Abstract: SA-PO445

Cognitive Function and Hyponatremia: Baseline Data from the SPRINT Trial

Session Information

Category: Chronic Kidney Disease (Non-Dialysis)

  • 306 CKD: Cognitive Dysfunction, Depression, Quality of Life

Authors

  • Weiner, Daniel E., Tufts Medical Center, Boston, Massachusetts, United States
  • Umanath, Kausik, Henry Ford, Derroit, Michigan, United States
  • Gaussoin, S., Wake Forest, Winston-Salem, North Carolina, United States
  • Kurella Tamura, Manjula, Stanford University, Palo Alto, California, United States
  • Cheung, Alfred K., University of Utah, Salt Lake City, Utah, United States
  • Cushman, William C., Memphis VA Medical Center, Memphis, Tennessee, United States
  • Killeen, Anthony Alexander, University of Minnesota, Minneapolis, Minnesota, United States
  • Rahman, Mahboob, Case Western Reserve University, Cleveland, Ohio, United States
  • Wall, Barry M., Memphis VA Medical Center, Memphis, Tennessee, United States
  • Dwyer, Jamie P., Vanderbilt University Medical Center, Nashville, Tennessee, United States
Background

Hyponatremia is stated as a reversible cause of cognitive impairment despite very limited data exploring this association.

Methods

To explore the relationship between serum sodium concentration and cognitive function, we evaluated baseline data from the Systolic Blood Pressure INTervention (SPRINT) cognition substudy, SPRINT-MIND. Five cognitive domains were defined from 11 cognitive tests using z-scores, and the association of serum sodium with cognitive performance and brain abnormal white matter volume quantified by MRI were evaluated using linear and quantile regression, respectively.

Results

Among 9361 SPRINT-MIND participants, 2853 were administered an expanded cognitive battery at baseline, 664 of whom had brain MRI. Mean age was 68 years; 20% had known CVD and 29% eGFR <60 ml/min/1.73m2. There were 120 participants with serum sodium <135 mEq/L, 485 with sodium 136-138, 983 with 139-140, 891 with 141-142, and 374 with >143 mEq/L. In analyses adjusted for age, sex, SPRINT network, education, race, diabetes, CVD, BMI, smoking, ACEi/ARB use, systolic and diastolic BP, lipids, eGFR, and albuminuria, lower serum sodium was associated with significantly worse executive function (p=0.002) and a trend to worse attention (p=0.08) and global cognitive function (p=0.12). Associations were unchanged following adjustment for thiazide and anti-depressant use. When examining thresholds, participants with Na >143 mEq/L also demonstrated worse cognitive test performance in most domains, consistent with a ‘J’-shape relationship between sodium and cognition. In the MRI subgroup, sodium was not associated with brain abnormal white matter volume in adjusted analyses (p=0.77).

Conclusion

In older adults with hypertension, lower serum sodium is associated with worse cognitive function, particularly executive function. This does not appear to reflect structural brain disease.

Funding

  • NIDDK Support