2型糖尿病合并低钠血症及低钙血症的机制探讨

摘要

Objective To investigate the pathogenesis of hypocalcemia in type 2 diabetics with hyponatremia.Methods A total of 30 type 2 diabetic patients with hyponatremia and 50 patients with normal plasma natrium levels, controlled for age, gender, and blood pressure, who had received treatment in our facility between March and June, 2004 were enrolled.Plasma levels of Na, K, Ca, P, serum levels of adreno - cortico - tropic - hormone ( ACTH ), 24 h urine free cortisol ( 24hUFC ), parathyroid hormone ( PTH ), 25 ( OH ) D3 and 1, 25 ( OH )2D3 were measured in all subjects.After a 2 - week substitution treatment of predinisone ( 5 mg/day ) for the hyponatremis group, plasma levels of Na, Ca, serum levels of 25 ( OH ) D3, 1, 25 ( OH )2 D3 before and after predinisone treatment were compared.Results The hyponatremia group showed significantly lower plasma levels of Na, Ca, and 1, 25 ( OH )2D3 and higher levels of potassium compared to the control group ( P ＜0.05 ).While cortisone levels in both the plasma and urine remained comparable ( P ＞ 0.05 ).Serum levels of 1, 25 ( OH )2 D3 in the hyponatremia group increased significantly after a small dose of predinisone replacement, while levels of 25 ( OH ) D3 remained unchanged.Conclusion The hypocalcemia status in type 2 diabetics with hyponatremia, might be a result from the possible existence of relative adrenocortical insufficiency among these patients.%目的 探讨2型糖尿病合并低钠、低钙血症的发病机制.方法 选取2004年3-6月在我院住院的2型糖尿病患者,从中筛选出年龄、性别、血压相匹配的30例低钠血症者和50例血钠正常者.测定低钠血症组和血钠正常组患者的血钠、钾、钙、磷、促肾上腺皮质激素(ACTH)、24 h尿游离皮质醇(UFC)、甲状旁腺激素(PTH)和血清25(OH)D3和1,25(OH)2D3水平.然后,低钠血症组患者给予补充小剂量泼尼松(5 mg/d)替代治疗后,比较治疗前后患者的血钠、钙和血清25(OH)D3、1,25(OH)2D3水平变化.结果 与血钠正常组比较,低钠血症组糖尿病患者血钠、钙及血清1,25(OH)2D3水平显著降低,血钾显著升高,差异有统计学意义(P＜0.05);而血、尿皮质醇仅有升高趋势,但差异无统计学意义(P＞0.05).低钠血症组患者补充泼尼松治疗后,血钠、钙及血清1,25(OH)2D3水平显著高于治疗前,差异有统计学意义(P＜0.05).结论 糖尿病合并低钠血症者可能存在肾上腺皮质功能相对不足,降低了1,25(OH)2D3的合成,导致低钙血症.适当补充小剂量糖皮质激素可能上调了肾脏近曲小管1α羟化酶活性,促进1,25(OH)2D3的形成,从而改善低钠和低钙血症.