title: Low vitamin D levels are associated with higher opioid dose in palliative cancer patients--results from an observational study in Sweden.
abstract: BACKGROUND
  Vitamin D deficiency is common among palliative cancer patients and has been connected to an increased risk for pain, depressions and infections. Therefore we wanted to test the hypothesis that low 25-hydroxyvitamin D (25OHD) levels are associated with higher opioid dose, higher infectious burden and impaired quality of life in palliative cancer patients. The secondary aim was to investigate the association between 25OHD-levels and survival time.
  
  
  METHODS
  In this prospective, observational study in palliative cancer-patients (n = 100) we performed univariate and multiple linear regression analysis to assess the association of 25OHD levels with opioid dose, infectious burden (antibiotic consumption), quality of life (Edmonton Symptom Assessment Scale, ESAS) and survival time, controlling for potential confounding factors.
  
  
  RESULTS
  The median 25OHD level was 40 nmol/L (range 8-154 nmol/L). There was a significant association between 25OHD levels and opioid dose, beta coefficient -0.67; p=0.02; i.e. a low 25OHD level was associated with a higher opioid dose. This association remained significant after adjustment for stage of the cancer disease in a multivariate analysis, beta coefficient -0.66; p = 0.04. There was no association between 25OHD levels and antibiotic use or quality of life. Univariate cox regression analysis showed a weak correlation between survival time and 25OHD levels (p<0.05). However, decreased albumin levels and increased CRP levels were superior markers to predict survival time; p<0.001 for both analyses.
  
  
  CONCLUSIONS
  Low 25OHD-levels are associated with increased opioid consumption in palliative cancer patients. Future interventional studies are needed to investigate if pain can be reduced by vitamin D supplementation in these patients. In addition, this study confirms previous findings that low albumin and increased CRP levels are useful markers for survival time in palliative cancer patients.
authors.affiliation: Department of Laboratory Medicine, Division of Clinical Microbiology, Karolinska Institutet and Karolinska University Hospital, Huddinge, Stockholm, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Bergman
authors.affiliation: ASIH Stockholm Södra, Långbro Park, Palliative Home Care and Hospice Ward, Bergtallsvägen, Älvsjö, Sweden.
authors.forename: Susanne
authors.initials: S
authors.lastname: Sperneder
authors.affiliation: Institute of Environmental Medicine, Unit of Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Jonas
authors.initials: J
authors.lastname: Höijer
authors.affiliation: ASIH Stockholm Södra, Långbro Park, Palliative Home Care and Hospice Ward, Bergtallsvägen, Älvsjö, Sweden; Department of Oncology/Pathology, Karolinska Institutet and Stockholms Sjukhem, Unit for Palliative Care, Stockholm, Sweden.
authors.forename: Jenny
authors.initials: J
authors.lastname: Bergqvist
authors.affiliation: Department of Laboratory Medicine, Division of Clinical Microbiology, Karolinska Institutet and Karolinska University Hospital, Huddinge, Stockholm, Sweden; ASIH Stockholm Södra, Långbro Park, Palliative Home Care and Hospice Ward, Bergtallsvägen, Älvsjö, Sweden.
authors.forename: Linda
authors.initials: L
authors.lastname: Björkhem-Bergman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000097:blood*; D010146:Pain / Q000097:blood / Q000188:drug therapy; D010166:Palliative Care / Q000379:methods; D011446:Prospective Studies; D011788:Quality of Life; D013548:Sweden; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood; D055815:Young Adult
chemical_list: D000701:Analgesics, Opioid; D015415:Biomarkers; D014807:Vitamin D; C104450:25-hydroxyvitamin D