Question 1

Q: Smoking is considered to be a modifiable risk factor for Coronary Heart Disease. Consider the following statements with regard to possible mechanisms on the basis of which it acts as a risk factor : 1. Nicotine stimulation of adrenergic drive raises the blood pressure and myocardial oxygen demand. 2. It increases carbon monoxide and induces atherogenesis. 3. It leads to fall in protective high density lipoproteins. 4. It reduces the apolipoprotein-B plasma levels. Which of the statements given above are correct ?

1, 2 and 3. **1, 2 and 3** - **Nicotine** in cigarette smoke stimulates the adrenergic nervous system, leading to increased heart rate, **vasoconstriction**, and elevated blood pressure, which **increases myocardial oxygen demand**. - **Carbon monoxide** from smoking binds to hemoglobin, reducing oxygen delivery to the myocardium, and also contributes to **endothelial damage** and **atherogenesis**. Smoking also **lowers HDL ("good" cholesterol)**, which normally helps remove cholesterol from arteries. *2, 3 and 4* - This option is incorrect because statement 4 is false; smoking typically **increases** apolipoprotein-B levels, associated with increased LDL cholesterol, not reduces them. - While statements 2 and 3 are correct mechanisms, the inclusion of statement 4 makes this option incorrect. *1 and 3 only* - This option is incomplete as it misses the crucial role of **carbon monoxide** in inducing atherogenesis (statement 2), which is a well-established mechanism of smoking-related CHD. - While statements 1 and 3 are correct mechanisms, the absence of statement 2 makes this option less comprehensive. *1 and 2 only* - This option omits the significant effect of smoking on **high-density lipoproteins (HDL)**; smoking is known to cause a **fall in protective HDL levels**, contributing to increased CHD risk. - While statements 1 and 2 are correct mechanisms, the exclusion of statement 3, which is also correct, makes this option incomplete.

Question

Smoking is considered to be a modifiable risk factor for Coronary Heart Disease. Consider the following statements with regard to possible mechanisms on the basis of which it acts as a risk factor :

1. Nicotine stimulation of adrenergic drive raises the blood pressure and myocardial oxygen demand.
2. It increases carbon monoxide and induces atherogenesis.
3. It leads to fall in protective high density lipoproteins.
4. It reduces the apolipoprotein-B plasma levels. Which of the statements given above are correct ?

Accepted Answer

1, 2 and 3

Answer

2, 3 and 4

Answer

1 and 3 only

Answer

1 and 2 only

UPSC-CMS 2023 — Internal Medicine