The association between inflammation and glucose levels in hospitalised patients with type 2 diabetes

Stress-induced hyperglycaemia can exacerbate existing diabetes. However, the relationship between inpatient inflammation and glucose levels is not well understood.

This post hoc analysis utilised data from the DIATEC trial (N = 166), a two-arm randomised controlled trial comparing glucose management with real-time continuous glucose monitoring (CGM) or point-of-care glucose testing in non-intensive care unit (non-ICU) patients with type 2 diabetes treated with a basal-bolus insulin regimen. Inflammation was measured as C-reactive protein (CRP) levels daily, and its association with daily glycaemic outcomes and insulin doses was assessed.

For every 100 mg/dL increase in CRP, time in range 3.9-10.0 mmol/L (70-180 mg/dL) decreased by 3.6%-points (95% CI: 1.2-6.1, p = 0.004). An interaction was found between high CRP (>75.0 mg/dL) and high HbA1c (>51.0 mmol/mol or 6.8%), associated with an 8.9%-point reduction in TIR (95% CI: 3.8-14.1). Time above range >10.0 mmol/L (>180 mg/dL) increased by 3.3%-points (95% CI: 0.8-5.8, p = 0.009), and mean glucose increased by 0.2 mmol/L (95% CI: 0.02-0.4) (4.0 mg/dL, 95% CI: 0.4-7.0) for every 100 mg/dL increase in CRP. No significant associations were found between CRP and time below range <3.9 mmol/L (<70 mg/dL), glycaemic variability, hypoglycaemic events, or total daily insulin dose (all p > 0.05).

Elevated CRP levels only modestly increased glucose levels. This suggests that inflammation during hospitalisation has a limited effect on glucose levels in non-ICU patients with type 2 diabetes.