Can Preoperative Nutritional Status Be One of the Parameters Evaluating Biological Age for Elderly Patients Undergoing Spinal Surgery?: A Propensity Score-Matched Analysis

Retrospective cohort study with propensity score-matched analysis. To evaluate the association between preoperative nutritional indices and postoperative health-related quality of life (HRQOL) in elderly patients who have undergone spinal surgery. In elderly patients, surgical decisions should also consider biological age. We hypothesized that preoperative nutritional status would be associated with postoperative improvement in HRQOL, independent of chronological age. We retrospectively analyzed 600 patients aged 60 years or older who underwent spinal surgery at a single institution. Nutritional status was assessed using the Geriatric Nutritional Risk Index (GNRI), the Prognostic Nutritional Index (PNI), and the Controlled Nutritional Status (CONUT) scores. HRQOL was evaluated using the EuroQol-5 Dimensions 5-level questionnaire (EQ-5D-5L) preoperatively and one and two years postoperatively. Propensity score matching was used to compare changes in EQ-5D-5L scores between the malnutrition and control groups for each index, while adjusting for age, sex, body mass index, surgical procedure, and surgical region. Malnutrition was defined as GNRI <98, PNI <45, or CONUT &#x2265;2, as previously reported. Patients with a low preoperative GNRI demonstrated significantly lower EQ-5D-5L scores than those with a high GNRI ( P =0.031), with lower postoperative scores at years 1 ( P =0.001) and 2 ( P =0.047). No differences were observed between the groups stratified by PNI ( P =0.085) or CONUT ( P =0.306). Patients who failed to achieve the minimal clinically important difference (&#x394;EQ-5D-5L &#x2265;0.08) showed significantly higher scores in the low GNRI group at postoperative years 1 and 2 ( P <0.001). No such association was found for PNI or CONUT. Preoperative malnutrition evaluated by GNRI was independently associated with impaired postoperative HRQOL in elderly patients undergoing spinal surgery. The GNRI may serve as a nutritional marker and a surrogate for biological age.