Bone remodeling rate and remodeling balance are not co-regulated in adulthood: Implications for the use of activation frequency as an index of remodeling rate

Abstract

UNLABELLED: Use of activation frequency as a measure of remodeling rate assumes co-regulation of remodeling rate and remodeling balance. In iliac crest biopsy specimens from 57 healthy subjects 19-80 yr of age, no correlations were shown between these variables, an observation that challenges the use of activation frequency as an estimate of remodeling rate. INTRODUCTION: The histomorphometric derivation of activation frequency assumes that the remodeling rate is dependent on the duration of the remodeling cycle and the amount of bone formed in individual remodeling units. This implies that remodeling balance and remodeling rate are co-regulated. We tested this assumption in normal human adu..