The Impact of Preoperative Malnutrition on Postoperative Outcomes in Older Patients Undergoing Lumbar Decompression

Introduction: Malnutrition is closely linked to frailty or sarcopenia and is more likely to occur in elderly individuals. However, the impact of preoperative nutritional status on postoperative health-related quality of life following spine surgery remains unclear, even though the impact of nutritional status on the incidence of perioperative complications or mortality following spine surgery is well described. Therefore, this study aimed to investigate the impact of preoperative malnutrition on postoperative health-related quality of life in older patients following lumbar decompression. Methods: We retrospectively analyzed our consecutive patients aged ≥ 65 years who underwent lumbar decompression. The primary outcome was assessed using the EuroQol five-dimension three-level questionnaire (EQ-5D-3L) administered preoperatively and one year postoperatively. Patients with preoperative geriatric nutritional risk index (GNRI) ≤ 98 were categorized as having malnutrition risk and were compared with those without such risk. Results: We identified 245 eligible patients (144 males and 101 females), and 44 were categorized into the malnutrition risk group. The malnutrition risk group comprised a significantly lower proportion of patients with diabetes (4/44 [9.1%] vs 51/201 [25.4%], P = 0.02) and a higher proportion with rheumatoid arthritis (6/44 [13.6%] vs 6/201 [3.0%], P = 0.01). There were no significant between-group differences in one-year patient satisfaction (32/44 [72.7%] vs 152/201 [75.6%]; P = 0.70), preoperative EQ-5D-3L values (0.52 ± 0.17 vs 0.55 ± 0.16; P = 0.29), postoperative EQ-5D-3L values (0.66 ± 0.16 vs 0.70 ± 0.19; P = 0.17), or the improvement in EQ-5D-3L (0.14 ± 0.20 vs 0.16 ± 0.21; P = 0.69). However, the malnutrition risk group had more patients experiencing a deterioration in EQ-5D-3L at one year (10/44 [22.7%] vs 22/201 [11.0%], P = 0.047). Multivariate analysis revealed that preoperative GNRI ≤ 98 was an independent risk factor for a decrease in EQ-5D-3L values at one year (odds ratio, 2.64; 95% confidence interval, 1.08-6.20, P=0.03). Conclusions: Despite comparable postoperative improvement in EQ-5D-3L between the two groups, a distinct subset of older patients with preoperative malnutrition risk exhibited a clinically significant deterioration in quality of life following lumbar decompression, underscoring the persistent vulnerability of this population.