PT  - JOURNAL ARTICLE
AU  - Markus Blaukovitsch
AU  - Stephan Rüller
AU  - Ernst Müller
AU  - Peter Zabel
AU  - Hans-Peter Hauber
TI  - Vitamin D deficiency and excessive daytime sleepiness in obstructive sleep apnea: Is there a correlation?
DP  - 2011 Sep 01
TA  - European Respiratory Journal
PG  - p2273
VI  - 38
IP  - Suppl 55
4099  - http://erj.ersjournals.com/content/38/Suppl_55/p2273.short
4100  - http://erj.ersjournals.com/content/38/Suppl_55/p2273.full
SO  - Eur Respir J2011 Sep 01; 38
AB  - Aim: In this study we investigated if vitamin D deficiency syndrome is associated with excessive daytime sleepiness (EDS) in patients (pts) who were screened for obstructive sleep apnea (OSA)with polysomnography. Mechanisms accounting for EDS beyond respiratory events may include disturbed sleep quality due to 25-OH-Vitamin D3 (VD) hypovitaminosis.Methods: We enrolled 42 pts, who were screened for sleep related breathing disorders. VD serum levels under 30nmol/l were evaluate as hypovitaminosis D. Epworth Sleepiness Score (ESS) and Respiratory Disturbance Index (RDI) were measured in subgroups and compared with levels of VD with Fisher's exact test.Results: 29 men and 13 women completed the study with a mean age of 62.8 yr. 39 patients had a RDI above normal (>5/h), mean RDI was 25.0, mean level of VD was 34.9. 15 pts had an ESS above 11. 3 of them had a RDI lower than 5 but a mean level of VD of 26.3 nmol/l. Pts with mild OSA (RDI 5-15/h) had significantly higher VD levels (41,6nmol/l, p=0.02) than pts without OSA (26,3 nmol/l) or with moderate (33 nmol/l) to severe OSA (32,8 nmol/l).Discussion: We found increased VD levels in pts with mild OSA compared to moderate and severe OSA. This could be associated with VD associated noninflammatory myopathy and an increasing central nervous system homeostatic sleep pressure via effects of decreased levels of VD on TNF-alpha and/or prostaglandin D2. Our results suggest that pts with EDS and low RDI (<5/h) may suffer from VD hypovitaminosis. More research is needed to determine if pts presenting with EDS and a low RDI should be screened for VD deficiency and if there is a molecular causation between EDS, OSA and low levels of VD.