Which of the following increases the susceptibility to coronary artery disease –
**Core Concept**
Hypertension is a major risk factor for coronary artery disease (CAD), as it increases the workload on the heart, leading to left ventricular hypertrophy and eventually myocardial ischemia. The increased pressure also accelerates atherosclerosis, contributing to the development of CAD.
**Why the Correct Answer is Right**
Hypertension increases the susceptibility to CAD by promoting atherosclerosis through several mechanisms:
* Increased pressure causes endothelial dysfunction, leading to decreased nitric oxide production and impaired vasodilation.
* Elevated blood pressure accelerates the formation of atherosclerotic plaques, which can rupture and cause acute coronary syndromes.
* Hypertension also increases the cardiac workload, leading to left ventricular hypertrophy, which can eventually result in myocardial ischemia and infarction.
**Why Each Wrong Option is Incorrect**
**Option A:** Obesity is a risk factor for CAD, but it is not the most direct cause of increased susceptibility. While obesity can contribute to hypertension, insulin resistance, and dyslipidemia, which are all risk factors for CAD, it is not the most specific answer choice.
**Option B:** Diabetes mellitus is a significant risk factor for CAD, but it is not the most direct cause of increased susceptibility. Diabetes can contribute to atherosclerosis, endothelial dysfunction, and increased cardiac workload, but it is not the most specific answer choice.
**Option C:** Smoking is a major risk factor for CAD, but it is not the most direct cause of increased susceptibility. Smoking can contribute to atherosclerosis, endothelial dysfunction, and increased cardiac workload, but it is not the most specific answer choice.
**Clinical Pearl / High-Yield Fact**
The J-shaped curve illustrates the relationship between blood pressure and cardiovascular risk. While very low blood pressure ( 160 mmHg) is associated with significantly increased risk.
**Correct Answer: B. Diabetes mellitus is a significant risk factor for CAD, but it is not the most direct cause of increased susceptibility.**