What Are the Consequences of Malnutrition in Hospital Patients?
Our blog post yesterday was based on reports that one out of three Americans admitted to hospital are malnourished. But why is this concerning? A scientific article published online yesterday by Quraishi and co-workers answers that question in reference to one of the most widely studied nutritional deficiencies, looking at whether there is a difference in rate of bloodstream infections acquired in the hospital according to vitamin D status.
The authors used data from a series of patients admitted to two teaching hospitals in Boston, Massachusetts, USA between 1993 and 2011. The study was retrospective and made use of the Research Patient Data Registry. Patients were selected if they had had vitamin D levels admitted 7 days to one year before hospital admission, and if they had blood cultures done more than 48 hours after hospital admission to attempt to identify patients with hospital-acquired infections.
Out of the study population of almost 25,000 the researchers could select 2135 patients meeting the criteria; the main reasons for not being included in the study was that there was no culture drawn after 48 hours in hospital (18,000 patients), and that patients that were critically ill (3,000 patients, see report by Braun et al. for research on this critically ill population). Therefore, the research population was not critically ill, vitamin D measurement was likely to be unrelated to hospital admission since it was taken more than a week before, and septicemia developed in the hospital.
The population was divided into four groups based on vitamin D levels: deficiency below 10 ng/ml, low vitamin D between 10 and 20 ng/ml, adequate levels between 20 and 30 ng/ml, and good vitamin D status at above 30 ng/ml. As this study was observational, there were some differences in demographics between these groups, namely that age increased with vitamin D status, and women and White patients were more likely to have a higher vitamin D level. Chronic disease burden, reason for admission (medical vs. surgical) and white blood cell count category did not differ between groups.
The main result was that patients with vitamin D levels in the deficient range were around twice as likely to develop a hospital acquired blood stream infection compared to patients with the highest vitamin D levels, in both the crude and adjusted models. In absolute terms, 12 percent of people with a vitamin D level under 10 ng/ml developed a blood infection in the hospital, while only 6 percent of those with levels between 20 and 30 ng/ml and over 30 ng/ml.
The CDC reports that hospital-acquired infections add to preventable illness, death and length-of-stay in hospital patients, and increase the costs of health care considerably. Vitamin D deficiency has been identified as a considerable issue both for diverse populations in the US (women of childbearing age, African American adults, overweight and obese children) and globally (Wahl and collaborators). Vitamin D has been shown to regulate the production of anti-microbial peptides (see review from Shuler), providing a potential mechanism for prevention of bacterial infections. While the results of the current study are observational and a causal link cannot be established, maintaining adequate vitamin D levels also benefits other areas of health, and the results link sufficient vitamin D with reduced risk of hospital-acquired blood stream infections, should one unfortunately land in the emergency room.
Sadeq A Quraishi, Augusto A Litonjua, Takuhiro Moromizato, Fiona K Gibbons, Carlos A Camargo, Jr, Edward Giovannucci, and Kenneth B Christopher. Association between prehospital vitamin D status and hospital-acquired bloodstream infections. Am J Clin Nutr 2013 ajcn.058909; First published online August 14, 2013. doi:10.3945/ajcn.113.058909
Gupta AK, Brashear MM, Johnson WD. Low vitamin D levels, prediabetes and prehypertension in healthy African American adults. Nutr Metab Cardiovasc Dis. 2012 Oct;22(10):877-82. doi: 10.1016/j.numecd.2012.01.006. Epub 2012 Apr 9.
R. Douglas Scott, II; Division of Healthcare Quality Promotion; National Center for Preparedness, Detection, and Control of Infectious Diseases; Coordinating Center for Infectious Diseases; Centers for Disease Control and Prevention. The Direct Medical Costs of Healthcare-Associated Infections in U.S. Hospitals and the Benefits of Prevention. http://www.cdc.gov/hai/pdfs/hai/scott_costpaper.pdf
Shuler FD, Hendrix J, Hodroge S, Short A. Antibiotic-like actions of vitamin D. W V Med J. 2013 Jan-Feb;109(1):22-5.
Turer CB, Lin H, Flores G. Prevalence of vitamin D deficiency among overweight and obese US children. Pediatrics. 2013 Jan;131(1):e152-61. doi: 10.1542/peds.2012-1711. Epub 2012 Dec 24.
Wahl DA, Cooper C, Ebeling PR, Eggersdorfer M, Hilger J, Hoffmann K, Josse R, Kanis JA, Mithal A, Pierroz DD, Stenmark J, Stöcklin E, Dawson-Hughes B. A global representation of vitamin D status in healthy populations. Arch Osteoporos. 2012 Dec;7(1-2):155-72. doi: 10.1007/s11657-012-0093-0. Epub 2012 Aug 29.
Zhao G, Ford ES, Tsai J, Li C, Croft JB. Factors Associated with Vitamin D Deficiency and Inadequacy among Women of Childbearing Age in the United States. ISRN Obstet Gynecol. 2012;2012:691486. doi: 10.5402/2012/691486. Epub 2012 Mar 4.