Division of Renal Diseases and Hypertension, University of Colorado Anschutz Medical Campus, Aurora, Colorado.
Departments of Psychiatry, Neurology, and Epidemiology, University of California San Francisco, San Francisco, California.
Clin J Am Soc Nephrol. 2018 Mar 7;13(3):366-374. doi: 10.2215/CJN.07400717. Epub 2018 Feb 8.
Mild hyponatremia is a common finding in older adults; however, the association of lower serum sodium with cognition in older adults is currently unknown. We determined whether lower normal serum sodium is associated with cognitive impairment and risk of cognitive decline in community-dwelling older men.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Five thousand four hundred thirty-five community-dwelling men aged ≥65 years who participated in Osteoporotic Fractures in Men, a cohort study with a median follow-up for cognitive function of 4.6 years, were included in this analysis. Multivariable logistic regression was used to examine the association between baseline fasting serum sodium levels and the odds of prevalent cognitive impairment (cross-sectional analysis; modified Mini-Mental Status [3MS] score <1.5 SD [<84] below or Trail Making Test Part B time >1.5 SD above the mean [>223 seconds]) and cognitive decline (prospective analysis [=3611]; decrease in follow-up 3MS score or increase in Trails B time >1.5 SD of the mean score/time change [>9 or >67 seconds]).
Participants were aged 74±6 years with a fasting mean serum sodium level of 141±3 mmol/L. Fifteen percent (=274), 12% (=225), and 13% (=242) had prevalent cognitive impairment in tertiles 1, 2, and 3, respectively. After adjustment, lower serum sodium was associated with prevalent cognitive impairment (tertile 1 [126-140 mmol/L] versus tertile 2 [141-142 mmol/L], odds ratio [OR], 1.30; 95% confidence interval [95% CI], 1.06 to 1.61). Fourteen percent (=159), 10% (=125), and 13% (=159) had cognitive decline in tertiles 1, 2, and 3, respectively. Lower serum sodium was also associated with cognitive decline (tertile 1 versus tertile 2, OR, 1.37; 95% CI, 1.06 to 1.77). Tertile 3 (143-153 mmol/L) was additionally associated with cognitive decline. Results were similar in sensitivity analyses according to clinical cut-offs and by quartiles.
In community-dwelling older men, serum sodium between 126-140, and 126-140 or 143-153 mmol/L, are independently associated with prevalent cognitive impairment and cognitive decline, respectively.
轻度低钠血症在老年人中较为常见；然而，目前尚不清楚血清钠浓度降低与老年人认知功能的关系。本研究旨在确定血清正常钠低值是否与社区居住的老年男性的认知障碍和认知下降风险相关。
设计、地点、参与者和测量方法：本研究纳入了 5435 名年龄≥65 岁的社区居住男性，他们参加了男性骨质疏松性骨折队列研究，中位随访时间为 4.6 年，用于认知功能的随访。采用多变量逻辑回归分析来检测基线空腹血清钠水平与认知障碍的相关性（横断面分析；改良的简易精神状态检查[3MS]评分＜1.5 个标准差[＜84]，或连线测试 B 部分时间＞1.5 个标准差[＞223 秒]）和认知下降（前瞻性分析[=3611]；随访期间 3MS 评分下降或 Trails B 时间增加＞1.5 个平均评分/时间变化[＞9 或＞67 秒]）。
参与者的年龄为 74±6 岁，空腹平均血清钠水平为 141±3 mmol/L。分别有 15%（=274）、12%（=225）和 13%（=242）的参与者在三分位数 1、2 和 3 中存在认知障碍。经调整后，血清钠较低与认知障碍相关（三分位数 1[126-140 mmol/L]与三分位数 2[141-142 mmol/L]相比，比值比[OR]为 1.30；95%置信区间[95%CI]为 1.06 至 1.61）。分别有 14%（=159）、10%（=125）和 13%（=159）的参与者在三分位数 1、2 和 3 中存在认知下降。血清钠较低也与认知下降相关（三分位数 1 与三分位数 2 相比，OR 为 1.37；95%CI 为 1.06 至 1.77）。三分位数 3（143-153 mmol/L）与认知下降也相关。根据临床界值和四分位数的敏感性分析结果相似。
在社区居住的老年男性中，血清钠在 126-140mmol/L 之间，以及 126-140mmol/L 或 143-153mmol/L 时，分别与认知障碍和认知下降相关。
