Monday, March 25, 2013

Insulin resistance syndromes

This review is one of the best discussions I've seen on the various insulin resistance syndromes. It centers around a case report of a patient with type 2 DM who developed DKA and extreme insulin resistance in the face of acute MI.

The case in question raises several discussion points. This is a case of DKA which, in defiance of the usual rule, developed in a patient with DM type 2. Traditional teaching holds that DKA is associated with DM 1. DM 1 strictly defined, however, is that type of DM in which DKA predictably develops spontaneously, in deprivation of administered insulin, in the basal state. This patient had acute MI and was therefore not in a basal state. But to further complicate matters this patient, being Hispanic, could have had ketosis prone type 2 diabetes, a syndrome in which patients seemingly flip-flop between type 1 and type 2 phenotypes. This is a condition of intermittent beta cell fatigue which may have rendered the patient more prone to glucose toxicity which the authors speculate was a factor. This patient's insulin resistance was not defined by the presence of DKA but rather by the amount of administered insulin it took to achieve glycemic control.

The activation of counter regulatory (stress) hormones by the AMI, and perhaps inflammatory cytokines, could explain the development of DKA but, in the opinion of the authors, probably not this degree of insulin resistance (extreme insulin resistance). While AMI has been cited as a situation causing extreme insulin resistance, it appears to do so by multiple and poorly understood mechanisms.

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