A 58-year-old man with a 16-year history of type 2 diabetes mellitus comes to the physician with recurrent hypoglycemic episodes. Most of the episodes occur after breakfast and dinner. He also complains of sweating during meals, occasional postural dizziness, postprandial fullness, early satiety, and constipation. He is currently on a basal-bolus insulin regimen with a bedtime dose of insulin glargine and a variable dose of short-acting insulin with meals. The patient has mild chronic renal disease (creatinine 1.6 mg/dL) that has been stable for the last 2 years, bilateral proliferative diabetic retinopathy, and distal sensory peripheral neuropathy. His pre-meal blood glucose levels are 150-250 mg/dL. Which of the following studies is most likely to confirm this patient's condition?

Question

A 58-year-old man with a 16-year history of type 2 diabetes mellitus comes to the physician with recurrent hypoglycemic episodes.  Most of the episodes occur after breakfast and dinner.  He also complains of sweating during meals, occasional postural dizziness, postprandial fullness, early satiety, and constipation.  He is currently on a basal-bolus insulin regimen with a bedtime dose of insulin glargine and a variable dose of short-acting insulin with meals.  The patient has mild chronic renal disease (creatinine 1.6 mg/dL) that has been stable for the last 2 years, bilateral proliferative diabetic retinopathy, and distal sensory peripheral neuropathy.  His pre-meal blood glucose levels are 150-250 mg/dL.  Which of the following studies is most likely to confirm this patient's condition?

Quizplus · Accepted Answer

Explanation: 11ec2b69_c158_4313_8f63_0b04873a79f3_MD0005_00 This patient has longstanding diabetes with multiple chronic complications, including peripheral neuropathy. His history and symptoms (eg, postprandial bloating, postural dizziness, abnormal sweating, constipation) suggest that he has a concurrent autonomic neuropathy and may have associated gastroparesis. Patients with gastroparesis often have labile diabetic control and frequent hypoglycemia as it is difficult to time their insulin dose to correspond with the delayed intestinal absorption of glucose. In evaluating patients with delayed gastric emptying, the first step is to rule out a mechanical obstruction. This is usually done with upper gastrointestinal endoscopy or barium swallow, with abdominal computed tomography (CT) or magnetic resonance imaging added if extrinsic compression is suspected. Unfortunately, these tests do not assess motility. If diabetic gastroparesis or another motility disorder is suspected, the patient will require a nuclear gastric emptying study to confirm the diagnosis. The foundation of managing gastroparesis is dietary modification. Smaller, more frequent meals with decreased fat and fiber intake can be helpful. If dietary changes alone are insufficient, promotility agents such as erythromycin or metoclopramide may be needed. Refractory cases may require a liquid diet or possibly feeding tube placement. (Choices A and E) Upper gastrointestinal endoscopy and contrast imaging studies such as barium swallow are used to exclude mechanical obstruction. They can identify gastro-duodenal tumors and ulcerations. However, they do not accurately assess gastric motility and so will not confirm the diagnosis of gastroparesis. (Choice B) CT scan is used primarily as a "structural test" in evaluating gastrointestinal disorders, but its usefulness as a "functional test" is much more limited. Although CT scan may identify mechanical gastric obstruction due to extrinsic compression, it will not accurately assess gastric motility. (Choice D) Ultrasonography is useful for assessing the liver and biliary tree (eg, in suspected cholelithiasis). In some facilities, ultrasonography may be used to assess gastric motility, but its accuracy is significantly lower than nuclear studies and so it is rarely used for this purpose. Educational objective: The typical symptoms of diabetic gastroparesis include early satiety and postprandial fullness. It is often accompanied by other autonomic symptoms and labile glucose control. Mechanical obstruction should be excluded. A nuclear gastric emptying study is the procedure of choice to confirm the diagnosis. References: Gastroparesis: pathogenesis, diagnosis and management. (http://www.ncbi.nlm.nih.gov/pubmed/21769117)

A 58-Year-Old Man with a 16-Year History of Type 2