Predictors for Obesity Hypoventilation Syndrome in Thai Population

Abstract

Background and Objective Obesity Hypoventilation Syndrome (OHS), is a condition with high morbidity and mortality. Body Mass Index (BMI) of more than 30 kg/m2 is used, to diagnose OHS. As BMI for obesity for Thais is 25 kg/m2, BMI more than 25 kg/m2 is used in our institution, to diagnose OHS. The purpose of this study was to evaluate if BMI of 25 kg/m2 is appropriate criterion for OHS in Thai patients. Methods This study was a retrospective study conducted at Khon Kaen University. Inclusion criteria were adult patients diagnosed with OHS in 2016. Patients diagnosed with obstructive sleep apnea (OSA), were randomly selected as control subjects. The ratio of OHS:OSA, was 1:4. Clinical factors associated with OHS were examined, using multivariate logistic regression analysis. Results During the study period, there were 25 OHS and 108 OSA patients. The OHS group had a significantly higher average BMI (48.9 kg/m2 vs. 29.2 kg/m2), than the OSA group. The OHS group also had higher proportions of patients with pulmonary hypertension (50% vs. 2%), and heart failure (76% vs. 6.5%). There were two independent predictors for OHS, including BMI and serum bicarbonate levels. Adjusted odds ratio (95% CI) for each of these factors was 1.08 (1.01, 1.17) and 1.96 (1.15, 3.34), respectively. Body mass index greater than 25 kg/m2 and serum bicarbonate more than 25 mEq/L, yielded 100% sensitivity for OHS. Conclusion s Appropriate diagnostic criteria for OHS for the Thai population, may be different from those for populations in Western countries.

Keywords

• Obstructive sleep apnea
• Sensitivity
• Diagnosis
• Obesity
• Serum bicarbonate