Waist and hip circumferences vs. waist-to-hip ratio - Obesity - Brief Article

Nutrition Research Newsletter, Oct, 2001

The waist-to-hip ratio is commonly used as an indicator of abdominal obesity in population studies, with a high ratio being associated with unfavorable cardiovascular disease risk factors. However, this could be due to either a relatively large waist or a small hip girth. As a result, recent studies are indicating that the waist circumference may be a better reflection of the accumulation of intra-abdominal or visceral fat than the waist-to-hip ratio. Since it is difficult to interpret simple anthropometric measures of fatness and fat distribution and their relationship with risk factors for cardiovascular disease and diabetes mellitus in population studies, further research is necessary. Therefore, a group of researchers from the Netherlands and Canada tried to separate the individual contributions of waist and hip circumferences and BMI to the risk factors often associated with fat distribution.

Three-hundred thirteen men and 382 women living in the greater Quebec City area were involved in this study, phase 2 of the Quebec Family Study. Percentage body fat by underwater weighing, height, weight, and waist and hip circumferences were obtained. Abdominal fat distribution (visceral and subcutaneous fat areas) was measured with a CT scan. BMI and waist-to-hip ratio were calculated. Several blood measures were also taken after an overnight fast, including a lipid profile and serum glucose and insulin concentrations.

A large waist circumference in men and women was significantly associated with low HDL-cholesterol levels and high fasting triacylglycerol, insulin, and glucose concentrations. These results show that an increased hip circumference is associated with decreased visceral fat and increased subcutaneous abdominal fat, especially in men. In addition, a large waist circumference was also associated with high LDL-cholesterol concentrations and blood pressure in women. A small hip circumference was associated with low HDL-cholesterol and high glucose levels in men and high triacylglycerol and insulin concentrations in men and women. In general, when compared with waist circumference and BMI, the waist-to-hip ratio correlations with fat mass and fat-free mass tended to be weaker, while waist-to-hip ratios showed relatively strong correlations with cardiovascular disease risk factors (cholesterol and triacylglycerol levels).

The results of this study confirm that interpreting an increased waist-to-hip ratio is more complex than assumed. The authors observed that larger waist and smaller hip circumferences are both independently related (but in opposite directions) to risk factors such as low HDL-cholesterol, high triacylglycerol, and high insulin levels as compared to what was predicted on the basis of BMI. The independent effects of these two girth measures are confounded in the waist-to-hip ratio. Further research is needed on risk factors and the protective effects of cardiovascular disease and the methods used to identify them.

Jacob C. Seidell, Louis Perusse, Jean-Pierre Despres, and Claude Bouchard. Waist and Hip Circumferences Have Independent and Opposite Effects on Cardiovascular Disease Risk Factors: the Quebec Family Study, American Journal of Clinical Nutrition 74(3): 315-321 (September 2001) [Address correspondence to J. C. Seidell, RIVM/C2E, National Institute of Public Health and the Environment, Antonie van Leeuwenhoeklaan 9, PO Box 1, Bilthoven, 3720 BA, Netherlands. E-mail: j.seidell@rivm.nl].