Parathyroid Hormone and Subclinical Cerebrovascular Disease: The Atherosclerosis Risk in Communities Brain Magnetic Resonance Imaging Study

Risk factors for intracerebral hemorrhage in patients undergoing maintenance hemodialysis

Background

In patients undergoing hemodialysis, intracerebral hemorrhage (ICH) is the main cause of mortality among stroke subtypes. It is unclear whether, along with traditional cardiovascular risk factors, the risk factors unique to the uraemic environment, such as the abnormal metabolism of intact parathyroid hormone (iPTH), can contribute to the risk of ICH in these patients.

Methods

This retrospective case-control study included 25 patients undergoing hemodialysis with ICH at a single center between 30 June 2015 and 10 October 2022. The controls were 95 patients undergoing maintenance hemodialysis treated at the same dialysis center in July 2020. We compared the characteristics of patients with ICH with those of the control group to identify factors that contributed to the development of ICH.

Results

Intracerebral hemorrhage (ICH) was located in the basal ganglia (14/25), cerebellum (6/25), and brainstem (6/25) in 25 patients. A total of 17 patients died in the first 16 days due to neurological complications. Univariate analysis showed significant differences in systolic BP, diastolic BP, iPTH, and alkaline phosphatase between the two groups (p < 0.05). Multivariate logistic regression analysis showed that higher systolic BP (OR, 1.053; 95% CI, 1.018-1.090; p = 0.003) and higher iPTH (OR, 1.007; 95% CI, 1.003-1.012; p = 0.001) were associated with the onset of ICH. ICH was predicted by systolic BP and iPTH by receiver operating characteristic (ROC) curve analysis, with areas under the curve (AUCs) of 0.732 and 0.624, respectively. The optimal cutoffs for systolic BP and iPTH were 151.9 mmHg and 295.4 pg./ml, respectively. Restricted cubic spline showed that the shape of the association of iPTH with the risk of ICH was approximately J-shaped (P for non-linearity <0.05).

Conclusion

Higher systolic BP and abnormal iPTH metabolism might be associated with ICH in patients undergoing hemodialysis. Comprehensive control of hypertension and iPTH may be a fundamental preventive strategy for ICH in these patients.

Silent neurological lesions detected by magnetic resonance imaging: Relationship to hyperparathyroidism among end-stage renal disease young patients on haemodialysis

BACKGROUND

End-stage renal disease (ESRD) patients on haemodialysis (HD) suffer from several peripheral and central neurological complications. They are at high risk for developing silent neurological lesions (SNL) that may be detected accidentally by magnetic resonance imaging (MRI). Many factors are implicated in the development of neurological deficits in ESRD patients on HD.

AIM OF THE WORK

Evaluation of SNL in young ESRD patients by using MRI and assessing its correlation with hyperparathyroidism.

METHODS

The study involved 48 young ESRD patients (mean age of 19.6 ± 6 years) with HD and do not have any apparent abnormalities in the neurological examination. Laboratory investigations and conventional brain MRI were done on all.

RESULTS

79.2% have SBI and 45.8% have white matter lesions. Regression analysis revealed that calcium level and duration of dialysis were independent predictor factors for the presence of silent brain MRI lesions (P = .034 & 0.045 respectively). ROC curve showed that parathyroid hormone (PTH) level >585 pg/mL, duration of dialysis >2 years, and calcium level >7.5 mg/dL predicted the presence of SNL.

CONCLUSION

The duration of HD and hyperparathyroidism (HPT) were independent predictors for the presence of SNL. MRI brain is considered as a mandatory affordable tool for HD patients >2 years and has HPT for early detection of SNL to help early intervention and avoid neurological complications and disabilities.

Serum magnesium, bone-mineral metabolism markers and their interactions with kidney function on subsequent risk of peripheral artery disease: the Atherosclerosis Risk in Communities Study

BACKGROUND

Few studies have investigated the association of magnesium levels with incident peripheral artery disease (PAD) despite emerging evidence of magnesium contributing to vascular calcification. Moreover, no data are available on whether the magnesium-PAD relationship is independent of or modified by kidney function.

