Association of psychosocial risk factors with risk of acute myocardial infarction in 11,119 MI cases

1
Association of psychosocial risk factors with
risk of acute myocardial infarction in 11,119 MI
cases and 13,648 controls from 52 countries. The
INTERHEART study.
2
Background and rationale

• Psychosocial factors have been reported to be
  independently associated with CHD
• Previous studies have been in mainly
  North-American or European, populations
• The INTERHEART study is the first to investigate
  PS factors in relation to CHD across several
  regions and ethnic groups

3
Objective

• To examine the relation of psychosocial factors
  to the risk of non-fatal MI in 24,767 subjects
  from 52 countries representing every inhabited
  continent of the world.

4
Psychosocial Potential pathways by which
psychosocial factors influence CHD etiology

• Health-related behaviors
• Smoking
• Diet
• Alcohol
• Physical activity

• Psychosocial
• stress factors
• External
• stressors (life
• events, financial
• troubles)
• Chronic
• stressors

Depression
Clinical CHD
Protective factors (income, education, high locus
of control
Direct pathophysiological mechanisms
atherosclerosis, plaque stability, coagulation /
fibrinolysis ??
5
Psychosocial stressors

• Stress at work
• Stress at home
• Financial stress
• Stressful life events
• Depression
• Locus of control

6
Chronic stress

• Response options
• Never/Some periods/Several Periods/Permanent
• Little-none/Moderate/High-severe
• Yes/No (0, 1, 2)

• Questions
• How often have you felt stress in the past year?
• at home /at work
• What level of financial stress do you feel?
• Have you experienced any of the following in the
  past year?? List of potentially stressful life
  events.

7
Depression locus of control

• Questions
• During the past 12 months, was there ever a time
  when you felt sad, blue or depressed for two
  weeks or more in a row? 0 to 7 items
• Locus of control 6 scale items eg I feel what
  happens in my life is often determined by factors
  beyond my control

• Response options
• Yes/No
• Strongly agree strongly disagree

Lose interest, tired/low energy, weight
loss/gain, sleep trouble, trouble concentrating,
think of death, feeling worthless
8
Overall results
9
Reported stress during the past year and risk of
MI
Odds ratio adjusted for age, sex, region, and
smoking
10
Reported depression during the past year and
risk of AMI
Odds ratio adjusted for age, sex, region, and
current smoking status
11
Reported depression items during the past year
and risk of AMI
Lose interest, tired/low energy, weight
loss/gain, sleep trouble, trouble concentrating,
think of death, feeling worthless
Odds ratio adjusted for age, sex, region, and
current smoking status
12
Risk of AMI by Locus of Control (LOC) Quartile
13
Odds ratios for combined effects of stress and
depression
Depression
Stress
14
Odds ratios for combined effects of stress and
locus of control
Locus of control
Stress
15
Population attributable risk for stress and all
psykosocial variables
Utilizing several periods of, or permanent work
stress and stress at home, financial stress, life
events, LoC, and depression in combination, 32.5
of the population attributable risk for MI is
explained.
16
Data by region and ethnicity
17
Association of Moderate/Severe General Stress to
Risk of MI Overall and by Region
of cases and of controls are age adjusted.
OR are adjusted for region, age, gender, and
smoking
18
Association of Moderate/Severe Gleneral Stress to
Risk of MI Overall and by Ethnicity
of cases and of controls are age adjusted.
OR are adjusted for region, age, gender, and
smoking
19
Association of Depression to Risk of MI Overall
and by Region
of cases and of controls are age adjusted.
OR are adjusted for region, age, gender, and
smoking
20
Depression Overall and by Ethnicity
of cases and of controls are age adjusted.
OR are adjusted for region, age, gender, and
smoking
21
Summary

• The findings of this study, representing patients
  and controls from all inhabited regions in the
  world, support the hypothesis that the presence
  of psychosocial stressors are associated with
  increased risk of acute myocardial infarction.
• Utilizing all measures of psychosocial factors,
  32.5 of the population attributable risk for MI
  is explained, provided that causality can be
  established.