“Obesity in men lowers testosterone levels and thereby reduces criminal perpetration rates.”

This study contradicts previous mathematical models that postulated lower criminal behavior in young adults with obesity, which the authors hypothesized that their body weights and lower levels of fitness may prevent them from participating in certain criminal behaviors.19… Increased surveillance for risk-taking behaviors and enhanced mental health screening can help identify comorbidities that can hinder both treatment and psychosocial well-being. Of note, as this was an observational study, this study did not answer whether treatment for obesity reduces the risk of these negative social outcomes. This study contradicts previous mathematical models that postulated lower criminal behavior in young adults with obesity, which the authors hypothesized that their body weights and lower levels of fitness may prevent them from participating in certain criminal behaviors.19 These data were based on population-averaged and conditional fixed effects logit models derived from a constructed panel dataset from the National Longitudinal Survey of Youth. The fact that our study utilized longitudinal patient data as opposed to mathematically derived data may explain the differences in results with the article by Kalist et al. The regional versus national crime differences may also explain the contradictory findings between studies. …

Children with obesity appear to have greater social risk than their peers in adulthood with higher rates of criminal behavior and lower rates of homeownership.… Overall, 9.6% of these adults were convicted of a felony compared to \~7% lifetime prevalence in Ohio (*p*= 0.03). Also, 14.7% of study patients purchased a home compared to 38.3% of Midwest adults <30 years old (*p*< 0.0001). Mortality, history of a criminal conviction, or homeownership was associated with any exercise or study parameter. **Conclusion:**Children with obesity appear to have greater social risk than their peers in adulthood with higher rates of criminal behavior and lower rates of homeownership. This appears to highlight the need for treatment in this vulnerable group of children and young adults. **Keywords:**Obesity; criminal behavior; fitness; homeownership; risk-taking behavior. ©The Author(s) 2022. [PubMed Disclaimer](https://pubmed.ncbi.nlm.nih.gov/disclaimer/) ## Conflict of interest statement The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. ## Figures …

Our results suggest that there is a causal effect of BMI on serum testosterone in men. … Conversely, our analyses provided no evidence for a causal role of serum T on BMI.### Conclusions Our results suggest that there is a causal effect of BMI on serum testosterone in men. Population level interventions to reduce BMI are expected to increase serum testosterone in men. Citation: Eriksson J, Haring R, Grarup N, Vandenput L, Wallaschofski H, Lorentzen E, et al. (2017) Causal relationship between obesity and serum testosterone status in men: A bi-directional mendelian randomization analysis. PLoS ONE 12(4): e0176277. https://doi.org/10.1371/journal.pone.0176277 … ## Discussion Obesity is associated with low serum T in men, but the direction of the association and the potentially causal effect is still debated. Herein, we presented evidence that higher BMI leads to lower serum T. Conversely, our analyses provided no evidence for a causal role of serum T on BMI. These results suggest that although increases in T status are not likely to help with weight regulation in the general male population, low serum T could contribute to the adverse health effects associated with obesity in men. Our study highlights the importance of considering obesity as a risk factor for low serum T in men with implications on the possible targeting of relevant health promotion strategies.

Obesity is associated with reduced testosterone and worsened erectile and sexual function in men. … Testosterone and its binding protein sex hormone binding globulin (SHBG) are also decreased in obesity [4]. Weight loss increases testosterone and SHBG [5], improves erectile function and sexual desire [2,6–9] and lower urinary tract symptoms (LUTS) [6,7].### Introduction Obesity is associated with reduced testosterone and worsened erectile and sexual function in men. Weight loss improves these outcomes. High protein diets potentially offer anthropometric and metabolic benefits, but their effects on reproductive and sexual outcomes is not known. ### Aim … In 2013 overweight and obesity were estimated to be present in over one third (36.9%) of the worlds men [1]. There is an increasing recognition in men of the association between excess weight and erectile dysfunction, reduced sexual desire or enjoyment of sexual activity [2] and lower urinary tract symptoms [3]. Testosterone and its binding protein sex hormone binding globulin (SHBG) are also decreased in obesity [4]. Weight loss increases testosterone and SHBG [5], improves erectile function and sexual desire [2,6–9] and lower urinary tract symptoms (LUTS) [6,7]. There is increasing interest in the optimal diet composition for achieving weight loss and associated metabolic, reproductive or psychological benefits. A recent systematic review reported that a low fat diet, higher in protein and lower in carbohydrate, attenuates loss of lean body mass and is more effective for reducing triglycerides and improving glycemia in comparison to a standard high carbohydrate low fat diet [10]. …

