title: Association of self-reported symptoms with serum levels of vitamin D and multivariate cytokine profile in healthy women.
abstract: BACKGROUND
  Although a large number of studies have investigated possible relationships among serum levels of vitamin D or cytokines with disease progress and prognosis, similar studies on self-reported symptoms are still controversial. The overall objective of this study was to look into the association between serum levels of vitamin D or cytokines with self-reported symptoms related to musculoskeletal pain, sleep disorders, and premenstrual syndrome (PMS) in healthy adult women.
  
  
  METHODS
  Venous blood samples were collected from 117 healthy adult women, and serum levels of vitamin D, pro-inflammatory cytokines (IL-1β, IL-6, IL-8, IL-17, IFN-γ, and TNF-α) and anti-inflammatory cytokines (IL-4, IL-10, and IL-13) were measured. Groups were tested for differences in single parameters, pro-:anti-inflammatory cytokine ratios, and differences in multivariate patterns.
  
  
  RESULTS
  There were no significant associations between serum levels of vitamin D and any of the self-reported symptoms studied. However, serum levels of certain pro-inflammatory cytokines were significantly higher in subjects with musculoskeletal pain (IL-8,P=0.008), sleep disorders (IFN-γ,P=0.02), and PMS (IL-8 and TNF-α,P=0.009 and 0.002, respectively) compared to subjects who reported no symptoms. The pro-:anti-inflammatory cytokine ratios showed pro-inflammatory cytokine dominance in subjects with self-reported symptoms, particularly in the groups with deficient levels of vitamin D. However, the multivariate cytokine-pattern analysis was significantly different between PMS groups only.
  
  
  CONCLUSIONS
  These data point to a possible role of pro-inflammatory cytokines as a contributing factor in self-reported symptoms related to musculoskeletal pain, sleep disorders, and PMS.
authors.affiliation: Department of Mathematics and Natural Sciences, Gulf University for Science and Technology, International Centre for Applied Mathematics and Computational Bioengineering, West Mishref, Kuwait.
authors.forename: Fawaz Y
authors.initials: FY
authors.lastname: Azizieh
authors.affiliation: Science Department, College of Basic Education, Public Authority for Applied Education and Training, Kuwait City, Kuwait.
authors.forename: Khulood O
authors.initials: KO
authors.lastname: Alyahya
authors.affiliation: Department of Mathematics and Natural Sciences, Gulf University for Science and Technology, International Centre for Applied Mathematics and Computational Bioengineering, West Mishref, Kuwait.
authors.forename: Kamaludin
authors.initials: K
authors.lastname: Dingle
keywords: adult women; cytokines; inflammation; self-reported symptoms; vitamin D