Protective effect of androgens against inflammation induced cartilage degradation in male rodents

The causal impact of bioavailable testosterone levels on osteoarthritis: a bidirectional Mendelian randomized study

BACKGROUND

It has been shown that low testosterone levels are associated with the development of osteoarthritis (OA). In our study, we aimed to investigate a bidirectional causal relationship between bioavailable testosterone levels and OA using Mendelian randomization (MR) analysis.

METHODS

In our study, the datasets from publicly available genome-wide association study (GWAS) were adopted, including the OA-related dataset (ukb-b-14486) and the bioavailable testosterone levels-related dataset (ebi-a-GCST90012104). The UKB-B-14,486 dataset contains 462,933 samples in total, including 38,472 OA samples, 424,461 control samples, and 9,851,867 SNPs, all collected from the European population in 2018. Additionally, the EBI-A-GCST90012104 dataset includes 382,988 samples and 16,137,327 SNPs, which reflect data from the European population in 2020. In total, five methods were utilized, namely MR Egger, Weighted median, Inverse variance weighted (IVW), Simple mode, and Weighted mode. Among them, IVW was the main analytical method. Additionally, the sensitivity analysis was carried out through the heterogeneity test, the horizontal pleiotropy test, and the Leave-One-Out (LOO) method.

RESULTS

The result of forward MR analysis demonstrated that bioavailable testosterone levels were considerably relevant to OA, and were a risk factor for OA (OR = 1.01, 95% CI: [1.00, 1.02], P = 0.02). However, through reverse MR analysis, we did not find a causal relationship between OA and bioavailable testosterone levels. Moreover, the results of the sensitivity analysis suggested that our results were reliable.

CONCLUSION

The results of our study supported a causal relationship between bioavailable testosterone levels and OA.

A History of Psycho-Neuro-Endocrine Immune Interactions in Rheumatic Diseases

BACKGROUND

All active scientists stand on the shoulders of giants and many other more anonymous scientists, and this is not different in our field of psycho-neuro-endocrine immunology in rheumatic diseases. Too often, the modern world of publishing forgets about the collective enterprise of scientists. Some journals advise the authors to present only literature from the last decade, and it has become a natural attitude of many scientists to present only the latest publications. In order to work against this general unempirical behavior, neuroimmunomodulation devotes the 30th anniversary issue to the history of medical science in psycho-neuro-endocrine immunology.

SUMMARY

Keywords were derived from the psycho-neuro-endocrine immunology research field very well known to the authors (R.H.S. has collected a list of keywords since 1994). We screened PubMed, the Cochran Library of Medicine, Embase, Scopus database, and the ORCID database to find relevant historical literature. The Snowballing procedure helped find related work. According to the historical appearance of discoveries in the field, the order of presentation follows the subsequent scheme: (1) the sensory nervous system, (2) the sympathetic nervous system, (3) the vagus nerve, (4) steroid hormones (glucocorticoids, androgens, progesterone, estrogens, and the vitamin D hormone), (5) afferent pathways involved in fatigue, anxiety, insomnia, and depression (includes pathophysiology), and (6) evolutionary medicine and energy regulation - an umbrella theory.

KEY MESSAGES

A brief history on psycho-neuro-endocrine immunology cannot address all relevant aspects of the field. The authors are aware of this shortcoming. The reader must see this review as a viewpoint through the biased eyes of the authors. Nevertheless, the text gives an overview of the history in psycho-neuro-endocrine immunology of rheumatic diseases.

Sex-dependent variation in cartilage adaptation: from degeneration to regeneration

Despite acknowledgement in the scientific community of sex-based differences in cartilage biology, the implications for study design remain unclear, with many studies continuing to arbitrarily assign demographics. Clinically, it has been well-established that males and females differ in cartilage degeneration, and accumulating evidence points to the importance of sex differences in the field of cartilage repair. However, a comprehensive review of the mechanisms behind this trend and the influence of sex on cartilage regeneration has not yet been presented. This paper aims to summarize current findings regarding sex-dependent variation in knee anatomy, sex hormones' effect on cartilage, and cartilaginous degeneration and regeneration, with a focus on stem cell therapies. Findings suggest that the stem cells themselves, as well as their surrounding microenvironment, contribute to sex-based differences. Accordingly, this paper underscores the contribution of both stem cell donor and recipient sex to sex-related differences in treatment efficacy. Cartilage regeneration is a field that needs more research to optimize strategies for better clinical results; taking sex into account could be a big factor in developing more effective and personalized treatments. The compilation of this information emphasizes the importance of investing further research in sex differences in cartilage biology.

