Are bone turnover markers associated with volumetric bone density, size, and strength in older men and women? The AGES–Reykjavik study

Abstract

Purpose The aim of this study was to examine the relationship between levels of bone turnover markers (BTM; osteocalcin (OC), C-terminal cross-linking telopeptide of type I collagen (CTX), and procollagen type 1 N propeptide (P1NP)) and quantitative computed tomography (QCT)-derived bone density, geometry and strength indices in the lumbar spine and femoral neck (FN). Methods A total of 1,745 older individuals (773 men and 972 women, aged 66-92 years) from the AGES-Reykjavik cohort were studied. QCT was performed in the lumbar spine and hip to estimate volumetric trabecular, cortical and integral BMD, areal BMD, bone geometry and bone strength indices. Association between BTM and QCT variables were explored using multivariable linear regression. Results Major findings showed that all BMD measures, FN cortical index and compressive strength had a low negative correlation with the BTM levels in both men and women. Correlations between BTM and bone size parameters were minimal or not significant. No associations were found between BTM and vertebral cross-sectional area in women. BTM alone accounted for only a relatively small percentage of the bone parameters variance (1 - 10%). Conclusion Serum CTX, OC and P1NP were weakly correlated with lumbar spine and FN areal and volumetric BMD and strength measures. Most of the bone size indices were not associated with BTM, thus the selected bone remodeling markers do not reflect periosteal bone formation. These results confirmed the limited ability of the most sensitive established BTM to predict bone structural integrity in older adults.

Association of bone turnover markers with volumetric bone loss, periosteal apposition, and fracture risk in older men and women: the AGES-Reykjavik longitudinal study

“…From a clinical point of view, the dual source of BTM weaken the appropriate interpretation of their levels to identify patients with higher risk of fracture, as they reflect simultaneously bone fragility due to accelerated bone loss and a possible increase in bone strength because the resistance of the bone to bending or torsional forces is related exponentially to its diameter. Additional studies are needed to clarify the relationship of biological markers of bone metabolism and periosteal apposition, since our results demonstrated weak associations with increased CSA at different locations compared to our previous cross-sectional report [17]. At present periosteal bone biology is insufficiently understood, and should be the focus of research to assist the development of prevention and treatment options (including mechanical loading and osteoporosis drugs) of bone fragility.…”

“…In two previous studies baseline bone formation and resorption markers were not significantly associated with cross-sectional data of bone size [29] or with the periosteal expansion rate at any skeletal site [9]. Previous cross-sectional studies in our laboratory and others have reported a positive association between BTM and proximal femur size [17,12]. …”

“…Drugs that may induce bone damage included use of oral glucocorticoid or antiepileptic medications. Participants were categorized as moderate/high physically active or occasionally physically active at most, as previously described [17]. …”

Associations of 24-hour sleep duration and CT-derived measurements of muscle and bone: The AGES-Reykjavik Study

“…We adjusted our analyses for previously described variables (Marques et al 2016) that are potentially confounding or are known to be associated with muscle and bone quality or sleep duration. These included age, body mass index (BMI), smoking and physical activity status, self-reported mobility disability status, use of medications known to affect bone density, and total 25-hydroxyvitamin D (25OHD).…”

Bone Health, Muscle Strength and Lean Mass: Relationships and Exercise Recommendations

“…[1][2][3] Bone mineral density (BMD), in turn, reflects the integrity of the bone tissue, being an indication of the structural remodeling capacity and, therefore, an index of the risk of propensity to the pathologies and lesions associated with the tissue. 1,4 At present, the loss of bone tissue integrity by the reduction of the mineral mass does not has been associated only with the aging process or hormonal disorders, but also with the reduction of fat mass (FM) and lean mass (LM), due to dietary interventions for body weight loss and sedentary lifestyle, respectively. 1,5,6 In general terms, resistance or resistive types of physical exercise tends to induce BMD changes due to mechanical stress on the bones, evidencing the exercise potential in the maintenance of BMC/BMD with aging.…”