# Pulse oximetry scoring detected about 20% fewer sleep apnea events in Black participants in two cohorts

- Published: 2026-11-05 14:58 UTC
- Section: Life & Health › Medicine
- Tags: pulse oximetry bias, sleep apnea diagnosis, oxygen desaturation criterion, skin pigmentation, AHI, heart-rate response, Mass General Brigham, MESA cohort, SHHS cohort, cardiovascular events
- URL: https://realtech.media/news/rt-f00e48a6666e28a788aa745c_pulse_oximetry_scoring/

**In MESA and SHHS, a smaller share of airflow-defined breathing events met the 4% desaturation criterion in Black than in White participants; heart-rate-based scoring showed no such gap.**

![Pulse oximetry scoring detected about 20% fewer sleep apnea events in Black participants in two cohorts](https://sgzwpqqelzmajkcubgkl.supabase.co/storage/v1/object/public/rt-media/2026/11/5eba00fe46d03f81.jpg)
*Jakub T. Jankiewicz, Wikimedia Commons, CC BY-SA 4.0*

Investigators from Mass General Brigham, with first author Ali Azarbarzin, analyzed two cohorts, the Multi-Ethnic Study of Atherosclerosis (MESA) and the Sleep Heart Health Study (SHHS), and published the results in the American Journal of Respiratory and Critical Care Medicine. They included participants without cardiovascular disease. The proportion of airflow-defined events meeting the ≥4% desaturation criterion was 21% lower in Black than in White participants in MESA and 20% lower in SHHS [1].

Sleep studies often use drops in blood oxygen, measured by pulse oximetry, to decide which breathing disturbances count toward sleep apnea severity. Pulse oximeters work by passing light through a part of the body and measuring its absorption. Melanin and other pigments in darker skin can absorb part of that light, so oximetry may overestimate oxygen saturation in people with darker pigmentation [1].

## Desaturation-based scoring versus heart-rate response

The authors modeled the apnea-hypopnea index (AHI) based on desaturation relative to the AHI defined by airflow. In MESA the ratio for Black versus White participants was 0.79 (95% CI 0.68–0.93; p = 0.003), and in SHHS it was 0.80 (0.68–0.94; p = 0.008). No other racial or ethnic group showed a lower proportion of airflow-defined events meeting the desaturation criteria than White participants [1].

As an oximetry-independent measure, the team used AHI-ΔHR6, which counts respiratory events accompanied by a heart-rate increase of at least 6 beats/min. Detection of such events was similar between Black and White participants in both cohorts [1].

## Association with cardiovascular events and death

Adjusted Cox models assessed a composite outcome: major adverse cardiovascular events or all-cause mortality. Among White participants, desaturation-based events were associated with this outcome in MESA but not in SHHS. Desaturation-based AHI measures were not significantly associated with it in Black participants in either cohort. AHI-ΔHR6 was associated with the outcome in MESA (HR 1.33; 95% CI 1.09–1.63; p = 0.006) and in SHHS (HR 1.26; 1.02–1.55; p = 0.033) [1].

The authors conclude that the results suggest oximetry-related under-detection in people with darker pigmentation. Azarbarzin said the group is not proposing different diagnostic thresholds by race; in his view, the underlying measurements need to be accurate and reliable across all patients.

## Sources

1. [American Journal of Respiratory and Critical Care Medicine](https://doi.org/10.1093/ajrccm/aamag573)
2. [EurekAlert](https://www.eurekalert.org/news-releases/1150120)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-f00e48a6666e28a788aa745c_pulse_oximetry_scoring/