Body-mass index, abdominal adiposity, and cardiovascular risk
2011; Elsevier BV; Volume: 378; Issue: 9787 Linguagem: Inglês
10.1016/s0140-6736(11)61120-3
ISSN1474-547X
Autores Tópico(s)Cardiovascular Disease and Adiposity
ResumoThe conclusion of the Emerging Risk Factors Collaboration (March 26, p 1085),1Emerging Risk Factors CollaborationSeparate and combined associations of body-mass index and abdominal adiposity with cardiovascular disease: collaborative analysis of 58 prospective studies.Lancet. 2011; 377: 1085-1095Summary Full Text Full Text PDF PubMed Scopus (746) Google Scholar that measures of abdominal obesity do not add to the association of body-mass index (BMI) with cardiovascular disease, is not supported by the data in the paper or those from several independent studies.First, after adjustment for systolic blood pressure, diabetes, and total and HDL cholesterol, the waist-to-hip ratio had a hazard ratio that was significantly greater (1·12, 95% CI 1·08–1·15) than that of BMI (1·07, 1·03–1·11; p for heterogeneity=0·028; assuming the two regression coefficients are correlated at ≥0·4, which is the lower confidence limit of the univariate correlation).Second, regression dilution bias will affect the hazard ratio of waist-to-hip ratio to a greater degree than for BMI. The regression dilution ratio is 0·95 for BMI, indicating that the adjusted hazard ratio will be very close to the unadjusted value of 1·07, whereas with a regression dilution ratio for waist-to-hip ratio of 0·63, its relation with cardiovascular events will be about 50% steeper on a logarithmic scale, after adjusting for this bias.Third, in data provided in figure 1 of the Collaboration's paper, the hazard ratio associated with waist-to-hip ratio is stronger than that with BMI for coronary heart disease and ischaemic stroke, after adjustment for intermediate risk factors.Fourth, data provided in figure 3 indicate that waist-to-hip ratio and waist circumference are associated with higher risk of cardiovascular disease within the lowest, middle, or upper third of BMI.Fifth, large case-control studies2Yusuf S Hawken S Ounpuu S et al.INTERHEART Study Investigators. Obesity and the risk of myocardial infarction in 27 000 participants from 52 countries: a case-control study.Lancet. 2005; 366: 1640-1649Summary Full Text Full Text PDF PubMed Scopus (2173) Google Scholar, 3O'Donnell MJ Xavier D Liu L et al.for the INTERSTROKE investigatorsRisk factors for ischaemic and intracerebral haemorrhagic stroke in 22 countries (the INTERSTROKE study): a case-control study.Lancet. 2010; 376: 112-123Summary Full Text Full Text PDF PubMed Scopus (2095) Google Scholar and large cohort studies4Pischon T Boeing H Hoffman K et al.General and abdominal adiposity and risk of death in Europe.N Engl J Med. 2008; 359: 2105-2120Crossref PubMed Scopus (1504) Google Scholar have shown a clear incremental association with abdominal obesity over BMI for non-fatal myocardial infarction, non-fatal ischaemic strokes, and for total mortality or death from circulatory causes. The data presented by the Emerging Risk Factors Collaboration are directionally consistent with these findings.Finally, both INTERHEART2Yusuf S Hawken S Ounpuu S et al.INTERHEART Study Investigators. Obesity and the risk of myocardial infarction in 27 000 participants from 52 countries: a case-control study.Lancet. 2005; 366: 1640-1649Summary Full Text Full Text PDF PubMed Scopus (2173) Google Scholar and the Emerging Risk Factors Collaboration1Emerging Risk Factors CollaborationSeparate and combined associations of body-mass index and abdominal adiposity with cardiovascular disease: collaborative analysis of 58 prospective studies.Lancet. 2011; 377: 1085-1095Summary Full Text Full Text PDF PubMed Scopus (746) Google Scholar are consistent in showing that adjustment for blood pressure, lipids, and glucose substantially attenuates the association between obesity and cardiovascular disease.We declare that we have no conflicts of interest. The conclusion of the Emerging Risk Factors Collaboration (March 26, p 1085),1Emerging Risk Factors CollaborationSeparate and combined associations of body-mass index and abdominal adiposity with cardiovascular disease: collaborative analysis of 58 prospective studies.Lancet. 