Intestinal absorption in myotonic dystrophy.

Area of Science:

• Gastroenterology
• Neurology
• Metabolic Disorders

Background:

• Myotonic dystrophy is a multisystem disorder.
• Intestinal absorption and glucose metabolism can be affected in myotonic dystrophy.

Purpose of the Study:

• To investigate intestinal absorption and glucose tolerance in patients with myotonic dystrophy.
• To differentiate between malabsorption and motility disturbances as causes of abnormal test results.

Main Methods:

• Oral vitamin A absorption test
• Faecal fat and nitrogen excretion analysis
• D-xylose absorption test
• Schilling test
• Oral glucose tolerance test (OGTT)
• Intravenous glucose tolerance test

Main Results:

• One of 11 patients had abnormal vitamin A absorption with increased faecal fat and nitrogen.
• Two of 12 patients had abnormal D-xylose tests, possibly due to urine collection issues.
• Schilling tests were generally normal.
• 26 of 35 patients showed abnormal OGTT results, including elevated fasting/peak glucose, delayed return to baseline, and biphasic response.
• Biphasic response to oral glucose loading was characteristic.
• Intravenous glucose loading yielded normal results.
• Abnormal oral glucose response was likely due to intestinal motility disturbances, not malabsorption.

Conclusions:

• Malabsorption appears to be a rare complication of myotonic dystrophy.
• Intestinal motility disturbances are a more probable cause of abnormal oral glucose tolerance tests in myotonic dystrophy.
• Further investigation into gastrointestinal motility is warranted in these patients.