A patient with long-standing type 1 diabetes develops hypoglycemia; the most likely contributing complication is which of the following?

A patient with long-standing type 1 diabetes develops hypoglycemia; the most likely contributing complication is which of the following?

• A. Autonomic neuropathy
• B. Excess insulin
• C. Diabetic nephropathy
• D. Hepatic disease

Answer: (C)

When hypoglycemia occurs in someone with long-standing type 1 diabetes, look for factors that increase insulin action or reduce glucose output. Diabetic nephropathy fits best because kidney dysfunction slows the clearance of insulin from the circulation, so insulin action lasts longer and drops blood glucose more. The kidneys also contribute to glucose production through renal gluconeogenesis; with nephropathy, this backup is diminished, further tipping toward hypoglycemia. Autonomic neuropathy mainly blunts the warning signs and counterregulatory responses rather than directly causing hypoglycemia, and excess insulin is the immediate cause rather than a complication. Hepatic disease can cause hypoglycemia too, but among the listed complications, nephropathy most directly explains the increased susceptibility in a long-standing patient.

When hypoglycemia occurs in someone with long-standing type 1 diabetes, look for factors that increase insulin action or reduce glucose output. Diabetic nephropathy fits best because kidney dysfunction slows the clearance of insulin from the circulation, so insulin action lasts longer and drops blood glucose more. The kidneys also contribute to glucose production through renal gluconeogenesis; with nephropathy, this backup is diminished, further tipping toward hypoglycemia. Autonomic neuropathy mainly blunts the warning signs and counterregulatory responses rather than directly causing hypoglycemia, and excess insulin is the immediate cause rather than a complication. Hepatic disease can cause hypoglycemia too, but among the listed complications, nephropathy most directly explains the increased susceptibility in a long-standing patient.