METHODS

A cohort of 11 839 participants free of PAD in the Atherosclerosis Risk in Communities Study at Visit 2 (1990-92) was studied. We investigated the association of serum magnesium and other bone-mineral metabolism markers [calcium, phosphorus, intact parathyroid hormone (iPTH) and intact fibroblast growth factor-23] with incident PAD using multivariable Cox proportional hazards regression.

RESULTS

Over a median of 23 years, there were 471 cases of incident PAD. The hazard ratio for incident PAD in Quartile 1 (<1.5 mEq/L) versus Quartile 4 (>1.7 mEq/L) of magnesium was 1.96 (95% confidence interval 1.40-2.74) after adjustment for potential confounders. Lower magnesium levels were associated with greater incidence of PAD, particularly in those with estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2 (n = 11 606). In contrast, the association was largely flat in those with eGFR <60 mL/min/1.73 m2 (n = 233) with P-for-interaction 0.03. Among bone-mineral metabolism markers, only higher iPTH showed an interaction with kidney function (P-for-interaction 0.01) and iPTH >65 pg/mL was significantly related to PAD only in those with eGFR <60 mL/min/1.73 m2.

CONCLUSIONS

Lower magnesium was independently associated with incident PAD, but this association was significantly weaker in those with reduced kidney function. In contrast, higher iPTH levels were particularly related to PAD risk in this clinical population.

Cerebrovascular events in hemodialysis patients; a retrospective observational study

BACKGROUND

This study reports findings in subjects who underwent brain imaging for any reason, and examined factors influencing cerebrovascular events (CVEs) in hemodialysis (HD) patients.

METHODS

We reviewed the files of patients on HD between January 2015 and January 2018. A total of 432 patients who underwent HD for at least 5 months by the January 2015 and who were older than 18 years were included in the study; 264 had been examined by cerebral computed tomography or magnetic resonance imaging examination within the 3 years. Cerebrovascular pathology was detected in 139 of 264 patients.

RESULTS

Of the 139 patients, 65 (24.62%) had ischemic lesions, 25 (9.47%) had hemorrhagic lesions, and 49 (18.56%) had cerebral small vessel disease (CSVD). We compared recorded data and later clinical findings between patients with and those without CVEs. The cause of end-stage renal disease was diabetes in 58.5% of patients with ischemic lesions, 52% in those with hemorrhagic lesions, and 55% in those with CSVD (P < 0.05). Patients with cerebrovascular ischemia were older (P = 0.0001) and had lower serum creatinine (sCr) (P = 0.0001) and higher serum C-reactive protein (CRP) (P = 0.002) levels than normal subjects. Hemorrhagic patients were older (P = 0.003) and had lower sCr (P = 0.003) and serum predialysis potassium (P = 0.003) and parathyroid hormone (PTH) (P = 0.004) levels than normal subjects. Patients with CSVD were older (P < 0.0001) and had lower sCr (P < 0.0001), phosphorus (P < 0.007), and PTH (P < 0.013) and higher CRP (P < 0.002) levels than normal subjects.

CONCLUSIONS

HD patients with CVEs are older and typically have diabetes mellitus and lower sCr levels.

Characterization of White Matter Hyperintensities in Large-Scale MRI-Studies

Background: White matter hyperintensities of presumed vascular origin (WMH) are a common finding in elderly people and a growing social malady in the aging western societies. As a manifestation of cerebral small vessel disease, WMH are considered to be a vascular contributor to various sequelae such as cognitive decline, dementia, depression, stroke as well as gait and balance problems. While pathophysiology and therapeutical options remain unclear, large-scale studies have improved the understanding of WMH, particularly by quantitative assessment of WMH. In this review, we aimed to provide an overview of the characteristics, research subjects and segmentation techniques of these studies.

Methods: We performed a systematic review according to the PRISMA statement. One thousand one hundred and ninety-six potentially relevant articles were identified via PubMed search. Six further articles classified as relevant were added manually. After applying a catalog of exclusion criteria, remaining articles were read full-text and the following information was extracted into a standardized form: year of publication, sample size, mean age of subjects in the study, the cohort included, and segmentation details like the definition of WMH, the segmentation method, reference to methods papers as well as validation measurements.

