Association Between Higher Insulin Resistance and Poor Short-Term Functional Outcome After Nonsurgical Intracerebral...

Insulin resistance has been implicated in unfavorable outcomes after ischemic stroke in recent studies, but its impact on functional outcomes after intracerebral hemorrhage (ICH) remains unclear.

We analyzed 704 patients with nonsurgical ICH (mean age, 68 years) enrolled in the multicenter Fukuoka Stroke Registry who were treated conservatively and followed for 3 months. Insulin resistance was assessed using the homeostasis model assessment of insulin resistance (HOMA-IR). There was a poor functional outcome, defined as a modified Rankin Scale score of 4 to 6 at 3 months. Logistic regression and restricted cubic spline analyses were performed. Sensitivity analyses estimated risk ratios and examined results in nondiabetic and nonobese patients. We also assessed the added predictive value of HOMA-IR when incorporated into the max-ICH score, a validated prognostic model, and the Fukuoka Stroke Registry ICH score, a developed model from the same registry, using the C statistic and 10-fold cross-validation.

Age- and sex-adjusted odds ratios (ORs) for poor outcome increased significantly with higher HOMA-IR (P for trend <0.001). This association remained significant after adjusting for confounders (OR for highest versus lowest quartile, 2.86 [95% CI, 1.39-5.90]). Findings were consistent in sensitivity analyses. The odds of poor outcome increased linearly, even within the normal range and plateaued >3.0. Adding HOMA-IR modestly improved discrimination for both risk scores, with similar results in 10-fold cross-validation.

Insulin resistance is independently associated with poor short-term outcome after acute ICH. Incorporating HOMA-IR improves prediction, identifying it as an early prognostic marker and a possible future therapeutic target.