CARDIOVASCULAR REACTIVITY IN OBSTRUCTIVE SLEEP-APNEA (OSA)

There are only few data on the influence of OSA-activity on blood pres sure (bp) and heart rate reactivity to standardized stress. Intraarter ial 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 c v diseases. Experiments (quiet rest and bicycle exercise) were perform ed after polysomnography. Patients were divided into different RDI cla sses. There were no differences in age, BMI, and pO(2) in the RDI clas ses 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 i n the patients' group with a RDI of > 80. Blood pressure reactivity to physical stress shows impaired function in severe OSA.