N-Terminal Pro Brain, N-Terminal Pro Atrial Natriuretic Peptides, and Dynamic Cerebral Autoregulation

Blood-Based Biomarkers in Alzheimer's Disease: Advancing Non-Invasive Diagnostics and Prognostics

Alzheimer's disease (AD), the most prevalent form of dementia, is expected to rise dramatically in incidence due to the global population aging. Traditional diagnostic approaches, such as cerebrospinal fluid analysis and positron emission tomography, are expensive and invasive, limiting their routine clinical use. Recent advances in blood-based biomarkers, including amyloid-beta, phosphorylated tau, and neurofilament light, offer promising non-invasive alternatives for early AD detection and disease monitoring. This review synthesizes current research on these blood-based biomarkers, highlighting their potential to track AD pathology and enhance diagnostic accuracy. Furthermore, this review uniquely integrates recent findings on protein-protein interaction networks and microRNA pathways, exploring novel combinations of proteomic, genomic, and epigenomic biomarkers that provide new insights into AD's molecular mechanisms. Additionally, we discuss the integration of these biomarkers with advanced neuroimaging techniques, emphasizing their potential to revolutionize AD diagnostics. Although large-scale validation is still needed, these biomarkers represent a critical advancement toward more accessible, cost-effective, and early diagnostic tools for AD.

NT-proBNP, cerebral small vessel disease and cardiac function in patients with a recent lacunar infarct

NT-proBNP is produced from both atria and ventricles and it is increased in patients with cardiac disease. NT-proBNP is also associated with cerebral small vessel disease(cSVD) but there are no studies that had carried out a systematic evaluation of cardiac function in this specific setting. We conducted a prospective observational study in 100 patients within 30 days after a recent lacunar infarct by means of brain MRI, 24 h ambulatory blood pressure monitoring, transthoracic echocardiography, and plasmatic NT-proBNP. Global cSVD burden was quantified using a validated visual score (0 to 4) and dichotomized into 2 groups (0-2 or 3-4). Age (73.8 vs 63.5 years) and NT-proBNP (156 vs 76 pg/ml) were increased in patients with SVD 3-4, while daytime augmentation index normalized for the heart rate of 75 bpm (AIx75) (22.5 vs 25.6%) was decreased. The proportion of patients with left atrial enlargement, left ventricular hypertrophy, or septal e' velocity <7 cm/s was not different between both groups. NT-proBNP was increased in patients with left atrial enlargement (126 vs 88 pg/ml). In multivariate analysis, age (OR 1.129 CI 95% 1.054-1.209), daytime AIx75 (OR 0.91 CI 95% 0.84-0.987,) and NT-proBNP (OR 1.007 CI 95% 1.001-1.012,) were independently associated with cSVD score 3-4. In conclusion, as well as in other patients with cSVD we found an association between NT-proBNP and cSVD. This association was independent of cardiac function.

N-Terminal Pro Brain, N-Terminal Pro Atrial Natriuretic Peptides, and Dynamic Cerebral Autoregulation

Background

Elevated natriuretic peptides (NP) are associated with adverse cerebrovascular conditions including stroke, cerebral small vessel disease, and dementia. However, the mechanisms underlying these associations remain unclear. In this study, we examined the relationship of NT‐proBNP (N‐terminal pro brain NP) and NT‐proANP (N‐terminal pro atrial NP) with cerebrovascular function, measured by cerebral autoregulation.

Methods and Results

We included 154 participants (mean age 56±4 years old) from the CARDIA (Coronary Artery Risk Development in Young Adults) cohort. NT‐proBNP and NT‐proANP were measured in blood samples from the year 25 examination using electrochemiluminescence Immunoassay and enzyme‐linked immunoassay, respectively. Dynamic cerebral autoregulation (dCA) was assessed at the year 30 examination by transcranial Doppler ultrasound, using transfer function analysis (phase and gain) of spontaneous blood pressure and flow velocity oscillations, where lower phase and higher gain reflect less efficient cerebral autoregulation. We used multivariable linear regression models adjusted for demographics, vascular risk factors, and history of kidney and cardiac diseases. Higher NT‐proBNP levels at year 25 were associated with lower phase (β [95% CI]=−5.30 lower degrees of phase [−10.05 to −0.54]) and higher gain (β [95% CI]=0.06 higher cm/s per mm Hg of gain [0.004–0.12]) at year 30. Similarly, higher NT‐proANP levels were associated with lower phase (β [95% CI]=−9.08 lower degrees of phase [−16.46 to −1.70]).

Conclusions

Higher circulating levels of NT‐proBNP and NT‐proANP are associated with less efficient dCA 5 years later. These findings link circulating NP to cerebral autoregulation and may be one mechanism tying NP to adverse cerebrovascular outcomes.