Polycystic ovary syndrome and (pre)osteoarthritis: assessing the link between hyperandrogenism in young women and cartilage oligomeric matrix protein as a marker of cartilage breakdown

INTRODUCTION

OBJECTIVES: Our aim was to analyze the link between hyperandrogenism and early clinical manifestations of osteoarthritis (OA), knee cartilage thickness, and serum cartilage oligomeric matrix protein (sCOMP) levels in patients with polycystic ovary syndrome (PCOS) and to compare them with healthy volunteers.

METHODS

Fifty-four PCOS patients who met the Rotterdam criteria with phenotypes A, B, and C were included. They were compared with 26 age- and body mass index (BMI)-matched controls. Detailed anthropometric measurements and clinical evaluation for hyperandrogenism were performed for all participants who also filled in the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire. Furthermore, laboratory tests including sCOMP and hormone quantification were performed in a fasting stage. Finally, an ultrasound assessment was carried out in randomly selected 56 study participants.

RESULTS

PCOS women reported more prominent knee-related symptoms (p = 0.035) and more impaired activities of daily living (ADL) (p = 0.001) than controls. Cartilage thickness of the left and right medial condyle and left lateral condyle was significantly greater in PCOS group (n = 41) than in control group (n = 15) (p = 0.05, p = 0.006, and p = 0.036, respectively). COMP correlated significantly and negatively with testosterone levels (p = 0.029, r =  - 0.297) in women with PCOS and the correlation remained significant after controlling for BMI.

CONCLUSIONS

Women with PCOS may experience knee-related symptoms and impaired ADL. They had greater knee femoral cartilage thickness. Although sCOMP levels did not significantly differ between the groups, lower levels of sCOMP may be inherent to PCOS patients with higher testosterone levels. Key Points • Although PCOS patients may experience more prominent knee related symptoms, their femoral cartilage of the knee joint is found thicker than controls. • PCOS patients did not have significantly elevated levels of sCOMP. • Lower sCOMP levels were related to higher testosterone levels.

The Effect of Androgens on Proinflammatory Cytokine Secretion from Human Ocular Surface Epithelial Cells

Purpose: The purpose of this study is to explore the effects of dihydrotestosterone (DHT) on lipopolysaccharide (LPS)-induced proinflammatory cytokine release in human ocular surface epithelial cells exposed to LPS and LPS-binding protein (LBP).Methods: Immortalized human corneal, conjunctival, and meibomian gland epithelial cells were cultured in keratinocyte-free medium. After confluency, they were exposed to a stratification medium Dulbecco's modified Eagle medium (DMEM)/F12 in the presence of fetal bovine serum and were exposed to vehicle, LPS + LBP, or DHT. Culture media were processed for multiplex-bead analysis of specific proinflammatory cytokines including interferon (IFN)-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-2, IL-4, IL-8, IL-6, IL-10, IL-1β, vascular endothelial growth factor (VEGF)-A. Cytokine concentrations were compared by analysis of variance with Tukey post hoc testing. p < 0.05 was considered statistically significant.Results: The results are LPS + LBP-induced the secretion of IFN-γ, IL-6, IL-10, IL-1β, VEGF-A cytokines in corneal epithelial cells; TNF-α, IL-2, IL-8, IL-6, IL-1β, VEGF-A cytokines in conjunctival epithelial cells; and IL-8, IL-6, IL-1β, VEGF-A cytokines in meibomian gland epithelial cells. When these LPS + LBP-stimulated cells were exposed to DHT for 2 days, it was found that DHT suppressed the secretion of IL-6, IL-10, IL-1β, VEGF-A cytokines in corneal epithelial cells; TNF-α, IL-6, IL-1β, VEGF-A cytokines in conjunctival epithelial cells; and IL-6, IL-1β, VEGF-A cytokines in meibomian gland epithelial cells.Conclusion: LPS + LBP is shown to induce the secretion of certain proinflammatory cytokines from ocular surface and adnexal epithelial cells. DHT showed anti-inflammatory activity by suppressing some of those cytokines in these cell lines.

Sex-associated Treatment Differences and Their Outcomes in Rheumatoid Arthritis: Results from the METEOR Register

OBJECTIVE

To assess differences in initial treatment and treatment response in male and female patients with rheumatoid arthritis (RA) in daily clinical practice.

