I am admitting a patient with diabetes mellitus (DM) due to chronic pancreatitis. Should I manage her diabetes any differently than my other patients with DM?

You may have to!  That’s because patients with DM due to pancreatic disease (also known as “pancreatogenic [Type 3C] diabetes”) tend to have more labile blood glucoses with particular predisposition to severe hypoglycemic episodes due to the impairment of glucagon production by pancreatic alpha-cells. 1-3

This observation dates back to a 1977 study where a high rate of hypoglycemic episodes was found among 59 patients with chronic pancreatitis (most with insulin-dependent DM), including 3 deaths and 2 suffering from severe brain damage following hypoglycemic coma. Interestingly, low basal glucagon levels were found in the latter patients, supporting impairment in glucagon synthesis. Of note, while hypoglycemia is a serious problem in these patients, they are not spared from complications of chronic hyperglycemia, including retinopathy and kidney disease.2

As for the blood glucose management in type 3C DM, since the principle endocrine defect is insulin deficiency, insulin therapy is preferred for most patients, particularly those who are acutely ill or are hospitalized. For otherwise more stable patients with mild hyperglycemia, metformin is an ideal agent as it enhances hepatic insulin sensitivity without the risk of hypoglycemia. As a bonus, metformin may also decrease the risk of pancreatic cancer in chronic pancreatitis, based on observational studies. 4

Also, don’t forget that concurrent pancreatic exocrine insufficiency is common in patients with type 3C DM and requires oral pancreatic enzyme requirement with meals.

Fascinating Pearl: Did you know that in patients with type 3C DM, hyperglycemia is mediated not only by decreased production of insulin, but also by decreased synthesis of pancreatic polypeptide, a peptide that mediates hepatic insulin sensitivity and glucose production? 5

If you liked this post, download the app, sign up under MENU and catch future pearls right into your inbox, all for free!

References

  1. Linde, J, Nilsson LH, Barany FR. Diabetes and hypoglycemia in chronic pancreatitis. Scand J Gastroenterol. 2012;12, 369–373. https://www.ncbi.nlm.nih.gov/pubmed/867001
  2. Andersen D. The practical importance of recognizing pancreatogenic or type 3c diabetes. Diabetes Metab Res Rev. 2012;28:326-328. https://onlinelibrary.wiley.com/doi/abs/10.1002/dmrr.2285
  3. Cui YF, Andersen DK. Pancreatogenic diabetes: Special considerations for management. Pancreatology. 2011;11(3):279-294. doi:10.1159/000329188. https://jhu.pure.elsevier.com/en/publications/pancreatogenic-diabetes-special-considerations-for-management-4
  4. Evans J, Donnelly L, Emsley-Smith A. Metformin and reduced risk of cancer in diabetic patients. Br Med J. 2005;330:1304-1305. https://www.researchgate.net/publication/7888859_Metformin_and_reduced_risk_of_cancer_in_diabetic_patients
  5. Rabiee A. Gafiatsatos P, Salas-Carnillo R. Pancreatic polypeptide administration enhances insulin sensitivity and reduces the insulin requirement of patents on insulin pump therapy. Diabetes Sci Technol 2011;5:1521-28.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3262724/

Contributed by Hugo Torres, MD, MPH, Hospital Medicine Unit, Mass General Hospital, Boston, Massachusetts

I am admitting a patient with diabetes mellitus (DM) due to chronic pancreatitis. Should I manage her diabetes any differently than my other patients with DM?

Is it possible to have acute pancreatitis with normal serum lipase?

Yes! Although an elevated serum lipase has a negative predictive value of 94%-100% for acute pancreatitis (1), there are ample reports in the literature of patients with CT findings of pancreatitis in the presence of abdominal symptoms but with normal serum lipase and/or amylase (2,3).

A case series and review of literature of acute pancreatitis with normal lipase and amylase failed to reveal any specific risk factors for such observation (2). More specifically, the etiologies of acute pancreatitis in the reported cases have varied, including drug-induced, cholelithiasis, alcohol, hypertriglyceridemia, and postoperative causes.

But what accounts for this phenomenon? Many cases have been associated with the first bout of pancreatitis without evidence of pancreatic calcifications which makes the possibility of a “burned-out” pancreas without sufficient acinar cells to release lipase as a frequent cause unlikely. Other potential explanations for normal lipase in acute pancreatitis have included measurement of serum lipase at a very early phase of the disease before significant destruction of acinar cells has occurred (increases in 3-6 h, peaks at 24 h [4]) and more rapid renal clearance of serum lipase due to tubular dysfunction (2).

Of note, unlike amylase, lipase is totally reabsorbed by renal tubules under normal conditions (5). Thus, it’s conceivable that even a reversible tubular dysfunction may lead to increased clearance of serum lipase and potentially lower its levels.
References
1. Ko K, Tello LC, Salt J. Acute pancreatitis with normal amylase and lipase. The Medicine Forum. 2011;11 Article 4. https://jdc.jefferson.edu/tmf/vol11/iss1/4/
2. Singh A, Shrestha M. Acute pancreatitis with normal amylase and lipase-an ED dilemma. Am J Emerg Med 2016;940.e5-940.e7. https://www.ncbi.nlm.nih.gov/pubmed/26521195
3. Limon O, Sahin E, Kantar FU, et al. A rare entity in ED: normal lipase level in acute pancreatitis. Turk J Emerg Med 2016;16:32-34. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4882216/
4. Shah AM, Eddi R, Kothari ST, et al. Acute pancreatitis with normal serum lipase: a case series. J Pancreas (Online) 2010 July 5;11:369-72. PDF
5. Lott JA, Lu CJ. Lipase isoforms and amylase isoenzymes: assays and application in the diagnosis of acute pancreatitis. Clin Chem 1991;37:361-68. https://www.ncbi.nlm.nih.gov/pubmed/1706232
If you liked this post, sign up under menu to receive future P4P pearls right into your mailbox!

