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

Abstract

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 +/- 4.95 pg/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.