METHODS

The proportion of patients with RA starting different antirheumatic treatments (disease-modifying antirheumatic drugs; DMARD) and the response to treatment were compared in the international, observational METEOR register. All visits from start of the first DMARD until the first DMARD switch or the end of followup were selected. The effect of sex on time to switch from first to second treatment was calculated using Cox regression. Linear mixed model analyses were performed to assess whether men and women responded differently to treatments, as measured by Disease Activity Score (DAS) or Health Assessment Questionnaire.

RESULTS

Women (n = 4393) more often started treatment with hydroxychloroquine, as monotherapy or in combination with methotrexate (MTX) or a glucocorticoid, and men (n = 1142) more often started treatment with MTX and/or sulfasalazine. Time to switch DMARD was shorter for women than for men. Women had a statistically significantly higher DAS over time than men (DAS improvement per year β -0.69, 95% CI -0.75 to -0.62 for men and -0.58, 95% CI -0.62 to -0.55 for women). Subanalyses per DMARD group showed for the conventional synthetic DMARD combination therapy a slightly greater decrease in DAS over time in men (-0.89, 95% CI -1.07 to -0.71) compared to women (-0.59, 95% CI -0.67 to -0.51), but these difference between the sexes were clinically negligible.

CONCLUSION

This worldwide observational study suggests that in daily practice, men and women with RA are prescribed different initial treatments, but there were no differences in response to treatment between the sexes.

Impact of gender on the response and tolerance to abatacept in patients with rheumatoid arthritis: results from the 'ORA' registry

Objective

The impact of gender on the response and tolerance to abatacept was assessed in a large prospective cohort during 2 years of follow-up.

Methods

From the 1017 patients included in the Orencia and Rheumatoid Arthritis registry, disease activity was assessed at baseline, 6, 12 and 24 months. The relationship between the European League Against Rheumatism (EULAR) response, Disease Activity Score 28 (DAS28) remission, rate of adverse events and gender was explored in multivariate analysis.

Results

990 patients, 79.3%female, with at least one follow-up visit were analysed. At baseline, women had longer disease duration, higher disease activity and more often received antitumour necrosis factor (TNF) drugs. The remission was not different between men and women during the follow-up after adjustment on age, disease duration and activity, rheumatoid factor and anti-cyclic citrullinated pyeptide (CCP) positivity, and current disease-modifying antirheumatic drugs (DMARDs), previous TNF blockers and corticosteroids use. The proportion of men and women achieving EULAR good-or-moderate response at any endpoints was similar (52.4% vs 55.5%), as well as time to achieving EULAR response (5.4±4.9 vs 5.6±5.2 months). Moderate EULAR response was more frequent in women at 6 months (OR=1.80, p=0.02) but was no longer significant at 12 or 24 months. During the follow-up, the DAS28, the tender joint count score and the patient global assessment remained higher in women (p=0.001, 0.04 and 0.06, respectively). Drug retention and safety were comparable.

Conclusion

In this large daily practice cohort of established rheumatoid arthritis treated with abatacept, women achieved similar remission and EULAR response than men despite higher disease activity and tender joint count during the treatment course.

Testosterone may increase rat anterior cruciate ligament strength

BACKGROUND

Women are more likely than men to injure the anterior cruciate ligament (ACL). Human and animal trials have linked circulating estradiol to injury rate and ligament strength. Fewer studies have examined the role of testosterone. The purpose of this study was to determine if male rats with normal testosterone levels would have stronger ACLs than castrated rats.

METHODS

Eight castrated (group C) and eight normal (group N) 12-week-old, male Sprague-Dawley rats were used for the study. Mean testosterone levels were 0.14ng/mL (95% CI: 0.10 to 0.17) in group C and 3.54ng/mL (95% CI: 1.32 to 5.76) in group N. After euthanasia, ACL cross-sectional area was calculated, and a servohydraulic material testing unit was used to measure ligament properties.

RESULTS

Specimens from both groups had similar cross-sectional area, but N specimens showed greater mean load-to-failure (34.5N [95% CI: 31.6 to 37.4] vs 29.2N [95% CI: 27.9 to 30.6]) and ultimate stress (38.7MPa [95% CI: 34.1 to 43.3] vs 31.8MPa [95% CI: 29.8 to 33.8]). Mean energy was 27.7mJ (95% CI: 23.1 to 32.2) in the N group and 23.4mJ (95% CI: 18.2 to 28.6) in the C group.

