Abstract 14035: Parathyroid Hormone and Subclinical Cerebrovascular Disease: Findings From the Atherosclerosis Risk in Communities (ARIC) Brain MRI Study

Abstract

Background: Elevated parathyroid hormone (PTH) levels have been associated with incident hypertension, insulin resistance, endothelial dysfunction, and increased cardiovascular disease events. We hypothesized that elevated PTH would also be associated with subclinical cerebrovascular disease. White matter hyperintensities (WMH) and subclinical infarcts measured on brain MRI are associated with reduced cognitive performance. We examined the relationship of elevated PTH levels with cerebrovascular pathology among white and black participants aged 55-72 in the ARIC Brain MRI study. Methods: We measured PTH from stored serum at visit 3 (1993-1994) among participants free of prior clinical stroke who underwent a brain MRI at visit 3 (n=1703) and a second brain MRI ~10 years later (n=948). PTH levels ≥65 pg/ml were considered elevated (n=204). Participants who did not return for a follow-up MRI had higher PTH levels and increased prevalence of cardiovascular risk factors at visit 3 (p<0.05 for all); therefore multiple imputation methods were used. The cross-sectional and prospective associations of PTH levels with WMH and MRI defined infarcts (and their progression) were investigated using multivariable regression models. Results: At visit 3, mean age of participants was 62 yrs, 60% female and 49% black. In models adjusted for demographic/lifestyle factors, elevated PTH was cross-sectionally associated with higher WMH score and prevalent infarcts ( Table ). Results were attenuated after adjustment for potential cardiovascular risk factor mediators. However, no prospective associations were found between PTH and incident infarcts or change in estimated WMH volume, although estimates were imprecise. Conclusions: Contrary to our hypothesis, we did not confirm any associations of elevated PTH with progression of cerebrovascular changes on serial brain MRIs ~10 years apart. The relationship of PTH with subclinical brain disease warrants further study.