medwireNews: Bone mineral density (BMD) does not contribute to musculoskeletal pain, researchers report in findings that shed light on the controversy over whether osteoporosis is a painless disease.
The study showed that BMD, calculated from dual-energy X-ray absorptiometry scans, was not associated with the intensity or presence of back, knee or hip pain in 387 postmenopausal women from Korea, 21.3% of whom had osteoporosis in the femoral neck or lumbar spine.
The women were aged at least 50 years and had a low calcium intake and low serum levels of 25-hydroxyvitamin D compensated by elevated levels of alkaline phosphatase and parathyroid hormone.
“In light of the clinical uncertainty regarding whether osteoporosis is a painful disease, the results of this study could be interpreted as showing that osteoporosis itself does not cause musculoskeletal pain”, write the study authors in Clinical Rheumatology.
They note, however, that some studies have shown significant correlations between improvements in lumbar pain and the percentage change in urinary N-telopeptide and increased BMD in bisphosphonate-treated patients.
This would suggest a possible link with the dynamic loss of BMD, measured using bone turnover markers, which were not assessed in the current study, rather than static BMD.
“Further study is needed to investigate this theory”, researcher Sang Young Mood (Seoul National University, Kyungki, South Korea) and colleagues remark.
The women participating in the study had an average numeric rating scale pain score for hip and knee joints of 0.6 and 1.1, respectively. None of them were taking pain medication.
Multiple regression analysis showed that age was the only factor significantly correlated with hip pain intensity, adjusted for degree of osteoarthritis, while Kellgren–Lawrence grade of knee osteoarthritis was the only factor significantly associated with knee pain intensity.
Age was also the only factor significantly associated with the presence of back pain in binary logistic regression analysis.
“BMD did not contribute significantly to the intensity or presence of musculoskeletal pain in any body part analyzed”, the team comments.
“Theoretically, osteoporosis could be a silent, painless disease defined by decreased BMD.”
medwireNews (www.medwirenews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2013
By Lucy Piper, Senior medwireNews Reporter