Ms Glover is a John A. Hartford Foundation Building Academic Geriatric Nursing Capacity Scholar
Vitamin D, race, and experimental pain sensitivity in older adults with knee osteoarthritis
Article first published online: 28 NOV 2012
Copyright © 2012 by the American College of Rheumatology
Arthritis & Rheumatism
Volume 64, Issue 12, pages 3926–3935, December 2012
How to Cite
Glover, T. L., Goodin, B. R., Horgas, A. L., Kindler, L. L., King, C. D., Sibille, K. T., Peloquin, C. A., Riley, J. L., Staud, R., Bradley, L. A. and Fillingim, R. B. (2012), Vitamin D, race, and experimental pain sensitivity in older adults with knee osteoarthritis. Arthritis & Rheumatism, 64: 3926–3935. doi: 10.1002/art.37687
- Issue published online: 28 NOV 2012
- Article first published online: 28 NOV 2012
- Accepted manuscript online: 7 NOV 2012 09:26AM EST
- Manuscript Accepted: 23 AUG 2012
- Manuscript Received: 31 JAN 2012
- NIH (National Institute on Aging). Grant Numbers: AG-033906, RR-029890
- University of Florida Clinical and Translational Science Institute
- Mayday Fund grantee. Grant Number: AAN 11-116
Low circulating serum levels of 25-hydroxyvitamin D (referred to hereafter as vitamin D) have been correlated with many health conditions, including chronic pain. Recent clinical practice guidelines define vitamin D levels <20 ng/ml as deficient and levels of 21–29 ng/ml as insufficient. Vitamin D insufficiency, including the most severe levels of deficiency, is more prevalent in black Americans. Ethnic and race group differences have been reported in both clinical and experimental pain, with black Americans reporting increased pain. The purpose of this study was to examine whether variations in vitamin D levels contribute to race differences in knee osteoarthritis pain.
The sample consisted of 94 participants (74% women), including 45 blacks and 49 whites with symptomatic knee osteoarthritis. Their average age was 55.8 years (range 45–71 years). Participants completed a questionnaire on knee osteoarthritis symptoms and underwent quantitative sensory testing, including measures of sensitivity to heat-induced and mechanically induced pain.
Blacks had significantly lower levels of vitamin D compared to whites, demonstrated greater clinical pain, and showed greater sensitivity to heat-induced and mechanically induced pain. Low levels of vitamin D predicted increased experimental pain sensitivity, but did not predict self-reported clinical pain. Group differences in vitamin D levels significantly predicted group differences in heat pain and pressure pain thresholds at the index knee and ipsilateral forearm.
These data demonstrate that race differences in experimental pain are mediated by differences in the vitamin D level. Vitamin D deficiency may be a risk factor for increased knee osteoarthritis pain in black Americans.