Do obesity and parental history of myocardial infarction improve cardiovascular risk prediction?

Conicity Index and Waist-to-Hip Ratio Are Superior Obesity Indices in Predicting 10-Year Cardiovascular Risk Among Men and Women

BACKGROUND

Central obesity has been recognized as a main risk factor for cardiovascular (CV) events. Three popular central obesity indices are waist circumference, waist-to-hip ratio (WHR), and waist-to-height ratio; abdominal volume index and conicity index are 2 recent novel obesity indices. The main aim of this study is to determine the performance of these indices to best predict 10-year CV events.

HYPOTHESIS

Some obesity indices can be used to predict cardiovascular risk.

METHODS

In total, 3199 subjects (age range, 40-79 years) were enrolled in this cross-sectional study. The American College of Cardiology/American Heart Association and Framingham risk score tools were used to estimate the 10-year CV events. Receiver operating characteristic curve analysis was used to determine the optimal discriminator(s) among the central obesity measures in the estimation of a 10-year risk of CV events ≥7.5%, ≥10%, and ≥20% separately.

RESULTS

Among the 5 central obesity indices, conicity index showed the most discriminatory power in estimation of a 10-year CV risk. In men, based on the American College of Cardiology/American Heart Association tool, the areas under the curve (AUCs) were from 0.671 to 0.682 based on the 3 above thresholds, whereas with the Framingham tool, AUCs were from 0.651 to 0.659. In women, all AUCs were >0.7. Our results also showed WHR to be an almost comparable discriminator of CV disease risk in the Iranian study population.

CONCLUSION

Conicity index and WHR had a more discriminatory accuracy for 10-year CV events compared with the other obesity indices.

New risk markers for cardiovascular prevention

The importance of total cardiovascular (CV) risk estimation before management decisions are taken is well established. Models have been developed that allow physicians to stratify the asymptomatic population in subgroups at low, moderate, high, and very high total CV risk. Most models are based on classical CV risk factors: age, gender, smoking, blood pressure, and lipid levels. The impact of additional risk factors is discussed here, looking separately at the predictive increments of novel biomarkers and of indicators of subclinical atherosclerotic disease. The contribution of biomarkers to the total CV risk estimation is generally modest, and their usage should be limited to subjects at intermediate total CV risk. Detection of subclinical vascular damage may improve total CV risk estimation in asymptomatic subjects who are close to a threshold that could affect management decisions and in whom the chances of re-classification in a different risk category are great. There is, however, an urgent need for trials in which the value of using total CV risk estimation models is tested.

Prevalence of obesity and associated cardiovascular risk: the DARIOS study

Background

To estimate the prevalence of overweight and obesity in the Spanish population as measured with body mass index (BMI), waist circumference (WC) and waist to height ratio (WHtR) and to determine the associated cardiovascular risk factors.

Methods

Pooled analysis with individual data from 11 studies conducted in the first decade of the 21st century. Participants aged 35–74 years were asked about the history of cardiovascular diseases, hypertension, diabetes and hypercholesterolemia. Height, weight, WC, blood pressure, glycaemia, total cholesterol, low-density and high-density lipoprotein cholesterol and coronary risk were measured. The prevalence of overweight (BMI 25–29.9 kg/m²), general obesity (BMI ≥30 kg/m²), suboptimal WC (≥ 80 cm and < 88 in women, ≥ 94 and < 102 in men), abdominal obesity (WC ≥88 cm ≥102 cm in women and men, respectively) and WHtR ≥0.5 was estimated, standardized for the European population.

Results

We included 28,743 individuals. The prevalence of overweight and suboptimal WC was 51% and 30% in men and 36% and 22% in women, respectively; general obesity was 28% in both sexes and abdominal obesity 36% in men and 55% in women. The prevalence of WHtR ≥0.5 was 89% and 77% in men and women, respectively. All cardiovascular risk factors were significantly associated with abnormal increased values of BMI, WC and WHtR. Hypertension showed the strongest association with overweight [OR = 1.99 (95% confidence interval 1.81-2.21) and OR = 2.10 (1.91-2.31)]; suboptimal WC [OR = 1.78 (1.60-1.97) and OR = 1.45 (1.26-1.66)], with general obesity [OR = 4.50 (4.02-5.04), and OR = 5.20 (4.70-5.75)] and with WHtR ≥0.5 [OR = 2.94 (2.52-3.43), and OR = 3.02 (2.66-3.42)] in men and women respectively, besides abdominal obesity in men only [OR = 3.51 (3.18-3.88)]. Diabetes showed the strongest association with abdominal obesity in women [OR = 3,86 (3,09-4,89).

Conclusions

The prevalence of obesity in Spain was high. Overweight, suboptimal WC, general, abdominal obesity and WHtR ≥0.5 was significantly associated with diabetes, hypertension, hypercholesterolemia and coronary risk. The use of lower cut-off points for both BMI and particularly WC and could help to better identify the population at risk and therefore achieve more effective preventive measures.