The Treatment Of Obstructive Sleep Apnea-hypopnea Syndrome (OSAHS) With Hypertension

Objective : Sleep apnea syndrome is a common obstructive disease which morbidity is about 2%-4% in crowds. The morbidity of obstructive sleep apnea-hypopnea syndrome(OSAHS)account of 80-90% in sleep apnea syndrome. Epidemiology survey showed that 60-90% of OSAHS company with hypertension and 30% hypertensive patients company with OSAHS. OSAHS is the first cause of secondary hypertension that is independent of age, diet and drink,body weigh and heredity. Most hypertensive patients with OSAHS are refractory to antihypertensive drugs. Sometimes 3-4 kinds of antihypertensive drugs together could not control blood pressure to the ideal level. Nasal continuous positive airway pressure (nCPAP) could fundamentally improve upper airway obstruction, effectively cut down the occurrence of sleep apnea-hypopnea, relieve and correct hypoxemia and hypercaponia that lead to high sympathetic activity that could be inhibited, so the blood pressure could be controlled effectively and its circadian rhythm could be improved. Through the 24h ambulatory blood pressure and polysomn -ography this study analysed the efficacy of antihypertensive therapy in hypertensive patients with obstructive sleep apnea-hypopnea syndrome and compare the data from 24hABP monitoring before and after nCPAP treatment. It would be helpful to explore the efficient treatment of OSAHS with hypertension.Methods:1 Object : The 72 cases were diagnosed OSAHS with hypertension by polysomnograhy (PSG) and 24h ambulatory blood pressure (exclusive of heart failure,renal inadequacy,renal arterial stenosis,primary aldosteronism,hyperadreno -corticism syndrome,asthma as well as cerebrovascular disease) from April 2005 to October 2006 in the 3rd hospital of Hebei medical university. Among them 50 cases are men and 22 cases are women. The cases who had taken antihypertensive drugs before diagnosis must stop taking drugs over 3 days and forbid drinking wine, tea, coffee and stop taking temperantia.2 Method: all of patients were monitored over 7 hours during sleep by PSG(R170-305 Type,Res Med Company). OSAHS were divided into three levels according to the apnea hypopnea index (AHI) and the saturation of oxygen (SaO₂)at night: light dimensional (AHI:5-20; SaO₂≥86%), midrange (AHI:21-40; SaO₂:80-86%) and weight dimensional (AHI≥41; SaO₂≤79%). 24h ambulatory blood pressure was monitored every 30 minutes in day and 60 minutes during night by Space Lab 90207 Hypertensive diagnostic criteria accord with WHO/ISH hypertensive guide in 1999(SBP≥140mmHg;DBP≥90 mmHg). The principle of antihypertensive therapy: (1). Using minimal effective dosage to obtain possible therapeutic effect and to degrade adverse effect. (2). Administering drugs once every day to degrade blood pressure equality in 24 hours. (3). When low dosage of single drug treat bad, combining two or more than two kinds of drugs to improve the effect of treatment.Treatment of nCPAP: Basing on using the same drugs in treated group as control group, use nCPAP (using Auto-CPAP BREAS-PV101 atraumatic airway positive pressure machine: breathing rate: 6-40 times/min; pressure scope: 4-16cmH2O) in treated group but not in control group.During the treatment checking the blood pressure at eight clock everybody every 3 days, cut down or plus the kinds of drugs and dosage according to the level of blood pressure until blood pressure was controlled satisfactorily.Control group (34 of 72 cases) was administered routine antihypertensive drugs, combining two or more than two kinds of drugs when the efficiency of single drug was poor. Treated group (38 cases) was given the same drugs as well as treated with nCPAP 12 weeks. In the treated group 6 cases were given up during the experience because of cannot obey the nCPAP treatment .The other 66 cases were monitored by PSG, 24hABP after 12 weeks about AHI, the lowest SaO₂ (LSaO₂), meanSaO₂(MSaO₂),the oxygen desaturation index(ODI: the times of SaO₂ under 90% in an hour),the longest apnea time; 24h mean systolic blood pressure (24hSBP), mean diurnal systolic blood pressure (dSBP) (6:00-22:00), mean nocturnal systolic blood pressure (nSBP) (22:00-6:00), 24h mean diastolic blood pressure (dDBP), mean diurnal diastolic blood pressure,(dDBP) (6:00-22:00), mean nocturnal diastolic blood pressure (nDBP) (22:00-6:00), 24h pulse pressure (24hPP), and the blood pressure day-nocturnal rhythm. Compare the results of general state of health, medication, AHI, LSaO₂, MSaO₂, ODI and the details of blood pressure before and after the treatment of nCPAP between two groups. The effect of nCPAP-treated was estimated in OSAHS with hypertension. The compare of values of two groups was managed based on Analysis of SAS statistical software, and p<0.05 was defined as statistically significantly.Results:1 12 weeks later in the control group the rate of blood pressure get to the object(<140/90mmHg) is 52.9% (18/34),while in the treated group it is 81.9% (26/32).There is significantly difference between two groups(P<0.01).2 In the control group the change of 24hSBP, 24hDBP,dSBP, dDBP and nDBP was significantly different before and after the antihypertensive treatment at the end of 12 weeks after treated only by antihypertensive drugs, but the change of nSBP, 24hPP was not significantly different.3 The change of 24hSBP, 24hDBP,dSBP, dDBP, nDBP, nSBP, 24hPP was significantly different before and after treated by nCPAP in treated group (P<0.05), and there is also significantly difference (P<0.05) except 24hPP (P>0.05) between control group and treated group at the end of 12 weeks.4 The improvement of day nocturnal rhythm of blood pressure in control and treated group are all significantly different before and after the treatment and also between them (P<0.05).5 The kinds of antihypertensive drugs were cut down along with the degrading of blood pressure in treated group. Among them 6 cases even stop antihypertensive drugs completely, the blood pressure can be controlled in normal range only relying on nCPAP treatment, the number of cases that need three or more kinds of drugs is only 8 while in control group it is 20, there was significantly different between control group and treated group (P<0.01).6 There is significantly different about AHI, LSaO2, MSaO2, ODI in treated group before and after treatment (P<0.01),but in control group there is no difference.Conclusions: The hypertension that relate to OSAHS is caused by hypoxemia and hypercaponia. The therapeutic efficacy of antihypertensive drugs was poor. The blood pressure can't be controlled satisfactorily even using many kinds of antihypertensive drugs. The treatment of nCPAP could eliminate the obstruction of upper airway and effectively relieve hypoxemia and hypercaponia, so high sympathetic activity could be inhibited, the disorder of nerve-body liquid can be corrected. The abnormal day-nocturnal rhythm can also be improved. The blood pressure could be controlled effectively and the kinds of antihypertensive drugs could be cut down even stop using, only nCPAP can keep the blood pressure in normal range. The nCPAP treatment can be used as an effective method of treating hypertension related to OSAHS.