Academic Department of Endocrinology, Beaumont Hospital and RCSI, Dublin, Ireland.
Department of Neurosurgery, Beaumont Hospital and RCSI, Dublin, Ireland.
Clin Endocrinol (Oxf). 2021 Apr;94(4):616-624. doi: 10.1111/cen.14367. Epub 2020 Dec 26.
Animal data and cross-sectional human studies have established that chronic hyponatraemia predisposes to osteoporosis; the effects of acute hyponatraemia on bone turnover have not been determined. Our objective was to test the hypothesis that acute hyponatraemia leads to dynamic effects on bone turnover.
A prospective observational pilot study.
Bone turnover markers [C-terminal crosslinking telopeptide of type 1 collagen (CTX-1), N-propeptide of type 1 collagen (P1NP) and osteocalcin] were measured prospectively over one week in 22 eunatraemic patients with subarachnoid haemorrhage. Patients treated with glucocorticoids were excluded.
Eight patients developed acute hyponatraemia, median nadir plasma sodium concentration 131 mmol/L (IQR 128-132), and 14 remained eunatraemic, nadir plasma sodium concentration 136 mmol/L (IQR 133-137). Significant main effects of hyponatraemia were found for P1NP (p = .02) and P1NP:CTX-1 ratio (p = .02), both fell in patients with acute hyponatraemia, with significant interaction between hyponatraemia and time from baseline for P1NP (p = .02). Significant main effects of time from baseline (p < .001) but not hyponatraemia (p = .07) were found for osteocalcin. For CTX-1, significant main effects of time from baseline (p = .001) but not hyponatraemia (p = .65) were found. There was a positive correlation between change in P1NP:CTX-1 ratio and nadir plasma sodium concentration, r = +.43, p = .04. Median serum cortisol (measured on days 1, 3 and 7) was higher in the hyponatraemia group than in those who remained eunatraemic, 545 nmol/L (IQR 373-778) versus 444 nmol/L (IQR 379-542) p = .03.
These data suggest that acute mild hyponatraemia is associated with a reduction in bone formation activity.
动物数据和横断面人体研究已经证实，慢性低钠血症使骨质疏松症易于发生；急性低钠血症对骨转换的影响尚未确定。我们的目的是检验这样一个假设，即急性低钠血症会对骨转换产生动态影响。
前瞻性观察性初步研究。
前瞻性地在 22 例蛛网膜下腔出血的尿钠正常患者中，在一周内测量骨转换标志物[I 型胶原 C 端交联肽（CTX-1）、I 型原胶原 N 端肽（P1NP）和骨钙素]。排除使用糖皮质激素治疗的患者。
8 例患者发生急性低钠血症，最低血浆钠浓度中位数为 131mmol/L（IQR 128-132），14 例患者仍保持尿钠正常，最低血浆钠浓度中位数为 136mmol/L（IQR 133-137）。低钠血症有显著的主要作用的 P1NP（p=0.02）和 P1NP：CTX-1 比值（p=0.02），这两者都在急性低钠血症患者中下降，且 P1NP 从基线的时间与低钠血症之间有显著的交互作用（p=0.02）。从基线的时间有显著的主要作用（p<0.001），而低钠血症没有（p=0.07），对骨钙素有显著的影响。对于 CTX-1，从基线的时间有显著的主要作用（p=0.001），而低钠血症没有（p=0.65）。P1NP：CTX-1 比值的变化与最低血浆钠浓度呈正相关，r=0.43，p=0.04。低钠血症组的血清皮质醇中位数（在第 1、3 和 7 天测量）高于仍保持尿钠正常的患者，分别为 545nmol/L（IQR 373-778）和 444nmol/L（IQR 379-542），p=0.03。
这些数据表明，急性轻度低钠血症与骨形成活性降低有关。
