This is a study in pre-menopausal and perimenopausal women with onset of rheumatoid arthritis (RA) of less than 10 years duration, to be conducted at the Clinical Center of National Institutes of Health and The General Clinical Research Center of the Johns Hopkins Bayview Medical Center, Baltimore, MD. This investigation will explore the possible impact of systemically released inflammatory cytokines on suppression of the GH/IGF-1 axis, and the relationships of altered endocrine-immune function with body composition, endocrine, metabolic and vascular functions thought to be associated with RA-related sarcopenia, osteopenia and increased cardiovascular risk. In phase I of the study, we shall admit RA patients and control subjects to the Clinical Center for a 26-36 hour period for assessments of the GH/IGF-I axis, cytokines, body composition, endocrine-metabolic and cardiovascular functions, and quality of life. We plan to initiate Phase I of the study to compare baseline endocrine and inflammatory parameters in RA patients to matched normal controls. Phase II of the study, we shall enroll a new group of RA patients to evaluate the above outcome measures at baseline and after six months of treatment with standard therapy, using the soluble p75 TNF receptor molecule etanercept, that has recently been approved by the FDA for the treatment of patients with early RA. Phase 2 of this study will be initiated upon access to etanercept and completion of Phase I of the study.