The Impact of Controlling Nutritional Status (CONUT) score on functional prognosis in hospitalized elderly patients with acute osteoporotic vertebral fractures

BACKGROUND: Nutritional status, which is associated with osteoporosis and muscle weakness is considered an important factor in the management of acute osteoporotic vertebral fracture (AOVF). However, few reports have investigated the nutritional status of hospitalized patients with AOVF and the impact of malnutrition on their functional prognosis. This study aimed to evaluate the nutritional status of hospitalized elderly patients with AOVF using the Controlling Nutritional Status (CONUT) score and to determine the usefulness of the CONUT score in predicting their functional prognosis. METHODS: The CONUT score on admission was retrospectively calculated for 134 hospitalized elderly patients (mean age 83 ± 7.6 years, 66% female) with AOVF who received conservative treatment between 2017 and 2020. Functional outcome was assessed by comparing ambulatory ability before the onset of AOVF and upon discharge. Patients were divided into two groups: CONUT-high ( ≥ 4) and CONUT-low ( ≤ 3), according to receiver operating characteristic (ROC) analysis to predict decline in ambulatory ability upon discharge. Logistic regression analysis was performed to obtain odds ratios (OR) and 95% confidence intervals (CI) of the relationships between the nutritional status and ambulatory ability. The discriminative power of the CONUT score was then compared with other nutritional assessment tools such as the Geriatric Nutritional Risk Index (GNRI) and prognostic nutritional index (PNI) by ROC analysis. RESULTS: 81% of hospitalized patients with an AOVF were malnourished at the time of admission. The CONUT-high group had a significantly higher rate of decline in ambulatory ability (P < 0.001) than the CONUT-low group. Logistic regression analysis revealed the CONUT score ( ≥ 4) as an independent risk factor for a decline in ambulatory ability (OR 3.44, 95% CI 1.61–7.37, P = 0.0014). ROC analysis showed that the area under the curve (AUC) for the CONUT score (AUC = 0.724) was significantly greater than that for the GNRI (AUC = 0.624, P = 0.021) and PNI (AUC = 0.636, P = 0.0008). CONCLUSIONS: This study showed that 81% of hospitalized elderly patients with AOVFs were malnourished and that the CONUT score was a useful predictive factor of functional prognosis.