This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Pharmacology
Niacin is dangerous in diabetes mellitus because: 
Select and explain. 
A. It causes insulin resistance, B. It causes sudden hypoglycemia, C. It decreases glucagon secretion, D. It decreases effect of other OHA
A: It causes insulin resistance
Answer: A: It causes insulin resistance 
Explanation: Ans. a. It causes insulin resistanceRef: Goodman Gilman 12th e/P 900Niacin causes insulin resistance and hence causes severe hyperglycemia in patients of diabetes mellitus.Hence it should be avoided in patients of diabetes mellitus.