During his annual physical examination,a 55-year-old man is noted to have a body mass index of 33 (30 indicates obesity)and high blood pressure.His blood chemistry profile indicates hyperlipidemia,hypertriglyceridemia,and hypercholesterolemia.Furthermore,his fasting blood glucose level is 120 mg/dL (elevated).His physician suspects type 2 diabetes and orders a glucose tolerance test.The patient drinks 75 g of glucose and then has his blood glucose measured 2 hours later.The 2-hour glucose level is 190 mg/dL (high end of glucose intolerance range; for the diagnosis of diabetes,the level is 200 mg/dL or higher).The most likely reason for this patient's glucose intolerance is:

Question

During his annual physical examination,a 55-year-old man is noted to have a body mass index of 33 (>30 indicates obesity)and high blood pressure.His blood chemistry profile indicates hyperlipidemia,hypertriglyceridemia,and hypercholesterolemia.Furthermore,his fasting blood glucose level is 120 mg/dL (elevated).His physician suspects type 2 diabetes and orders a glucose tolerance test.The patient drinks 75 g of glucose and then has his blood glucose measured 2 hours later.The 2-hour glucose level is 190 mg/dL (high end of glucose intolerance range; for the diagnosis of diabetes,the level is 200 mg/dL or higher).The most likely reason for this patient's glucose intolerance is:

Quizplus · Accepted Answer

The patient's high body mass index, hyperlipidemia, high blood pressure, and elevated fasting glucose all suggest insulin resistance, which is a common cause of type 2 diabetes. The glucose tolerance test result of 190 mg/dL at 2 hours confirms glucose intolerance, which is also indicative of insulin resistance. Option A is incorrect because autoimmune destruction of the β cells is the cause of type 1 diabetes. Option B is incorrect because impairment of ATP-sensitive potassium channel causes a rare form of diabetes called neonatal diabetes. Option D is incorrect because low leptin levels result in increased appetite and obesity, but not necessarily glucose intolerance. Option E is incorrect because impairment of GLUT-2 function causes a rare form of diabetes called Fanconi syndrome.

During His Annual Physical Examination,a 55-Year-Old Man Is Noted to Have