A study in the February 2005 issue of Preventive Medicine looked at the superiority of the waist-to-height ratio as an anthropometric index to evaluate clustering of coronary risk factors among non-obese men and women. Researchers compared BMI, waist circumference, and waist-to-height ratios for 4,668 men and 1,853 women with a BMI < 25 as indices for estimating coronary risk factors. The researchers found that the sum of all coronary risk factors correlated positively with all the indexes, with the closest correlation found for waist-to-height ratios. Among the various proposed indexes the evaluation of risk factors were highest for a waist-to-height ratio greater than 0.5000. They concluded that waist-to-height ratio is more sensitive than BMI or waist circumference alone to evaluate coronary risk factors among non-obese men and women (Hsieh, S. D., et al, 2005: 216-220).
A 2002 study in the American Journal of Clinical Nutrition, indicates that "a cross-sectional study, which supports the consistent conclusion from a large body of literature that waist circumference (WC) is at least as strong as is a body mass index (BMI) in predicting cardiovascular disease" (Lean, 2002:699). The report goes on to claim that men with a WC > 94 cm and women with a WC > 80 cm would virtually identify anyone with a BMI > 25. While a WC > 102 cm for men and > 88 cm for women would identify everyone with a BMI > 30. This study correlates well with the Air Forces decision to drop the Weight and Body Fat Management Program and rely on WC measures as a means of determining one's health.
In the November 2003 issue of Public Health and the Environment, Dr. Henry Kahn and others determined that a waist-to-height ratio is a good predictor of BMI. Regardless of sex and age, his cross-sectional, weighted sample estimated the risk factors as high if one's waist-to-height ratio was greater than 0.543 and only moderate between 0.498 and 0.543 (Kahn, 2003).
A study in the Nippon Rinsho: Japanese Journal of Clinical Medicine looked at various anthropometric indices (BMI, waist circumference, and waist-to-height ratio) to find a simple method for assessing the risk of metabolic syndrome. Waist-to-height ratios correlated more closely than any other index to the sum of 4 or 5 coronary risk factors. A waist-to-height index greater than 0.5000 was capable of identifying approximately all overweight individuals and also identified more individuals of normal weight as at risk than any other measure of central fat distribution.
Even normal-weight subjects with a waist-to-height ratio greater than 0.5000 demonstrated significantly higher risk for 2 or more coronary risk factors than those individuals with a waist-to-height ratio less than 0.5000 (Hsieh, Shiun Dong and Takashi Muto, 2004: 1143-1149).
A study in the November 2000 issue of International Journal of Obesity, etc.*determined waist-to-height ratios are a better predictor of cardiovascular disease in children than BMI. Waist-to-height ratios have been used as a proxy measure of visceral adipose tissue, mainly in adults. The objective was to validate BMI, waist circumference and waist-to-height ratio as predictors for the presence of cardiovascular risk factors in children. Their conclusions were that waist circumference and waist-to-height ratios are better predictors of cardiovascular disease in children than BMI (Savva et al, 2000: 1453-1458).
A second study in the November 2002 issue of International Journal of Obesity, etc. determined the optimal cut-off values of four anthropometric indices (BMI, waist circumference, waist-to-hip ratio, and waist-to-height ratio) to estimate cardiovascular disease risk factors.
Data was collected on 26,359 Asian men and 29,204 Asian women with a mean age of 37. Individual body weight, height and waist circumference and a series of tests related to cardiovascular risk were assessed and their relationships were examined. Of the four indices studied, waist-to-height ratios were found to have the largest areas under the curve relative to at least one risk factor. The conclusions are that waist-to-height ratios may be a better indicator for screening overweight or obesity-related cardiovascular disease risk factors than the other three indexes (BMI, waist circumference, and waist-to-hip ratio) The optimal cut off values for overweight or obesity waist-to height ratios were 0.4800 for men and 0.4500 for women (Lin, W. Y.,et al, 2002: 1232-1238).
In the May 2003 issue of International Journal of Obesity, etc., researchers hypothesized that the waist-to-height ratio can be used to identify subjects who are at higher metabolic risk within the normal as well as the overweight range. The researchers compared the values for BMI, waist circumference, and waist-to-height ratios for 6141 men and 2137 women at various age levels.
The researchers found that for various indexes in all age groups; the gender ratio for waist-to-height was closest to 1. They determined that a single set of values for waist-to-height ratios can be used for men and women. For both men and women, the highest correlation coefficient was between waist-to-height ratio and the morbidity index for coronary risk factors. Nearly all overweight men and women (BMI > 25) had waist-to-height ratios > 0.5000 (98% of men and 97.5% of women). The conclusions are that waist circumference is improved by relating it to height to categorize fat distributions of different genders and ages (Hsieh, S. D., et al, 2003: 610-616).
*(The full name of the publication is International Journal of Obesity and Related Metabolic Disorders: Journal of the International Association for the Study of Obesity).
The AHA's stroke prevention team takes what would appear to be a safe approach to stroke prevention and salt intake: "People with high blood pressure should increase their intake of potassium and decrease the amount of salt they eat to reduce their blood pressure — along with medications prescribed by their physicians."