Men, in general, are much more aggressive than women ± a fact that has led researchers to investigate possible links between levels of male hormones (particularly testosterone) and aggressive or criminal behavior. … It can thus be concluded that high testosterone levels play a role in some criminal behavior, particularly when other risk factors such as low socioeconomic status are present.… Testosterone acts as a prohormone which, when converted into 5-alpha-dihydrotestosterone, acts on androgen receptors, or when converted to estradiol by the enzyme aromatase, acts on estrogen receptors. There is overwhelming evidence that most of the effects of testosterone in mediating aggression occur after aromatization [11]. Furthermore, the intensity of aggressive behavior was directly correlated with the aromatase activity in the posterior hypothala mus [12]. Men, in general, are much more aggressive than women ± a fact that has led researchers to investigate possible links between levels of male hormones (particularly testosterone) and aggressive or criminal behavior. Testosterone may affect levels of aggression beginning early in life. In a study conducted among 28 male and 20 female preschoolers, children were videotaped while playing. Levels of aggression in social and play situations were observed and measurements of salivary testosterone levels evaluated. Results indicated a positive correlation in boys (but not in girls) between testosterone levels and serious aggression in social situations, but no correlation with playful aggression [13]. … This study also shows that inmates with higher testosterone levels violated more prison rules, especially those involving overt confrontation [15]. When salivary testosterone levels of young adult delinquents were compared with levels in a group of college students, matched for age, gender and race, the delinquent subjects had higher testosterone levels than the student controls, a finding that was true for both male and female subjects [16]. It can thus be concluded that high testosterone levels play a role in some criminal behavior, particularly when other risk factors such as low socioeconomic status are present. High testosterone levels have also been found in cases of antisocial behavior in a subtype of alcoholics. Levels of free testosterone, total testosterone, and sex hormone-binding globulin (which influences total testosterone concentration) were measured in 61 men undergoing forensic psychiatric examination. All subjects had been detoxified from drugs and alcohol while hospitalized or in prison. …

Obesity and excess body fat are linked to reduced testosterone levels, which can lead to metabolic dysfunctions, reduced libido, and diminished muscle mass.… [PMC Copyright notice](https://pmc.ncbi.nlm.nih.gov/about/copyright/) PMCID: PMC11745839 PMID: [39840189](https://pubmed.ncbi.nlm.nih.gov/39840189/) ## Abstract The purpose of this review is to explore the relationship between weight loss (WL), specifically reductions in body mass index (BMI), and increases in testosterone levels. Obesity and excess body fat are linked to reduced testosterone levels, which can lead to metabolic dysfunctions, reduced libido, and diminished muscle mass. To attain this purpose, this review will summarize current evidence on how weight reduction interventions, including dietary changes, exercise, and bariatric surgery, affect testosterone production in overweight and obese individuals. WL, particularly through fat reduction, has a positive influence on testosterone levels. Both moderate and significant reductions in BMI are associated with notable increases in serum testosterone levels. …

