CPAP and HIGH hematocrit


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Hi ‍

I am diagnosed with Sleep Apnea and from next Friday I will use it I also found out that my hematocrit is always between 50-52 and hemoglobin 16.4-17.3 after 3 blood test this 3 last months .. my doctor said the high levels can be from the sleep apnea and will get better after CPAP .. how long does take it to get better blood levels ? I am not on TRT yet but I will be because my test levels are low ..

Nelson Vergel

Sleep Breath. 2006 Sep;10(3):155-60. doi: 10.1007/s11325-006-0064-z.

Does obstructive sleep apnea increase hematocrit?

Jong Bae Choi 1, José S Loredo, Daniel Norman, Paul J Mills, Sonia Ancoli-Israel, Michael G Ziegler, Joel E Dimsdale

This study assessed the relationship between hematocrit levels and severity of obstructive sleep apnea (OSA) and examined how this relationship was affected by the degree of hypoxia as well as by possible confounding factors. Two-hundred sixty three subjects (189 men and 74 women) underwent nocturnal polysomnography with oximetry and had measurements of hematocrit, hemoglobin, white blood cell count, body mass index (BMI), blood pressure (BP), and 24-h urine norepinephrine (NE). Patients with severe OSA [respiratory disturbance index (RDI) >30] had significantly higher hematocrit values than patients with mild to moderate OSA or nonapneic controls (p < 0.01). However, only one patient had a hematocrit in the range of clinical polycythemia. Hematocrit levels were significantly correlated with BMI, BP, urinary NE, RDI, percent of time spent at oxygen saturation <90%, and with mean oxygen saturation. Multiple linear regression analysis revealed that mean oxygen saturation, RDI, and percent of time spent at oxygen saturation <90% were significant predictors of hematocrit level, even after controlling for gender, ethnicity, 24-h urine NE, BMI, and BP (p < 0.05). The severity of OSA is significantly associated with increased hematocrit, even after controlling for possible confounding variables. However, nocturnal hypoxemia in OSA does not usually lead to clinical polycythemia.

Chest. 1990 Mar;97(3):729-30. doi: 10.1378/chest.97.3.729.

Overnight decrease in hematocrit after nasal CPAP treatment in patients with OSA

J Krieger 1, E Sforza, M Barthelmebs, J L Imbs, D Kurtz

To clarify the paradox of a decrease in urine and sodium excretion occurring along with the elimination of peripheral edema when patients with obstructive sleep apnea (OSA) are treated with nasal continuous positive airway pressure (CPAP), we investigated the immediate effects of this treatment on the hematocrit and red blood cell count in eight patients with OSA. The hematocrit decreased in all patients, from a mean of 45.6 +/- 1.2 percent to 43.0 +/- 1.4 percent, with a parallel decrease in the red blood cell count from 4.777 +/- 0.168 millions/cu mm to 4.577 +/- 0.174 millions/cu mm (p less than 0.0005, one-tailed, in both cases). These results suggest that nasal CPAP treatment causes a hemodilution in patients with OSA, and are compatible with the hypothesis of an atrial natriuretic peptide-induced fluid shift from the intravascular to the extravascular volume in untreated patients with OSA. The reversal of these changes with CPAP treatment could explain the simultaneous decrease in sodium and urine excretion and the reduction of peripheral edema.

Nelson Vergel

Eur Respir J. 1992 Feb;5(2):228-33.

Decrease in hematocrit with continuous positive airway pressure treatment in obstructive sleep apnea patients

J Krieger 1, E Sforza, C Delanoe, C Petiau
Affiliations expand
PMID: 1559588
Previous preliminary results have shown an overnight decrease in haematocrit and red cell count after the first night of treatment with nasal continuous positive airway pressure (CPAP) in obstructive sleep apnoea (OSA) patients. The present study was designed to confirm these preliminary data, and to analyse the long-term effects of CPAP. The haematocrit and red cell count (RCC) were measured in 80 OSA patients on two consecutive mornings, after an untreated night and after a CPAP treatment night. The haematocrit and RCC significantly decreased with CPAP (from 44.0 +/- 0.5 to 42.4 +/- 0.4%, p less than 0.0001 and from 4.769 +/- 0.051 to 4.597 +/- 0.052 x 10(12) red cells.l-1, p less than 0.0001, respectively). Neither the decrease in haematocrit nor the decrease in RCC were correlated with the decrease in urine volume or flow which occurred with CPAP. Thirty five of these patients remained untreated for 45 +/- 4 days, before home treatment with CPAP was initiated. The haematocrit and RCC had returned to values close to those before initial treatment and decreased again after the first treatment night. Twenty one of the patients were re-evaluated after at least one year of home treatment with CPAP, again on two consecutive nights either with CPAP or untreated. The follow-up, post-CPAP haematocrit and RCC were slightly and nonsignificantly higher than after the baseline CPAP night, but still lower than after the baseline untreated night (p less than 0.02). After the untreated follow-up night, no significant change in haematocrit was observed.

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