Low-density granulocytes: A new marker of bone deterioration in patients on peritoneal dialysis

Objetive: In kidney patients, bone-metabolic disease, systemic inflammation and malnutrition exacerbate the risk of vascular calcification (VC) and morbidity and mortality. Given the strong association between VC and fragility fractures, the objective of this study is to assess the contribution of the major determinants of VC to bone deterioration in patients on peritoneal dialysis (PD). Methods: In 31 non-diabetic patients on PD (>6 months), markers of alterations in bone metabolism, vascular damage, inflammation and malnutrition, and their impact on bone deterioration (radiological osteopenia and/or history of fragility fracture) were studied. Results: In these patients (20 men and 11 women; age=540±15 and 60±11 years, respectively (p=0.24)), the prevalence of fragility fractures was 5% in men and 27% in women. Bone deterioration was greater in older people, females, high Charlson and Kauppila indexes, lower muscle mass and with expansion of a highly inflammatory subpopulation of immature low-density granulocytes (iLDG). A logistic regression analysis showed that bone deterioration risk is more influenced by the female sex than by age and that, of the multiple factors associated with greater bone deterioration studied, only the expansion of iLDG estimates the risk of bone alterations in these patients regardless of age and sex. Conclusion: The expansion of iLDG provides an accurate biomarker for the diagnosis of bone deterioration and to monitor strategies that attenuate its progression in PD patients of any age and sex.