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

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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?

My patient is admitted with diabetic ketoacidosis (DKA) and is testing positive for cocaine. Can cocaine cause DKA?

Cocaine use has been generally linked to DKA but whether it’s through its antagonizing effect on insulin action or more indirectly through its association with non-compliance with insulin, or both, is not totally clear.

A retrospective study found cocaine users to account for 14% of all DKA admissions.1 Cocaine users were also less likely than controls to have an intercurrent illness identified as a precipitant for DKA, and more likely to have missed taking insulin prior to admission. Another study also reported active cocaine use to be associated with DKA, but found its effect to be independent of non-compliance. 2

Yet another retrospective study limited to patients admitted with hyperglycemia, found no significant association between active cocaine use and development of hyperglycemic crisis.

There are reasons to believe that cocaine may contribute to DKA. Cocaine has been proposed as a possible precipitant of DKA due to its ability to potentially enhance counterregulatory mechanisms designed to antagonize the effect of insulin by increasing catecholamine and cortisol levels. 1,3

So next time you have a patient with DKA, consider cocaine as a possible precipitant, particularly when the cause of DKA is unclear.

 

References

  1. Warner EA, Greene GS, Buchsbaum MS et al. Diabetic ketoacidosis associated with cocaine use. Arch Intern Med 1998; 158:1799-802. https://www.ncbi.nlm.nih.gov/pubmed/9738609
  2. Nyenwe E, Loganathan R, Blum S, et al. Active use of cocaine: An independent risk factor for recurrent diabetic ketoacidosis in a city hospital. Endocr Pract 2007;13:22-29. https://www.ncbi.nlm.nih.gov/pubmed/17360297
  3. Modzelewski KL, Rybin DV, Weinberg JM, et al. Active cocaine use does not increase the likelihood of hyperglycemic crisis. J Clin Transl Endocrinol 2017;9:1-7 http://www.jctejournal.com/article/S2214-6237(16)30056-4/pdf

 

Contributed in part by Quin L Sievers, Medical Student, Harvard Medical School

My patient is admitted with diabetic ketoacidosis (DKA) and is testing positive for cocaine. Can cocaine cause DKA?

My diabetic patient complains of acute blurred vision past few days since her blood glucoses have been out of control. How does high blood glucose affect the vision acutely?

“Vision loss or blurriness” is one of the most common manifestations of acute hyperglycemia in diabetic patients and is due to the osmotic swelling of the lens resulting in changes in its characteristics and the inability to properly focus an image.1

Since glucose acts as a solute, an increase in the concentration of glucose causes a rise in osmotic forces and movement of fluid into the lens, resulting in transient myopia. Interestingly, the increase in the fluid in the lens causes a change in its refractory index which is associated with focusing an image at a different length; it does not affect  its curvature or position. 

Baseline vision should be eventually restored by correcting glucose levels.2 Also remember that rapid correction of hyperglycemia may make the lens swelling worse, causing increased visual disturbances.3  

Fun fact: Did you know that chronic hyperglycemia is associated with cataract formation due to excess conversion of glucose to sorbitol in the lens? 4

References

  1. Bron A.J, Sparrow J, Brown N, Harding J, Blakytny, R. The Lens in Diabetes. Eye 1993; 7: 260-75 https://www.nature.com/articles/eye199360.pdf
  2. Huntjens B. O’Donnell C. Refractive error changes in Diabetes Mellitus. Optometry in Practice 2006; 7:103-114. http://openaccess.city.ac.uk/6185/3/Refractive_Error_Changes_in_DM_FINAL.pdf
  3. Sychev YV, Zepeda EM, Lam DL. Bilateral cateract formation via acute spontaneous fracture of the lens following treatment of hyperglycemic hyperosmolar syndrome: Case report. Am J Ophthalmol 2017;7:66-69. https://www.ncbi.nlm.nih.gov/pubmed/29260081
  4. Pollreisz A, Ursula SE. Diabetic Cataract—Pathogenesis, Epidemiology and Treatment. Journal of Ophthalmology 2010; vol. 2010, Article ID 608751. https://www.hindawi.com/journals/joph/2010/608751

 

Contributed by Felicia Hsu, Medical Student, Harvard Medical School

My diabetic patient complains of acute blurred vision past few days since her blood glucoses have been out of control. How does high blood glucose affect the vision acutely?