Clinical use of bone markers: a challenge to variability

Abstract

Bone markers are a group of substances released into circulation during bone formation and/or resorption. These substances can be measured in blood and urine to obtain information about metabolic bone disorders. This review provides an insight into factors influencing bone marker variability and describes different approaches to minimize variability and interpret results appropriately. Variability in bone marker concentrations results from biological and analytical variability across assays. Other influencing factors include gender, age, physical exercise, circadian rhythm, and diet. The multiplicity of influencing factors hinders the establishment of accurate reference values. Gaining a deep understanding of bone marker variability is the first step to ascertain their clinical usefulness. Bone marker variability can be minimized by controlling as many variables as it is possible and through the standardization of patient preparation and sample collection and handling.

Exhaled breath metabolites reveal postmenopausal gut-bone cross-talk and non-invasive markers for osteoporosis

“…Although serum bone markers are repeatedly proposed for assessing the osteoporosis risk, we observed random expressions of these markers with relatively large variations and no tracible reproducibility in both BMD and age wise categorizations. This is in line with already reported confounding effects from intra-subject variations (15,16) that hamper optimal bone marker selection in routine practice.…”

“…are based on invasive blood sampling. Beyond this, there is no clear consensus on the selection of optimal markers and the interpretation of results are frequently confounded by intra-subject and/or intra-and inter-assay variations (15,16). Though hand grip strength measurement is considered for musculoskeletal integrity assessment in osteoporosis (17), various confounding physio-metabolic effects from subject's overall biological aging dilute a clear clinical relationship only to bone health (18,19).…”