A Study on Metabolic Syndrome in Young Ischemic Stroke

INTRODUCTION: Stroke is the leading cause of adult disability and is the second commonest cause of death worldwide. More than two-thirds of the global burden of stroke is borne by developing countries, where the average age of patients with stroke is 15 years younger than in developed countries. The available data indicate that stroke occurring in young people is more often atherothrombotic in origin in developing countries, in contrast to the developed countries where arterial dissection and cardioembolic etiologies predominate. Ischemic stroke occurring in young Indians may be a manifestation of accelerated cerebrovascular atherosclerosis, paralleling the early age of onset of cerebrovascular diseases noted for this population. Additionally based on prior data on increased propensity for insulin resistance among South Asians, the ischemic stroke in young adults in India may be associated with the metabolic syndrome. The term metabolic syndrome refers to a cluster of metabolic abnormalities related to a state of insulin resistance. The characteristics include insulin resistance, abdominal obesity, elevated blood pressure(BP), triglycerides (TG) and low levels of High density lipoprotein(HDL). To assess the association between the metabolic syndrome (according to NCEP ATP III criteria) and the acute ischemic non-embolic stroke a case control study was conducted, comparing 60 cases aged less than 45 years with a first ischemic (non embolic) stroke with 30 controls of same age group without prior history of stroke and heart disease. Metabolic syndrome was diagnosed by using NCEP ATP III criteria except waist circumference. Cutoff point for abnormal waist circumference according to NCEP ATP III criteria is >102cm for males and >82cm for females. This may be fit for western population but it is very high for Indians. So the cutoff point for abnormal waist circumference was taken as per the new International Diabetes Federation(IDF) criteria where ethnic specific values were given. Cutoff point for South Asians as per the IDF criteria is >90cm for males and >80cm for females. AIM OF THE STUDY: To assess the association between the metabolic syndrome and its individual components- fasting blood sugar (FBS), blood pressure (BP), HDL cholesterol (HDL-C), triglyceride (TG) and waist circumference (WC) and the first ischemic (non embolic) stroke in young adults below 45 years. MATERIALS AND METHODS: Study site: This study was conducted in Government Royapettah Hospital, Chennai during the period of 2006- 2008. Study Population: 60 patients aged less than 45 years hospitalized with the history of first ischemic stroke were included. Inclusion Criteria: 1. Subjects aged less than 45 years. 2. Presented with first acute ischemic stroke-CT or/and MRI brain was taken for confirmation of ischemic stroke. Exclusion Criteria: 1. Prior history of Stroke. 2. Hemorrhagic stroke. 3. Presentation to the hospital more than 6 months after the stroke onset. 4. Embolic stroke – complete cardiac evaluation & carotid Doppler was done to rule out embolic stroke. 5. Stroke due to intra cranial sinus thrombosis. Controls: 30 subjects from a community based sample of individuals aged less than 45 years without prior history of stroke and heart disease were included. Data collection: Data collection was done by using a structured proforma. BP, fasting blood sugar, fasting lipids were taken at approximately a week or later after stroke onset, as elevations in BP, blood sugar and lipids are well documented during the acute phase of stroke.[57,58]Waist circumference was measured at the highest point of iliac crest at the end of normal expiration. RESULTS AND ANALYSIS: Characteristics of study population were assessed and the values were expressed as mean + standard deviation except for age, sex and smoking. Prevalence of the individual risk factors and the metabolic syndrome in both groups were compared. The association between the metabolic syndrome and its individual components and stroke was determined by the logistic regression analysis. Odds ratio and their 95% confidence intervals were assessed. Significance was defined as P value <0.05 in all cases. Characteristics of the study population: Stroke patients had high level of fasting blood sugar, BP, total cholesterol, triglycerides and increased waist circumference compared to control group. Stroke was common in males.73% stroke patients were males. Stroke was more prevalent in 40-45 yrs age group. 53% of stroke patients were in the age group of 41-45yrs. 60% of stroke patients had metabolic syndrome and 10% of control group had metabolic syndrome. SUMMARY: 1. Prevalence of stroke increases as the age advances. 2. Stroke was more prevalent in males than females. 3. Stroke patients had high fasting blood sugar, high BP, elevated total cholesterol, triglyceride, low HDL-C and increased waist circumference than control group. 4. Metabolic Syndrome was more prevalent in stroke patients. 60% of stroke patients had metabolic syndrome ; 10% in control group. 5. High FBS was associated with 4 fold stroke risk (4 odds, p 0.01) compared to control group. 6. Low HDL-C was associated with 2 fold stroke risk (2 odds, p 0.03) compared to control group. 7. Metabolic Syndrome was associated with 9.6 fold stroke risk (9.6 odds, p 0.01) compared to control group. 8. Smoking was associated with 8 fold stroke risk (8 odds, p 0.02) compared to control group. CONCLUSION: 1. Metabolic syndrome and its individual components (high FBS and low HDL-C) were associated with increased risk for ischemic stroke in young adults. 2. Smoking is an independent risk factor for ischemic stroke.