2011; 377: 1085-1095Summary Full Text Full Text PDF PubMed Scopus (746) Google Scholar that measures of abdominal obesity do not add to the association of body-mass index (BMI) with cardiovascular disease, is not supported by the data in the paper or those from several independent studies. First, after adjustment for systolic blood pressure, diabetes, and total and HDL cholesterol, the waist-to-hip ratio had a hazard ratio that was significantly greater (1·12, 95% CI 1·08–1·15) than that of BMI (1·07, 1·03–1·11; p for heterogeneity=0·028; assuming the two regression coefficients are correlated at ≥0·4, which is the lower confidence limit of the univariate correlation). Second, regression dilution bias will affect the hazard ratio of waist-to-hip ratio to a greater degree than for BMI. The regression dilution ratio is 0·95 for BMI, indicating that the adjusted hazard ratio will be very close to the unadjusted value of 1·07, whereas with a regression dilution ratio for waist-to-hip ratio of 0·63, its relation with cardiovascular events will be about 50% steeper on a logarithmic scale, after adjusting for this bias. Third, in data provided in figure 1 of the Collaboration's paper, the hazard ratio associated with waist-to-hip ratio is stronger than that with BMI for coronary heart disease and ischaemic stroke, after adjustment for intermediate risk factors. Fourth, data provided in figure 3 indicate that waist-to-hip ratio and waist circumference are associated with higher risk of cardiovascular disease within the lowest, middle, or upper third of BMI. Fifth, large case-control studies2Yusuf S Hawken S Ounpuu S et al.INTERHEART Study Investigators. Obesity and the risk of myocardial infarction in 27 000 participants from 52 countries: a case-control study.Lancet. 2005; 366: 1640-1649Summary Full Text Full Text PDF PubMed Scopus (2173) Google Scholar, 3O'Donnell MJ Xavier D Liu L et al.for the INTERSTROKE investigatorsRisk factors for ischaemic and intracerebral haemorrhagic stroke in 22 countries (the INTERSTROKE study): a case-control study.Lancet. 2010; 376: 112-123Summary Full Text Full Text PDF PubMed Scopus (2095) Google Scholar and large cohort studies4Pischon T Boeing H Hoffman K et al.General and abdominal adiposity and risk of death in Europe.N Engl J Med. 2008; 359: 2105-2120Crossref PubMed Scopus (1504) Google Scholar have shown a clear incremental association with abdominal obesity over BMI for non-fatal myocardial infarction, non-fatal ischaemic strokes, and for total mortality or death from circulatory causes. The data presented by the Emerging Risk Factors Collaboration are directionally consistent with these findings. Finally, both INTERHEART2Yusuf S Hawken S Ounpuu S et al.INTERHEART Study Investigators. Obesity and the risk of myocardial infarction in 27 000 participants from 52 countries: a case-control study.Lancet. 2005; 366: 1640-1649Summary Full Text Full Text PDF PubMed Scopus (2173) Google Scholar and the Emerging Risk Factors Collaboration1Emerging Risk Factors CollaborationSeparate and combined associations of body-mass index and abdominal adiposity with cardiovascular disease: collaborative analysis of 58 prospective studies.Lancet. 2011; 377: 1085-1095Summary Full Text Full Text PDF PubMed Scopus (746) Google Scholar are consistent in showing that adjustment for blood pressure, lipids, and glucose substantially attenuates the association between obesity and cardiovascular disease. We declare that we have no conflicts of interest. Body-mass index, abdominal adiposity, and cardiovascular risk – Authors' replyThe Emerging Risk Factors Collaboration (ERFC)1 analysed individual data from 58 prospective studies involving 221 934 people to assess body-mass index (BMI), waist circumference, and waist-to-hip ratio in the prediction of cardiovascular disease. The hazard ratio—adjusted for age, sex, and smoking—for coronary disease was 1·32 (95% CI 1·24–1·41) per 5 kg/m2 higher baseline BMI, similar to findings in other large-scale prospective analyses, such as corresponding hazard ratios of 1·3–1·4 reported in the Prospective Studies Collaboration2 and in the pan-European EPIC study. Full-Text PDF
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