Male T is inversely correlated to body fat whether measured by body mass index (BMI) or by weight [6], [7]. … At the same time, it is clear that adding weight reduced T.There have been scattered reports that mean testosterone (T) for men of a given age is decreasing among Americans [1] and Scandinavians [2]–[4]. The reliability and extent of, and reasons for, this “secular” decline are unknown. If valid, a secular decline in T is disquieting because it is congruent with other indications of degradation in male reproductive health such as falling sperm counts [5]. Male T is inversely correlated to body fat whether measured by body mass index (BMI) or by weight [6], [7]. There appears to be a causal connection behind this correlation, though whether it is one-way or bidirectional is uncertain. Obese men after gastric bypass surgery show higher T levels as their weight drops [8]–[10]. T gain (or loss) is also associated with weight loss (or gain) via nonsurgical means [11]. It is plausible that the secular (population level) decline in T, as well as declining T during an individual’s maturity, is accounted for by increasing fatness. … Figure 5. Mean testosterone by cycle, by percent gain/loss of weight in 20 years. At the same time, it is clear that adding weight reduced T. The scattergram in Figure 6, showing percentage change in T (from cycle 1 to cycle 6) as a function of percentage gain in weight (across the same period), is fit with a linear regression line. Weight gain explains 16 percent of the variance in changing T (r = .41, p <.0001). The distribution of points shows that most men gained weight and lost T during the study, some considerably. …

Obesity in men is associated with low serum testosterone and both are associated with several diseases and increased mortality. … Herein, we presented evidence that higher BMI leads to lower serum T. Conversely, our analyses provided no evidence for a causal role of serum T on BMI.## Abstract Obesity in men is associated with low serum testosterone and both are associated with several diseases and increased mortality. Examine the direction and causality of the relationship between body mass index (BMI) and serum testosterone. Bi-directional Mendelian randomization (MR) analysis on prospective cohorts. Five cohorts from Denmark, Germany and Sweden (Inter99, SHIP, SHIP Trend, GOOD and MrOS Sweden). 7446 Caucasian men, genotyped for 97 BMI-associated SNPs and three testosterone-associated SNPs. ## Introduction … ## Discussion Obesity is associated with low serum T in men, but the direction of the association and the potentially causal effect is still debated. Herein, we presented evidence that higher BMI leads to lower serum T. Conversely, our analyses provided no evidence for a causal role of serum T on BMI. These results suggest that although increases in T status are not likely to help with weight regulation in the general male population, low serum T could contribute to the adverse health effects associated with obesity in men. Our study highlights the importance of considering obesity as a risk factor for low serum T in men with implications on the possible targeting of relevant health promotion strategies.

Higher adult BMI was found to be associated with a lower BT (IVW: β = -0.13; 95% CI, -0.16 to -0.09; P = 5.37E-13) and TT levels (IVW: β = -0.25; 95% CI, -0.30 to -0.20; P = 2.29E-23), and similar results were found in most sensitivity analyses (Fig. 1 ).## Effects of Weight Traits on Testosterone Levels in Men Higher adult BMI was found to be associated with a lower BT (IVW: β = -0.13; 95% CI, -0.16 to -0.09; P = 5.37E-13) and TT levels (IVW: β = -0.25; 95% CI, -0.30 to -0.20; P = 2.29E-23), and similar results were found in most sensitivity analyses (Fig. 1 ). Likewise, higher childhood BMI was related to a decreased BT (IVW: β = -0.13; 95% CI, -0.17 to -0.09; P = 1.23E-09) and TT levels (IVW: β = -0.14; 95% CI, -0.19 to -0.10; P = 1.26E-09). The results were consistent in all sensitivity analyses (see Fig. 1 ). For birthweight, it was inversely associated with BT levels (IVW: β = -0.08; 95% CI: -0.12 to -0.03; P = .001). …

The elevated testosterone levels observed in young offenders, though within the normal clinical range, support previous associations between androgens and aggression.… Moreover, early-life variables such as nutrition, health status, and socioeconomic context - factors not measured in this study - likely contributed to these differences; other interacting neurobiological and environmental factors must be considered. Interpretation and generalizability The results of this study contribute to ongoing efforts to understand the biological underpinnings of antisocial behavior. The elevated testosterone levels observed in young offenders, though within the normal clinical range, support previous associations between androgens and aggression. However, hormonal profiles alone are not sufficient to explain criminal behavior. Neurobiological dysfunctions in impulse control, emotional processing, and reward systems likely interact with psychosocial stressors to shape behavioral outcomes. While the case-control design offers valuable comparative insight, the study's generalizability is constrained by its limited sample size, specific age group, and the absence of comprehensive background data. …

