AbstractBackground and purpose
A study was undertaken to evaluate the relationship between dermal thickness and bone density. Ninety-eight female subjects were recruited from a population of patients attending a university hospital osteoporosis clinic. The subject population ranged in age from 30 to 88 years with a mean age of 60. The weight range was from 91 to 274 pounds, mean 142 pounds.Methods
Dermal thickness measurements were taken at the right forearm using a Longport high resolution 20 MHz ultrasound scanner. Bone density measurements were taken using a GE Lunar Prodigy DXA scanner at both hips.Results
Statistical analysis using the intraclass correlation coefficient (ICC) of the skin measurements showed that the dermal measurement technique was highly reliable (CI=0.87, 0.92). Linear regression was used to examine the value of dermal thickness as a predictor of bone density. The correlation coefficient between dermal thickness and hip T score was statistically significant in the positive direction (corr.=0.304, P=0.001). We further investigated the relationship between dermal thickness and T scores using penalized splines.Conclusion
This analysis indicated that the strongest association with bone density occurred between 1.0 and 1.5 mm of dermal thickness. In those subjects identified as having osteoporosis dermal thickness measure of ≥1.04 corresponds to 4% of the subjects having osteoporosis. If dermal thickness is <1.04 then 23% have osteoporosis.