Osteoporosis, densidad mineral ósea y complejo CKD-MBD (I): consideraciones diagnósticas

Abstract

Osteoporosis (OP) and chronic kidney disease (CKD) independently influence bone and cardiovascular health. A considerable number of patients with CKD, especially those with stages 3a to 5D, have a significantly reduced bone mineral density leading to a high risk of fracture and a significant increase in associated morbidity and mortality. Independently of classic OP related to age and/or gender, the mechanical properties of bone are also affected by inherent risk factors for CKD ("uraemic OP"). In the first part of this review, we will analyse the general concepts regarding bone mineral density, OP and fractures, which have been largely undervalued until now by nephrologists due to the lack of evidence and diagnostic difficulties in the context of CKD. It has now been proven that a reduced bone mineral density is highly predictive of fracture risk in CKD patients, although it does not allow a distinction to be made between the causes which generate it (hyperparathyroidism, adynamic bone disease and/or senile osteoporosis, etc.). Therefore, in the second part, we will analyse the therapeutic indications in different CKD stages. In any case, the individual assessment of factors which represent a higher or lower risk of fracture, the quantification of this risk (i.e. using tools such as FRAX) and the potential indications for densitometry in patients with CKD could represent an important first step pending new clinical guidelines based on randomised studies which do not exclude CKD patients, all the while avoiding therapeutic nihilism in an area of growing importance.

Kynurenine Pathway in Chronic Kidney Disease: What’s Old, What’s New, and What’s Next?

“…Pathological changes in the bone tissue, as the one of the most commonly occurring during the CKD progression, have been classified as the CKD-mineral and bone disorder (CKD-MBD). 42,191,192 Evidence for the accumulation of the metabolites of the kynurenine pathway in the course of chronic renal insufficiency and their impact on bone tissue, prompted some researchers, including our team, to deal with the topic of connections between the CKD, changes in kynurenine system activation and bone metabolism. 31,35,98,187,[192][193][194] In vitro studies have proven, that the accumulation of KYN and 3-HKYN in bone marrow stromal cells (BMSCs) have been associated with a decrease in cell proliferation and differentiation, though the mechanism which is directly mediated by their pro-oxidative properties.…”

Early steroid withdrawal has a positive effect on bone in kidney transplant recipients: a propensity score study with inverse probability-of-treatment weighting

“…Indeed, low BMD in patients with end-stage renal disease and renal osteodystrophy (i.e. osteitis fibrosa as a result of hyperparathyroidism, osteomalacia or ABD) is due to perturbed calcium, phosphate and calcitriol levels; 44 however, these variables normalize within 3–12 months of transplantation. 45 , 46 Nevertheless, two of the patients had a PTH value at M12 below the assay’s limit of detection (4.6 pg/ml); there were few changes in these variables during this time frame.…”

Clinical Approach to Vascular Calcification in Patients With Non-dialysis Dependent Chronic Kidney Disease: Mineral-Bone Disorder-Related Aspects

“…Lateral abdominal X-ray is helpful not only to semiquantify an aortic risk score such as Kauppila's (KS) ( 45 ) ( Figure 1 ) but also to detect unnoticed vertebral fractures, with potential therapeutic renewed interest in CKD-associated osteoporosis guidelines ( 35 , 44 , 46 , 47 ). Spanish CKD-MBD guidelines also suggest use of the simpler Adragão's score (AS) ( 19 , 48 ) ( Figure 1 ).…”