Association of psychosocial risk Association of psychosocial risk factors with risk of acute myocardial factors with risk of acute myocardial

infarction in 11,119 MI cases and infarction in 11,119 MI cases and 13,648 controls from 52 countries. 13,648 controls from 52 countries.

The INTERHEART study.The INTERHEART study.

Background and rationaleBackground and rationale

Psychosocial factors have been reported to be Psychosocial factors have been reported to be independently associated with CHDindependently associated with CHD

Previous studies have been in mainly North-Previous studies have been in mainly North-American or European, populationsAmerican or European, populations

The INTERHEART study is the first to The INTERHEART study is the first to investigate PS factors in relation to CHD investigate PS factors in relation to CHD across several regions and ethnic groupsacross several regions and ethnic groups

ObjectiveObjective

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

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

Direct pathophysiological

mechanisms*

Clinical CHD

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

Psychosocial: Potential pathways by whichPsychosocial: Potential pathways by which psychosocial factors influence CHD etiologypsychosocial factors influence CHD etiology

Protective factors(income, education, highlocus of control

*atherosclerosis, *atherosclerosis, plaque stability, plaque stability, coagulation / coagulation / fibrinolysis ??fibrinolysis ??

Depression

Psychosocial stressorsPsychosocial stressors

• Stress at workStress at work• Stress at homeStress at home

• Financial stressFinancial stress• Stressful life eventsStressful life events

• DepressionDepression• Locus of controlLocus of control

QuestionsQuestions• How often have you felt stress How often have you felt stress

in the past year?in the past year?– ……at home /…at workat home /…at work

• What level of financial stress What level of financial stress do you feel?do you feel?

• Have you experienced any of Have you experienced any of the following in the past year?the following in the past year? List of potentially stressful List of potentially stressful life events.life events.

Response optionsResponse options

Never/Some periods/Several Never/Some periods/Several Periods/PermanentPeriods/Permanent

Little-none/Moderate/High-Little-none/Moderate/High-severesevere

Yes/No (0, 1, 2+)Yes/No (0, 1, 2+)

Chronic stressChronic stress

QuestionsQuestions• During the past 12 months, During the past 12 months,

was there ever a time when was there ever a time when you felt sad, blue or you felt sad, blue or depressed for two weeks or depressed for two weeks or more in a row? + 0 to 7 more in a row? + 0 to 7 items*items*

• Locus of control: 6 scale items Locus of control: 6 scale items eg I feel what happens in my life eg I feel what happens in my life is often determined by factors is often determined by factors beyond my controlbeyond my control

Response optionsResponse options

Yes/NoYes/No

Strongly agree – strongly Strongly agree – strongly disagreedisagree

Depression & locus of Depression & locus of controlcontrol

* Lose interest, tired/low energy, weight loss/gain, sleep trouble, trouble concentrating, think of death, feeling worthless

Overall resultsOverall results

Reported stressduring the past year and risk of MI

0

0,5

1

1,5

2

2,5

Never Some pd Several pd Permanent

Odd

s R

atio

Home

Work

General

* Odds ratio adjusted for age, sex, region, and smoking

Reported depression during the past year and risk of AMI

1

1.56

0

0,4

0,8

1,2

1,6

No depression Depression

Od

ds

Rat

io

* Odds ratio adjusted for age, sex, region, and current smoking status

Reported depression items* during the past year and risk of AMI

1

1,651,441.56

0

0,4

0,8

1,2

1,6

Nodepression

+ 0-1 items 2-4 items 5+ items

Od

ds

Rat

io

* Odds ratio adjusted for age, sex, region, and current smoking status

* Lose interest, tired/low energy, weight loss/gain, sleep trouble, trouble concentrating, think of death, feeling worthless

Risk of AMI by Locus of Control (LOC) Quartile

0.680.70

0.86

0

0,2

0,4

0,6

0,8

1

1st (low) 2nd 3rd 4th (high)

LOC quartile

Od

ds

rati

o

Depression

Stress

Odds ratios for combined effects of stress and depression

Locusofcontrol Stress

Odds ratios for combined effects of stress and locus of control

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.

Data by region andData by region and

ethnicityethnicity

Region N % Contr. % Cases

Adj. OR (99% CI)

Overall 26358 20.0 27.3 1.54 (1.39, 1.71)

Western Europe 1383 29.7 39.5 1.71 (1.16, 2.52)

C/E Europe 3592 23.4 27.0 1.16 (0.89, 1.51)

Middle East 3317 23.3 29.6 1.11 (0.84, 1.46)

Africa 1327 21.9 29.4 1.67 (1.10, 2.53)

South Asia 3776 17.2 25.5 1.46 (1.13,1.88)

China /H.K. 6000 7.8 15.8 2.05 (1.59, 2.64)

S.E. Asia/Japan 2057 23.9 29.1 1.08 (0.78, 1.50)

Aust/N. Z. 1267 31.2 42.8 1.96 (1.30, 2.96)

South Am./Mex. 3018 24.4 40.0 2.26 (1.70, 3.00)

North America 621 35.3 44.0 1.99 (1.08, 3.69)

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

Ethnicity N% Contr.

% Cases

Adj. OR (99% CI)

Overall 26358 20.0 27.3 1.54 (1.39, 1.71)

European 6881 27.2 34.1 1.45 (1.21, 1.75)

Chinese 6185 8.0 16.0 2.03 (1.58, 2.59)

South Asian 4730 17.5 25.1 1.51 (1.20, 1.88)

Other Asian 2820 24.0 32.0 1.30 (0.97,1.73)

Arab 2195 23.5 27.1 0.87 (0.61,1.24)

Latin American 2877 24.5 39.6 2.22 (1.66, 2.97)

Black African 502 24.0 33.2 1.65 (0.79, 3.45)

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

Region N % Contr. % Cases

Adj. OR (99% CI)

Overall 25499 17.5 24.2 1.56 (1.43, 1.70)

Western Europe 1401 22.8 28.6 1.21 (0.87, 1.67)

C/E Europe 3592 15.7 17.3 1.05 (0.82, 1.33)

Middle East 2978 14.7 24.4 1.96 (1.52, 2.53)

Africa 1288 20.0 31.4 1.73 (1.23, 2.42)

South Asia 3404 18.9 31.0 1.69 (1.36, 2.10)

China /H.K. 6011 9.7 20.2 2.35 (1.92, 2.88)

S.E. Asia/Japan 2009 12.5 19.2 1.66 (1.19,2.30)

Aust/N. Z. 1270 21.9 25.3 1.17 (0.82, 1.67)

South Am./Mex. 2921 29.7 34.7 1.21 (0.98, 1.51)

North America 625 19.1 23.5 1.35 (0.79, 2.31)

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

Ethnicity N % Contr.% Cases

Adj. OR (95% CI)

Overall 24966 17.53 24.22 1.56 (1.43, 1.69)

European 6739 18.53 21.96 1.17 (1.00, 1.36)

Chinese 6143 9.61 20.07 2.40 (1.94, 2.98)

South Asian 4027 18.61 26.64 1.56 (1.30, 1.88)

Other Asian 2777 14.29 27.04 2.04 (1.56, 2.66)

Arab 2016 15.46 22.68 1.69 (1.35, 2.12)

Latin American 2667 29.41 34.61 1.24 (1.03, 1.51)

Black African 460 22.82 37.06 1.72 (1.14, 2.58)

Depression Overall and by Ethnicity

% of cases and % of controls are age adjusted. OR are adjusted for region, age, gender, and smoking

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.