Is serum hypovitaminosis D associated with chronic widespread pain including fibromyalgia? A meta-analysis of observational studies

Background: chronic widespread pain (cwp) is a global musculoskeletal disorder leading todisability and a reduced quality of life. low levels of serum vitamin d has long been proposedto be associated with cwp,but previous research remains inconclusive.objectives: to determine whether hypovitaminosis d was independently associated withcwp.study design: meta-analysis of observational study.methods: electronic databases were searched for studies published up to november 2014comparing the prevalence of hypovitaminosis d and serum vitamin d levels between participantswith and without cwp. the crude and adjusted odds ratios (ors) of hypovitaminosis d withcwp were calculated. subgroup analysis according to gender,threshold of hypovitaminosis,and definition of patients was performed,as well as meta-regression to test the linearrelationship between crude ors and the latitude of study locations.results: twelve studies were included,comprising 1,854 patients with cwp. the patientgroup showed a significantly higher risk of hypovitaminosis d than the control group (crudeor,1.63; 95% ci,1.20 – 2.23). the association was slightly attenuated after adjustingconfounders,with a pooled adjusted or of 1.41 (95% ci,1.00 – 2.00). there was an increasein ors of hypovitaminosis d using a lower diagnostic value of serum vitamin d (8 and 10ng/ml). the subgroup analysis according to gender and definition of cwp did not revealsignificant between-group differences. the meta-regression showed no linear relationshipbetween latitude and the crude ors.conclusions: there was a positive crude association between hypovitaminosis d and cwp,and the association was likely to remain after adjusting confounding factors. use of a cut-offvalue of hypovitaminosis d (8 – 10 ng/ml) could better define the population with and withoutcwp. further prospective follow-up studies are warranted to clarify the causal relationshipbetween hypovitaminosis d and cwp. © 2015,american society of interventional pain physicians. all rights reserved.