Interpretation on the Severity Levels of Sleep Duration and Obstructive Sleep Apnea Leading to Stroke:a Case-Control Study

Background: The stroke and obstructive sleep apnea is intertwined in such a manner that obstructive sleep apnea is an independent risk factor for stroke and do explains of 30-40% of risk to stroke. But the proper evidences are still poor. Hence we explore the risk relation between obstructive sleep apnea and stroke by conducting a case-control study over a period of 6 months. Methods: The study included both case and control groups in which the population suffering from stroke is taken as a case group and the healthy population is taken as a control group. We have used set of questtionnaires(Berlin questionnaire, STOP-Bang questionnaire, Epworth sleepiness scale) for estimating the risk of obstructive sleep apnea within the entire population and the odds ratio is calculated between the groups to estimate the amount of risk. Logistic regression is also performed to estimate the individual variable (hypertension, snoring, BMI, age, gender, neck circumference) risk for OSA. Results: Positive association is confirmed between the stroke and obstructive sleep apnea with a 3.68 odds ratio, indicating that a person suffering from OSA is at 3.68- fold risk of developing a stroke. The variables Snoring and BP had a p-value of 0.015 and <0.001. This indicates that this influence is statistically significant. The odds ratio of Snoring was 1.73, which means that the probability of Stroke increases by 1.73 times. The odds ratio of BP was 6.99 showing a 6.99-fold greater risk for stroke occurrence. However, the variable Neck circumference had a p-value of 168 indicating that this influence is not statistically significant but had an Odds ratio of 1.45. Limitations: The social history of case and control groups was not considered. This and short time period could become a limitation in our study as smoking and substance abuse may contribute to OSA in the population. Conclusion: Our study have provided an additional insights on explaining the risk of obstructive sleep apnea to the stroke which is also stastically proved. Hence obstructive sleep apnea should also be considered as an important risk factor for the stroke to reduce the stroke occurrence. Keywords: Obstructive sleep apnea(OSA), stroke, case-control study, snoring, odds ratio, berlin questionnaire, STOP-Bang questionnaire.