Exercise-induced haemoglobin oxygen desaturation in patients with SCD

Area of Science:

• Hematology
• Pulmonology
• Exercise Physiology

Background:

• Sickle cell disease (SCD) patients face severe complications with low tissue oxygenation due to hemoglobin S polymerization.
• Predictors of post-exercise oxygen desaturation in SCD are not well-defined.
• This study investigated lung function and exercise tolerance in SCD patients with and without exercise-induced hemoglobin oxygen desaturation (EIHOD).

Purpose of the Study:

• To compare lung function and the six-minute walk test (6MWT) in SCD patients with and without EIHOD.
• To identify predictors of EIHOD in adult patients with SCD (HbSS and HbSC genotypes).

Main Methods:

• A cross-sectional study of 119 adult SCD patients in Ghana.
• Assessment of lung function and 6MWT, with oxygen saturation measured pre- and post-exercise.
• EIHOD defined as a ≥3% decrease in oxygen saturation post-6MWT.
• Analysis of haemolytic markers and predictors of EIHOD.

Main Results:

• Prevalence of EIHOD was 41% in HbSS and 36.1% in HbSC patients.
• No significant differences in hemoglobin, liver enzymes, bilirubin, or 6MWT distance between groups.
• Decreasing hemoglobin predicted EIHOD in HbSC patients, but not in HbSS patients.
• Lung function abnormalities did not predict EIHOD in either genotype.

Conclusions:

• SCD patients experiencing EIHOD exhibit comparable levels of hemolysis and lung function to those without EIHOD.
• Hemoglobin levels are a significant predictor of EIHOD specifically in HbSC patients.
• Lung function is not a reliable predictor of exercise-induced desaturation in SCD.