The impact of metabolic syndrome on one-year patient-reported outcomes after lumbar fusion surgery

Background

The prevalence of Metabolic Syndrome (MetS) is increasing and negatively impacts a variety of surgeries. In lumbar fusions, MetS is associated with an increased risk of complications, however no studies have focused on patient-reported outcome measures (PROMs). The aim of this study was to explore the relationship between MetS and 1-year PROMs in lumbar fusion patients using the Patient-Reported Outcomes Measurement Information System (PROMIS).

Methods

Retrospective review of 212 patients who underwent 1- to 3-level lumbar fusion for degenerative pathologies between March 2021 and December 2023 from a single institution was performed. Patients were categorized based on the presence of MetS, defined as having 3 or more qualifying metabolic conditions, and assessed using PROMIS surveys (Physical Function [PF], Mental Health, and Pain Interference) preoperatively and at 1-year postoperatively. Univariate and multivariate analyses were performed to evaluate the impact of MetS on PROMIS improvement.

Results

Patients with MetS (n=64, 30.2%) had a longer length of stay, were more likely to be discharged to a skilled nursing facility, and experienced higher rates of 1-year complications (37.5vs. 20.9%, p=.016). After risk-adjustment, MetS patients had lower odds of achieving clinically significant improvement in PROMIS-PF (OR: 0.46, p=.020). In obese patients, the presence of MetS was associated with less improvement (β: -3.22, p=.049) and lower odds of clinically significant improvement in PROMIS-PF (OR: 0.34, p=.017). No significant associations between MetS and mental health or pain interference scores were observed in the overall population or obese patients.

Conclusions

MetS negatively impacts outcomes following lumbar fusion, and this difference in outcomes is not solely explained by obesity. Patients should be encouraged to modify their lifestyle to reduce the adverse effects of MetS on outcomes, and surgeons should consider the impact of MetS on outcomes following lumbar fusion and communicate these expectations with patients.