Effects of menopausal status on circulating calcitonin gene-related peptide and adipokines: implications for insulin resistance and cardiovascular risks

Objectives To determine, first, the effects of menopausal status on circulating calcitonin gene-related peptide (CGRP) levels and, second, the correlation between circulating CGRP levels and biomarkers for cardiovascular disease. Methods Cross-sectional study of healthy premenopausal and postmenopausal women volunteers and women admitted for elective benign abdominal surgery in a district general hospital. All women were non-smokers, had no history of endocrinological problems and were not receiving any hormone therapy. Fasting blood samples (premenopausal (n=45): follicle stimulating hormone (FSH) <20 IU/l, estradiol (mean +/- SEM) 440.33 +/- 51.82 pmol/l; postmenopausal women (n=28): FSH > 20 IU/l, estradiol 93.79 +/- 17.40 pmol/l) were analyzed for CGRP, resistin, leptin, adiponectin, insulin and lipids using ELISA and immunoassays. Results Mean circulating CGRP levels were higher in the postmenopausal women compared with premenopausal women (pre: 41.79 +/- 9.01 pg/ml, post: 138.14 +/- 45.75 pg/ml; p = 0.047). Among women who were experiencing hot flushes, the postmenopausal women had significantly higher CGRP levels than the premenopausal women (pre: 21.98 +/- 4.95pg/ml, post: 171.08 +/- 61.80 pg/ml; p=0.028). Serum CGRP levels positively correlated with serum insulin levels (r = 0.652, p = 0.016) and HOMA index (r = 0.54, p <0.001). Conclusion These data show that circulating CGRP levels are influenced by menopausal status and suggest additional mechanisms through which increased risk of hyperinsulinemia and cardiovascular disease may arise in postmenopausal women.