Study of the link between hemotopoietic and skeletal systems in patients attending a referral center for osteoporosis

Abstract

Purpose To investigate the link between hematopoietic and skeletal tissues in patients with fragility fractures. Methods We retrospectively analyzed the medical records of women older than 40 years who attended the Bone Disease Unit of “Sapienza” University of Rome for their first visit for osteoporosis from January 2020 to June 2022. Results Fragility fractures were found in 61.8% of the sample. In particular, vertebral fractures in 35.5%, femoral fractures in 6.3%, Colles fractures in 16.5% and non-vertebral non-hip in 42.5%. Fractured patients were significantly older compared to non-fractured, had lower mean values of lumbar spine (p = 0.01), and femoral neck BMD (p = 0.007). A red blood cell distribution width (RDW) value higher than 15% was observed four times more in those with fractures compared to non-fractured patients (8.9% vs 2%, p = 0.01) and was associated with vertebral fracture after adjusting for age, BMI, menopause, nutritional status, smoking, osteoporosis and anemia (OR = 4.1, 95% CI 1.6–11.4, p = 0.003). Hematocrit was negatively associated with hip fracture also adjusting for age, BMI, menopause, nutritional status, smoking, osteoporosis (p = 0.025). Conclusion Our study demonstrates that RDW values were significantly associated with vertebral fracture and hematocrit with hip fracture. Since both parameters are included in the initial evaluation of patients with suspected bone fragility, our results should push doctors to look at these values with no incremental cost for national health services.

The Association between Red Blood Cell Distribution Width and Mortality Risk after Hip Fracture: A Meta-Analysis

“…Although it is uncommon to encounter RDW values below the normal range in clinical settings, and their significance is questionable, values exceeding the normal range, which suggest significant variability in RBC size, are frequently seen in various physiological and pathological conditions [ 15 ]. The literature has revealed that oxidative stress and inflammation considerably increase RBC heterogeneity, thus increasing RDW values [ 37 , 38 ]. High RDW values were reported to be significantly associated with elevated high-sensitivity CRP levels and erythrocyte sedimentation rates—two frequently used markers of inflammation—in unselected inpatients; moreover, high RDW values might indicate selenium deficiency, which can lead to reduced glutathione peroxidase activity in RBCs and can thus engender erythrocyte deformity [ 39 ].…”

“…This suggests that hip fracture patients hospitalized with initially high RDW values may experience a subsequent increase in RDW because of factors such as inflammation and oxidative stress. Other hypotheses have been described in previous papers, including bone marrow disorder, clonal hematopoiesis, poor renal function, and abnormalities of erythropoietin response, which could elevate the RDW value [ 34 , 38 ]. The increase in RDW could be a key factor to indicate a greater risk of complications and mortality in these patients.…”

“…Studies have shown a consistent association between elevated RDW levels and increased mortality after hip fracture. This association is potentially due to RDW reflecting underlying chronic inflammation, nutritional deficiencies, or impaired bone marrow function, all of which contribute to poorer outcomes [ 38 ]. With the above results, the initial clinical implications are promising.…”