Serum sodium and cognition in older community-dwelling men

TY - JOUR

T1 - Serum sodium and cognition in older community-dwelling men

AU - Nowak, Kristen L.

AU - Yaffe, Kristine

AU - Orwoll, Eric

AU - Ix, Joachim H.

AU - You, Zhiying

AU - Barrett-Connor, Elizabeth

AU - Hoffman, Andrew R.

AU - Chonchol, Michel

PY - 2018/3/7

Y1 - 2018/3/7

N2 - Background and objectives 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 [n=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]). Results Participants were aged 7466 years with a fasting mean serum sodium level of 14163 mmol/L. Fifteen percent (n=274), 12% (n=225), and 13% (n=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 (n=159), 10% (n=125), and 13% (n=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. Conclusions 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.

AB - Background and objectives 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 [n=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]). Results Participants were aged 7466 years with a fasting mean serum sodium level of 14163 mmol/L. Fifteen percent (n=274), 12% (n=225), and 13% (n=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 (n=159), 10% (n=125), and 13% (n=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. Conclusions 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.

KW - Aging

KW - Cognition

KW - Cognitive

KW - Cognitive Dysfunction

KW - Cross-Sectional Studies

KW - Electrolytes

KW - Fasting

KW - Follow-Up Studies

KW - Hyponatremia

KW - Independent Living

KW - Logistic Models

KW - Osteoporotic Fractures

KW - Prevalence

KW - Prospective Studies

KW - Prospective Studies

KW - Sodium

KW - Trail Making Test

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UR - http://www.scopus.com/inward/citedby.url?scp=85043332788&partnerID=8YFLogxK

U2 - 10.2215/CJN.07400717

DO - 10.2215/CJN.07400717

M3 - Article

VL - 13

SP - 366

EP - 374

JO - Clinical Journal of the American Society of Nephrology

JF - Clinical Journal of the American Society of Nephrology

SN - 1555-9041

IS - 3

ER -