Is it possible to have acute pancreatitis with normal serum lipase?

Is measurement of amylase and lipase useful in patients with renal insufficiency suspected of pancreatitis?

Depends on how high the serum levels are! Although the clearance of both amylase and lipase appears to be impaired in patients with significant renal insufficiency (eg,  creatinine clearance <50ml/min), serum levels greater than 2-4 times the upper limits of normal for these enzymes are still considered suggestive of pancreatitis in these patients1-3.

Interestingly, in hemodialysis patients, elevation of lipase may also be due to the lipolytic effect of heparin during this procedure.  That’s why obtaining serum lipase levels before, not after,  hemodialysis has been recommended4

Also fascinating is that most of the elevation of serum amylase in patients with significant renal insufficiency appears to be related to the elevation of salivary, not pancreatic, isoenzyme of amylase4.

Final fun fact: Did you know that at one time the diagnosis of pancreatitis was based on the activity of serum on starch (for amylase) and olive oil (for lipase)? 5

References

  1. Levitt MD, Rapoport M, Cooperband SR. The renal clearance of amylase in renal insufficiency, acute pancreatitis, and macroamylasemia. Ann Intern Med 1969;71:920-25. http://annals.org/aim/article/683643/renal-clearance-amylase-renal-insufficiency-acute-pancreatitis-macroamylasemia
  2. Collen MJ, Ansher AF, Chapman AB, et al. Serum amylase in patients with renal insufficiency and renal failure. Am J Gastroenterol 1990;85:1377-80. https://www.ncbi.nlm.nih.gov/pubmed/1699413
  3. Royce VL, Jensen DM, Corwin HL. Pancreatic enzymes in chronic renal failure. Arch Intern Med 1987;147:537-39. https://www.ncbi.nlm.nih.gov/pubmed/2435254
  4. Vaziri ND, Change D, Malekpour A, et al. Pancreatic enzymes in patients with end-stage renal disease maintained on hemodialysis. Am J Gastroenterol 1988;83:410-12. https://www.ncbi.nlm.nih.gov/pubmed/2450453
  5. Editorial. Pancreatic enzymes. N Engl J Med 1963;268:901-2. http://www.nejm.org/doi/pdf/10.1056/NEJM196304182681613
Is measurement of amylase and lipase useful in patients with renal insufficiency suspected of pancreatitis?

Should I order serum procalcitonin on my patient with suspected infection?

Two things to ask before you order procalcitonin (PCT): 1. Will it impact patient management?; and 2. If so, will the result be available in a timely manner ie, within hours not days?

Whatever the result, PCT should always be interpreted in the context of the patient’s illness and other objective data. Not surprisingly then, as a “screening” test, PCT may be more useful in patients with low pre-test likelihood of having bacterial infection, not dissimilar to the use of D-dimer in patients with low pre-test probability of pulmonary embolism1.  

Several potential clinical uses of this biomarker have emerged in recent years,  including:1,2

  • Helping decide when to initiate antibiotics in patients with upper acute respiratory tract infections and bronchitis. A normal or low PCT supports viral infection.
  • Helping decide when to discontinue antibiotics (ie, when PCT normalizes) in community-acquired or ventilator-associated pneumonia.
  • Helping monitor patient progress with an expected drop in PCT of about 50% per day (half-life ~ 24 hrs) with effective therapy.

Few caveats…

  • PCT may be unremarkable in about a third of patients with bacteremia (especially due to less virulent bacteria, including many gram-positives)3.  
  • PCT levels are lowered by high-flux membrane hemodialysis, so check a baseline level before, not after, hemodialysis4.
  • Lastly, despite its higher specificity for bacterial infections compared to other biomarkers such as C-reactive protein, PCT may be elevated in a variety of non-infectious conditions, including pancreatitis, burns, pulmonary edema or aspiration, mesenteric infarction (ischemic bowel), cardiogenic shock, and hypotension during surgery2.

 

References:

  1. Schuetz P, Muller B, Chirst-Crain M, et al. Procalcitonin to initiate or discontinue antibiotics in acute respiratory tract infections (review). Evid-Based Child Health (A Cochrane Review Journal) 2013;8:4;1297-137. http://onlinelibrary.wiley.com/doi/10.1002/ebch.1927/pdf
  2. Gilbert GN. Use of plasma procalcitonin levels as an adjunct to clinical microbiology. J Clin Microbiol 2010;48:2325-29. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2897488/pdf/0655-10.pdf
  3. Yan ST, Sun LC, Jia HB. Procalcitonin levels in bloodstream infections caused by different sources and species of bacteria. Am J Emerg Med 2017;35:779-83. https://www.ncbi.nlm.nih.gov/m/pubmed/27979420/#fft
  4. Grace E, Turner RM. Use of procalcitonin in patients with various degrees of chronic kidney disease including renal replacement therapy. Clin Infect Dis 2014;59:1761-7. https://www.ncbi.nlm.nih.gov/pubmed/25228701
Should I order serum procalcitonin on my patient with suspected infection?