Intravenous catheters induce a local inflammatory response

Chronic inflammation has been associated to the development of cardiometabolic dysfunctions. The use of an intravenous (IV) catheter is highly recommended for physiology testing. Yet, the presence of an IV catheter triggers local inflammation that does not reflect systemic inflammatory status. The aim of this study was to assess the effect of an IV catheter on serum concentrations of IL-6, IL-8 and hsCRP in a fasting state and after a high-fat meal known to trigger low-grade inflammation.

Twenty-two healthy subjects (7 men, 15 women) were included in this study. The trial included 2 visits. After an overnight fast, a venous catheter was inserted into an antecubital vein. A first blood sample was collected through this catheter at T = 0 min. On each visit, participants were requested either to drink only water for the whole duration of the test (WO test), or to consume a high-fat meal (HFM). Blood samples were collected through the catheter at T60, T120, T180 and T300 min. Additional venous punctures were performed on the contralateral arm at T180 and T300 min. Serum inflammatory mediators were measured at each time point of both interventions.

When serum was collected by venous punctures, IL-6 concentrations remained unchanged during both WO and HFM tests (P_time = 0.15 and P_time = 0.23, respectively), whereas the concentrations increased progressively over time when serum was collected through the catheter (P_time < 0.001). The high-fat meal had no additional effect on IL-6 levels (P_meal = 0.27) neither in serum collected by venous puncture nor in serum collected through the catheter. Serum IL-8 and hsCRP concentrations did not vary over time, and were influenced neither by the meal type nor by the blood collection method.

The insertion of an indwelling catheter is associated with a local inflammatory response possibly mediated by IL-6 but not IL-8. This inflammatory response was not enhanced by a pro-inflammatory high-fat meal.