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-mediate 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 (μmol/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.