A 67-year-old man is brought to the emergency department by his wife after experiencing sudden onset weakness on his right side. She noticed that he was having difficulty speaking and seemed confused when she tried to communicate with him. On examination, he is found to have a right-sided facial droop, decreased strength in his right upper and lower extremities, and difficulty in comprehension. His medical history is notable for type 2 diabetes mellitus and hyperlipidemia. He has smoked one pack of cigarettes per day for the past 40 years but denies alcohol or recreational drug use. His vital signs reveal a blood pressure of 165/98 mmHg, a pulse of 82 beats per minute, and a BMI of 29.5. Laboratory studies show: Blood glucose: 156 mg/dL Hemoglobin A1c: 8.0% Total cholesterol: 230 mg/dL LDL: 160 mg/dL Triglycerides: 180 mg/dL C-reactive protein: mildly elevated Which of the following is the greatest risk factor for this patient’s condition? A. Type 2 diabetes mellitus B. Hypertension C. Hyperlipidemia D. Smoking E. Obesity Explanations: A. Type 2 diabetes mellitus: While diabetes mellitus is a well-known risk factor for ischemic stroke, its impact is generally due to its long-term effects on blood vessels and predisposition to atherosclerosis. However, it is not the greatest single risk factor in this patient’s case. B. Hypertension: (Correct Answer) Hypertension is the most significant modifiable risk factor for stroke, particularly in older adults, as it directly contributes to endothelial damage and the formation of atherosclerotic plaques. Elevated blood pressure in this patient is likely the primary contributor to his risk of an MCA stroke. C. Hyperlipidemia: Elevated lipid levels are associated with an increased risk of vascular events, especially over time, as they contribute to atherosclerosis. Although this is a risk factor, it is less predictive of acute events than hypertension in stroke cases. D. Smoking: Smoking increases the risk of ischemic stroke through mechanisms including inflammation, oxidative stress, and increased blood coagulability. While this is a strong risk factor and contributes to stroke risk, its relative risk is lower than that of hypertension in most cases of stroke. E. Obesity: Obesity is associated with metabolic changes that elevate stroke risk. However, it indirectly affects stroke likelihood by increasing the risk of diabetes, hypertension, and dyslipidemia. It is not the most significant individual risk factor for stroke in this patient.