To the Editor: A challenging issue with the study reported onby Pischon et al. (Nov. 13 issue)1 is where to measure the waist.The accepted standard for measuring the waist circumferenceput forth by the third National Health and Nutrition ExaminationSurveys (NHANES III) protocol,2 as noted by Mahley in the WilliamsTextbook of Endocrinology,3 is: "to measure waist circumference,locate the top of the right iliac crest. Place a measuring tapein a horizontal plane around the abdomen at the level of theiliac crest. Before reading the tape measure, ensure that thetape is snug but does not compress the skin and is parallelto the floor. Measurement is made at the end of a normal expiration."However, Pischon et al. report that in their study, "waist circumferencewas measured either at the narrowest circumference of the torsoor at the midpoint between the lower ribs and the iliac crest."International acceptance of measurement tools is paramount.
Margaret M. Gaglione, M.D. Tidewater Bariatrics Chesapeake, VA 23320 doctor{at}twb4u.com
References
Pischon T, Boeing H, Hoffmann K, et al. General and abdominal adiposity and risk of death in Europe. N Engl J Med 2008;359:2105-2120. [Free Full Text]
Department of Health and Human Services, Public Health Service. NHANES III anthropometric procedures video. Washington, DC: Government Printing Office, 1996.
Mahley RW. Disorders of lipid metabolism. In: Kronenberg HM, Melmed S, Polonsky KS, Larsen PR, eds. Williams textbook of endocrinology. 11th ed. Philadelphia: Saunders Elsevier, 2008:1589-631.
To the Editor: Pischon et al. support the use of waist circumferenceor waist-to-hip ratio in addition to body-mass index (BMI) inassessing the risk of death. Engeland et al. found that heightis inversely associated with mortality among men and to somedegree among women.1 My recent study2 and a meta-analysis,3both of which used cross-sectional data, provide support forthe superiority of measures of central obesity — especiallywaist-to-height ratio — over BMI for discriminating thepresence or absence of cardiologic and metabolic risk factors.Pischon et al. appropriately adjusted for height when calculatingthe mortality risk associated with anthropometric indexes. Itwould be helpful if the authors would determine the relativerisk of death according to waist-to-height ratio and its comparisonwith other anthropometric data. For a fair comparison, heightshould not be adjusted for other studied anthropometric indexes.
Pischon et al. indicated that they observed no significant associationbetween hip circumference and mortality risk. Larger hip circumferencewas shown to be an independent predictor of a lower mortalityrate in a Swedish female cohort.4 Did Pischon et al. confirmthat?
Engeland A, Bjorge T, Selmer RM, Tverdal A. Height and body mass index in relation to total mortality. Epidemiology 2003;14:293-299. [CrossRef][Web of Science][Medline]
Can AS, Bersot TP, Gonen M. Anthropometric indices and their relationship with cardiometabolic risk factors in a sample of Turkish adults. Public Health Nutr 2008 May 19 (Epub ahead of print).
Lee CM, Huxley RR, Wildman RP, Woodward M. Indices of abdominal obesity are better discriminators of cardiovascular risk factors than BMI: a meta-analysis. J Clin Epidemiol 2008;61:646-653. [CrossRef][Web of Science][Medline]
Lissner L, Björkelund C, Heitmann BL, Seidell JC, Bengtsson C. Larger hip circumference independently predicts health and longevity in a Swedish female cohort. Obes Res 2001;9:644-646. [Web of Science][Medline]
To the Editor: Pischon et al. show that assessment of abdominalobesity adds important information to BMI. However, the questionas to how abdominal obesity should be measured still remainsunanswered. We have previously shown that waist circumferenceand waist-to-height ratio are better indicators of prevalentconditions associated with cardiovascular risk than other variables.1,2To analyze the predictive value of these variables, we assessedmortality in pooled data from two cohort studies, Diabetes CardiovascularRisk-Evaluation: Targets and Essential Data for Commitment ofTreatment (DETECT)2 and the Study of Health in Pomerania (SHIP),3which involved a total of 10,652 subjects, 55.9% of whom werewomen. The mean age (±SD) was 54.8±15.6 years,and the mean follow-up was 6.4±3.3 years. After multipleadjustments for confounders, comparing the fifth with the thirdquintile, only a high waist-to-height ratio was significantlyassociated with mortality in both men and women.
Even though our two studies were far smaller than the studyconducted by Pischon et al., our results indicate that it istoo early to generally recommend the use of waist circumference.Waist-to-height ratio is as easy to assess as waist circumferenceand might add more information. Moreover, if a general cutoffpoint is used, unlike waist-to-height ratio, waist circumferencemight underestimate the relative amount of abdominal fat inshort subjects and overestimate it in tall subjects.
