Obesity is a modifiable risk factor for acute myocardial infarction (MI), but lean body mass (LBM) may also be an important factor. Low LBM may increase the risk of MI and LBM may modify the effect of obesity on MI. Thus, the inability of the classical anthropometric measures to evaluate LBM may lead to misclassification of MI risk in both lean and obese persons.
We investigated the associations between incident MI and measures of body composition derived by bioelectrical impedance analyses (BIA) in combination with classical anthropometric measures.
Methods and Results
From 1993 to 1997, 27 148 men and 29 863 women, aged 50 to 64 year, were recruited into the Danish prospective study Diet, Cancer and Health. During 11.9 years of follow-up we identified 2 028 cases of incident MI (1 487 men and 541 women). BIA and anthropometric measurements were performed at baseline. We used Cox proportional hazard models with age as time axis and performed extensive control for confounding.
Weight, body mass index, classical estimates of abdominal obesity and BIA of general obesity showed significant positive associations with incident MI. Both high and low LBM was associated with a higher risk of incident MI. LBM substantially modified the effect of obesity on the risk incident MI in women.
Obesity was positively associated with MI. Estimates of obesity achieved by BIA seemed, regarding MI risk, not to ad additional information to classical anthropometric measures. Both high and low LBM may be positively associated with MI.