Night sweats indicate how bad sleep apnea is

Severity of sleep apnea and intermittent hypoxemia affect human sweat metabolome.


In Greek, apnea means “absence of breathing,” and obstructive sleep apnea is when breathing stops repeatedly during sleep. Symptoms include breathlessness, fatigue, and drowsiness, possibly linked to cardiovascular issues. Diagnosing the disease’s severity is crucial to address these concerns accurately.

Researchers at the University of Córdoba and the Maimonides Institute for Biomedical Research explored a less invasive approach by studying changes in the metabolism of individuals with sleep apnea, typically assessed through blood or urine. Their groundbreaking work now reveals the potential of using sweat samples to determine the severity of sleep apnea.

Laura Castillo, the study’s lead author, explains, “By analyzing sweat metabolome and its alterations, mainly at night, we could see what stage of the disease the patients were in.” For her, the advantages of using sweat over other samples are clear: “it is a non-invasive and clean sample since, unlike the case with blood, we don’t have to remove proteins, and it’s much easier to analyze and detect metabolites.”

Researchers used gas chromatography and high-resolution mass spectrometry on sweat samples, identifying 78 metabolites related to energy production and oxidative stress. According to Castillo, the changes in sweat metabolism can indicate alterations during sleep, affecting energy production and increasing oxidative stress.

Using sweat during sleep, this personalized approach allows for tracking the disease’s progression and monitoring potential effects like cardiovascular problems. The study successfully differentiated between those with the disease and a control group. Additionally, it emphasizes considering the oxygen desaturation index in sleep apnea diagnosis.

Currently, sleep apnea diagnosis relies on the Apnea-Hypopnea Index (AHI), which counts the number of shortness-of-breath episodes per hour. However, this index might only partially capture the severity of the disease.

The team emphasizes the importance of also considering the oxygen desaturation index, which measures the seriousness of episodes by tracking events where oxygen levels drop by more than 3%. This additional index provides a more comprehensive understanding of the disease, considering the frequency of events and their severity regarding oxygen saturation loss.

In conclusion, this study shows that night sweats are essential signs of severe sleep apnea. By studying changes in sweat, the research helps us understand how sleep apnea affects our body’s energy production and stress levels. Using a personalized approach to monitor sleep apnea through sweat analysis could help track its progress and identify related health issues, especially those linked to the heart.

The study also emphasizes the need to consider the oxygen desaturation index, giving us a better overall picture of how severe sleep apnea is compared to traditional diagnostic methods. These findings improve how we diagnose and understand the effects of sleep apnea on our bodies.

Journal reference:

  1. Laura S. Castillo-Peinado, Mónica Calderón-Santiago et al., Changes in human sweat metabolome conditioned by severity of obstructive sleep apnea and intermittent hypoxemia. Journal of Sleep Research. DOI: 10.1111/jsr.14075.


See stories of the future in your inbox each morning.