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Study indicates nine risk factors explain most heart attacks

BMJ 2004; 329 doi: https://doi.org/10.1136/bmj.329.7465.527 (Published 02 September 2004) Cite this as: BMJ 2004;329:527

Rapid Response:

Missing figures from the INTERHEART study

For many years we have been told that too much
saturated fat, and too little polyunsaturated fat, are primary causes of heart
disease, butthe authors of the
INTERHEART study are silent on this point.1 Is it because they, like
the authors of numerous case-control and cohort studies2 did not find
any correlation
between saturated or polyunsaturated fat intake and CHD?
More
critically, the authors are also silent on LDL cholesterol
, claimed to be the strongest independent
risk factor for coronary heart disease.

The authors´ conclusion that abnormal lipidsare a powerful risk factor for myocardial infarction in both sexes and at
all ages in all regions is not in accordance neither with the data they have
presented themselves or with previous findings.2 3 If odds ratios for
high ApoB/ApoA1 (the only lipid parameter given) in the ten regions are plotted
against the median age in each region (figure), a prolongation of the regression
line suggests that this ratio may not be a risk factor after age 65-70, in
accordance with the findings of at least twelve previous studies of old people.3
This is not a minor aberration from the cholesterol hypothesis. In 1996 for
instance, 23060 individuals died from coronary heart disease in Sweden,21087 of whom were 65 years or older.4 Thus, for more than 90
% ofthose who died from coronary
heart disease the ApoB/ApoA1 ratio, LDL or total cholesterol may not have been
risk factors.

INTERHEART has confirmed the importance of risk
factors such as
smoking,
hypertension, diabetes, abdominal obesity and psychosocial factors,
but is also a strong challenge to the
very foundation of the cholesterol campaign.

Figure.
Risk of acute myocardial infarction (odds ratio) associated with the ApoB/ApoA1
ratio (top vs lowest quintile) after adjustment for age, sex and smoking, by age
in the ten regions. The figure is constructed using published data from theINTERHEART study.1

1. Yusuf S, Hawken S, Ôunpuu S et al.
Effect of potentially modifiable risk factors associated with myocardial
infarction in 52 countries (the INTERHEART study): case-control study. Lancet
2004; 364: 937-52.

2. Ravnskov U. A hypothesis out-of-date: The diet-heart idea.
J Clin Epidemiol
2002; 55: 1057-63.

3.
Ravnskov U. High cholesterol may protect
against infections and atherosclerosis. QJM 2003; 96: 927-34.

4. Statistics, Sweden.
http://www.scb.se/default____2154.asp

Competing interests:
None declared

Competing interests: No competing interests

20 October 2004
Uffe Ravnskov
Independent researcher
Malcolm Kendrick
Magle Stora Kyrkogata 9, S-22350 Lund, Sweden