Question
Beta blockers mask all effects of hypoglycemia except ‑
| A. |
Sweating |
| B. |
Palpitations |
| C. |
Dizziness |
| D. |
Tremors |
Show Answer
|
Correct Answer » A Explanation |
 |
Hypoglycemia produces two groups of symptoms:
1. Autonomic (Adrenergic) Symptoms
Caused by catecholamine release:
- Palpitations
- Tremors
- Anxiety
- Tachycardia
2. Cholinergic Symptoms
Mediated by acetylcholine:
- Sweating
- Hunger
- Paresthesias
Effect of Beta-Blockers
Beta-blockers suppress the adrenergic manifestations of hypoglycemia by blocking β-adrenergic receptors.
Therefore, the following warning signs may be masked:
- Palpitations
- Tachycardia
- Tremors
- Anxiety
However, sweating is mediated predominantly through cholinergic sympathetic fibers, so it is usually not masked by beta-blockers.
Thus, sweating remains an important warning sign of hypoglycemia in patients receiving beta-blockers.
Why Other Options Are Incorrect
B. Palpitations
- Adrenergic symptom.
- Commonly masked by beta-blockers.
C. Dizziness
- Neuroglucopenic symptom resulting from cerebral glucose deprivation.
- Not a classic autonomic warning sign.
- The standard answer tested is sweating.
D. Tremors
- Adrenergic symptom.
- Suppressed by beta-blockers.