Mild hyponatremia is not associated with degradation of trabecular bone microarchitecture despite bone mass loss.

CONTEXT: Hyponatremia is associated with increased risk of osteoporosis and fractures. The impact of hyponatremia on non-invasive indices of bone quality, however, is unknown. OBJECTIVE: To evaluate whether trabecular bone microarchitecture, assessed non-invasively by trabecular bone score (TBS), is altered in patients with hyponatremia. METHODS: We conducted a cross-sectional analysis of the population-based 2005-2008 cycles of the National Health and Nutrition Examination Survey (NHANES), in which TBS measurement was performed. The main outcome measures were TBS values and bone mineral density (BMD) T-scores at the lumbar spine, total hip and femoral neck. RESULTS: A total of 4204 subjects aged 50 years or older were included (4041 normonatremic, 163 hyponatremic - 90.8% with mild hyponatremia). Univariate analyses did not show any difference in TBS between patients with and without hyponatremia (1.308 ± 0.145 vs 1.311 ± 0.141, p = 0.806). Hyponatremic subjects had lower BMD T-score at total hip (-0.70 ± 1.46 vs -0.13 ± 1.32, p < 0.001) and femoral neck (-1.11 ± 1.26 vs -0.72 ± 1.14, p = 0.004), while no difference was observed at lumbar spine (-0.27 ± 1.63 vs -0.31 ± 1.51, p = 0.772). After adjustment for relevant confounders, hyponatremia was confirmed as an independent predictor of lower BMD T-score at the total hip (ß=-0.20, 95%CI:[-0.39, -0.02], p = 0.029), while the significance was lost at the femoral neck (p = 0.308). Again, no association between hyponatremia and lumbar spine BMD (p = 0.236) or TBS (p = 0.346) was observed. CONCLUSIONS: Hyponatremia, at least in mild forms, is not associated with a degradation of trabecular microarchitecture, assessed non-invasively by TBS. An independent association between hyponatremia and loss of bone mass is confirmed, particularly at the total hip.

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). Trabecular bone score (TBS) has been developed as a reliable non-invasive 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 < 0.01), in dialysis patients (-0.106, 95%CI:[-0.141, -0.070], p < 0.01) and in kidney transplant recipients (KTRs) (-0.058, 95%CI:[-0.103, -0.012], p = 0.01). With respect to fracture risk, TBS was able to predict incident fractures in non-dialysis patients at unadjusted analyses (hazard ratio (HR) per standard deviation decrease: 1.45, 95%CI:[1.05,2.00], p = 0.02), though only a non-significant trend was maintained when fully adjusting the model for FRAX® (HR = 1.26, 95%CI:[0.88,1.80], p = 0.21). Dialysis patients with prevalent fractures had lower TBS values compared to unfractured ones (-0.070, 95% CI:[-0.111, -0.028], p < 0.01). 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. CONCLUSIONS: 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.

Recurrence and mortality rate in an Italian multi-center case series of parathyroid atypical adenomas and carcinomas.

Introduction: There are few data regarding the clinical outcome of patients with parathyroid carcinoma (PC) and atypical adenoma (AA) after surgery. Aim of our study was to investigate disease recurrence and mortality rate as well as their predictors in a series of patients with PC or AA. Methods: Clinical and biochemical parameters, histological features, incidence of disease recurrence and mortality rate were retrospectively assessed in 39 patients (51% males, mean age 56.2 ± 17.2 years) diagnosed with PC (n=24) or AA (n=15) and followed up for 6.8 ± 5.0 years after surgery. Results: No differences in baseline characteristics were registered between the two groups, except for higher KI67 values in PC than AA (6.9 ± 3.9% vs 3.4 ± 2.1%, p<0.01). Eight patients (21%) experienced recurrence after a mean follow-up of 5.1 ± 2.7 years, with higher relapse rate in PC than AA (25% vs 13%), though this difference did not reach statistical significance. Mortality rate was 10% in the whole sample, without significant differences between PC and AA. Relapsing cases had been undergone the most extensive surgery more frequently and they had a higher mortality rate in comparison to non relapsing patients (38% vs 6% and 38% vs 3%, respectively, p<0.03 for both). In comparison to survivors, deceased patients were submitted to the most extensive surgery more frequently (50% vs 9%), they were older (74.8 ± 4.6 vs 53.2 ± 16.3 years), and they had higher KI67 values (11.7 ± 4.9 vs 4.8 ± 2.8, p<0.03 for all comparisons). Conclusions: During seven-year follow-up after surgery, no significant differences in recurrence and mortality rate were observed between PC and AA patients. Death was associated with disease relapse, older age and higher KI67 values. These findings suggest a similar and careful long-term follow-up in both parathyroid tumors, especially in older patients, and emphasize the need of further studies in large cohorts to throw light on this crucial clinical issue.