Obese individuals experience hypogonadotropic hypogonadism which is characterized by reduced testosterone and testicular function (15, 17, 18) .… Our findings illustrated that MBS leads to significant improvements in the sex hormone status among obese men. However, its effect on semen quality appears to be challenging. The MBS has distinct effects on semen quality based on various surgical techniques and follow-up duration. Our findings demonstrated that obese men have increased levels of TT and FT across all post-operative intervals. This consistent elevation in circulating androgens offers endocrinological responses to MBS. Obese individuals experience hypogonadotropic hypogonadism which is characterized by reduced testosterone and testicular function (15, 17, 18) . Likewise, the MBS is able to reverse this process and exert its beneficial effects on TT and FT levels. Also, mechanistically MBS contribute to reduced adipose tissue which is accompanied with diminished activity of aromatase to converts androgens to estrogens (19, 20) . Despite the consistency in the direction and statistical significance of MBS, there was a statistical significance heterogeneity in pooled estimates for TT and FT. …

Although a strong inverse association exists between the degree of obesity and circulating testosterone concentrations, a much weaker relationship is observed when comparing the relationship between obesity and testosterone in the opposite direction… Furthermore, pseudo-hypogonadism of obesity is a major contributor to the quasi-epidemic of testosterone misuse, with a 100-fold increase in testosterone prescribing over 3 recent decades without any new approved indications ([9](javascript:;)). ### Obesity Effects on the Hypothalamic-pituitary-testicular Axis There is no high-quality evidence supporting obesity as a cause of pathological hypogonadism. Although a strong inverse association exists between the degree of obesity and circulating testosterone concentrations, a much weaker relationship is observed when comparing the relationship between obesity and testosterone in the opposite direction ([10](javascript:;)). This stark contrast is best highlighted in men with prostate cancer undergoing androgen deprivation therapy, whereby serum testosterone concentrations are reduced to castrate levels with minimal increase (2.4%) in underlying body weight ([11](javascript:;)). …

Based on a mendelian randomisation analysis an increase of BMI from 25 to 30kgm2 is causally associated with a decrease in serum testosterone concentration of 13–15%.… ## 2 Obesity and obesity related chronic disorders and the HPT axis In a metanalysis of 68 studies and almost 20,000 men with obesity, 42.8% had a serum total testosterone < 10.4 nmol/L (< 300ng/dl) [[7](https://link.springer.com/article/10.1007/s11154-022-09746-5#ref-CR7)]. Based on a mendelian randomisation analysis an increase of BMI from 25 to 30kgm2 is causally associated with a decrease in serum testosterone concentration of 13–15%. The reverse was not the case, and the effect was only partially dependent on an obesity related decrease in SHBG [[8](https://link.springer.com/article/10.1007/s11154-022-09746-5#ref-CR8)]. Dysfunction of the HPT axis that occurs in people with obesity and associated disorders, lifestyle behaviours. or medication use, is reversible with management directed to the causative factor(s). …

An inverse correlation between BMI and total testosterone (TT) has been reported in our population in previous publications using cross-sectional data materials (Zhao et al., 2017).… For females, the probability of a spontaneous pregnancy declined linearly with a BMI > 29 kg/m 2 (Van der Steeg et al., 2008). For males, overweight and obesity are associated with an increased prevalence of azoospermia or oligozoospermia (Sermondade et al., 2013). Obesity is an independent contributor to erectile dysfunction (Bacon et al., 2003; Derby et al., 2000). An inverse correlation between BMI and total testosterone (TT) has been reported in our population in previous publications using cross-sectional data materials (Zhao et al., 2017). This result is consistent with a systemic review of 31 studies with strong evidence of a negative relationship between TT, free testosterone (FT), and increased BMI (Macdonald et al., 2010). However, few studies have tested whether weight loss can result in a rise in testosterone levels. Several randomized, controlled clinical trials and cohort studies with interventions on obese subjects have attempted to address this question, which obtained positive conclusions (Corona et al., 2013). …

