Prognosis of the middle-aged and aged patients with obstructive sleep apnea syndrome.
The long-term natural course of obstructive sleep apnea syndrome (OSAS) is studied in order to determine whether severity of nocturnal oxygen desaturation associated with apnea/hypopnea, body mass index (BMI), and hypertension influence survival in young (<40 years), middle-aged (40-64 years), and aged (> or = 65 years) using a questionnaire survey. One hundred and forty-eight patients with OSAS aged 17-78 years (136 men, 12 women, mean 52.0+/-12.3 years), who were diagnosed by standard polysomnography (PSG) between 1983 and 1993, participated in the study. The survey revealed 15 deaths and 101 survivors; 32 subjects could not be located. The survival rate was 71.4% (95% confidence interval: 55.6-87.2%). The survival rate in patients with OSAS was significantly lower than that in the age and sex-adjusted control Japanese population (87.6%). In the young group, only one death (a 19-year-old woman) occurred unexpectedly during sleep. The patient showed an apnea/hypopnea index (AHI) of 33 per h and the length of time that the nocturnal oxygen saturation (SaO2) fell below 90% (time of SaO2 <90%) of 205 min. The survival rate in middle-aged patients with OSAS was significantly lower than that in the age and sex-adjusted control Japanese population (79.2 vs 91.0%), but this pattern was not seen among the aged. Time of SaO2 <90% was significantly longer in the middle-aged patients than in the aged patients, but AHI did not differ between the two groups. Moreover, it was significantly correlated with AHI in middle-aged patients, but not in the aged patients. The survival rate was significantly lower in patients with hypertension than in the patients without such complications in the middle-aged group (57.9 vs 90.4%). Cox proportional-hazard regression model including age, hypertension, BMI, AHI, lowest SaO2, and time of SaO2 <90% showed that hypertension was only significantly associated with lower survival rate in total group and middle-aged patients, but not in the young or aged patients. The prognosis in patients with OSAS may differ among the generations. The prognosis in the middle-aged population may depend on the role of OSAS on the complications of hypertension or severity of oxygen desaturation, but not on AHI only.
Nagoya University School of Health Sciences, Department of Clinical Laboratory Medicine, Nagoya University Hospital, Japan.
A
A
Noda
T
T
Okada
F
F
Yasuma
T
T
Sobue
N
N
Nakashima
M
M
Yokota
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D015992:Body Mass Index; D002423:Cause of Death; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology; D007564:Japan; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D017286:Polysomnography; D012737:Sex Factors; D012891:Sleep Apnea Syndromes / Q000175:diagnosis / Q000401:mortality* / Q000503:physiopathology; D015996:Survival Rate
D010100:Oxygen