CONCLUSIONS

Rats with normal circulating testosterone had higher ACL load-to-failure and ultimate stress, indicating that testosterone may influence ACL strength and the injury rate of the ligament.

Effect of gonadal steroid hormones on formalin-induced temporomandibular joint inflammation

We have recently demonstrated that gonadal steroid hormones decrease formalin-induced temporomandibular joint nociception in rats. Given that the attenuation of inflammation is a potential mechanism underlying this antinociceptive effect, we evaluated the effect of gonadal steroid hormones on formalin-induced temporomandibular joint inflammation. Plasma extravasation, a major sign of acute inflammation, and neutrophil migration, an important event related to tissue injury, were evaluated. Formalin induced significantly lower temporomandibular joint plasma extravasation and neutrophil migration in proestrus females than in males and in diestrus females. Since estradiol serum level is high in proestrus females and low in diestrus females and in males, these findings suggest that the high physiological level of estradiol decreases temporomandibular joint inflammation. Estradiol but not progesterone administration in ovariectomized females significantly decreased formalin-induced plasma extravasation and neutrophil migration, an effect that was blocked by the estrogen receptor antagonist ICI 182780. Plasma extravasation and neutrophil migration were not affected by orchiectomy, but testosterone or estradiol administration in orchidectomized males significantly decreased them. The androgen receptor antagonist flutamide blocked the anti-inflammatory effect of testosterone while ICI 182780 blocked that of estradiol in males. Previous intravenous administration of a nonspecific selectin inhibitor significantly decreased formalin-induced temporomandibular joint nociception and neutrophil migration in males, revealing a potent and positive correlation between temporomandibular joint nociception and inflammation. Taken together, these findings demonstrate a pronounced anti-inflammatory effect of estradiol and testosterone in the temporomandibular joint region and suggest that this effect may mediate, at least in part, the antinociceptive effect of these hormones.

Carcinogenesis induced by foreign bodies

This review deals with the contemporary investigations of carcinogenesis induced by foreign bodies. The main attention is given to the interactions of macrophages with an implanted foreign body and their possible role in tumorigenesis.

Modulation of pain by estrogens

It has become increasingly apparent that women suffer a disproportionate amount of pain during their lifetime compared to men. Over the past 15 years, a growing number of studies have suggested a variety of causes for this sex difference, from cellular to psychosocial levels of analysis. From a biological perspective, sexual differentiation of pain appears to occur similarly to sexual differentiation of other phenomena: it results in large part from organizational and activational effects of gonadal steroid hormones. The focus of this review is the activational effects of a single group of ovarian hormones, the estrogens, on pain in humans and animals. The effects of estrogens (estradiol being the most commonly examined) on experimentally induced acute pain vs. clinical pain are summarized. For clinical pain, the review is limited to a few syndromes for which there is considerable evidence for estrogenic involvement: migraine, temporomandibular disorder (TMD) and arthritis. Because estrogens can modulate the function of the nervous, immune, skeletal, and cardiovascular systems, estrogenic modulation of pain is an exceedingly complex, multi-faceted phenomenon, with estrogens producing both pro- and antinociceptive effects that depend on the extent to which each of these systems of the body is involved in a particular type of pain. Forging a more complete understanding of the myriad ways that estrogens can ameliorate vs. facilitate pain will enable us to better prevent and treat pain in both women and men.

Organizational and activational effects of testosterone on carrageenan-induced inflammatory pain and morphine analgesia

Men are typically reported to have higher pain thresholds than women. Gonadal hormones, particularly testosterone for males, may contribute to this effect. This study tested whether changes in the male hormonal milieu early or late in development alter the inflammatory pain induced by carrageenan (CARR, 3%, intraarticular). Male rats were either gonadectomized or sham gonadectomized neonatally. Once adults, the same rats underwent either sham surgery or gonadectomy, and received a testosterone or oil implant. After baseline testing two weeks later, animals were tested in response to mechanical and thermal stimulation following CARR-induced inflammation and injection of saline, 1 mg/kg, or 5 mg/kg morphine. Hormone alterations did not affect baseline responses, but CARR induced mechanical and thermal hyperalgesia in the injured limb. Gonadectomy in adult males injected with saline enhanced inflammation-induced sensitivity to mechanical but not thermal stimulation and the effect was reversed by testosterone. After inflammation, saline-treated males gonadectomized neonatally displayed lower mechanical threshold than control sham animals but this effect was not reversed by testosterone. Both doses of morphine increased mechanical and thermal thresholds. However, compared with the control group, 1 mg/kg morphine was equally effective in reducing mechanical hyperalgesia among groups of animals gonadectomized as adults, but less effective in males gonadectomized neonatally. The results suggest that in males: 1. the antihyperalgesic effect of testosterone (or its metabolites) in CARR-induced inflammation is established during development and maintained by circulating levels of testosterone in adulthood; 2. the nociception-related interaction between the opioid and gonadal systems influences the sensitivity to mechanical stimuli and is likely established during the period of sexual differentiation.

