This article is more than 5 years old. Information may no longer be current.

Sleep-disordered breathing linked to cognitive impairment

Sleep-disordered breathing, or SDB, was associated with a higher risk for cognitive impairment and a slight worsening in executive function, according to findings published in JAMA Neurology.

“Owing to different study designs and methods to assess SDB, it is difficult to draw conclusions on the consistency of the associations. Moreover, because each study has reported on specific domains using different scales, it is unclear if SDB has differential effects on cognitive domains,” Yue Leng, PhD, of the department of psychiatry at the University of California, San Francisco, and colleagues wrote. “Therefore, a meta-analytic approach is particularly useful for synthesizing these studies and elucidating pooled estimates.”

The high occurrence of cognitive impairment in older persons necessitates such an analysis, according to the researchers.

Leng and colleagues searched PsychINFO, EMBASE and PubMed, finding 14 studies that discussed the association between SDB and cognitive function. These studies had 4 million participants (mean age, 40 years or older). SDB was determined by either apnea-hypopnea index or clinical diagnosis. Cognitive outcomes were based on standard examinations or a diagnosis of cognitive impairment.

Researchers reported that there was no link between SDB and memory or global cognition. However, a pooled analysis of the six prospective studies suggested that those with SDB were 26% (RR = 1.26; 95% CI, 1.05-1.5) more likely to develop cognitive impairment, with no evidence of publication bias, but significant heterogeneity between studies. After removing one study that mentioned significant heterogeneity, the pooled risk ratio was 1.35 (95% CI, 1.11-1.65).

In addition, a pooled analysis of the seven cross-sectional studies implied that those with SDB had slightly worse executive function (standard mean difference, 0.05; 95% CI, 0.09 to 0), with no proof of publication or heterogeneity bias.

“Our findings provide evidence that SDB may be an important modifiable risk factor for cognitive impairment in elderly persons,” Leng and colleagues wrote. “Clinicians should closely follow patients who experience significant levels of SDB for the occurrence of cognitive dysfunction and might consider administering full neuropsychological batteries in some instances. This is potentially important for the early detection of dementia.” – by Janel Miller

Disclosures : The authors report no relevant financial disclosures.