Nocturia as a clinical indicator of severe obstructive sleep apnea syndrome and its response to CPAP or surgical treatment

INTRODUCTION: Obstructive sleep apnea syndrome (OSAS) is a common condition that has been associated to a number of metabolic, cardiovascular and cognitive consequences. Its diagnosis relies on a polysomnographic or polygraphic study, but clinical findings remain as an important part of the diagnostic process. Nocturia is a common symptom that may indicate severe OSAS, but it is often forgotten in the initial evaluation of these kind of patients. Positive airway pressure (CPAP) is known to reduce nocturia, but the roll of surgery is not clear about it. MATERIAL AND METHODS: A case series is presented. We compare 2 groups of male adults with severe OSAS, the first group treated with CPAP for 3 months, while group 2 underwent a multilevel surgical management. Apnea-hypopnea index (AHI) and the nocturia events number (NEN) were assessed before and after the treatment. Frequencies, descriptive statistics and a related sample Student’s t-test were performed for statistical analysis. RESULTS: 97 male patients were included, age ranged from 29 to 71 years old. In group 1, treated with CPAP, AHI mean was 54.59 and nocturia mean 4.53 before treatment. With CPAP, the AHI mean was 6.63 and NEN mean 0.51. In group 2, AHI mean before surgery was 40.02, NEN mean 3.78, and after the surgical management AHI mean was 7.74 and NEN mean 0.7. Student’s t-test in groups 1 and 2 showed a p=0.000. CONCLUSIONS: AHI and NEN were clearly related in both groups, and the improvement of NEN and AHI were consistent in both groups, the CPAP and the surgical treatment. The presence of a NEN value of 4-5 may be an indicator of severe OSAS and should always be clinically evaluated.