Prognostic nutritional index as a predictor of mortality in nontuberculous mycobacterial lung disease

Background: Although the association between nontuberculous mycobacterial lung disease (NTM-LD) and malnutrition is known, there are a few reports on the association between the nutritional score and death in patients with NTM-LD. This study investigated the association between the nutrition data at the time of NTM-LD diagnosis and death. Methods: A retrospective study was conducted for patients with NTM-LD who visited the Maebashi Red Cross Hospital from January 2014 to December 2018. The patients were divided into the survival and death groups and analyzed statistically. Results: The diagnostic criteria for NTM-LD were met by 150 patients. The median age was 70 years (range, 20-94 years). There were 51 (34.0%) men and 99 (66.0%) women. In the death group, the body mass index was significantly low, and there were significantly more patients with asthma. Further, computed tomography at the first visit revealed significantly fewer cases of the nodular bronchiectasis type. In the hematologic examination at the time of NTM-LD diagnosis, the white blood cell, neutrophil, and platelet counts and C-reactive protein and serum calcium levels were significantly higher in the death group, while the serum albumin level was significantly lower. In the death group, the prognostic nutritional index (PNI), calculated from the hematologic findings, was significantly lower, while the Glasgow Prognostic Score (GPS) was significantly higher. A logistic regression analysis was performed on items with significant differences, and the PNI and platelet count were independent factors predicting death. Conclusions: PNI might be effective as a prognostic factor for NTM-LD.