Three previously described clinical phenotypes of obstructive sleep apnea (OSA) have been validated in a large and diverse Hispanic/Latino community-based population for the first time, according to findings presented at the virtual annual meeting of the Associated Professional Sleep Societies.
The three OSA symptom profiles present in this population – labeled “minimally symptomatic,” “disturbed sleep,” and “daytime sleepiness” – are consistent with recent findings from the Sleep Apnea Global Interdisciplinary Consortium, which were published in Sleep, but there are notable differences in the prevalence of these clusters, with the minimally symptomatic cluster much more prevalent than in prior research, reported Kevin Gonzalez, of the University of California, San Diego.
“Other biopsychosocial factors may be contributing to OSA phenotypes among Hispanics and Latinos,” Mr. Gonzalez said in his presentation. Prior research to characterize the heterogeneity of sleep apnea has not included a diverse Latino population, he emphasized.
The adults studied were aged 18-74 years and participants in the multisite Hispanic Community Health Study/Study of Latinos (HCHS/SOL), a comprehensive study of Hispanic/Latino health and disease in the United States. Their respiratory events were measured overnight in HCHS/SOL sleep reading centers with an ARES Unicorder 5.2, B-Alert. Sleep patterns and risk factors were assessed using the Sleep Heart Health Study Sleep Habits Questionnaire and the Epworth Sleepiness Scale.
Participants meeting the criteria for moderate to severe OSA (with an Apnea Hypopnea Index of 15 or above) were included in the analysis (n = 1,623). Their average age was 52.4 ± 13.9 years, and 34.1% were female.
To identify phenotype clusters, investigators performed a latent class analysis using 15 common OSA symptoms and a survey weighted to adjust for selection bias. The three clusters offering the “best” fit for the data aligned with the previously reported phenotypes and identified daytime sleepiness in 15.3%, disturbed sleep (insomnia-like symptoms) in 37.7%, and minimally symptomatic (a low symptom profile) in 46.9%.
These phenotypes were reported in the European Respiratory Journal in 2014 in a cluster analysis of data from a sleep apnea cohort in Iceland and later replicated in the analysis of data from the Sleep Apnea Global Interdisciplinary Consortium published in Sleep in 2018. The consortium study also added two additional phenotypes, labeled “upper airway symptoms dominant” and “sleepiness dominant.”
The prevalence of a “minimally symptomatic group” in the new analysis of the Hispanics/Latinos in the United States is much higher than reported in these prior studies, at least partly, the investigators believed, because the “prior studies were clinical samples, and the people who were minimally symptomatic didn’t get to the sleep centers,” Mr. Gonzalez said in an interview after the meeting.
Patients with a phenotype of daytime sleepiness – the most common phenotype in prior research – constituted only a minority in the Hispanic/Latino population, he said.
Alberto Ramos, MD, of the University of Miami and the principal investigator, said in an interview that the research team is currently analyzing “if and how these different [phenotypic] clusters could affect the incidence of comorbidities” recorded in the HCHS/SOL study, such as hypertension, diabetes, cardiovascular disease, and cognitive decline.
For now, he said, the findings suggest that OSA may be especially underrecognized in Hispanics and Latinos and that there is more research to be done to better identify and stratify patients with varying symptomatology for more personalized treatment and for clinical trial selection. “Maybe we should expand our criteria ... broaden our [recognition] of the presentation of sleep apnea and the symptoms associated with it, not only in Hispanics but maybe in the general population,” Dr. Ramos said.
Dr. Krishna M. Sundar
In commenting on the study, Krishna M. Sundar, MD, FCCP, director of the Sleep-Wake Center at the University of Utah, Salt Lake City, said that insomnia and daytime sleepiness are “key associations with obstructive sleep apnea and may predict different outcomes with untreated OSA.” Such heterogeneity is “only beginning to be appreciated,” he said. “The expression of OSA with these symptoms points to how OSA impacts quality of life” and how symptomatology in addition to Apnea Hypopnea Index “may be an important determinant of treatment benefit and compliance.”
The investigators reported no relevant disclosures. Dr. Sundar said that he is cofounder of Hypnoscure, software for population management of sleep apnea, but with no monies received.