Study on Correlations among Polysomnogram Indices for Obstructive Sleep Apnea-Hypopnea Patients

Shim, Hyun Joon; Koo, Bon Jo; Park, Kyung Hoon; Kwon, Soon Uk; Yoon, Sang Won; Kim, Eui Joong

Abstract

BACKGROUND AND OBJECTIVES
The polysomnography is essential for diagnosis of obstructive sleep apnea-hypopnea (OSAH) and provides important objective information. But, in fact, there are some difficulties for comprehensive interpretation of multiple indices from the polysomnogram. This study was designed to find out which polysomnogram indices were significant to respiratory distress indices (RDI) and apnea index (AI) on statistical correlation and which other indices should be considered together for proper management plan apart from RDI and AI (respiratory index). SUBJECTS AND METHOD: We evaluated 40 patients whose RDI were over 5 as the result of overnight polysomnography before any management from February 2003 to September 2003 at Eulji medical center. By multiple linear regression analysis, we studied the relationship of RDI and AI as dependent variables to ST, O2 desaturation events (O2DE), lowest O2 saturation (LoO2), slow wave sleep portion (S3&S4), arousal index (ArI), body-mass index (BMI) and age. We also studied the relationship of ST as an dependent variable to O2DE, LoO2, S3&S4, ArI, BMI, and age. RESULTS: 1) There were significant correlations between RDI and O2DE, ArI as was true between AI and O2DE, ArI (p<0.05). And there was no significant difference in the degree of the correlation between RDI and AI. 2) Other variables such as ST, LoO2, S3&S4, BMI and age were not significant. 3) ST had no significant correlation with respiratory index and any other variables (p<0.05). CONCLUSION: Because the respiratory index may not the entire physical status during sleep for OSAH patients, multiple indices (such as LoO2, BMI, ST, S3&S4, age) should be considered together apart from the respiratory index for proper management plan.