From the Guidelines
The primary focus for a patient with obstructive sleep apnea (OSA) and hemoglobin (Hb) levels of 15.8 and 15.5 g/dL should be on treating the underlying OSA, as the elevated hemoglobin is likely a result of compensatory erythrocytosis due to chronic intermittent hypoxia. The most effective treatment for OSA is continuous positive airway pressure (CPAP) therapy, which should be used nightly as prescribed by a sleep specialist 1. Weight loss of 5-10% of body weight is also recommended for overweight patients, as it can significantly improve OSA symptoms and overall health outcomes. Additionally, positional therapy (avoiding sleeping on the back) and oral appliances may be helpful adjuncts to CPAP therapy. With effective OSA treatment, hemoglobin levels often normalize over time as oxygen saturation improves during sleep. These hemoglobin values, while at the upper end of normal or slightly elevated, are not concerning enough to warrant phlebotomy or other interventions if they're solely due to OSA. However, if hemoglobin continues to rise despite adequate OSA treatment, further evaluation for other causes of erythrocytosis would be warranted. Key considerations in managing OSA include:
- Initiating treatment based on a technically adequate polysomnography (PSG) or home sleep apnea test (HSAT) study 1
- Early follow-up after initiation of therapy to assess treatment efficacy and adjust as necessary
- Monitoring for potential complications of OSA, such as cardiovascular disease, stroke, and diabetes, which can be reduced with effective PAP treatment 1.
From the Research
Hemoglobin Levels and OSA
- Hemoglobin (Hb) levels of 15.8 and 15.5 are considered elevated, and Obstructive Sleep Apnea (OSA) has been reported to be a cause of secondary polycythemia 2.
- A study found that the prevalence of polycythemia is greater in severe OSA, and Continuous Positive Airway Pressure (CPAP) treatment can reduce hemoglobin and hematocrit levels 2.
CPAP Treatment and Hemoglobin Levels
- CPAP treatment has been shown to reduce hemoglobin levels by 3.76 g/L (95% CI -4.73 to -2.80 g/L) in patients with OSA 2.
- Another study found that CPAP treatment can also reduce hematocrit levels by 1.1% (95% CI -1.4 to -0.9%) in patients without baseline polycythemia 2.
OSA and Anemia of Aging
- A study found that treatment of OSA may paradoxically restore anemia of aging (AOA) in elderly patients, and that OSA and AOA share common inflammatory processes 3.
- The study also found that post-treatment of OSA hematocrit distributed bimodally, with significant increases and declines of hematocrit, but these changes did not correlate significantly with selected sleep-breathing variables 3.
CPAP Treatment and Glycemic Control
- A study found that CPAP treatment can improve glycemic control in patients with type 2 diabetes and OSA, with significant reductions in 1-hour postprandial glucose values and hemoglobin A1c levels 4.
- The study also found that the reduction in hemoglobin A1c level was significantly correlated with days of CPAP use in subjects who used CPAP for more than 4 hours per day 4.