Results: Our search resulted in the inclusion and full-text review of 137 articles. One hundred and thirty-four of them belonged to 37 prospective cohort studies. Median sample size was 1,030 with no increase over the covered years. Eighty studies investigated in the association of WMH and risk factors. Most of them focussed on arterial hypertension, diabetes mellitus type II and Apo E genotype and inflammatory markers. Sixty-three studies analyzed the association of WMH and secondary conditions like cognitive decline, mood disorder and brain atrophy. Studies applied various methods based on manual (3), semi-automated (57), and automated segmentation techniques (75). Only 18% of the articles referred to an explicit definition of WMH.

Discussion: The review yielded a large number of studies engaged in WMH research. A remarkable variety of segmentation techniques was applied, and only a minority referred to a clear definition of WMH. Most addressed topics were risk factors and secondary clinical conditions. In conclusion, WMH research is a vivid field with a need for further standardization regarding definitions and used methods.

Diagnostic performance of bone metabolic indexes for the detection of stroke

Objectives:

To explore the diagnostic performance of 25-hydroxyvitamin D (25(OH)D), parathyroid hormone (PTH), bone alkaline phosphatase (BALP), and osteocalcin (OC) in predicting stroke.

Methods:

This retrospective survey was conducted in The Second Affiliated Hospital to Nanchang University, Nanchang, Jiangxi Province, China. involved 121 cerebral infarction patients and 103 cerebral hemorrhage patients as the experimental groups, 100 volunteers as the healthy control group and 80 brain trauma patients as the disease control group. The 25(OH)D, PTH, BALP, and OC levels of all participants were measured by electrochemiluminescence immunoassay.

Results:

The serum concentration of 25(OH)D in stroke patients was appreciably lower than that of the control groups (p<0.05), and subsequently, the deficiency level of 25(OH)D in the stroke population was considerably higher than that of the control groups (p<0.05). The serum concentrations of PTH and OC in stroke patients exceeded those found in the control groups (p<0.05), and the abnormal level in the stroke patients was also higher than that of the control. Compared with the control group, BALP concentrations in cerebral infarction patients were increased significantly. Additionally, abnormal levels of BALP in stroke patients were found to be higher than those in the control groups. However, concentrations and abnormal levels of BALP in cerebral hemorrhage patients were not found to be significantly different than those found in cerebral infarction and the control groups, There were no substantial differences between the 2 control groups.

Conclusion:

Lack of 25(OH)D and excessive PTH, BALP, and OC could indicate a high risk of stroke.

Association of parathyroid hormone with 20-year cognitive decline: The ARIC study

OBJECTIVE

We hypothesized that elevated parathyroid hormone (PTH) levels will be independently associated with 20-year cognitive decline in a large population-based cohort.

METHODS

We studied 12,964 middle-aged white and black ARIC participants without a history of prior stroke who, in 1990-1992 (baseline), had serum PTH levels measured and cognitive function testing, with repeat cognitive testing performed at up to 2 follow-up visits. Cognitive testing included the Delayed Word Recall, the Digit Symbol Substitution, and the Word Fluency tests, which were summed as a global Z score. Using mixed-effects models, we compared the relative decline in individual and global cognitive scores between each of the top 3 quartiles of PTH levels to the reference bottom quartile. We adjusted for demographic variables, education, vascular risk factors, and levels of calcium, phosphate, and vitamin D. We imputed missing covariate and follow-up cognitive data to account for attrition.

RESULTS

The mean (SD) age of our cohort was 57 (6) years, 57% were women, and 24% were black. There was no cross-sectional association of elevated PTH with cognitive global Z score at baseline (p > 0.05). Over a median of 20.7 years, participants in each PTH quartile showed a decline in cognitive function. However, there was no significant difference in cognitive decline between each of the top 3 quartiles and the lowest reference quartile (p > 0.05). In a subset, there was also no association of higher mid-life PTH levels with late-life prevalent adjudicated dementia (p > 0.05).

CONCLUSIONS

Our work does not support an independent influence of PTH on cognitive decline in this population-based cohort study.