Analyses based on a large sample of undergraduates indicated that testosterone had a positive and statistically significant association with impulsive and violent criminal behavior.## Abstract Only two studies to date have considered the joint effects of testosterone and cortisol on direct measures of criminal behavior. The current study extends this earlier work by incorporating the direct and interactive effects of baseline hormone measures and hormone change scores in response to social stress. The current study also extends prior work by considering distinct measures of different criminal behavior types and sex differences. Analyses based on a large sample of undergraduates indicated that testosterone had a positive and statistically significant association with impulsive and violent criminal behavior. The interaction of testosterone with cortisol had a negative association with income generating crime. Simple slopes analyses of this interaction indicated testosterone had a positive association with income generating crime when cortisol was low (-1 SD). Associations between hormones and criminal behavior were not moderated by sex. Keywords: Cortisol; Crime; Hormones; Testosterone; Violence.

Evidence that hormones and autonomic nervous system activity exert a joint influence on antisocial behavior suggests that they may work together to explain risk for criminal behavior (Bauer et al., 2002). Thus, the current study explored the interactive effects of hormones (testosterone, cortisol) and ANS activity (heart rate, skin conductance) on impulsive and violent criminal behavior in a large sample of University students (n = 495).## Abstract Evidence that hormones and autonomic nervous system activity exert a joint influence on antisocial behavior suggests that they may work together to explain risk for criminal behavior (Bauer et al., 2002). Thus, the current study explored the interactive effects of hormones (testosterone, cortisol) and ANS activity (heart rate, skin conductance) on impulsive and violent criminal behavior in a large sample of University students (n = 495). Initial analyses found positive direct associations between impulsive and violent crime and both testosterone and cortisol, and a negative direct association between heart rate reactivity and impulsive and violent crime. Subsequent analyses revealed a statistically significant interaction between testosterone and heart rate in association with impulsive and violent criminal behavior. …

In men, higher BioT was associated with lower hip circumference and lower fasting glucose. Reciprocally, obesity was associated with lower BioT and higher E2, while upper-body fat distribution and raised triglycerides were associated with lower E2.Results: In women, higher BioT was associated with obesity, upper-body fat distribution, and low HDL-cholesterol although, based on analyses modelling the sex hormone-binding globulin-independent effects of BioT, the last two associations might be indirect. Conversely, obesity and android fat distribution were associated with elevated serum BioT. In men, higher BioT was associated with lower hip circumference and lower fasting glucose. Reciprocally, obesity was associated with lower BioT and higher E2, while upper-body fat distribution and raised triglycerides were associated with lower E2. Conclusions: Adipose tissue and metabolic dysfunction are associated with deranged sex hormone levels in both sexes.

It is well known that obesity decreases testosterone levels, but it is difficult to determine the causal relationship between body composition and testosterone.## Abstract Background: Testosterone is an essential sex hormone that plays a vital role in the overall health and development of males. It is well known that obesity decreases testosterone levels, but it is difficult to determine the causal relationship between body composition and testosterone. Methods: To investigate potential causal associations between body composition and testosterone levels by a first time application of Mendelian randomization methods. Exposure variables in men included body composition (fat mass, fat-free mass, and body mass index). In addition to whole body fat and fat-free mass, we examined fat and fat-free mass for each body part (e.g., trunk, left arm, right arm, left leg and right leg) as exposures. …

