Obstructive sleep apnea tied to brain white-matter hyperintensities

Reuters Health - 12/10/2021 - Obstructive sleep apnea (OSA) was associated with brain white matter hyperintensities (WMHs) in a German cohort study.

WMHs are linked to an increased risk of dementia, cognitive decline, stroke, depression and other neurological conditions, as well as death.

"The significant, robust associations between OSA and brain WMH might indicate a novel, potentially treatable white matter disease pathomechanism by targeting OSA," Drs. Helen Zacharias and Hans Grabe of University Medicine Greifswald told Reuters Health by email. "As next steps, we are going to investigate the longitudinal course of WMH under exposure of OSA."

As reported in JAMA Network Open, the team analyzed clinical and imaging data from 529 participants (mean age, 52; 53% women) enrolled in the Study of Health in Pomerania-Trend baseline (SHIP-Trend-0), a general population-based, cross-sectional, observational study that investigates relationships among common risk factors, disorders and diseases.

OSA was diagnosed after an assessment of the apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) during a single-night, laboratory-based polysomnography measurement. WMH data was segmented from 1.5-T magnetic resonance images.

A total of 209 individuals (40%) were diagnosed with OSA according to AHI criteria (mean AHI, 7.98 events per hour); 102 (19%) were diagnosed according to ODI criteria (mean ODI, 3.75 events per hour).

Both AHI and ODI were significantly associated with brain WMH volumes. These associations persisted even in the presence of additional vascular, metabolic, and lifestyle WMH risk factors.

Region-specific WMH analyses found the strongest associations between periventricular frontal WMH volumes and both AHI and ODI, and between periventricular dorsal WMH volumes and AHI.

Dr. Kirk Wilhelmsen, Chief of Cognitive Neurology at the West Virginia University Rockefeller Neuroscience Institute in Morgantown, commented in an email to Reuters Health, "This paper provides more evidence that treating OSA is an important part of health care, and can reduce the risk of vascular disease such as stroke, heart attack and dementia."

"The study does not fully answer whether or not you can prevent the accumulation of vascular changes seen on MRI by treating OSA," he noted. "We need more research to reach that conclusion."

"I, along with many of my specialist peers, routinely ask questions to examine whether patients have a history, or are at risk, of contributing factors that can lead to cognitive decline," he noted. "If you're not asking these questions, you're missing an opportunity to intervene and help your patient in the long run. This study's findings further illustrate the importance of this investigation."

Dr. Carl Bazil, a professor of neurology in the division of Epilepsy and Sleep at Columbia University College of Physicians and Surgeons in New York City also commented by email. "Although it is plausible that treatment of OSA would decrease WMHs, and therefore the incidence and/or severity of brain pathology (particularly dementia), this is not addressed in the current study."

The study provides "at least indirect evidence that one of the most underdiagnosed conditions in medicine, OSA, may be associated with brain pathology, making identification and treatment more important," he concluded.

SOURCE: https://bit.ly/3v97Ifl JAMA Network Open, online October 5, 2021.

By Marilynn Larkin



Posted on 12 October 202120 October 2021