The aim of the study was to estimate the sympathetic activity in patients with obstructive sleep apnea (OSAS) and to evaluate the correlation between serum concentration of epinephrine and norepinephrine compared with body mass index and other constitual parameters. All patients underwent polysomnography. They were all classified as having OSA with AHI>10.
30 patients (27 M,3 F),aged 30-71(x= 50,96 ±9,90)were included in the study. In 5 cases hypertensive disorder were diagnosed. Based on body mass index (BMI) the obesity was found in 15 patients and overweight in 11 ones.The serum concentration of epinephrine, norepinephrine, urine acid, glucose and lipids level were measured in all patients.The HPLC methods(BIO- Rad Laboratories)were used to estimate the concentration of catecholamines.
The middle serum concentration of epinephrine in hypertension group vs non hypertension group was 97.12±45.04 vs 57.25±26.56 pg/mL ( N:10-82pg/mL, x=27pg/mL vs 10-67 pg/ml x= 25pg/mL), and norepinephrine 625,26±147,81 vs 482.57±157.27pg/mL (N:41-773pg/mL x=288pg/mL vs 95-446 pg/mL x= 286pg/mL).There were observed positive correlation between epinephrine concenration(1)and norepinephrine(2) and body weigh (kg) (r1=0.44, r2=0.44), BMI (r1=0.44. r2=0.38) and waist/hips index (r2 = 0.38). The were also statistically significant correlation between catecholamines level and with uric acid concentration(r1=0.49, r2=0.77).CONCLUSIONS: We found the higher plasma catecholamines concentration in study group than in normal population, which is suggested a chronic elevation of sympathetic activity in OSAS. There were statistically significant correlation between serum catecholamines level and body weigh, BMI, waist/hips index and serum uric acid concentration.
Elevated sympathetic activity may explain the increased cardiovascular morbidity associated with obstructive sleep apnoea.
R. Chazan, Medical University of Warsaw, University monies.