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Published on: December 6, 2016

Cysteine: a potential biomarker for obstructive sleep apnea

Fatima Cintra1, Sergio Tufik1, Vânia D'Almeida2

  • 1Department of Psychobiology, Universidade Federal de São Paulo, Brazil.

Chest
|July 24, 2010
PubMed

Insights

Elevated cysteine (Cys) plasma levels are linked to obstructive sleep apnea (OSA). Effective continuous positive airway pressure (CPAP) treatment for OSA significantly reduces these Cys levels, suggesting Cys as a potential biomarker.

Area of Science:

  • Cardiovascular Research
  • Sleep Medicine
  • Biochemistry

Background:

  • Obstructive sleep apnea (OSA) is a known risk factor for cardiovascular diseases.
  • Homocysteine (Hcy) and cysteine (Cys) are recognized cardiovascular risk factors, but their role in OSA is understudied.
  • Investigating Cys and Hcy in OSA patients is crucial for understanding disease mechanisms and potential biomarkers.

Purpose of the Study:

  • To evaluate plasma concentrations of Hcy and Cys in patients with OSA compared to controls.
  • To determine the influence of obesity on Hcy and Cys levels in OSA patients.
  • To assess the impact of continuous positive airway pressure (CPAP) treatment on Hcy and Cys levels.

Main Methods:

  • Recruited 75 OSA patients and 75 age- and sex-matched controls for polysomnography and blood sample analysis.
  • Analyzed plasma Cys and Hcy levels, including a subgroup of lean OSA patients (BMI < 25 kg/m²).
  • Assessed changes in Cys and Hcy levels after 6 months of effective CPAP therapy in 15 randomly assigned patients.

Main Results:

  • Cys plasma levels were significantly higher in OSA patients (490.16 ± 67.00 μmol/L) versus controls (439.81 ± 76.12 μmol/L, P < .01).
  • Elevated Cys levels were also observed in lean OSA patients compared to lean controls (484.21 ± 71.99 μmol/L vs 412.01 ± 70.73 μmol/L, P = .009).
  • Homocysteine (Hcy) plasma levels did not differ between groups. Cys levels decreased significantly after effective CPAP treatment.

Conclusions:

  • Cysteine (Cys) shows potential as a biomarker for obstructive sleep apnea (OSA) in both obese and nonobese individuals.
  • Effective treatment of OSA with CPAP leads to a reduction in plasma Cys levels.
  • Cys may serve as a valuable indicator for OSA diagnosis and treatment response.
Abstract

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