Urosepsis is a systemic inflammatory response syndrome caused by UTI. Elderly men with BPH are more prone to UTI, and some of them may even develop into urosepsis. However, there were few reports on nutritional risk factors related to urosepsis in BPH patients. Thus, we conducted this study and focused on the effect of nutritional status on the occurrence of urosepsis in patients with BPH.
We found that patients with BPH with malnutrition were more likely to develop urosepsis, and the CONUT score, NPS, hypoproteinemia, and height were significant and independent risk factors for urosepsis.
In previous studies, the CONUT, NPS, and PNI scores were commonly used composite measures to assess immune and nutritional status14–16. The CONUT score was a comprehensive index reflecting protein metabolism, lipid metabolism, and immune activity, which had been used to evaluate the nutritional status of patients with inflammatory diseases. The NPS was a scoring system that comprehensively reflected the patients' immune and nutritional status and had been proven to have higher predictive value than other inflammatory markers and scoring systems. The PNI score was an evaluation method to determine the relationship between immune nutritional status and the prognosis of patients.
In our study, the CONUT score and NPS of patients with urosepsis were significantly higher than those of non-infection group, and the PNI scores were significantly lower than those of non-infection group. Multivariate analysis indicated that the CONUT score and NPS were independent risk factors for developing urosepsis in BPH patients.
However, we found that the PNI score was not an independent risk factor for urosepsis. It did not contradict the conclusion above because PNI was calculated from plasma Alb and TLC, and fewer indicators were included than CONUT and NPS. Thus, we considered that the CONUT score and NPS were more comprehensive and had higher confidence in evaluating the occurrence of urosepsis in patients with BPH.
The exact mechanism of malnutrition for the occurrence of urosepsis was still unclear. It may be multifactorial, including immune changes, inflammatory pathways, and microbiota. Malnutrition causes systemic regulatory functions and immune suppression alterations, further leading to a disturbance of dynamic balance and limited reserves to fight against stressors, significantly increasing the risk of severe infection. At the same time, overactivated neutrophils and the decrease of lymphocytes will further suppress immune function. Additionally, NLR and LMR reflect the balance between organism immunity and inflammation.
Hypoalbuminemia is associated with disease severity and prognosis. Some studies have shown that hypoproteinemia is related to the occurrence and prognosis of septic shock. Inflammation leads to the increase of intercellular fluid and the consumption of systemic factors, which may reduce the level of Alb. Therefore, the decrease of serum Alb is not only a sign of malnutrition, but represents a persistent systemic inflammatory reaction. Our study accommodated the abovementioned studies that patients with urosepsis had significantly lower serum Alb than the non-infection group. Additionally, multivariate analysis showed that it was an independent risk factor for predicting the occurrence of urosepsis.
We found that BPH patients with lower BMI were more likely to develop urosepsis. Meanwhile, BPH patients with high height had higher risks of developing urosepsis. We speculated that this was due to the absence of significant differences in weight. Patients with higher height had relatively lower BMI, which was in keeping with the above results of BMI.
Nevertheless, BMI was not an independent risk factor in multivariate analysis. It was an extremely poor surrogate for determining nutritional status because few calculation indicators were included, and many with a BMI more than or equal to 30.0 kg/m2 could be malnourished. More comprehensive predictors urgently needed to be validated.
Besides, we found that BPH patients with pneumonia were more likely to develop urosepsis, which might be related to the interaction of inflammatory mediators. The secretion of inflammatory mediators, immune dysfunction, endotoxin translocation, and other factors played essential roles in pneumonia. The synergistic action of inflammatory factors might lead to the more likely occurrence of urosepsis in patients with BPH complicated with pneumonia. Although pneumonia was not a risk factor for urosepsis in multivariate analysis, the interaction between inflammatory factors could not be ignored. However, there was no correlation between other basic diseases and the occurrence of urosepsis, which might be due to our limited sample size.
Above all, some limitations should be taken into consideration. First, this was a retrospective study, making it challenging to avoid incomplete data. Second, the sample included in this study was minimal, which would primarily affect the quality of our study. In addition, this study was conducted at a single institution, which might cause selection bias. Finally, the specific mechanisms underlying the association between nutritional status and the risk of urosepsis remained obscure and required further study. However, to our knowledge, the present study is the first to describe the relationship between nutritional status and the risk of urosepsis in BPH patients. Moreover, the standard statistical method was adopted in this study, and the patients included met the diagnostic criteria of BPH and urosepsis.