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.

Prolactin-secreting tumors, dopamine agonists and pregnancy: a longitudinal experience of a tertiary neuroendocrine center.

PURPOSE: Prolactin (PRL)-secreting tumours are associated with infertility and can be reverted by dopamine agonist (DA) therapy. The suspension of DA is recommended once pregnancy is established, as all DAs cross the placenta. The aim of the study was to evaluate the rate of maternal-foetal complications in women treated with cabergoline (CAB) or bromocriptine (BRM) for prolactinoma during gestation and the effect of pregnancy on prolactinoma progression. METHODS: This was a retrospective observational study involving 43 women affected by prolactinoma who became pregnant during therapy with CAB or BRM for a total of 58 pregnancies. For each patient, medical records were analysed by integrating the data with outpatient or telephone interview. RESULTS: At the time of conception, 18 women were in the BRM group, while 40 were in CAB group. No differences were found in obstetric or neonatal outcomes between the two groups. There was a significant difference (p = 0.046) in child complications reported in maternal interview found exclusively in the CAB group. No further confounding factors were detected. Disease remission rate after the first pregnancy was 42.9% and the main predictor was a lower PRL nadir before pregnancy (p = 0.023). No difference was detected between the two groups in terms of tumor remission. Breastfeeding did not modify the outcome. CONCLUSION: Foetal exposure to DAs during the first weeks of embryogenesis is not associated with a greater risk of complications. The transient and mild developmental disorders recorded resolved spontaneously and the prevalence was substantially overlapping with that observed in the general population.

Are prolactin levels efficient in predicting a pituitary lesion in patients with hyperprolactinemia?

PURPOSE: Data regarding the presence of a prolactin (PRL) threshold above which a pituitary magnetic resonance imaging (MRI) is mandatory in patients with hyperprolactinemia (hyperPRL) are controversial and derived primarily from studies focused on female populations. Aim of our study was to evaluate in a cohort of patients of both sexes with confirmed hyperPRL, the possible correlation between PRL values and the presence of pituitary abnormalities. METHODS: We retrospectively analyzed data from patients who underwent serial PRL sampling at our Division between January 2015 and December 2022. Patients diagnosed with monomeric hyperPRL at serial sampling and with subsequent contrast-enhanced MRI results available for the pituitary region were included in the study. Exclusion criteria were prior pituitary disease, severe renal insufficiency, liver cirrhosis, uncompensated primary hypothyroidism and ongoing therapy with hyperprolactinemic drugs. Physiological causes of hyperPRL were also ruled out. RESULTS: Out of the 1253 patients who underwent serial PRL sampling, 139 patients (101 women and 38 men) met the inclusion criteria: 106 (76.3%) patients had some form of pituitary disease, with microlesions observed in 69.8%, macrolesions in 25.5% and other findings in 4.7% of subjects. PRL values showed a modest accuracy in predicting the presence of a pituitary abnormality and the best cut-offs identified were >25 µg/L (AUC 0.767, p = 0.003) and >44.2 µg/L (AUC 0.697, p < 0.001) in men and women, respectively; however, if only patients with PRL values > 500 µg/L were excluded from the analysis, as they were already supposed to harbor a macroprolactinoma, PRL levels were not able to predict the presence of a macrolesion neither in men nor women. CONCLUSION: Given the high prevalence of pituitary abnormalities in patients of both sexes with hyperPRL at serial sampling, performing a pituitary imaging in all cases of hyperPRL, even if mild, appears to be a cautious choice.