Trabecular Bone Score as a Marker of Skeletal Fragility Across the Spectrum of Chronic Kidney Disease: A Systematic Review and Meta-analysis

Skeletal fragility in pituitary disease: how can we predict fracture risk?

Pituitary hormones play a crucial role in regulating skeletal physiology, and skeletal fragility is a frequent complication of pituitary diseases. The ability to predict the risk of fracture events is crucial for guiding therapeutic decisions; however, in patients with pituitary diseases, fracture risk estimation is particularly challenging. Compared to primary osteoporosis, the evaluation of bone mineral density by dual X-ray absorptiometry is much less informative about fracture risk. Moreover, the reliability of standard fracture risk calculators does not have strong validations in this setting. Morphometric vertebral assessment is currently the cornerstone in the assessment of skeletal fragility in patients with pituitary diseases, as prevalent fractures remain the strongest predictor of future fracture events. In recent years, new tools for evaluating bone quality have shown promising results in assessing bone impairment in patients with pituitary diseases, but most available data are cross-sectional, and evidence regarding the prediction of incident fractures is still scarce. Of note, apart from measures of bone density and bone quality, the estimation of fracture risk in the context of pituitary hyperfunction or hypofunction cannot ignore the evaluation of factors related to the underlying disease, such as its severity and duration, as well as the specific therapies implemented for its treatment. Aim of this review is to provide an up-to-date overview of all major evidence regarding fracture risk prediction in patients with pituitary disease, highlighting the need for a tailored approach that critically integrates all clinical, biochemical, and instrumental data according to the specificities of each disease.

Trabecular Bone Score as a Marker of Skeletal Fragility Across the Spectrum of Chronic Kidney Disease: A Systematic Review and Meta-analysis

CONTEXT

The impairment of bone microarchitecture is a key determinant of skeletal fragility in patients with chronic kidney disease (CKD). The trabecular bone score (TBS) has been developed as a reliable noninvasive index of bone quality. However, its utility in this setting is still debated.

OBJECTIVE

The aim of this systematic review and meta-analysis was to summarize the available evidence about TBS as a marker of skeletal fragility across the spectrum of CKD.

METHODS

PubMed/Medline, EMBASE, and Cochrane Library databases were systematically searched until July 2023 for studies reporting data about TBS in patients with CKD. Effect sizes were pooled through a random-effect model.

RESULTS

Compared to controls, lower TBS values were observed in CKD patients not on dialysis (-0.057, 95%CI:[-0.090, -0.024], P < .01), in dialysis patients (-0.106, 95%CI:[-0.141, -0.070], P < .01), and in kidney transplant recipients (KTRs) (-0.058, 95%CI:[-0.103, -0.012], P = .01). With respect to fracture risk, TBS was able to predict incident fractures in nondialysis patients at unadjusted analyses (hazard ratio [HR] per SD decrease: 1.45, 95%CI:[1.05, 2.00], P = .02), though only a nonsignificant trend was maintained when fully adjusting the model for FRAX® (HR = 1.26, 95%CI:[0.88, 1.80], P = .21). Dialysis patients with prevalent fractures had lower TBS values compared to unfractured ones (-0.070, 95% CI:[-0.111, -0.028], P < .01). Some studies supported a correlation between TBS and fracture risk in KTRs, but results could not be pooled due to the lack of sufficient data.

CONCLUSION

CKD patients are characterized by an impairment of bone microarchitecture, as demonstrated by lower TBS values, across the whole spectrum of kidney disease. TBS can also be helpful in the discrimination of fracture risk, with lower values being correlated with a higher risk of prevalent and incident fractures.

Ten tips on how to assess bone health in patients with chronic kidney disease

Patients with chronic kidney disease (CKD) experience a several-fold increased risk of fracture. Despite the high incidence and the associated excess morbidity and premature mortality, bone fragility in CKD, or CKD-associated osteoporosis, remains a blind spot in nephrology with an immense treatment gap. Defining the bone phenotype is a prerequisite for the appropriate therapy of CKD-associated osteoporosis at the patient level. In the present review, we suggest 10 practical 'tips and tricks' for the assessment of bone health in patients with CKD. We describe the clinical, biochemical, and radiological evaluation of bone health, alongside the benefits and limitations of the available diagnostics. A bone biopsy, the gold standard for diagnosing renal bone disease, is invasive and not widely available; although useful in complex cases, we do not consider it an essential component of bone assessment in patients with CKD-associated osteoporosis. Furthermore, we advocate for the deployment of multidisciplinary expert teams at local, national, and potentially international level. Finally, we address the knowledge gaps in the diagnosis, particularly early detection, appropriate "real-time" monitoring of bone health in this highly vulnerable population, and emerging diagnostic tools, currently primarily used in research, that may be on the horizon of clinical practice.