Relationship between heart rate recovery and inflammatory markers in patients with polycystic ovary syndrome: a cross-sectional study

Background: Polycystic ovary syndrome (PCOS) is an endocrine disease closely related to several risk factors for cardiovascular disease. An abnormal heart rate recovery (HRR), an easily-obtained measure derived from exercise stress test and closely related to an increased risk for cardiovascular mortality, has been recently described in PCOS women. A subclinical increase of the inflammation markers has been also observed in the PCOS. This study was designed to study the relationships between HRR and inflammatory markers in PCOS women. Methods: Two-hundred forty-three young PCOS patients without known risk factors for cardiovascular risk were enrolled. All patients underwent hormonal and metabolic profile, white blood cells (WBCs) count and C-reactive protein (CRP). HRR was calculated as the difference between heart rate at peak exercise and heart rate at first minute of the cool-down period. Abnormal HRR was defined as <= 18 beats/min for standard exercise testing. Results: Eighty-nine out of 243 patients presented abnormal HRR. Serum CRP (1.8 +/- 0.7 vs. 1.1 +/- 0.4 mg/dl, p < 0.001) and WBCs (7.3 +/- 1.8 vs. 6.6 +/- 1.5 10(9) cells/l, p < 0.001) concentrations were significantly higher in PCOS patients with abnormal versus normal HRR. HRR was significantly associated with both CRP (r = -0.33, p < 0.001) and WBCs (r = -0.29, p < 0.001), although in a stepwise multiple regression HRR resulted independently associated with CRP (beta = -0.151, p = 0.001) alone. In a logistic multivariate model, the group within the highest quartile of CRP (odds ratio 1.59, 95% CI 1.07-2.33) was more likely to have abnormal HRR than those within the lowest quartile. Conclusion: Abnormal HRR and inflammatory markers are closely associated in PCOS women acting probably in concert to increase the cardiovascular risk profile of these patients.