(1323) Impact of CRRT on Insulin Sensitivity: Role of the Microelements

Introduction: Insulin sensitivity is usually impaired in septic patients with AKI. The role of CRRT in modulating insulin signaling probably depends on the molecules/cofactors that are actively removed during dialysis. We describe the case of a patient with poorly controlled type 2 diabetes admitted for septic shock who developed severe AKI and required CRRT. Glucose level and insulin requirements significantly worsened post initiation of CRRT mandating an extensive work up.

Description: 64 yo male with DM2 [A1C 7.8%], HTN and CKD stage 3a admitted to ICU with gram negative bacteremia secondary to UTI. On admission patient required mechanical ventilation, vasopressor support (norepinephrine 18 ug/min, vasopressin 0.03 UI/min) and stress dose hydrorcortisone. AKI stage 1 on admission progressed to stage 3 by day #3. Patient was started on CVVHD (delivered dose 40 cc/kg) on day #3. During the first 3 days of ICU, glucose was managed with lispro sliding scale, glargine and low carbohydrate enteral feeding. Insulin requirement before CRRT increased progressively from 180 units/d to 264 units/d. Post initiation of CVVHD, insulin dose continued to increase, and it reached 432 units/d by day #6 despite discontinuation of steroids. Based on the insulin signaling pathway, it was decided to order chromium (Cr) level in serum and dialysis ultrafiltrate fluid to calculate rate of removal. Calculated rate of Cr removal was 0.096 ug/L corresponding to 21% of daily dose of Cr (expected daily dose of Cr removal was 9%). Serum Cr level was 0.44 ug/L (Cr deficiency defined as less than 1.5 ug/L). Given the high Cr removal rate and low serum levels, CVVHD dose was decreased to 25 cc/kg and oral supplement of chromium picolinate 200 ug q12hs was administered for 6 days. Insulin requirement dropped from 432 units/d to 124 units/d after 3 days of Cr therapy. Serum level of Cr increased to 1.4 ug/L and rate Cr removal decreased to 13%.

Discussion: Chromium deficiency is an important cause of refractory hyperglycemia due to impaired insulin signaling. Causes of Cr deficiency in the ICU include CRRT overdose, high dose vasopressors leading to intestinal ischemia, diarrhea and nutritional deficit. Measuring Cr in serum and dialysis ultrafiltrate fluid is easy and can help to direct the therapy with oral Cr picolinate.