Regardless of gender, individuals exhibiting aggressive behavior were proved to have significantly higher testosterone levels and lower cortisol concentrations in saliva measurements.… Most of the papers included in the analysis came from the USA and Europe. Studies typically included adults as well as children, while focusing mainly on men. Among the hormones, salivary testosterone levels were the ones analyzed most frequently. On the basis of the included studies, a meta-analysis was conducted on the relationship between aggressive behavior and the levels of concentration of testosterone and cortisol measured in saliva. Regardless of gender, individuals exhibiting aggressive behavior were proved to have significantly higher testosterone levels and lower cortisol concentrations in saliva measurements. The obtained results indicate the feasibility of using the examined parameters for initial detection of perpetrators of aggression-related violence. However, further research is necessary to more precisely determine the relationship between aggressive behavior and hormonal changes in order to determine the feasibility of using these parameters as an objective marker for early identification of perpetrators. ## Authors

Analyses based on a large sample of undergraduates indicated that testosterone had a positive and statistically significant association with impulsive and violent criminal behavior.… The current study extends this earlier work by incorporating the direct and interactive effects of baseline hormone measures and hormone change scores in response to social stress. The current study also extends prior work by considering distinct measures of different criminal[behavior](https://www.sciencedirect.com/topics/neuroscience/behavior-neuroscience)types and[sex differences](https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/sex-difference). Analyses based on a large sample of undergraduates indicated that testosterone had a positive and statistically significant association with impulsive and violent criminal behavior. The interaction of testosterone with cortisol had a negative association with income generating crime. Simple slopes analyses of this interaction indicated testosterone had a positive association with income generating crime when cortisol was low (−1 SD). Associations between hormones and criminal behavior were not moderated by sex. ## Introduction The costs of crime are substantial. …

Results are consistent with the hypothesis that testosterone leads to antisocial behavior, including perpetration of violence.Conclusion: Results are consistent with the hypothesis that testosterone leads to antisocial behavior, including perpetration of violence. The results are also consistent with the dual hormone hypothesis, i.e., that testosterone and cortisol work together to jointly regulate social dominance and aggression. Both the increased freestanding testosterone and the increased cortisol following exposure to stress places these men at risk for perpetrating violence. Clinical implications are discussed. ## Hormonal differences in perpetrators of intimate partner violence

However, circulating testosterone consistently shows positive associations with antisocial behaviors throughout childhood, adolescence, and adulthood, particularly in males.… Item in Clipboard Full text linksCite Display options Display options FormatAbstractPubMedPMID ## Abstract Life-course persistent antisocial behavior is 10 to 14 times more prevalent in males and it has been suggested that testosterone levels could account for this gender bias. Preliminary studies with measures of fetal testosterone find inconsistent associations with antisocial behavior, especially studies that use the 2D:4D ratio as a proxy for fetal testosterone. However, circulating testosterone consistently shows positive associations with antisocial behaviors throughout childhood, adolescence, and adulthood, particularly in males. It is suggested that high fetal/circulating testosterone interactively influence the maturation and functionality of mesolimbic dopaminergic circuitry, right orbitofrontal cortex, and cortico-subcortical connectivity, resulting in a strong reward motivation, low social sensitivity, and dampened regulation of strong motivational/emotional processes. …

Men, in general, are much more aggressive than women ± a fact that has led researchers to investigate possible links between levels of male hormones (particularly testosterone) and aggressive or criminal behavior.… Testosterone acts as a prohormone which, when converted into 5-alpha-dihydrotestosterone, acts on androgen receptors, or when converted to estradiol by the enzyme aromatase, acts on estrogen receptors. There is overwhelming evidence that most of the effects of testosterone in mediating aggression occur after aromatization [11]. Furthermore, the intensity of aggressive behavior was directly correlated with the aromatase activity in the posterior hypothala mus [12]. Men, in general, are much more aggressive than women ± a fact that has led researchers to investigate possible links between levels of male hormones (particularly testosterone) and aggressive or criminal behavior. Testosterone may affect levels of aggression beginning early in life. In a study conducted among 28 male and 20 female preschoolers, children were videotaped while playing. Levels of aggression in social and play situations were observed and measurements of salivary testosterone levels evaluated. Results indicated a positive correlation in boys (but not in girls) between testosterone levels and serious aggression in social situations, but no correlation with playful aggression [13]. …

