Prediction of Abdominal Aortic Aneurysm Growth Using Geometric Assessment of Computerized Tomography Images Acquired During the Aneurysm Surveillance Period.

OBJECTIVE: We investigated the utility of geometric features for future AAA growth prediction. BACKGROUND: Novel methods for growth prediction of AAA are recognized as a research priority. Geometric feature have been used to predict cerebral aneurysm rupture, but not examined as predictor of AAA growth. METHODS: Computerized tomography (CT) scans from patients with infra-renal AAAs were analyzed. Aortic volumes were segmented using an automated pipeline to extract AAA diameter (APD), undulation index (UI), and radius of curvature (RC). Using a prospectively recruited cohort, we first examined the relation between these geometric measurements to patients' demographic features (n = 102). A separate 192 AAA patients with serial CT scans during AAA surveillance were identified from an ongoing clinical database. Multinomial logistic and multiple linear regression models were trained and optimized to predict future AAA growth in these patients. RESULTS: There was no correlation between the geometric measurements and patients' demographic features. APD (Spearman r = 0.25, P < 0.05), UI (Spearman r = 0.38, P < 0.001) and RC (Spearman r =-0.53, P < 0.001) significantly correlated with annual AAA growth. Using APD, UI, and RC as 3 input variables, the area under receiver operating characteristics curve for predicting slow growth (<2.5 mm/yr) or fast growth (>5 mm/yr) at 12 months are 0.80 and 0.79, respectively. The prediction or growth rate is within 2 mm error in 87% of cases. CONCLUSIONS: Geometric features of an AAA can predict its future growth. This method can be applied to routine clinical CT scans acquired from patients during their AAA surveillance pathway.

Integrated Plasma and Tissue Proteomics Reveals Attractin Release by Intraluminal Thrombus of Abdominal Aortic Aneurysms and Improves Aneurysm Growth Prediction in Humans.

OBJECTIVE: Discovery of novel biomarkers for AAA growth prediction. BACKGROUND: Novel biomarker of AAA growth is a recognized priority in research. Our prior work implicated intraluminal thrombus (ILT) in AAAs to be a potential source of systemic mediators during AAA progression. Here we applied a mass spectrometry proteomics pipeline to discover novel biomarkers for AAA growth prediction. METHODS: Patients were prospectively recruited. Plasma samples were collected at baseline (n = 62). AAA growth was recorded at 12 months. In Experiment 1, plasma samples from the fastest and slowest growth patients (n = 10 each) were compared. In Experiment 2, plasma samples were collected before and at 10-12 weeks after surgery (n = 29). In Experiment 3, paired ILT and omental biopsies were collected intra-operatively during open surgical repair (n = 3). In Experiment 4, tissue secretome was obtained from ex-vivo culture of these paired tissue samples. Samples were subjected to a liquid chromatography tandem mass spectrometry workflow to discover novel biomarkers. RESULTS: We discovered 3 proteins that are: (i) present in ILT; (ii) released by ILT; (iii) reduced in circulation after AAA surgery; (iv) differs between fast and slow growth AAAs. One of these is Attractin. Plasma Attractin correlates significantly with future AAA growth (Spearman r = 0.35, P < 0.005). Using Attractin and AAA diameter as input variables, the area under receiver operating characteristics for predicting no growth and fast growth or AAA at 12 months is 85% and 76%, respectively. CONCLUSION: We show that ILT of AAAs releases mediators during the natural history of AAA growth. These are novel biomarkers for AAA growth prediction in humans.

The role of dipeptidyl peptidase-IV in abdominal aortic aneurysm pathogenesis: A systematic review.

Abdominal aortic aneurysm (AAA) is an important vascular disease carrying significant mortality implications due to the risk of aneurysm rupture. Current management relies exclusively on surgical repair as there is no effective medical therapy. A key element of AAA pathogenesis is the chronic inflammation mediated by inflammatory cells releasing proteases, including the enzyme dipeptidyl peptidase IV (DPP-IV). This review sought to recapitulate available evidence on the involvement of DPP-IV in AAA development. Further, we assessed the experimental use of currently available DPP-IV inhibitors for AAA management in murine models. Embase, Medline, PubMed, and Web of Science databases were utilised to access the relevant studies. The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). A narrative synthesis approach was used. Sixty-four studies were identified from the searched databases; a final 11 were included in the analysis. DPP-IV was reported to be significantly increased in both AAA tissue and plasma of patients and correlated with AAA growth. DPP-IV inhibitors (sitagliptin, vildagliptin, alogliptin, and teneligliptin) were all shown to attenuate AAA formation in murine models by reducing monocyte differentiation, the release of reactive oxygen species (ROS), and metalloproteinases (MMP-2 and MMP-9). DPP-IV seems to play a role in AAA pathogenesis by propagating the inflammatory microenvironment. This is supported by observations of decreased AAA formation and reduction in macrophage infiltration, ROS, matrix MMPs, and interleukins following the use of DPP-IV inhibitors in murine models. There is an existing translational gap from preclinical observations to clinical trials in this important and novel mechanism of AAA pathogenesis. This prior literature highlights the need for further research on molecular targets involved in AAA formation.

Illness perceptions, self-care practices, and glycemic control among type 2 diabetes patients in Chiang Mai, Thailand.

