A patient with controlled hypertension, COPD, periodontal disease, and asthma presents with increased susceptibility to infection. The PRIMARY reason is:

Correct answer: A. Diabetes/hyperglycemia — if uncontrolled

• A. Correct. Diabetes (particularly when uncontrolled) is the primary systemic condition that increases susceptibility to periodontal infection. Hyperglycemia impairs neutrophil function, alters collagen metabolism, and impairs vascular response — all of which increase infection risk. The question implies the patient has diabetes as the underlying systemic condition.
• B. COPD increases susceptibility to respiratory infections but is not the primary reason for increased periodontal infection risk.
• C. Asthma medications (corticosteroids) can impair immunity but are secondary to diabetes in this context.
• D. Hypertension itself does not directly impair immune defense against periodontal pathogens.