Objectives To estimate the risk of fatal and non-fatal myocardial infarction (MI) and stroke in patients with bipolar I disorder compared to people without bipolar I disorder. Method Utilizing a records-linkage system spanning 30 years (1966-1996), a population-based cohort of 334 subjects with bipolar I disorder and 334 age and sex-matched referents from Olmsted County, Minnesota, U.S. was identified. Longitudinal follow-up continued until incident MI or stroke (confirmed by board-certified cardiologist/neurologist), death, or study end date (December 31, 2013). Cox proportional hazards models assessed the hazard ratio (HR) for MI or stroke, adjusting for potential confounders. Results There was an increased risk of fatal or non-fatal MI or stroke (as a composite outcome) in patients with bipolar I disorder [HR 1.54, 95% confidence interval (CI) 1.02, 2.33; p=0.04]. However, after adjusting for baseline cardiovascular risk factors (alcoholism, hypertension, diabetes, and smoking), the risk was no longer significantly increased (HR 1.19, 95% CI 0.76, 1.86; p=0.46). Limitations Small sample size for the study design. Findings were not retained after adjustment for cardiovascular disease risk factors. Psychotropic medication use during the follow-up was not ascertained and was not included in the analyses. Conclusion This study in a geographically defined region in the U.S. demonstrated a significant increased risk of MI or stroke in bipolar I disorder, which was no longer significant after adjustment for cardiovascular risk factors.
Bibliographical noteFunding Information:
This project was made possible by the Rochester Epidemiology Project (Grant number R01-AG034676 ; from the National Institute on Aging [NIA]). It was partially supported by Grant UL1-TR000135 from the National Center for Advancing Translational Sciences (NCATS). Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIH. It was partially supported by Mayo Foundation for Medical Education and Research , the Marriott Foundation and the Government of Chile (CONICYT Becas Chile Grant number 73130844) .
Dr. Frye has been a consultant (unpaid) for Allergan, Merck, Myriad, Sanofi-Aventis, Sunovion, Takeda Global Research, Teva Pharmaceuticals, United Biosource Corporation, has received grant support from Myriad, Pfizer, National Alliance for Schizophrenia and Depression (NARSAD), National Institute of Mental Health (NIMH), National Institute of Alcohol Abuse and Alcoholism (NIAAA), Mayo Foundation, and has received travel support from the Chilean Society of Neurology, Psychiatry and Neurosurgery (Sociedad de Neurologia, Psiquiatria y Neurocirugia), Advanced Health Media, GlaxoSmithKline, Colombian Society of Neuropsychopharmacology, AstraZeneca, Bristol-Myers-Squib, Otsuka, Sanofi-Aventis.
We thank Merle J. Belz, RN, Cynthia L. Nosek, RN, and Cynthia J. Stoppel, BS for their work abstracting the medical records, Jennifer St. Sauver, PhD for her advice on the Rochester Epidemiology Project, and Renato D. Alarcón, MD, MPH, Timothy W. Lineberry, MD, and Glenn E. Smith, PhD for their advice and support to this project.
© 2016 Published by Elsevier B.V.
- Bipolar disorder
- Cardiovascular diseases
- Cohort studies