Sleep apnea and markers of vascular endothelial function in a large community sample of older adults.
Clinical studies have suggested that sleep apnea is associated with impaired brachial artery flow-mediated dilation, a surrogate of endothelial dysfunction. We examined this question among older participants in the baseline examination of the Sleep Heart Health/Cardiovascular Health Study cohort (n = 1,037, age 68 years or older, 56% female). Indices of sleep apnea, derived from 12-channel home polysomnography, were the apnea-hypopnea index (average number of apneas/hypopneas per hour) and the hypoxemia index (percentage of time below 90% O2 saturation). Baseline arterial diameter and percentage of flow-mediated dilation were measured by ultrasound. Sleep apnea measures were associated with baseline diameter and the percentage of flow-mediated dilation, although these associations were weakened after adjustment for other cardiovascular risk factors, particularly body mass index. However, a statistically significant linear association between the hypoxemia index and baseline diameter was observed even after adjustment for body mass index and other confounders (p < 0.01). The associations were stronger among participants who were younger than 80 years and among those who with hypertension. This study adds to the growing body of evidence linking sleep apnea with vascular dysfunction in older subjects. Whether these relationships are entirely independent of obesity is unclear. This association might be one of the mechanisms explaining the relationship between sleep apnea, hypertension, and cardiovascular disease.
Nieto
F Javier
FJ
Department of Population Health Sciences, University of Wisconsin Medical School, Madison, Wisconsin 53705-2397, USA. fjnieto@wisc.edu
Herrington
David M
DM
Redline
Susan
S
Benjamin
Emelia J
EJ
Robbins
John A
JA
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis; D015992:Body Mass Index; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000503:physiopathology; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000453:epidemiology*; D015331:Cohort Studies; D015897:Comorbidity; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000453:epidemiology*; D016014:Linear Models; D008297:Male; D017286:Polysomnography; D015995:Prevalence; D011336:Probability; D012111:Residence Characteristics; D018570:Risk Assessment; D012494:Sampling Studies; D012720:Severity of Illness Index; D012891:Sleep Apnea Syndromes / Q000175:diagnosis* / Q000453:epidemiology*; D018608:Ultrasonography, Doppler
D015415:Biomarkers