Conference report

Consensus development conference: prophylaxis and treatment of osteoporosis

Observational studies of osteoporosis medications can provide critical real-world evidence (RWE) that fills knowledge gaps left by clinical trials. However, careful consideration of study design is needed to yield reliable estimates of association. In particular, obtaining valid measurements of exposure to osteoporosis medications from real-world data (RWD) sources is complicated due to different medication classes, formulations, and routes of administration, each with different pharmacology. Extended half-lives of bisphosphonates and extended dosing of denosumab and zoledronic acid require particular attention. In addition, prescribing patterns and medication taking behavior often result in gaps in therapy, switching, and concomitant use of osteoporosis therapies. In this review, we present important considerations and provide specialized guidance for measuring osteoporosis drug exposures in RWD. First, we compare different sources of RWD used for osteoporosis drug studies and provide guidance on identifying osteoporosis medication use in these data sources. Next, we provide an overview of osteoporosis pharmacology and how it can influence decisions on exposure measurement within RWD. Finally, we present considerations for the measurement of osteoporosis medication exposure, adherence, switching, long-term exposures, and drug holidays using RWD. Ultimately, a thorough understanding of the differences in RWD sources and the pharmacology of osteoporosis medications is essential to obtain valid estimates of the relationship between osteoporosis medications and outcomes, such as fractures, but also to improve the critical appraisal of published studies.

To investigate the relationship of body composition metrics with bone mineral density (BMD) and trabecular attenuation in a cohort of healthy individuals.

We retrospectively analyzed data of consecutively evaluated individuals who underwent dual-energy X-ray absorptiometry (DXA) and abdominopelvic computed tomography (CT) on the same day during routine medical check-ups between January 2021 and December 2021. Trabecular attenuation was measured at L1 level, while body composition metrics, including skeletal muscle index (SMI), skeletal muscle attenuation (SMA), visceral fat index (VFI), and subcutaneous fat index (SFI), were measured at L3 level. The association of body composition metrics with BMD and trabecular attenuation was analyzed using partial correlation analysis.

A total of 634 patients (median age, 56 years; range 50–62 years; 392 men) were included. In men, the SMI and SMA were positively correlated with BMD and trabecular attenuation, both before (r, 0.157–0.344; p < 0.05) and after (r, 0.103–0.246; p < 0.05) adjusting for age and body mass index. The VFI showed negative correlations with trabecular attenuation in both men (r, −0.170; p = 0.001) and women (r, −0.394; p < 0.001), which remained significant after adjusting for age and body mass index (r, −0.181 to −0.122; p < 0.05).

Low skeletal muscle mass and attenuation were significantly correlated with low BMD and trabecular attenuation in men. Visceral adiposity was associated with reduced BMD and trabecular attenuation in both men and women, demonstrating a stronger correlation with trabecular attenuation.

Purpose: The first objective of the study was to assess the agreement between the Stratos DR (DMS) and the GE Prodigy (GE) DXAs in determining femoral neck, total hip and lumbar spine aBMD. The second objective was to assess the potential impact of leg positioning (hip flexed at 90° or not) on lumbar spine aBMD. Methods: Forty-six individuals (n=42 women, 91.3%), with a mean age of 59.7 ± 13 years and mean BMI of 23.8 ± 4.7 kg/m², were scanned consecutively on the same day using the two devices. In a subgroup (n=30), two consecutive Stratos DR scans (with hip flexed at 90° or not) at the lumbar spine were conducted. Predictive equations for hip and lumbar spine aBMD were derived from linear regression of the data. Results: Correlation coefficients for aBMD measured with the two DXAs were characterised by an R² of 0.76 for the femoral neck, 0.89 for the total hip, and 0.86 for the lumbar spine. However, the derived equations for aBMD determination showed an intercept significantly different from 0 for hip aBMD, and a slope significantly different from 1 for lumbar spine aBMD. These results highlight a bias between the two measurements, thus requiring the determination of specific cross-calibration equations for hip and lumbar spine, femoral neck excepted. When compared with values on the Prodigy, mean aBMD on the Stratos DR was higher at the femoral neck (+4.8%, p<0.001) and total hip (+9.6%, p<0.001) and lower at L2-L4 (-8.8%, p<0.001). The coefficient of variation (CV%) for the two consecutive measures at lumbar spine (with different positioning) with the Stratos DR was 2.9%. Conclusions: The difference in aBMD measured with the two DXAs illustrates the need to define cross-calibration equations when comparing data across systems in order to avoid erroneous conclusions.

Bone and muscle are recognised as interacting tissues, the so-called ‘muscle-bone unit’, in which these two tissues communicate to coordinate their development (chemically and metabolically), as well as their response to loading or injury. Musculoskeletal disorders of ageing, specifically osteoporosis and sarcopenia, are highly prevalent in older individuals. They signify a significant burden for older people affecting their mobility, confidence, and quality of life, as well as being a major cost to healthcare systems worldwide. This review considers the coexistence of osteoporosis and sarcopenia in individuals and describes risk factors, clinical consequences, approaches to management, and the link with functional capacity.