Waist to Height Ratio Better Risk Predictor Than BMI

Waist to height ratio (WHtR) is a better predictor of heart disease and diabetes risk than body mass index (BMI), according to new research.

Researchers at Ashwell Associates (Ashwell; United Kingdom), and Oxford Brookes University (Oxford, United Kingdom) conducted a systematic review and meta-analysis of 31 studies to differentiate the screening potential of WHtR and waist circumference (WC) for adult cardiometabolic risk in people of different nationalities, and to compare both with BMI. The researchers used receiver-operating characteristics (ROC) curves for assessing the discriminatory power of anthropometric indices in distinguishing adults with hypertension, type-2 diabetes, dyslipidaemia, metabolic syndrome, and general cardiovascular disease (CVD).

The researchers found that compared with BMI, WC improved discrimination of adverse outcomes by 3%, and WHtR improved discrimination even further, by 4%-5%. Statistical analysis also showed WHtR to be significantly better than WC for diabetes, hypertension, CVD, and all outcomes, in both men and women. The researchers stressed the advantage of WHtR was the simplicity of the health message, which recommends keeping waist circumference to less than half body height. The study was presented at the 19th Congress on Obesity, held during May 2012, in Lyon (France).

“For the first time, robust statistical evidence from studies involving more than 300,000 adults in several ethnic groups shows the superiority of waist to height ratio over BMI for detecting cardiometabolic risk factors in both sexes, and should be considered as a screening tool,” said lead author and study presenter Margaret Ashwell, PhD, an independent consultant and former science director of the British Nutrition Foundation.

“Keeping your waist circumference to less than half your height can help increase life expectancy for every person in the world.”

To measure waist circumference accurately, the World Health Organization (WHO) recommends it should be measured mid-way between the lower rib and the iliac crest (the top of the pelvic bone at the hip).

Related Links:
Ashwell Associates
Oxford Brookes University