Cardiovascular reactivity in obstructive sleep apnea (OSA)

There are only few data on the influence of OSA-activity on blood pressure (bp) and heart rate reactivity to standardized stress. Intraarterial bp was investigated in 55 consecutively investigated male patients (mean age 50.9 years, mean BMI 31.6 kg/m(2)) with OSA (mean RDI 48.8), HT (mean bp 157 +/- 18.7/100 +/- 11.1 mmHg) and exclusion of other cv diseases. Experiments (quiet rest and bicycle exercise) were performed after polysomnography. Patients were divided into different RDI classes. There were no differences in age, BMI, and pO(2) in the RDI classes 0-60. Only patients with RDI > 60 were significantly younger (44.2) and more obese (35.7 kg/m(2)). BP at rest increases in the patients' group with RDI of < 20 from 135.68 mmHg to 146.92 mmHg when RDI was > 80. Bp increase to 100 Watt exercise was 62.02 mmHg in the patients' group with RDI of < 20 and was significantly reduced with 45.65 mmHg in the patients' group with a RDI of > 80. Blood pressure reactivity to physical stress shows impaired function in severe OSA.