KL2 Scholar Studies Effect of Vitamin D Status on Hospital-Acquired Infections in Critically Ill Adults

Jordan A. Kempker, MD, MSc

Vitamin D supports the immune system, and low levels of vitamin D may be associated with increased risk for infections in certain patient populations. Jordan A. Kempker, MD, MSc, Atlanta Clinical & Translational Science Institute (ACTSI) KL2 Mentored Clinical and Translational Research Scholar, and 2013 graduate of the ACTSI Master of Science in Clinical Research (MSCR) program explored this relationship further in a study entitled, “Vitamin D status and the risk for hospital-acquired infections in critically ill adults: a prospective cohort study,” published in the journal, PLoS One. Kempker and colleagues from the Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, the Division of Infectious Diseases, and the Division of Endocrinology, Metabolism, and Lipids in the Emory University School of Medicine did not find an association between low vitamin D status and the subsequent risk of hospital-acquired infections in their single-center prospective study in a medical intensive care unit (ICU).

Low vitamin D was previously associated with risk of hospital-acquired infections in surgical patients, and evidence from other studies in critically ill patients found low vitamin D levels to be associated with increased risk of death and illness. “Vitamin D upregulates a protein called cathelicidin, which is produced in immune cells and has antimicrobial properties,” said co-author Vin Tangpricha, MD, PhD, associate professor, Emory University School of Medicine, and director of the Vitamin D Research Laboratory at Emory. The immune function of vitamin D may explain the previous associations of low vitamin D status with increased risk for infection, but the relationship had not been explored in the medical ICU. For this study, the research team enrolled 314 adult patients from the medical ICU at Grady Memorial Hospital who had an anticipated ICU stay of at least one day, and followed them for 30 days, death, or hospital discharge (whichever came first). Patients were determined to have a hospital-acquired infection if a new infection developed that was not present in the first 48 hours of admission. The authors found that 57% of the patients enrolled in the study had low vitamin D levels and 11% of patients developed hospital-acquired infections. Low vitamin D status was not associated with hospital-acquired infections in this study population. “These findings suggest that in the critically ill population, the potential immune-modulating effects of vitamin D may not be apparent when intensive infection-control measures are also in place,” said Kempker, assistant professor of medicine, Emory University School of Medicine.

This study, which served as Kempker’s ACTSI MSCR thesis project, was funded entirely by a seed grant from ACTSI. “I participated in an ACTSI Studio Consultation in the early stages of the project in which I received feedback on the practical aspects of the study and was made aware of resources available through ACTSI including the Georgia CTSA Clinical Research Centers (GCRCs) and funding opportunities,” said Kempker. “I also received a statistical consultation as part of the MSCR program to review the study’s analytic plan.” Kempker was awarded an ACTSI pilot grant to cover assay costs for vitamin D, and the study team utilized several services at GCRCs Grady Memorial Hospital Clinical Research Site, including nursing services for phlebotomy, laboratory services for initial sample processing, storage, and tracking using the Laboratory Information Management Software (LIMS), and the Research Electronic Data Capture tool (REDCap) for data management.

Kempker, whose work is also focused on sepsis epidemiology and critical care medicine, is a current ACTSI KL2 Mentored Clinical and Translational Research Scholar. For his KL2 project entitled, “The Roles of Health Condition, Health Behaviors, and Socioeconomic Factors in Racial Disparities in Sepsis," he is using a large national dataset to develop the first longitudinal cohort to investigate risk factors for sepsis and how they may affect racial difference in risk of death from sepsis in the United States. The goal of the ACTSI KL2  program is to support career development for junior faculty (MD, PhD, or MD/PhD) from a wide variety of disciplines at Emory University, Morehouse School of Medicine (MSM), and Georgia Institute of Technology (Georgia Tech) to become independent, established, and ethical clinical and/or translational research investigators. The Emory Master of Science in Clinical Research (MSCR) degree program, from the Laney Graduate School at Emory University, provides didactic and mentored clinical and translational research training.  The degree is designed for participants at Emory and Georgia Tech who hold a doctorate or equivalent degree (such as physicians and PhD-level scientists) or predoctoral trainees enrolled in a dual degree program (MD/MSCR and PhD/MSCR tracks) and have demonstrated a commitment to a career in clinical investigation. MSM also has an MSCR program for MSM applicants supported through the Research Centers for Minority Institutions (RCMI) grant.

ACTSI Studio Consultations aid in the successful design and implementation of clinical and translational science research proposals. The Studio Consultation concept involves a clinical investigator(s) presenting their proposals to representatives of the Biostatistics, Epidemiology, & Research Design program (BERD), Biomedical Informatics Program (BIP), and GCRCs who in-turn give the investigator their expert feedback. By pulling together experts from these key programs, ACTSI hopes to improve a proposal's design, implementation, and analysis to maximize competitiveness. In short, a Studio Consultation is a pre-review by a panel of experts designed to improve an investigator's chances of success. A Studio will assist researchers in biostatistics, bioinformatics, database development, project generation planning, research design, and/or protocol planning and implementation. Consultations are available to Emory, MSM, or Georgia Tech faculty. To arrange for a Studio Consultation, please submit a request.

The Georgia CTSA Clinical Research Centers (GCRCs) is a multilayered, flexible, and geographically distributed network created to meet the needs of translational and clinical investigators from Emory, MSM, and Georgia Tech. The GCRCs includes nearly 35 clinical research sites across the city incorporating hospital, medical office, and community-based clinical research sites, such as Emory University Hospital, Emory Midtown Hospital, Grady Memorial Hospital, Children’s Health Care of Atlanta, the Ponce Infectious Diseases Clinic, the Hope Clinic, Wesley Woods Health Center, and the Morehouse School of Medicine Clinical Research Center.

The ACTSI is a city-wide partnership between Emory, MSM, and Georgia Tech and is one of over 60 in a national consortium striving to improve the way biomedical research is conducted across the country. The consortium, funded through the National Center for Advancing Translational Sciences (NCATS) and the National Institutes of Health’s Clinical and Translational Science Awards, shares a common vision to translate laboratory discoveries into treatments for patients, engage communities in clinical research efforts, and train the next generation of clinical investigators.