Association of insulin-like growth factor 1 serum levels with early recovery and in-hospital complications after spinal fusion.

Objective: Sterile surgical trauma triggers a hormonal stress response that promotes a catabolic state, leading to fatigue, muscle loss, and impaired recovery. This postoperative catabolism is mediated, in part, by a decrease in insulin-like growth factor 1 (IGF-1), a key anabolic hormone regulated by human growth hormone (HGH). Given the established role of IGF-1 in muscle maintenance, tissue regeneration, and as a sensitive marker of nutritional status, the authors aimed to determine whether baseline IGF-1 levels, assessed using age- and sex-adjusted z-scores, predict short-term postoperative medical complications and discharge disposition following spinal fusion surgery.

Methods: Preoperative serum IGF-1 levels were collected within 1 month before spinal fusion surgery and assessed using standardized sex- and age-adjusted z-scores. Primary outcomes included medical complications (according to the International Spine Study Group-AO Spine criteria) and self-sufficiency at discharge, defined as discharge home without the need for home health care (vs daily home nursing or a rehabilitation facility), and were retrospectively analyzed. Independent predictors were identified by multivariate regression analysis adjusted for age, the number of levels fused, estimated blood loss, BMI, Charlson Comorbidity Index (CCI), and IGF-1 z-scores.

Results: Seventy-nine patients (44 male, mean age of 68 years) with a mean of 3.2 levels fused were included in the analysis. In-hospital complications, discharge needs, and progress with physical therapy were associated with IGF-1 z-scores. The regression analysis revealed that a higher IGF-1 z-score (p = 0.004) and shorter operative duration (p = 0.007) were independently associated with fewer in-hospital complications. The regression model controlled for confounders and correctly classified 93.7% of patients. Similarly, a higher IGF-1 z-score (p = 0.006), reduced intraoperative blood loss (p = 0.004), and lower CCI (with age adjustment, p = 0.001) were independently associated with a higher likelihood of achieving self-sufficiency at discharge in a model that correctly classified 77.2% of patients.

Conclusions: Higher preoperative IGF-1 z-scores were independently associated with fewer medical complications and increased self-sufficiency at discharge. The HGH/IGF-1 axis might be a target for therapeutic interventions designed to improve early recovery.