The Controlling Nutritional Status (CONUT) score measures the nutritional status of patients using serum albumin, cholesterol, and total lymphocyte count as parameters. To date, reports have stated that the malnutrition assessed using CONUT score is a poor prognostic factor for cancer patients and a risk factor for postoperative infection. Meanwhile, there are patients who require intermittent catheterization due to underactive bladder after removal of the indwelling bladder catheter because Activities of Daily Living decreases after hospitalization or surgery. However, no study has examined the relationship between nutritional status using CONUT score at admission and the outcome of underactive bladder. Therefore, this study aimed to clarify the relationship.

This retrospective included patients admitted to our hospital for non-urological diseases, who developed an underactive bladder after removing an indwelling bladder catheter and temporarily required intermittent catheterization. CONUT scores were measured by blood test at admission and the outcome of underactive bladder was assessed at discharge. We defined poor outcome of underactive bladder as intermittent or permanent catheterization at discharge. Based on CONUT score, the patients were divided into low score (L group; 0-3 points) and high score (H group; 4 points or more) groups. We compared the outcome of underactive bladder between the two groups and determined the risk factors for the poor outcome of underactive bladder using multivariate logistic regression analysis. P values < 0.05 were considered statistically significant.

Of the total 254 patients, 182 (71.7%; 68 men and 114 women) and 72 (28.3%; 20 men and 52 women.) were in the L and H groups, respectively; mean age of all patients was 78.4 ± 10.3 years. There was no significant difference in sex between the two groups (P = 0.188); however, the patients in L group were significantly younger than those in H group (L group: 76.7±10.1 years old, H group: 82.6±9.5 years old, P < 0.001). Patient age was significantly positively correlated with CONUT score (r = 0.385, P < 0.001). Conversely, body mass index was significantly negatively correlated with CONUT score (r = -0.332, P < 0.001). The incidences of poor outcome of underactive bladder were 22/182 (12.1%) in the L group and 53/72 (73.6%) in the H group (P < 0.001). 
Univariate analysis showed that presence of cerebrovascular disease(OR: 1.27, 95% CI: 0.710-2.336, P = 0.422), spinal cord disease(OR: 1.19, 95% CI: 0.641-2.301, P = 0.582), or diabetes(OR: 1.14, 95% CI: 0.617-2.170, P = 0.680) was not an independent risk factor for poor outcome in underactive bladder.
Multivariate analysis showed that high CONUT score was an independent risk factor for poor outcome of underactive bladder (odds ratio [OR]: 20.31, 95% confidence interval [CI]: 9.751-45.309, P < 0.001) and high performance status (2 or higher) (OR: 2.57, 95% CI: 1.245-5.358, P = 0.011).

Our study indicates that poorly nourished with high CONUT scores at the time of admission are more likely to suffer from underactive bladder after removal of the indwelling bladder catheter, regardless of whether they have general comorbidities related to lower urinary tract dysfunction.

Low nutritional status at admission is associated with poor outcome of underactive bladder.