE, PsycINFO and the Cochrane library. The PRISMA and Cochrane guidelines were followed. The pooled effect sizes were calculated with the random-effects model, using Hedges' g-values, and heterogeneity was measured using the I² statistic. The contribution of different characteristics of participants and programmes were assessed by meta-regression models, using beta coefficients.

Results: Five RCTs with 190 participants in total were included in this systematic review. The overall effect size (ES) for improving the state of health related to cortisol levels was moderately low (g = 0.41; p = 0.025), although moderate heterogeneity was found (I² = 55; p = 0.063). There were no significant differences between active (g = 0.33; p = 0.202) and passive (g = 0.48; p = 0.279) controls, but significant differences were found when comparing standard (g = 0.81; p = 0.002) and raw (g = 0.03; p = 0.896) measures. The percentage of women in each study was not related to ES. Nevertheless, age (beta = −0.03; p = 0.039), the number of sessions (beta = 0.33; p = 0.007) and the total hours of the MBI (beta = 0.06; p = 0.005) were significantly related to ES, explaining heterogeneity (R² = 1.00).

Conclusions: Despite the scarce number of studies, our results suggest that MBIs might have some beneficial effect on cortisol secretion in healthy adult subjects. However, there is a need for further RCTs implemented in accordance with standard programmes and measurements of salivary cortisol under rigorous strategies in healthy adult populations.