This headline is very misleading. The study is basically saying that those with higher ab muscle
density will be less likely to have CVD while those with higher ab muscle
area will be at a greater risk to have CVD in men. Greater muscle area without having high muscle density would be due to intramuscular fat or fat behind the ab muscle (visceral fat), stretching the ab muscles outward or enlarging the area of the muscle.
From the study:
Unfavorable body composition is a known risk factor for cardiovascular disease (CVD) independent of health behaviors, with a large body of research showing associations between excess adiposity and CVD morbidity and mortality.
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2 Recent studies have highlighted the important role lean muscle may play in preventing morbidity, independent of adiposity. Across studies, muscle has been associated with lower risk of type 2 diabetes, cardiovascular disease, and all‐cause mortality.
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Different characteristics of lean muscle may be more relevant to this association. A growing body of evidence has shown that higher muscle density, a proxy measure of intramuscular fat infiltration and indicator of muscle quality,
8 may be more strongly associated with reduced morbidity and mortality than muscle mass or size, which, in some studies, has been associated with greater risk.
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10 Consistent with this, we recently showed that muscle density predicted markedly lower risk of all‐cause mortality in a diverse cohort, whereas those with greater muscle area had greater risk of all‐cause mortality over the 12‐year follow‐up period.
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