Altered brain structural and cognitive impairment in end-stage renal disease patients with secondary hyperparathyroidism

Cognitive impairment has received attention as an important problem in patients with end-stage renal disease, although end-stage renal disease patients with secondary hyperparathyroidism have not been studied.

To assess the pattern of brain volume changes in end-stage renal disease patients with secondary hyperparathyroidism by using voxel-based morphometry and correlating these measures with clinical markers and the Montreal Cognitive Assessment scores.

Fifty end-stage renal disease patients with no anatomical abnormalities in conventional MRI (25 patients with secondary hyperparathyroidism, 14 men, mean age 42.20 ± 7.53 years; 25 patients without secondary hyperparathyroidism, 15 men, mean age 41.96 ± 6.17 years) were selected in this study. All patients underwent laboratory tests, neuropsychological tests, and MRI. Voxel-based morphometry analysis was performed to detect regional gray matter volume differences between the two groups. The relationships between abnormal gray matter volume and clinical markers and Montreal Cognitive Assessment scores were investigated.

Voxel-based morphometry revealed increased gray matter volume in end-stage renal disease patients with secondary hyperparathyroidism in the bilateral caudate and bilateral thalamus compared with non- secondary hyperparathyroidism end-stage renal disease patients (P < 0.05, FWE corrected). Regarding the laboratory and neuropsychological tests, we found significant correlations between volume in these brain regions and intact parathyroid hormone levels and negative correlations with the Montreal Cognitive Assessment scores. There were no significant associations between brain volume changes and other clinical data (disease duration, urea, creatinine, and uric acid levels).

Our results showed significantly increased gray matter volume in end-stage renal disease patients with secondary hyperparathyroidism, which was associated with intact parathyroid hormone levels and cognitive impairment. Serum intact parathyroid hormone levels may be a risk factor for cognitive impairment in end-stage renal disease patients with secondary hyperparathyroidism.