Postmenopausal women with vasomotor symptoms have increased urinary excretion of calcitonin gene-related peptide.

Objectives: To establish whether 24 h urinary excretion of the potent vasodilator calcitonin gene-related peptide (CGRP) was higher in postmenopausal women with vasomotor symptoms compared to the level in women without symptoms. We also wanted to establish whether urinary excretion of CGRP changed during the menstrual cycle in women of fertile age.

Material And Methods: Thirteen postmenopausal women with and 13 women without vasomotor symptoms were included. Urine was collected over 24 h and CGRP excretion was measured utilizing radio-immunoassay technique. Twenty-four hour CGRP excretion was also measured in ten fertile women with regular cycles in early follicular, preovulatory and midluteal phase.

Results: Twenty-four hour urinary excretion of CGRP was significantly higher in women with vasomotor symptoms compared to non-flushing women (median 7.16 vs 5.15 pmol/24 h; P = 0.028). CGRP concentrations were stable throughout the ovulatory cycles.

Conclusion: The 24 h urinary excretion of CGRP is higher in women with vasomotor symptoms than in women without these symptoms. CGRP may be the mediator of vasodilator signals originating from the thermoregulatory center.