title: Nutritional parameters affecting severity of pneumonia and length of hospital stay in patients with pneumococcal pneumonia: a retrospective cross-sectional study.
abstract: BACKGROUND
  Pneumococcal pneumonia is the most common form of community-acquired pneumonia (CAP). Although a pneumococcal conjugate vaccine has contributed to a reduction in the incidence of pneumococcal pneumonia among older children and adults, no significant decrease in the incidence has been observed among persons aged ≥65 years. A low body mass index and hypoalbuminemia are common in Japanese patients with CAP, but the association of other nutritional parameters with the severity of pneumonia or length of hospital stay in patients with pneumococcal pneumonia is unclear.
  
  
  METHODS
  Fifty-seven previously healthy inpatients who presented with pneumococcal pneumonia were divided into two groups: those aged ≥65 years (n = 36) and those aged <65 years (n = 21). Patients' characteristics (the Confusion, Urea, Respiratory rate, Blood pressure, age >65 years (CURB-65) score), the pneumonia severity index (PSI), and inflammatory and metabolic nutritional parameters were compared between the two groups.
  
  
  RESULTS
  The older group showed significantly lower serum albumin and cholinesterase (ChE) levels. Multivariate linear regression analysis revealed that the PSI was positively correlated with age in both groups. In the younger age group, both the CURB-65 score and PSI showed significant negative correlations with the serum ChE level, and there was a significant negative correlation between the length of stay and serum total cholesterol (T-cho) level. In the older group, the fasting period, lymphocyte count, and age showed significant positive correlations with the length of stay. There was a significant negative correlation between the length of stay and serum albumin level, but no correlation with the serum ChE or T-cho levels, in the older patients.
  
  
  CONCLUSIONS
  Our findings suggest that in patients aged <65 years, age and serum ChE and T-cho levels were associated with both the severity of pneumococcal pneumonia and length of stay. In contrast, the length of stay in older patients was associated with multiple factors that differed from those in younger patients. These differences may reflect age-related immunosenescence in older patients and a greater effect of serum ChE and T-cho levels on immunity in younger patients.
authors.affiliation: Nutrition Support Team, Gunma Chuo Hospital, 1-7-13 Koun-cho, Maebashi, Gunma, 371-0025, Japan. akuzawa_nobuhiro@yahoo.co.jp.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Akuzawa
authors.affiliation: Nutrition Support Team, Gunma Chuo Hospital, 1-7-13 Koun-cho, Maebashi, Gunma, 371-0025, Japan. main@gunma.jcho.go.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Naito
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002784:Cholesterol / Q000097:blood; D002802:Cholinesterases / Q000097:blood; D017714:Community-Acquired Infections / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009752:Nutritional Status; D011018:Pneumonia, Pneumococcal / Q000453:epidemiology*; D011379:Prognosis; D012189:Retrospective Studies; D012720:Severity of Illness Index
chemical_list: D002784:Cholesterol; D002802:Cholinesterases