Year: 2016
Type: dissertation
Study design: Observational Study
Abstract: Early development of cardiovascular disease (CVD) is consistently reported in bipolar disorder (BD). The overall aim of my thesis was to examine potential biomarkers of BD and CVD, with proxies of atherosclerosis. First, method validation of non-invasive standard measures was done to examine if they were associated with traditional cardiovascular risk factors (CVRFs) in adolescents with BD, despite fluctuating disease state, medication(s) and comorbid conditions. Results revealed that carotid intima media thickness (cIMT) and flow-mediated dilation (FMD) are associated with CVRFs in a heterogeneous adolescent clinical sample, and that they may be used in further research in this population as a proxy for CVD. Next, I confirmed that oxidative stress (OS) markers were detectable in the periphery of adolescents with BD, and that OS was associated with CVD risk measures. This supports the hypothesis that there are underlying biological mechanisms that link BD and CVD pathology. Finally, to investigate the early progression of CVD in BD adolescents, we examined pro-inflammatory markers (PIMs), trophic factors and CVRFs, with non-invasive atherosclerosis proxies in psychiatrically healthy adolescents (HC) and adolescents with BD. This case-controlled study allowed us to test for: 1) between group differences at an early stage in disease course; 2) investigate whether potential biomarkers in adult BD are elevated in adolescent BD compared to HC and 3) these biomarkers are associated with atherosclerosis proxies. We found that adolescents with BD had elevated inflammation compared to HC adolescents. Interestingly, there were no between-group differences in non-invasive vascular measures, indicating that there is perhaps an opportunity for prevention. Lower levels of brain derived neurotrophic factor (BDNF) were associated with worse vascular structure (cIMT) in symptomatic BD adolescents. This suggests that there is possible interplay between biomarkers and vascular risk in BD. Moreover, while inflammation, neurotrophins and OS may play a role in BD symptomology and CVD progression, adolescents with BD do not yet show signs of early atherosclerosis, as determined by proxy ultrasound measures. These findings underscore the importance of behavioral and pharmacological interventions aimed at mitigating cardiovascular risk.
Source: TSpace (University of Toronto)
Author: Jessica Hatch
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: green
Award: G7740427224
OpenAlex ID: W2616303607