Serum Bilirubin As A Severity And Prognostic Indicator In Acute Ischemic Stroke – A Hospital Based One Year Observational Study In Kle’s Dr Prabhakar Kore Hospital And Medical Research Centre, Belagavi

Abstract

BACKGROUND & OBJECTIVES: Stroke is a common cause of mortality and morbidity and has an increasing prevalence across the world.1 Bilirubin is now being considered an antioxidant which increases in response to diseases associated with increased oxidative stress. Thus, various studies have been done to see the role of bilirubin in conditions like coronary artery disease which are associated with oxidative stress. Bilirubin being an antioxidant may limit the neurologic damage after a stroke. It may have a preventive or a therapeutic role.2 There is insufficient data about the role of bilirubin and how bilirubin levels predict the severity of stroke and influence its prognosis. This study was conducted to improve our understanding of the same. MATERIALS AND METHODS: This study was conducted from January 2018 to December 2018 on 64 ischemic stroke patients admitted at KLE'S Dr.Prabhakar kore hospital at Belagavi, Karnataka. This was an observational study and purposive sampling was done. Informed consent was taken for all cases included in the study. All adult patients > 18 years of age presenting with cerebro vascular accident and proved as ischemic stroke on CT scan or MRI scan. Patients with hemorrhagic stroke, hemolytic anaemias, hepatobiliary disease, patients on hepatotoxic drugs were excluded. A detailed history was taken and clinical features were assessed. Basic laboratory tests were conducted such as complete blood counts, liver function tests, renal function tests. National Institute of Health Stroke Scale, serum total bilirubin and direct bilirubin levels were assessed at the time of admission. Modified Rankin scale was performed at the time of discharge. The patients were empirically divided into Group 1 or low total bilirubin group with serum total bilirubin values less than 0.7mg/dL and Group 2 or high total bilirubin group with values greater than or equal to 0.7mg/dL. Likewise, they were divided into Group 1 or low direct bilirubin group with serum direct bilirubin values less than 0.2mg/dL and Group2 or High direct bilirubin values greater than or equal to 0.2mg/dL. They were then analysed with their NIHSS scores for assessing stroke severity. MR scores of 0-3 were considered good outcome and 4-6 as poor outcome and compared to the bilirubin groups and assessed for the correlation of level of functional disability at the time of discharge with bilirubin levels. RESULTS A total of 64 subjects/patients were included in the final analysis. Mean age of patients in this study was 60.25 years (SD - 12.54Years) with the highest number of patients belonging to the age group 50-59 years. Out of 64 patients, 45 patients were male and 19 were females. Majority of the patients were males constituting 70.3%. The most common presenting complaints were related to the motor system(87.5%) followed by cranial nerve symptoms, speech related symptoms and the least being sensory symptoms. Hypertension was the most common risk factor in the patients included in the study and was seen in 50% of study population. The other risk factors were diabetes mellitus (34%), alcoholism (30%) and smoking(23%). 44% patients had a blood pressure of more than 140/90 mmHg at the time of admission. Middle cerebral artery territory was the most common site of involvement seen in 73.4% patients. HDL levels were low in 37 patients (57.81%).45.31%% (29 patients) had high LDL levels. 20.3% had high levels of triglycerides. High levels of cholesterol were seen in 13(20.31%) . The mean total bilirubin level in the patients was 0.68±0.34 mg/dl ( mean±SD). 34.3% (22) of ischemic stroke patients in the study had serum total bilirubin levels 0.7 mg/dl or more. Direct bilirubin levels were 0.25+/-0.15 mg/dl (mean+/-SD) and 40 patients (62.5%) had direct bilirubin 0.2 mg/dl or more. Mean NIHSS Score for Group 1(Low) total bilirubin group was 9.37 and for Group 2(High) bilirubin group was 10.9, which was statistically not significant (p value > 0.05). This indicates that there was no significant correlation between total bilirubin and severity of symptoms at the time of admission. The mean NIHSS for Group 1(Low)direct bilirubin was 9.37 and 10.95 for Group 2(High) direct bilirubin. There was no statistically significant correlation between NIHSS and direct bilirubin levels. Mean MR Score for the Group 1 total bilirubin group was 2.0 (1.58,SD) and for Group 2 total bilirubin group was 2.5 (1.46 ,SD), which is statistically not significant Mean MR Score for the Group 1 direct bilirubin group was 2.21 (1.61, SD) and for Group 2 direct bilirubin group was 2.23 (1.54, SD), which is statistically not significant (p value -0.89). CONCLUSIONS: The current study has documented no association between the bilirubin levels and stroke severity, prognosis and residual functional impairment. There is a need to conduct large scale prospective studies to further assess the association between serum bilirubin and stroke severity and its impact on outcomes and mortality.