Bone strength is determined not only by bone quantity [bone mineral density (BMD)] but also by bone quality, including matrix composition, collagen fiber arrangement, microarchitecture, geometry, mineralization, and bone turnover, among others. These aspects influence elasticity, the load-bearing and repair capacity of bone, and microcrack propagation and are thus key to fractures and their avoidance. In chronic kidney disease (CKD)-associated osteoporosis, factors traditionally associated with a lower bone mass (advanced age or hypogonadism) often coexist with non-traditional factors specific to CKD (uremic toxins or renal osteodystrophy, among others), which will have an impact on bone quality. The gold standard for measuring BMD is dual-energy X-ray absorptiometry, which is widely accepted in the general population and is also capable of predicting fracture risk in CKD. Nevertheless, a significant number of fractures occur in the absence of densitometric World Health Organization (WHO) criteria for osteoporosis, suggesting that methods that also evaluate bone quality need to be considered in order to achieve a comprehensive assessment of fracture risk. The techniques for measuring bone quality are limited by their high cost or invasive nature, which has prevented their implementation in clinical practice. A bone biopsy, high-resolution peripheral quantitative computed tomography, and impact microindentation are some of the methods established to assess bone quality. Herein, we review the current evidence in the literature with the aim of exploring the factors that affect both bone quality and bone quantity in CKD and describing available techniques to assess them.

Chronic kidney disease (CKD) is a highly prevalent condition worldwide in which the kidneys lose many abilities, such as the regulation of vitamin D (VD) metabolism. Moreover, people with CKD are at a higher risk of multifactorial VD deficiency, which has been extensively associated with poor outcomes, including bone disease, cardiovascular disease, and higher mortality. Evidence is abundant in terms of the association of negative outcomes with low levels of VD, but recent studies have lowered previous high expectations regarding the beneficial effects of VD supplementation in the general population. Although controversies still exist, the diagnosis and treatment of VD have not been excluded from nephrology guidelines, and much data still supports VD supplementation in CKD patients. In this narrative review, we briefly summarize evolving controversies and useful clinical approaches, underscoring that the adverse effects of VD derivatives must be balanced against the need for effective prevention of progressive and severe secondary hyperparathyroidism. Guidelines vary, but there seems to be general agreement that VD deficiency should be avoided in CKD patients, and it is likely that one should not wait until severe SHPT is present before cautiously starting VD derivatives. Furthermore, it is emphasized that the goal should not be the complete normalization of parathyroid hormone (PTH) levels. New developments may help us to better define optimal VD and PTH at different CKD stages, but large trials are still needed to confirm that VD and precise control of these and other CKD-MBD biomarkers are unequivocally related to improved hard outcomes in this population.

Diabetes mellitus (DM) in kidney transplant recipients (KTR) is a risk factor for mortality, increases the risk of infections and, in the long term, can lead to graft loss due to diabetic kidney disease. A preventive approach applied to those on the waiting list could decrease the incidence of post-transplant DM (PTDM) by detecting those patients at risk, thus allowing strategies to minimize the probability of developing a New Onset Diabetes After Transplant (NODAT). On the other hand, modifications of immunosuppressive therapy may improve glucose control in patients with KTR. In recent years, two new classes of antidiabetic drugs and non-steroidal mineralocorticoid receptor antagonists have demonstrated cardiovascular and renal benefits in randomized clinical trials where the transplant population has not been represented. Because of the potential benefit expected in this population, the clinical use of glucagon-like peptide-1 receptor agonists (GLP-1RA), sodium-glucose cotransporter 2 inhibitors (SGLT2i) and finerenone is increasing in the kidney transplant setting. This review focuses on comprehensive pharmacological interventions in KTR with glucose metabolism disorders. In-depth knowledge in this area will allow prevention and identification of potential adverse effects or drug interactions in the clinical course of KTR with DM.

It is now widely recognized that maintaining magnesium (Mg) homeostasis is critical for health, especially in the context of chronic kidney disease (CKD). Patients with CKD commonly develop hyperphosphatemia and secondary hyperparathyroidism, which are controlled by therapies targeting intestinal phosphate absorption and circulating calcium levels or by modulating parathyroid calcium sensing. Notably, Mg supplementation may provide dual benefits by promoting bone formation and maintaining normal mineralization with slightly elevated serum levels. Importantly, low Mg levels are associated with mortality risk in CKD, highlighting the importance of maintaining adequate serum Mg levels in these patients. Particularly, kidney transplant (KT) patients have lower circulating Mg levels, likely due to interactions with immunosuppressive treatments. Sodium-glucose co-transporter 2 (SGLT2) inhibitors have shown survival benefits in CKD and increased serum Mg levels, suggesting that Mg regulation may contribute to these outcomes. Overall, Mg plays a key role in CKD-associated mineral and bone disorders (CKD-MBD). Thus, understanding the mechanisms underlying the alteration of Mg homeostasis in CKD could improve clinical outcomes. This review summarizes the basic and clinical studies demonstrating (1) the key actions of Mg in CKD-MBD, including secondary hyperparathyroidism and bone abnormalities; (2) the distinctive profile of KT patients for Mg homeostasis; and (3) the interaction between commonly used drugs, such as SGLT2 inhibitors or immunosuppressive treatments, and Mg metabolism, providing a broad understanding of both the key role of Mg in the context of CKD and the treatments that should be considered to manage Mg levels in CKD patients.

Osteoporosis and fragility fractures are among the most prevalent and clinically significant complications in patients with chronic kidney disease (CKD), particularly in stages G4–G5 and in those undergoing dialysis (G5D). These skeletal disorders are associated with markedly increased morbidity and mortality, including a 2- to 9-fold higher risk of hip fractures compared to the general population, prolonged hospitalization, functional decline, and excess postoperative mortality. Despite this substantial burden, CKD-associated osteoporosis remains underrecognized and undertreated. Limited inclusion of CKD patients in pivotal osteoporosis trials and the absence of high-evidence guidance in clinical guidelines have contributed to a persistent therapeutic gap. PTH analog agents such as teriparatide and abaloparatide have demonstrated robust efficacy in increasing bone mass and reducing fracture risk in the general population. However, their use in CKD remains limited. PTH analog are poorly prescribed in patients with CKD stage G3 and remain off-label for stages G4–G5D, despite the high prevalence of adynamic bone disease across all stages of CKD. Abaloparatide, a selective PTH1 receptor agonist, exerts potent anabolic effects with a lower incidence of hypercalcemia than teriparatide and may offer a favourable safety profile in carefully selected patients. Preliminary data suggest preservation of bone microarchitecture and potential benefits in low-turnover bone disease, although evidence in CKD is still limited. This narrative review examines current evidence on abaloparatide’s potential role in CKD, emphasizing its mechanism of action, efficacy, safety, and relevance for patients with low bone turnover and high fracture risk.