It is known that obesity in men is associated with low testosterone and reduced sex hormone-binding globulin (SHBG) levels (19, 20, 21, 22, 23) .… However, available randomized trials are still very few and of limited size and duration (15, 16) . Furthermore, some recent observational studies have suggested caution about the benefits of bariatric surgery, showing no improvement in mortality when compared with standard care (17) and a high rate of long-term surgical complications especially for laparoscopic gastric banding procedures (18) . It is known that obesity in men is associated with low testosterone and reduced sex hormone-binding globulin (SHBG) levels (19, 20, 21, 22, 23) . An obesityassociated decline in SHBG might partially explain the observed fall in testosterone levels (19, 20, 21, 22, 23) . However, it is important to note that an increased BMI was associated with a low measured, or calculated, free and bioavailable testosterone (24) . Specific pathogenetic mechanisms involved in this phenomenon are complex and not completely understood. …

The fact that obese men have lower testosterone compared to lean men has been recognized for more than 30 years.## OBESITY AND LOW TESTOSTERONE: EVIDENCE FROM POPULATION-BASED STUDIES The fact that obese men have lower testosterone compared to lean men has been recognized for more than 30 years. 14 Since then, multiple cross-sectional and prospective studies have consistently found negative linear correlations between both total and free testosterone levels and adiposity in men. …

Testosterone has also been shown to greatly influence male behavior, particularly aggressive behaviors which can termed as antisocial, while also stimulating generosity when it can serve to increase the male’s dominance [15,16].… The safety of testosterone supplement usage has been called into question, with increased incidents of cardiovascular events observed in patients undergoing therapy [12]. Two large-scale observational studies have since confirmed increased occurrence of cardiovascular events as a result of TRT [13,14], leading Health Canada and the US Food and Drug Administration (FDA) to place labels on TRT products in an attempt to warn the public of the potentially adverse cardiological effects of TRT. Testosterone has also been shown to greatly influence male behavior, particularly aggressive behaviors which can termed as antisocial, while also stimulating generosity when it can serve to increase the male’s dominance [15,16]. Over the past few decades, testosterone has been consistently linked to cognitive decline, particularly in the elderly [17]. Results from several epidemiological studies have suggested that testosterone acts as a metabolic hormone in males, as there is a negative correlation between testosterone levels (both free as well as SHBG bound) and obesity across all age groups [18,19,20,21].

More often researchers have examined differences in baseline testosterone concentrations between groups known to differ in aggressiveness (e.g., violent vs non-violent criminals) or within a given sample using a correlational approach.--- Testosterone is often considered a critical regulator of aggressive behaviour. There is castration/replacement evidence that testosterone indeed drives aggression in some species, but causal evidence in humans is generally lacking and/or-for the few studies that have pharmacologically manipulated testosterone concentrations-inconsistent. More often researchers have examined differences in baseline testosterone concentrations between groups known to differ in aggressiveness (e.g., violent vs non-violent criminals) or within a given sample using a correlational approach. Nevertheless, testosterone is not static but instead fluctuates in response to cues of challenge in the environment, and these challenge-induced fluctuations may more strongly regulate situation-specific aggressive behaviour. Here, we quantitatively summarize literature from all three approaches (baseline, change, and manipulation), providing the most comprehensive meta-analysis of these testosterone-aggression associations/effects in humans to date. …

Two hypotheses have been offered to explain the relation between testosterone and antisocial behavior in delinquent and criminal populations. One is that testosterone leads directly to antisocial behavior.## Abstract Two hypotheses have been offered to explain the relation between testosterone and antisocial behavior in delinquent and criminal populations. One is that testosterone leads directly to antisocial behavior. The other is that a constellation of dominance, competitiveness, and sensation seeking associated with testosterone leads to either antisocial or prosocial behavior, depending upon an individual's resources and background. Analysis of archival data from 4,462 U.S. military veterans supported the first hypothesis: Testosterone was correlated with a variety of antisocial behaviors among all individuals. …