Background: Guidelines for treating overweight and obesity have been suggested by the World Health Organization and other expert groups. We asked whether most men and women targeted in obesity guidelines would already be included in existing clinical recommendations for the prevention of coronary heart disease (CHD) or whether a new group of patients would be added to current workloads.
Subjects and methods: In 1997 the Norwegian National Health Screening Service examined CHD risk factors in subjects aged 40-42 y living in three counties. We studied 6911 men and 7992 women who did not report treatment for diabetes, hypertension or the presence of cardiovascular disease. Estimated 10 y risk of CHD was calculated using the Framingham equation.
Results: The prevalence of single risk factors (systolic blood pressure > or =160 mmHg, diastolic blood pressure > or =95 mmHg, total cholesterol level > or =7.8 mmol/l and nonfasting glucose > or =11.1 mmol/l) ranged between 0 and 11% among subjects with body mass index > or =25 kg/m2. Adding low HDL cholesterol (<1.0 mmol/l for men, <1.1 mmol/l for women) and 10 y risk CHD risk to the classical risk factors increased prevalence to 16-50% (one or more risk factors or 10 y risk > or =10%). Sensitivities and specificities of using body mass index (BMI) or BMI and waist circumference as a screen for elevated CHD risk ranged between 22 and 91%. Screening for 10 y CHD risk of > or =10% or one or more risk factors among men and screening for one or more risk factors among women gave positive predictive values of 19-50%; however, the positive predictive value of screening for 10 y CHD risk of > or =10% was only 1-2% among women. Compared with men with BMI<30 kg/m2 or waist circumference <102 cm, those with measurements equal to or above these levels had statistically significantly higher adjusted odds ratios of elevated CHD risk (1.49, 95% CI 1.24-1.79 and 1.48, 95% CI 1.22-1.80, respectively); these associations were not observed among women.
Conclusion: Using BMI and waist circumference to screen for CHD risk yields low positive prediction values, thus doubling the number of men and adding even more to the number of women seen by the practitioner for prevention of CHD.