Being fit is more important than being fat for women and heart disease
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《英国医生杂志》
For women, being fat poses a lesser risk of heart disease than being unfit, says a recent study (JAMA 2004;292:1179-87). Many previous studies have shown that being overweight increases the risk of cardiovascular disease, but few studies have examined the specific effect of physical activity and fitness. This recent study found that although the individual contributions of obesity and physical fitness to risk of coronary artery disease in women remain unclear, being inactive is a more useful predictor than body mass index of existing coronary disease and future adverse events such as congestive heart failure, unstable angina, and heart attack.
Researchers used coronary heart disease risk factors, coronary angiograph findings, and adverse cardiovascular events for 906 women having coronary artery angiography to evaluate suspected ischaemia. Among these women, 76% were overweight (body mass index 25 or more), 70% had low functional exercise capacity (Duke activity status index scores less than 25), and 39% had obstructive coronary artery disease.
During follow up, 337 women (37%) had a first adverse event, 118 (13%) had a major adverse event, and 68 (8%) died. Overweight women were more likely than normal weight women to have coronary artery disease risk factors, but neither body mass index nor abdominal obesity measures were significantly associated with obstructive coronary artery disease or adverse cardiovascular events after adjusting for other risk factors (P values from 0.05 to 0.88).
Conversely, women with lower Duke activity status index scores were significantly more likely to have coronary artery disease risk factors and obstructive coronary artery disease (46% v 26%; P<0.001) at baseline, and each metabolic equivalent increase in activity score was independently associated with an 8% decrease in the risk of major adverse cardiovascular events during follow up (hazard ratio 0.92; 95% confidence interval 0.85 to 0.99; P=0.02).
Senior author of the study, Dr C Noel Bairey Merz, cardiologist and director of Cedars-Sinai Medical Centre抯 preventive and rehabilitative cardiac centre and director of the women抯 health programme, concluded, "Despite the fact that excess body weight is associated with numerous risk factors, including hypertension, diabetes and metabolic syndrome, we found the body mass index to be a poor predictor of both baseline angiographic coronary artery disease as well as prospective risk of adverse events. Our findings suggest that self reported level of physical activity and functional capacity are more important than weight status or body type for determining cardiovascular risk in women."
A second study (JAMA 2004;292:1188-94) found that higher body mass index had a stronger association with development of diabetes than did physical inactivity, although both factors were significant predictors of incident diabetes.
Compared with normal weight individuals (body mass index less than 25), overweight individuals (body mass index 25 to less than 30) had 3.2 times the risk for diabetes, and obese individuals (body mass index 30 or higher), had 9.1 times the risk.
An accompanying editorial (JAMA 2004;292:1232-3) says that, "physicians, researchers, and policymakers should spend less energy debating the relative health importance of fitness and obesity and more time focusing on how to get sedentary individuals to become active."(Quebec David Spurgeon)
Researchers used coronary heart disease risk factors, coronary angiograph findings, and adverse cardiovascular events for 906 women having coronary artery angiography to evaluate suspected ischaemia. Among these women, 76% were overweight (body mass index 25 or more), 70% had low functional exercise capacity (Duke activity status index scores less than 25), and 39% had obstructive coronary artery disease.
During follow up, 337 women (37%) had a first adverse event, 118 (13%) had a major adverse event, and 68 (8%) died. Overweight women were more likely than normal weight women to have coronary artery disease risk factors, but neither body mass index nor abdominal obesity measures were significantly associated with obstructive coronary artery disease or adverse cardiovascular events after adjusting for other risk factors (P values from 0.05 to 0.88).
Conversely, women with lower Duke activity status index scores were significantly more likely to have coronary artery disease risk factors and obstructive coronary artery disease (46% v 26%; P<0.001) at baseline, and each metabolic equivalent increase in activity score was independently associated with an 8% decrease in the risk of major adverse cardiovascular events during follow up (hazard ratio 0.92; 95% confidence interval 0.85 to 0.99; P=0.02).
Senior author of the study, Dr C Noel Bairey Merz, cardiologist and director of Cedars-Sinai Medical Centre抯 preventive and rehabilitative cardiac centre and director of the women抯 health programme, concluded, "Despite the fact that excess body weight is associated with numerous risk factors, including hypertension, diabetes and metabolic syndrome, we found the body mass index to be a poor predictor of both baseline angiographic coronary artery disease as well as prospective risk of adverse events. Our findings suggest that self reported level of physical activity and functional capacity are more important than weight status or body type for determining cardiovascular risk in women."
A second study (JAMA 2004;292:1188-94) found that higher body mass index had a stronger association with development of diabetes than did physical inactivity, although both factors were significant predictors of incident diabetes.
Compared with normal weight individuals (body mass index less than 25), overweight individuals (body mass index 25 to less than 30) had 3.2 times the risk for diabetes, and obese individuals (body mass index 30 or higher), had 9.1 times the risk.
An accompanying editorial (JAMA 2004;292:1232-3) says that, "physicians, researchers, and policymakers should spend less energy debating the relative health importance of fitness and obesity and more time focusing on how to get sedentary individuals to become active."(Quebec David Spurgeon)