01/02/12

Is vitamin D a neglected analgesic for chronic musculoskeletal pain? Dr. Suzan Abou-Raya, professor of geriatric medicine at the University of Alexandria in Egypt, thinks it could be and recommends that physicians consider supplementation for all pain patients.

Dr. Abou-Raya based her opinion on the findings of a recent study in which she and her colleagues compared the vitamin D status of 265 adults aged 65 years and older who presented to their institution for musculoskeletal pain management with that of 200 matched controls who were free of such pain, Dr. Abou-Raya said at the annual European Congress of Rheumatology.

Individuals with known vitamin D deficiency and calcium abnormality were excluded, as were those with blood, hepatic, and renal disorders. All of the participants underwent an initial survey about sun exposure and nutritional intake to assess daily intake of vitamin D and calcium and a comprehensive clinical examination, during which pain was assessed using the Brief Pain Inventory and Visual Analog Scale and a joint-pain questionnaire. They were directed to record daily pain in a diary.

Levels of pain were assessed at monthly intervals during follow-up, as was physical performance using activities of daily living, grip strength, six-minute walk distance, and the timed Get Up and Go Test of mobility. Serum vitamin D levels between 10 and 30 ng/mL were classified as vitamin D insufficiency and levels lower than 10 ng/mL were classified as vitamin D deficiency.

In musculoskeletal patients, the mean 25-hydroxy vitamin D level was 18.4 ng/mL compared with 28.9 ng/mL in the control group, a statistically significant difference, Dr. Abou-Raya reported. “The overall prevalence of suboptimal vitamin D levels among patients was 70% vs. 32% in the controls,” she said, noting that 41% of the chronic musculoskeletal pain patients and only 1% of the controls met the criteria for vitamin D deficiency. Patients “with more severe pain at baseline had significantly lower vitamin D levels than those with less severe pain.” said Dr. Abou-Raya.

After multivariate adjustment, “chronic, multisite, musculoskeletal pain was associated with lower levels of 25-hydroxy vitamin D, and lower levels of vitamin D correlated with pain severity and poor physical performance,” Dr. Abou-Raya stated. One likely contributing factor is that sun exposure in the chronic pain group was significantly lower than that of the controls, with 40% of the pain patients reporting that they received fewer than 15 minutes of sun exposure weekly compared with 11% of the controls, she said.

The results of this observational study should not be used to infer causation, Dr. Abou-Raya stressed, but “the possibility of inadequate vitamin D should be considered in the differential diagnosis of chronic musculoskeletal pain sufferers.” Dr. Abou-Raya disclosed having no financial conflict of interest related to her presentation.

 

Diana Mahoney is with the New England bureau of Elsevier Global Medical News.