News:Anxious individuals are at risk for heart attacks

January 20, 2008 By Benjamin A. Olenchock, M.D. Ph.D. [mailto:bolenchock@partners.org]

Data were prospectively collected from 735 initially healthy men in the Boston area since 1986. Anxiety measures were collected by participants’ completion of the Minnesota Multiphasic Personality Inventory (MMPI). Measures of anxiety included psychasthenia (excessive doubts, ruminations or irrational compulsions), social introversion, phobia, manifest anxiety, and an overall anxiety factor, which was computed from the previous measures in a weighted fashion. Relative risks were reported per standard deviation increase in anxiety index score. Cases of MI were collected after review of hospital records by a cardiologist.

Participants were almost entirely white, mean age of 60 years old (range 42 to 87), married (76%) and educated (68% had more than a high school education). They were overall healthy, with mean systolic blood pressure 129 mm Hg and LDL of 157 mg/dl. Mean follow up was 12.4 years, and through 2004 there were 75 events of MI.

In unadjusted analyses, every anxiety index was associated with MI, with RR of around 1.3. Multivariable models adjusted for age, level of education, marital status, fasting glucose, body mass index, HDL level, and systolic blood pressure. After adjustment, there remained a statistically significant association between pyschasthenia (RR 1.37, CI 1.12 to 1.68), social introversion (RR 1.31, CI 1.05 to 1.63), phobia (RR 1.36, CI 1.10 to 1.68), manifest anxiety (RR 1.42, CI 1.16 to 1.73) and overall anxiety (RR 1.43, CI 1.17 to 1.75) and risk of future MI. In a subset (n=638 men), further analyses adjusted for smoking status, calorie intake and alcohol consumption, and the association between anxiety indices and risk of MI remained. The investigators further controlled for various psychological characteristics that might confound the relationship between anxiety and MI, including depression, Type A personality, anger, negative emotion, and hostility). Interestingly, none of these psychological variables was predictive of future MI, and overall anxiety remained significantly associated with future MI risk after adjustment for these psychologic variables (RR 1.85, CI 1.15 to 2.96).  Dividing the participants into quartiles revealed a dose-responsive relationship between overall anxiety index and risk of future MI, with 29 of the 75 MIs occurring in those participants in the highest anxiety quartile.

A number of mechanisms might explain the observed association, including greater stress response or disruption of the hypothalamic-pituitary-adrenal axis in anxious individuals. Future work might delve deeper into the association and determine whether areas for intervention such as improved social support or behavioral and medical treatment of anxiety might lessen the cardiovascular risk.