Hormonal and immunologic risk factors for the development of rheumatoid arthritis: an integrative physiopathogenetic perspective

Evidence indicates that women who are susceptible to premenopausal onset of RA and men each have identifiable risk factors or risk markers long before onset of the clinical disease. Accordingly, further definition of such predictive factors promises to identify persons who are susceptible to developing RA during preclinical phases. Like coronary artery disease, once risks for developing RA can be reliably quantitated, research in primary prevention should become a realistic objective. Disease prevention objectives are central to the public health strategy of the National Arthritis Action Plan and the US Public Health Service "Healthy People 2000" plan (2010 plan also proposed). The decade of arthritis and musculoskeletal diseases (2000-2010) offers an incentive to nurture a new paradigm of RA prevention. Further research in neuroendocrine, immunologic, and microvascular risk factors for the development of RA promises to unravel its complex physiopathogenetic mechanisms and permit identification of persons who are at high risk for developing this disease. Successful research in identifying reliable risk factors (or markers) can be expected to lead to prevention strategies. Effective programs in identifying persons susceptible to RA could lead to earlier control measures and significantly reduce the enormous burden of this common disease, which affects all segments of the population.

Sex steroid regulation of the inflammatory response: sympathoadrenal dependence in the female rat

To investigate the role of sex steroids in sex differences in the response of rats to the potent inflammatory mediator bradykinin (BK), we evaluated the effect of sex steroid manipulation on the magnitude of BK-induced synovial plasma extravasation (PE). The magnitude of BK-induced PE is markedly less in females. Ovariectomy of female rats increased BK-induced PE, and administration of 17beta-estradiol to ovariectomized female rats reconstituted the female phenotype. Castration in male rats decreased BK-induced PE, and administration of testosterone or its nonmetabolizable analog dihydrotestosterone reconstituted the male phenotype. The results of these experiments strongly support the role of both male and female sex steroids in sex differences in the inflammatory response. Because the stress axes are sexually dimorphic and are important in the regulation of the inflammatory response, we evaluated the contribution of the hypothalamic-pituitary-adrenal and the sympathoadrenal axes to sex differences in BK-induced PE. Neither hypophysectomy nor inhibition of corticosteroid synthesis affected BK-induced PE in female or male rats. Adrenal denervation in females produced the same magnitude increase in BK-induced PE as adrenalectomy or ovariectomy, suggesting that the adrenal medullary factor(s) in females may account for the female sex steroid effect on BK-induced PE. Furthermore, we have demonstrated that in female but not male rats, estrogen receptor alpha immunoreactivity is present on medullary but not cortical cells in the adrenal gland. These data suggest that regulation of the inflammatory response by female sex steroids is strongly dependent on the sympathoadrenal axis, possibly by its action on estrogen receptors on adrenal medullary cells.

Sex steroid regulation of the inflammatory response: sympathoadrenal dependence in the female rat

To investigate the role of sex steroids in sex differences in the response of rats to the potent inflammatory mediator bradykinin (BK), we evaluated the effect of sex steroid manipulation on the magnitude of BK-induced synovial plasma extravasation (PE). The magnitude of BK-induced PE is markedly less in females. Ovariectomy of female rats increased BK-induced PE, and administration of 17beta-estradiol to ovariectomized female rats reconstituted the female phenotype. Castration in male rats decreased BK-induced PE, and administration of testosterone or its nonmetabolizable analog dihydrotestosterone reconstituted the male phenotype. The results of these experiments strongly support the role of both male and female sex steroids in sex differences in the inflammatory response. Because the stress axes are sexually dimorphic and are important in the regulation of the inflammatory response, we evaluated the contribution of the hypothalamic-pituitary-adrenal and the sympathoadrenal axes to sex differences in BK-induced PE. Neither hypophysectomy nor inhibition of corticosteroid synthesis affected BK-induced PE in female or male rats. Adrenal denervation in females produced the same magnitude increase in BK-induced PE as adrenalectomy or ovariectomy, suggesting that the adrenal medullary factor(s) in females may account for the female sex steroid effect on BK-induced PE. Furthermore, we have demonstrated that in female but not male rats, estrogen receptor alpha immunoreactivity is present on medullary but not cortical cells in the adrenal gland. These data suggest that regulation of the inflammatory response by female sex steroids is strongly dependent on the sympathoadrenal axis, possibly by its action on estrogen receptors on adrenal medullary cells.

