High prevalence of increased interleukin-17A serum levels in postmenopausal estrogen deficiency

OBJECTIVE: Postmenopausal estrogen deficiency is associated with chronic inflammatory events that cause cardiovascular and osteoporosis diseases. The aim of this study was to investigate the relationship between interleukin (IL)-17 and serum estradiol levels, age, and postmenopausal duration, as well as bone loss. METHODS: The relationship between serum IL-17A and estradiol levels was studied in 72 postmenopausal women and 22 premenopausal women. Enzyme-linked immunosorbent assay and chemiluminescence were used to detect IL-17A and estradiol, respectively. RESULTS: Estradiol levels were significantly higher and IL-17A levels were significantly lower in premenopausal women compared with postmenopausal women (estradiol: 239.44 [226.17] vs 74.21 [4.44] pmol/L, P < 0.0001; IL-17A: 2.88 [0.08] vs 3.5 [0.56] ng/mL, P < 0.0001). Seventy-eight of 94 women had lower estradiol levels (<83 pmol/L) with elevated IL-17A levels, in comparison with 16 women who had normal estrogen levels (3.43 [0.56] vs 3.01 [0.38] ng/mL, P < 0.0001). IL-17A levels inversely correlated with the total lumbar T-scores calculated in all women (P < 0.0001). IL-17A levels showed age-related dependency and a remarkable association with the postmenopausal period (P < 0.03). CONCLUSIONS: The results demonstrate a high prevalence of increased serum IL-17A levels in postmenopausal estrogen deficiency, which can play an inducing role in chronic inflammatory events such as bone loss.