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
[{'content': 'Niacin is dangerous in diabetes mellitus because: \nSelect and explain. \nA. It causes insulin resistance, B. It causes sudden hypoglycemia, C. It decreases glucagon secretion, D. It decreases effect of other OHA', 'role': 'user'}, {'content': 'Answer: A \nExplanation: 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.', 'role': 'assistant'}]