Perturbations of hypothalamic-pituitary-gonadal (HPG) axis and adrenal androgen (AA) functions in rheumatoid arthritis

The available evidence reviewed does not allow definitive response to the question of a primary versus secondary role of sex hormone perturbations in RA. However, this conclusion should not be discouraging in view of the relatively recent focus upon this facet of the physiopathogenesis of RA and the enormous complexities of sex hormone biology and this disease. Specifically, data on the incidence of RA as well as life cycle changes in serum androgenic-anabolic (A-A) and sex hormone levels suggest important risk correlations. Furthermore, HLA-susceptibility markers for RA, gender, menopause and older age are all factors which significantly relate to the risk of developing RA and each has been shown to associate with sex hormone status. Whether or not HPG-AA hormonal status may modulate RA risk (or its course) primarily and independently or merely be predictive markers of other biological mechanisms was critically considered and requires further study. Sex hormone influences on cellular and humoral immunological reactivity and vascular pathogenetic mechanisms in RA were summarized. Androgens generally suppress immunoreactivity and cartilage responses to inflammation-mediated injury processes and may enhance synovial macrophage-like lining cell apoptosis. Oestrogens generally enhance immunoreactivity, offer some protection to inflammation-mediated cartilage damage (but less than androgens) and may inhibit apoptosis in certain in vitro cell models. Scant information is available on the balance of sex hormones (and glucocorticoids) in RA or its presumed pathogenetic mechanisms. Data were reviewed which support the concept of a spectrum of androgenicity in the normal population, particularly among women. A simplified schema of trophic and tropic steroidogenic mechanisms was proposed which could influence androgenic-anabolic (A-A) status and might relate to RA. Serum concentrations of DHAS (mumol/l), T (nmol/l) and O2 (pmol/l) span several orders of magnitude in normal physiology. The effects of alterations in the individual levels of these sex hormones and deviations from their normal physiological balance are not well understood. Critical attention to their biological functions is needed in RA as well as in health and disease generally. Such focused clinical and experimental investigations of HPG-AA functions promise to clarify the complex physiopathology of RA and contribute to its improved long-term management.

Hormonal and pregnancy relationships to rheumatoid arthritis: convergent effects with immunologic and microvascular systems

OBJECTIVE

To review sex hormones and rheumatoid arthritis (RA) and the interrelationships between hormonal, immunological, and vascular systems.

DATA SOURCES

Publications detailing serum sex hormone levels and their HLA interactions, steroidogenesis, pregnancy, and therapeutic uses of sex hormones in RA.

STUDY SELECTION

Controlled studies of sex hormone levels in RA patients not previously treated with glucocorticoids.

DATA EXTRACTION

Mean (+/- SD) serum levels of dehydroepiandrosterone sulfate (DHEAS), testosterone (T), and estradiol (E2).

DATA SYNTHESIS

Mean (+/- SD) levels were collated into tables for women with pre-versus postmenopausal onsets of disease and men. Data were also ordered across all study groups by increasing mean levels of the control subjects. Pooled data were summarized statistically, and major sources of variation between the studies were identified.

CONCLUSIONS

Serum DHEAS, an adrenal androgen, was impressively decreased among women with premenopausal onset of RA. One study showed such deficiency years before disease onset. Serum T was somewhat decreased in the premenopausal onset group, but could be explained by decreased peripheral conversion of the lower levels of adrenal androgens. Women with postmenopausal onset of RA had modestly decreased serum DHEAS levels overall, but no difference in serum T, compared with controls. Male RA cases had consistently decreased serum levels of T, but not of DHEAS. Serum E2 was comparable in all RA versus control groups. The complex biology of pregnancy was interpreted as an example of vital interactions between hormonal, immunological, and vascular systems, as they may relate to the physiopathology of RA. The major age, sex, and hereditable determinants of RA were compared within a composite table of estimated relative risks. Elucidation of the interacting risk factors offers promising avenues of research in this complex disease.