Publication Date

2009-08-10

Availability

Open access

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PHD)

Department

Psychology (Arts and Sciences)

Date of Defense

2009-07-23

First Committee Member

Neil Schneiderman - Committee Chair

Second Committee Member

Maria Llabre - Committee Member

Third Committee Member

Matthias Siemer - Committee Member

Fourth Committee Member

Marc Gellman - Committee Member

Fifth Committee Member

Ronald Goldberg - Outside Committee Member

Abstract

BACKGROUND: Risk factors associated with Metabolic Syndrome (MetS) have been implicated in cardiovascular disease (CVD) development and outcomes. Few studies have investigated relationships between psychological variables, MetS factors, and indices of cardiac structure and function (CSF) among healthy individuals in a single conceptual model. No studies to date have analyzed such relationships in patients with CVD. METHODS: The present study examined associations between cynical hostility (CynHo), MetS factors, and CSF in 186 multi-ethnic post-myocardial infarction (MI) patients. Structural equation modeling was used to test a theory driven model of MetS that had good statistical fit. Primary MetS variables included waist circumference (WC), the homeostatic model of insulin resistance (HOMA-IR), glucose area under the curve (G-AUC), triglycerides (TRIG), high-density lipoprotein cholesterol (HDL-C), and diastolic blood pressures (DBP). Secondary MetS variables included plasminogen activator inhibitor-1 (PAI-1) and a latent inflammation variable comprised of CRP and IL-6. Cardiac function variables were fractional shortening (FS), E/A ratio, and rate-pressure product (RPP). A latent cardiac mass (CM) variable was also created. RESULTS: The final structural model had good model fit (Chi-Square(102)=100.65, p=0.52, CFI=1.00, RMSEA=0.00, and SRMR=0.04). Direct paths were supported between WC and CM and all MetS factors except TRIG and G-AUC. WC was indirectly associated with DBP via CM. The model supported positive direct paths between HOMA-IR and G-AUC, TRIG, and PAI-1, but not inflammation or HDL-C. HOMA-IR demonstrated a direct positive association with RPP and direct inverse associations with FS and E/A ratio. No direct paths were supported between other MetS variables except one between TRIG and HDL-C. CynHo demonstrated a direct positive relationship with HOMA-IR. CONCLUSIONS: Similar to findings in healthy individuals, central adiposity and IR play primary roles in CSF impairment in post-MI patients. Findings suggest that CynHo could promote the progression of metabolic dysfunction and cardiac disease via factors that influence the efficiency of glucose metabolism. Interventions for post-MI patients should take into account both direct and indirect effects of CynHo, central adiposity, and IR on the progression of CVD in this population to reduce adverse outcomes and improve quality of life.

Keywords

Hyperinsulinemia; Hyperglycemia; Glucose; Central Adiposity; Metabolic Syndrome; Obesity; Dyslipidemia; Diabetes; Coronary Heart Disease; Insulin Resistance

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