Assessing the Correlation between Severity of Obstructive Sleep Apnoea and Systemic Hypertension
OC10-OC13
Correspondence
Dr. Neha Kakria,
Assistant Professor, Department of Radiology, Armed Forces Medical College, Pune-411040, Maharashtra, India.
E-mail: docyadvirgarg@gmail.com
Introduction: Patients suffering from Obstructive Sleep Apnoea (OSA) have a strong association with acute cardiovascular events and chronic conditions such as systemic hypertension, coronary artery disease and heart failure.
Aim: To study the prevalence of hypertension in OSA patients and correlating the severity of hypertension with severity of OSA in terms of Apnoea-Hypopnoea Index (AHI).
Materials and Methods: A descriptive cross-sectional study was conducted at OPD of a tertiary care centre. The patients suffering from OSA as detected by a whole night polysomnography were included in the study. History of hypertension and number of antihypertensive medications taken for Blood Pressure (BP) control was obtained. BP measurement was done on two consecutive days and average of the readings was taken to calculate systolic and diastolic pressure. All continuous variables were summarised in terms of mean±SD, and categorical variables were expressed as percentages. Pearson’s linear correlation was applied for continuous variables for comparison with AHI values and Fisher’s exact test was used for nominal variables.
Results: Out of the total number of 42 patients suffering from OSA, 29 (69%) were found to be hypertensive and 4 (13.79%) of these 29 subjects were suffering from drug-resistant hypertension. Severe OSA (AHI >30) was found in 26 patients and frequency of hypertension in patients suffering from severe OSA was 23/26 (88.46%). Mild to moderate OSA (AHI <30) was seen in 16 patients and 6 (37.5%) out of these 16 patients were detected to be having hypertension. Fisher’s exact test found statistically significant association between severe OSA and hypertension (p-value-0.0008). In non-obese patients, association between severe OSA and hypertension was assessed separately with p-value-0.0065. Pearson’s correlation coefficient was greater for association between BP (SBP 0.643, DBP 0.653) with AHI than that of BMI.
Conclusion: Our study found the statistically significant correlation between systemic hypertension and OSA patients, independent of the confounding factor of obesity. Severity of hypertension showed linear correlation with the severity of OSA as indicated by AHI score.