In this study, a well-characterized group of pre- and perimenopausal women with clinically and biochemically active RA, compared with age- and BMI-matched healthy women, exhibited reduced morning serum concentrations of IGF-I, a trend toward lower IGFBP-3, accelerated GH circulatory half-life, trends toward increases in IGFBP-1 and IL-6 levels (and total GH production), unaltered pulsatile, nycthemeral, or feedback-sensitive (entropic) features of cortisol or DHEA secretion, and substantially decreased LBM, especially in the legs. Here, IGFBP1 is linked to rheumatoid arthritis.