Harald J. Schneider, M.D. University Hospital at Ludwig-Maximilans University 80336 Munich, Germany harald.schneider{at}med.uni-muenchen.de
Hans-Ulrich Wittchen, Ph.D. Technical University Dresden 01187 Dresden, Germany
Henri Wallaschofski, M.D. University of Greifswald 17475 Greifswald, Germany
References
Schneider HJ, Klotsche J, Stalla GK, Wittchen HU. Obesity and risk of myocardial infarction: the INTERHEART study. Lancet 2006;367:1052-1052. [CrossRef][Web of Science][Medline]
Schneider HJ, Glaesmer H, Klotsche J, et al. Accuracy of anthropometric indicators of obesity to predict cardiovascular risk. J Clin Endocrinol Metab 2007;92:589-594. [Free Full Text]
Völzke H, Friedrich N, Schipf S, et al. Association between serum insulin-like growth factor-I levels and thyroid disorders in a population-based study. J Clin Endocrinol Metab 2007;92:4039-4045. [Free Full Text]
The authors reply: In the European Prospective Investigationinto Cancer and Nutrition (EPIC), most centers followed theguidelines established by World Health Organization (WHO)1 formeasuring waist circumference (i.e., midway between the inferiormargin of the last rib and the crest of the ilium, in a horizontalplane), while a few centers chose to measure waist circumferenceas the narrowest torso circumference. A recent systematic review2revealed that 30% of published studies on the association ofwaist circumference with health outcomes adopted the WHO recommendationsand 27% adopted the method of measuring the narrowest torsocircumference, whereas only 4% adopted the method describedin the NHANES III protocol cited by Gaglione. In addition, thereview indicated that the type of protocol adopted in thesestudies had no substantial influence on the association of waistcircumference with health outcomes.2
As indicated by Can and by Schneider and colleagues, the waist-to-heightratio was proposed as a measure of abdominal adiposity thattakes height directly into account.3 We used BMI and waist circumference(or waist-to-hip ratio) to assess the degree of general andabdominal adiposity, respectively, and we adjusted our analysisfor height. Within our study, waist-to-height ratio was correlatedwith BMI to a similar extent to that which we reported for waistcircumference (Pearson partial-correlation coefficients, adjustedfor age and study center, were 0.87 among men and 0.85 amongwomen). Also, the overall results for the association with riskof death were similar to those derived from our calculationwith the use of waist circumference. For example, the relativerisk in the highest as compared with the lowest quintile ofthe waist-to-height ratio in the multivariable-adjusted model(including BMI) was 2.22 (95% confidence interval [CI], 1.94to 2.55; P<0.001 for trend) among men and 2.03 (95% CI, 1.76to 2.34; P<0.001 for trend) among women.
As Can indicated, hip circumference was associated with mortalityin some studies; however, this association may depend on adjustmentsfor other anthropometric variables. As we mentioned in our article,hip circumference was not significantly related to risk of deathin the multivariable-adjusted model that also included BMI.The relative risk in the highest as compared with the lowestquintile was 1.02 (95% CI, 0.91 to 1.14; P=0.48 for trend) amongmen and 0.92 (95% CI, 0.80 to 1.06; P=0.53 for trend) amongwomen.
We feel that our data support the use of waist circumferenceor waist-to-hip ratio as the most established anthropometricmeasures of abdominal adiposity in addition to BMI for the assessmentof the risk of death in middle-aged and older persons.
Tobias Pischon, M.D., M.P.H. Heiner Boeing, Ph.D., M.S.P.H. German Institute of Human Nutrition, Potsdam-Rehbruecke 14558 Nuthetal, Germany pischon{at}dife.de
Elio Riboli, M.D., M.P.H., Sc.M. Imperial College London London W2 1PG, United Kingdom
References
Physical status: the use and interpretation of anthropometry: report of a WHO expert committee. World Health Organ Tech Rep Ser 1995;854:1-452. [Medline]
Ross R, Berentzen T, Bradshaw AJ, et al. Does the relationship between waist circumference, morbidity and mortality depend on measurement protocol for waist circumference? Obes Rev 2008;9:312-325. [CrossRef][Web of Science][Medline]
Willett W. Anthropometric measures and body composition. In: Willett W, ed. Nutritional epidemiology. 2nd ed. New York: Oxford University Press, 1998:244-72.
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