Study objective: Sleep apnea and milder forms of sleep-disordered breathing (SDB) have been associated with overt clinical cardiovascular disease, but it is unknown whether SDB is associated with arterial microvascular pathology. We examined the relation between SDB and retinal microvascular abnormalities.
Design: Cross-sectional study.
Participants: Subjects were 2,927 men and women, aged 51 to 97 years, who participated in the Sleep Heart Health Study and had retinal photographs taken within approximately 3 years of overnight, unattended, at-home polysomnography.
Measurements and results: A respiratory disturbance index (RDI), calculated as the average number of apneas and hypopneas per hour of sleep, was used as an indicator of SDB in analysis. The overall prevalence of retinopathy was slightly higher in people with higher RDI values (5.4%, 4.9%, 8.6%, and 7.6%, respectively, in increasing quartiles of RDI), but after adjustment for age, body-mass index, hypertension, diabetes, and other factors, the presence of retinopathy was not associated with SDB. With the possible exceptions of microaneurysms and generalized arteriolar narrowing, as measured by lower arteriole-to-venule ratio, specific retinal abnormalities were not associated consistently with the RDI. Relative to the first quartile of RDI, the adjusted odds ratios (95% confidence interval) for the presence of microaneurysm in the second, third, and fourth quartiles of RDI were 1.05 (0.44-2.55), 1.97 (0.89-4.37), and 1.79 (0.78-4.10), respectively. An increase of RDI from 0 to 10 was associated with a predicted decrease in arteriole-to-venule ratio of 0.01. Results were similar when analyses were conducted in normotensive and nondiabetic persons separately.
Conclusions: These data do not demonstrate a notable relation between SDB and retinal abnormalities. However, since this is the first investigation of a link between retinopathy and SDB, similar studies should be conducted in other population samples to demonstrate either consistency or inconsistency of our findings across studies.