Abstract P217: Parathyroid Hormone is Not Independently Associated With Cognitive Decline: 20 Year Follow-up From the Atherosclerosis Risk in Communities (ARIC) Study
Background: Little is known about the role of parathyroid hormone (PTH) in cognitive decline. Elevated PTH may contribute to cognitive impairment and dementia by mechanisms of endothelial dysfunction, increased vascular stiffness, hypertension, and atherosclerosis, as well as via small vessel cerebral disease. We hypothesized that elevated PTH levels will be independently associated with 20-year cognitive decline in a large population-based cohort study.
Methods: We studied 12,964 middle-aged white and black ARIC participants without history of prior stroke who had serum PTH levels and cognitive function testing measured in 1990-92 (baseline) and repeat cognitive testing at up to 2 follow-up visits in 1996-98 and 2011-13. The cognitive tests included the Delayed Word Recall, Digit Symbol Substitution, and Word Fluency tests, which were summed as a global z score. Using mixed-effects models, we compared the relative decline in global cognitive score between each of the top three quartiles of PTH levels to the reference bottom quartile. Time since baseline was modeled by using a linear spline with a knot at 6 years. We adjusted for demographic variables, education, vascular risk factors, and calcium, phosphorous, and vitamin D levels. We imputed missing covariates and follow-up cognitive data using multiple imputation by chained equations (MICE) methods to account for attrition during study follow-up.
Results: The mean (SD) age of our cohort was 57(6) years, 57% were women, and 24% black race. There was no cross-sectional association of elevated PTH with cognitive global Z score at baseline (all p>0.05). Over a median of 20.7 years, participants in each PTH quartile showed decline in cognitive function (Table Part A). However, cognitive decline was not steeper in participants with PTH levels in the higher quartiles than participants with the lowest PTH levels (all p>0.05). [Table Part B].
Conclusions: Our work does not support an independent influence of PTH on cognitive decline in this biracial population-based cohort study.
Author Disclosures: S.M. Kim: None. D. Zhao: None. A.L.C. Schneider: None. S. Korada: None. P.L. Lutsey: None. E. Guallar: None. A. Alonso: None. B. Windham: None. R.F. Gottesman: None. E.D. Michos: None.
- © 2017 by American Heart Association, Inc.