238-OR: A Single Hypoglycemic Event Causes a Prolonged Immune Response

Hypoglycemia acutely activates the immune system and is associated with an increased risk for atherosclerotic disease. Since atherosclerosis is driven by inflammation, we set out to determine the duration of the pro-inflammatory response to a hypoglycemic event in people with and without diabetes.Adults with type 1 diabetes (n = 47) or insulin-treated type 2 diabetes (n = 15) , and age-matched controls without diabetes (n = 32) underwent a hyperinsulinemic-euglycemic (5.2 ± 0.4 mmol/L) -hypoglycemic (2.8 ± 0.1 mmol/L) glucose clamp. Before, during and up to a week thereafter, blood was drawn to determine circulating immune cell composition and function combined with measurements of and circulating hs-CRP concentrations. At baseline, participants with diabetes had higher counts of produced cytokines and hs-CRP compared to individuals without diabetes (all p < 0.01) . In response to hypoglycemia, absolute numbers of lymphocytes (1.57 ± 0.53 vs. 2.69 ± 0.95·10³/µL) and monocytes (0.40 ± 0.14 vs. 0.62 ± 0.22·10³/µL) increased acutely and remained elevated for one week in all subgroups (all p < 0.001) . During hypoglycemia, the proportion of pro-inflammatory CD16⁺-monocytes increased from 26.9 ± 13.3% to 38.1 ± 14.9% and the proportion of phagocytotic CD14⁺-monocytes decreased from 65.2 ± 14.4% to 54.5 ± 15.9% in all subgroups (all p < 0.01) . Stimulated monocytes released more TNF-α and IL-1β, and less IL-during hypoglycemia. Similarly, hs-CRP concentrations increased from 2.± 3.20 µg/mL to 2.71 ± 3.57 µg/mL 1 day after the clamp (p < 0.001) and remained elevated for one week (p < 0.001) thereafter to similar extent in all subgroups.

In conclusion, a single hypoglycemic event induces a prolonged immune response in humans independent of the presence of diabetes.