Plasma HMGB1 levels and physical performance in ICU survivors

PURPOSE Physical impairment after critical illness is recognized as a part of the post-intensive care syndrome (PICS). About one third of intensive care unit (ICU) survivors suffer from long-term physical disability, yet the underlying pathophysiological mechanisms remain poorly understood. The pro-inflammatory alarmin, high mobility group box 1 (HMGB1), promotes muscle dysfunction in experimental models, and HMGB1 stays elevated in some patients after ICU discharge. Accordingly, we investigated the relationship between HMGB1 plasma levels and physical performance in ICU survivors. METHODS Prospective cohort study of 100 ICU survivors from the general ICU at the Karolinska University Hospital, Sweden. Patients returned for follow up at 3 (58 patients) and 6 months (51 patients) after ICU discharge. Blood samples were collected, and a 6-minute walk test (6-MWT), a handgrip-strength test (HST), and a timed-stands test (TST) were performed. RESULTS Compared to reference values of the different physical tests, 16% of patients underperformed at all tests at 3 months and 12% at 6 months. All test results, except hand-grip strength left, improved significantly over the follow-up period (P