A 32-year-old man comes to the office due to a substernal burning sensation that has been occurring intermittently over the last 6 months. The sensation worsens with spicy and fatty meals and is associated with food regurgitation and a sour taste in the back of the throat. He has no projectile vomiting, dysphagia, or unexpected weight loss. Medical history is significant for cystic fibrosis complicated by pancreatic insufficiency, for which the patient takes pancreatic enzyme replacement therapy with all meals. Vital signs are within normal limits. The abdomen is soft and nontender. He is prescribed omeprazole with subsequent improvement in his gastroesophageal reflux symptoms. In this patient, absorption of which of the following nutrients will likely improve due to initiation of this new medication?

Question

A 32-year-old man comes to the office due to a substernal burning sensation that has been occurring intermittently over the last 6 months.  The sensation worsens with spicy and fatty meals and is associated with food regurgitation and a sour taste in the back of the throat.  He has no projectile vomiting, dysphagia, or unexpected weight loss.  Medical history is significant for cystic fibrosis complicated by pancreatic insufficiency, for which the patient takes pancreatic enzyme replacement therapy with all meals.  Vital signs are within normal limits.  The abdomen is soft and nontender.  He is prescribed omeprazole with subsequent improvement in his gastroesophageal reflux symptoms.  In this patient, absorption of which of the following nutrients will likely improve due to initiation of this new medication?

Quizplus · Accepted Answer

11ec160b_3bd6_3c81_9249_add2415eaa85_MD0001_00 This patient with heartburn and regurgitation has the classic manifestations of gastroesophageal reflux disease, a common disorder that occurs when gastric acid refluxes into the esophagus. The mainstay of therapy is gastric acid suppression, usually with proton pump inhibitors (PPIs) (eg, pantoprazole, omeprazole). PPIs irreversibly inhibit the hydrogen-potassium-ATPase pump found in parietal cells, thereby inhibiting hydrochloric acid secretion into the stomach lumen. Although this effectively raises the stomach pH and prevents gastric acid irritation of the esophagus, the acidic environment of the stomach is necessary to absorb certain nutrients. Therefore, common adverse effects of PPIs include malabsorption of calcium, iron, magnesium, and vitamin B₁₂ (Choices B, D, and E). Patients with pancreatic insufficiency (eg, cystic fibrosis, chronic pancreatitis) cannot synthesize the pancreatic enzymes required for digestion of protein, fat, and carbohydrates. As such, the condition is managed with pancreatic enzyme replacements, which contain varying amounts of lipase, amylase, and protease. Unlike amylase and protease, which are activated by the low pH of the stomach, lipase, which plays a vital role in fat digestion, is inactivated by the acidic environment of the stomach. Therefore, by decreasing gastric hydrochloric acid production, PPI use increases lipase activity (ie, it prevents exogenous lipase from being denatured as it passes through the stomach), enhancing fat absorption in patients dependent on pancreatic enzyme replacement therapy. (Choice A) Protein digestion of amino acids requires the activity of a protease known as pepsin, which is more active at low pH. Although one might expect the elevated stomach pH to inhibit protein absorption, chronic PPI use has not been associated with protein malabsorption (likely due to functional overlap with pancreatic and enteric proteases). Educational objective: Proton pump inhibitors (PPI) prevent the hydrogen-potassium-ATPase pump found in parietal cells from releasing hydrochloric acid into the stomach lumen. Chronic PPI use protects exogenously administered lipase and enhances fat absorption in patients dependent on pancreatic enzyme replacement therapy. __________ References: Optimising the therapy of exocrine pancreatic insufficiency by the association of a proton pump inhibitor to enteric coated pancreatic extracts. (http://www.ncbi.nlm.nih.gov/pubmed/16766768) Proton pump inhibitors and risk of vitamin and mineral deficiency: evidence and clinical implications. (http://www.ncbi.nlm.nih.gov/pubmed/25083257)

A 32-Year-Old Man Comes to the Office Due to a Substernal