A Study On Blood Pressure Variability In Sleep Apnea Population

Obstractive:â‘ To study the influence of sleep apnea on blood pressure.â‘¡To assess whether sleep apnea is an independent influence factor forhigher blood pressure and blood pressure varability after controllingconfondering factors(such as age, gender, BMI, smoke, drink, et al).â‘¢To explore the relationship between the state of oxygeon desatuationand blood pressure elevation or abnormal blood pressure variabilityin sleep hyponea.Methods:857 cases all come from the general hospital outpatient sleepclinical of Tan Jin Medical University. All subjects accepted the simplephysicial examination and filled in the same sleepquestionnaire. Performed the full nocturnal polysomnography and measuredthe blood pressure before subjects onset sleep and in the next morningat the moment awaken. Classfied all cases into four groups includedwithout SA,mild SA,moderate SA and severe SA. Compared the blood pressureand blood pressure variation among the groups and then analysised thecorrelation between them and sleep parameters. Chosed 217 cases from thesubjects who came to the clinic on the dates and mesure the blood pressurein the midnight.Categorized the 217 cases into hypertensive andnormotensive on the base of their blood pressures. Compare the decreasevalue of the blood pressure and then analysised the correlations.Result:â‘ The blood pressure(SBP,DBP,MAP) of severe SA group weresignificanlly higher than the other three groups. MAP on the awakeningmoment decreased (1.74±9.03) mmHg(P=0.02) in the no SA group and (2.14±9.75) mmHg (P=0.002) in the mild SA group but increased (1.14± 10.48)mmHg(P=0.010)in the severe SA group and no significance in themoderate SA group. The increase value of blood pressure between afterawaken and before sleep was significantly higher than the other threegroups.â‘¡AHI could predict MAP before sleep and at the awake momentindependently. With AHI increased 1 time/h MAP before sleep increased0.098mmHg and MAP awaken increased 0.075mmHg.â‘¢AHI was significantlyhigher and minSaO₂,MSaO₂ were significantly lower inhypertensive than normotensive(P＜0.05).â‘£SBP before go to bed,SBP,DBP in midnight and SBP,DBP on awakening were all higher inhypertensive than nonhypertensive significantly(P＜0.05).⑤The decreasevalue of blood pressure from before sleep to midnight(â–³SBP,â–³DBP,â–³MBP) were significantly lower in hypertensive than normotensive(P＜0.05).â‘¥There were positive correlation between midnight SBP and AHI,age, BMI, between DBP and AHI, BMI and between midnight MAP and AHI,age,BMI. AHI could predict midnighte SBP,DBP,MAP independently, companied withAHI increased 1 time/h midnighte SBP increased 0.135mmHg, DBP increased0.099mmHg and MAP increased O. 109mmHg.⑦The analysis correlat ion ofdecrease of midnight blood pressure:There were negativecorrelation betweenâ–³SBP(before onset sleep—midnight) with AHI, T90, andthere were positive correlation betweeâ–³SBP(before onset sleep-midnight)with minSaO₂,MSaO₂. T90,minSaO₂,and ANI could predictâ–³SBP(before onsetsleep-midnight) independently.There was negative correlation betweenâ–³DBP(awakening time—midnight) and Tg0 and here was positive correlationbetweenâ–³DBP(awakening time—midnight) and minSaO₂.T90 and minSaO₂ couldpredictâ–³DBP(awakening time—midnight) independently.Conclusion:AHI was independent predict factor of MAP prior to onset of sleep and immediately on awakening, In no SA and mild SA blood pressurewas lower on awakening time but in severe SA morning blood pressure washigher.â‘¡AHI was higher in hypertensive than normotensive, and minSaO₂,MSaO₂ were lower. Especially midnight blood pressure decreased morelittle in hypertensive. T90, minSaO₂,AHI were independent predictor ofnight blood pressure variability.â‘¢AHI was independent predictor ofmidnight blood pressure. Hypoxia,arousal and pleura] pressure changelargely result from sleep apnea maybe the etiology of sleep apneacompanied with hypertension.