Prognostic nutritional index instead of serum Vitamin D levels as a determinant of the presence of osteoporosis in adult male patients with neurological impairment

Background: Complications of non-traumatic fractures and osteoporosis, which reduce mobility and quality of life, should not be ignored in patients with neurological impairment (NI). Aim: To diagnose osteoporosis in adult patients with NI, a readily available and easily obtained index, instead of serum Vitamin D level or bone mineral density (BMD), was explored. Methods: This was a single-center retrospective study. The participants were inpatients with NI admitted between August 2020 and June 2022. Patient data regarding (1) patient information, (2) blood data, including the prognostic nutrition index (PNI), which predicts outcomes of various diseases, (3) body composition, (4) T-score by BMD, (5) nutritional measures, and (6) outcome measures were collected. Enrolled patients were divided into two groups, with or without osteoporosis, according to their T-score. The data were analyzed by three methods: (1) comparison of all collected data between the two groups to analyze the factors influencing osteoporosis; (2) multiple logistic regression analysis; and (3) receiving operating characteristic curve analysis. Results: Patients with osteoporosis had a significantly lower PNI (45 vs. 49, P = 0.045), and higher Vitamin D insufficiency (71% vs. 31%, P = 0.031). PNI was the strongest influencing factor, and its cutoff value for osteoporosis was 50. Conclusion: The PNI is the strongest determinant of osteoporosis in patients with NI. Therefore, PNI can potentially be used as a surrogate for BMD instead of serum Vitamin D levels in institutionalized and homebound patients who do not have BMD measurement devices. Relevance for Patients: Prognostic nutrition index, which is a simple blood test, outperforms serum vitamin D concentration as a good indicator for early detection of osteoporosis.