BACKGROUND: Diabetes Self-Management Education (DSME) is a fundamental aspect of diabetes care, but no standard program exists in Thailand. Understanding current patterns of illness perceptions (concerns) and self-management practices among patients with diabetes in Thailand is vital to develop culturally tailored DSME programs. This study sought to explore the association between reported self-management practices and diabetes perceptions on glycemic control among patients with type 2 diabetes in Chiang Mai Province, Thailand. Specifically, the study examined whether the association between illness perceptions and diabetes control was mediated by self-management. METHODS: This was a cross-sectional study conducted among type 2 diabetes patients on outpatient care and follow-up in four districts hospitals in Chiang Mai, Thailand. Illness perceptions was measured by the Brief Illness Perceptions Questionnaire (BIPQ). Self-management practices were measured by Summary Diabetes Self-Care activities (SDSCA). For illness perceptions and self-management practices, patients were classified into two groups, high level and low level based on the median values. Univariate and multivariable analyses were done to determine the association between the determinant factors: self-care practices and illness perceptions and the outcome of interest- good glycemic control (HbA1c < 7%). RESULTS: Of the 200 participants recruited into the study, 180 completed the questionnaire. Only 35% of participants had good glycemic control (HBA1c < 7.0). Both illness perceptions and self-management practices were independently linked to glycemic control. Among illness perceptions, a sense of personal control was strongly associated with good glycemic control (p = 0.01). For self-management, appropriate diet (p = 0.03) and medication adherence (p = 0.05) were associated with good glycemic control. After adjustments for key baseline characteristics, patients with high levels of illness perceptions were less likely to achieve glycemic control (OR 0.55, 95% CI 0.29 to 1.14, p = 0.11) and those with high level of self-management were more likely to achieve glycemic control (OR 2.11, 95% CI 1.04 to 4.30, p = 0.04). The effect size for illness perception attenuated when further adjusted for levels of self-management (OR 0.88, 95% CI 0.39 to 1.96, p = 0.75) while the effect size for self-management and glycemic control did not materially change (OR 2.30, 95% CI 1.06 to 5.02, p = 0.04). CONCLUSION: Illness perceptions and self-management practices are associated with glycemic control. Future culturally tailored interventions in Thailand aimed at improving glycemic should focus on personal control, improving diet and treatment adherence as these are more likely to help improve diabetes control as demonstrated in this study.

Clinical audit of adherence to hypertension treatment guideline and control rates in hospitals of different sizes in Thailand.

A clinical audit of hospitals in Thailand was conducted to assess compliance with the national hypertension treatment guidelines and determine hypertension control rates across facilities of different sizes. Stratified random sampling was used to select sixteen hospitals of different sizes from four provinces. These included community (<90 beds), large (90-120 beds), and provincial (>120 beds) hospitals. Among new cases, the audit determined whether (i) the recommended baseline laboratory assessment was completed, (ii) the initial choice of medication was appropriate based on the patient's cardiovascular risk, and (iii) patients received medication adjustments when indicated. The hypertension control rates at six months and at the last visit were recorded. Among the 1406 patients, about 75% had their baseline glucose and kidney function assessed. Nearly 30% (n = 425/1406) of patients were indicated for dual therapy but only 43% of them (n = 182/425) received this. During treatment, 28% (198/1406) required adjustments in medication but this was not done. The control of hypertension at six months after treatment initiation was 53% varying between 51% in community and 56% in large hospitals (p < .01). The hypertension control rate at last visit was 64% but varied between 59% in community hospitals and 71% in large hospitals (p < .01). Failure to adjust medication when required was associated with 30% decrease in the odds of hypertension control (OR 0.69, 95% CI 0. 50 to 0.90). Failure to comply with the treatment guidelines regarding adjustment of medication and lost to follow-up are possible target areas to improve hypertension control in Thailand.

Process evaluation protocol of a cluster randomised trial for a scalable solution for delivery of Diabetes Self-Management Education in Thailand (DSME-T).

INTRODUCTION: Type 2 diabetes mellitus is a major global challenge, including for Thai policy-makers, as an estimated 4 million people in Thailand (population 68 million) have this condition. Premature death and disability due to diabetes are primarily due to complications which can be prevented by good risk factor control. Diabetes Self-Management Education (DSME) programmes provide patients with diabetes with the necessary knowledge and skills to effectively manage their disease. Currently, a trial is being conducted in Thailand to evaluate the effectiveness, defined as HbA1c<7 at 12 months after enrolment, of a culturally tailored DSME in Thailand. A process evaluation can provide further interpretation of the results from complex interventions as well as insight into the success of applying the programme into a broader context. METHODS AND ANALYSIS: The aim of the process evaluation is to understand how and why the intervention was effective or ineffective and to identify contextually relevant strategies for future successful implementation. For the process evaluation, the design will be a mixed-method study collecting data from nurse providers, and village health volunteers (community health workers) as well as patients. This will be conducted using observations, interviews and focus groups from the three purposively selected groups at the beginning and end of trial. Quantitative data will be collected through surveys conducted at the beginning, during 6-month follow-up, and at the end of trial. The mixed-methods analysis will be triangulated to assess differences and similarities across the various data sources. The overall effectiveness of the intervention will be examined using multilevel analysis of repeated measures. ETHICS AND DISSEMINATION: Study approved by the Chiang Mai University Research Ethics Committee (326/2018) and the London School of Hygiene & Tropical Medicine (16113/RR/12850). Results will be published in open access, peer-reviewed scientific journals. TRIAL REGISTRATION NUMBER: NCT03938233.