A new study by researchers at the University of Eastern Finland and the Robert W. Johnson Medical School at Rutgers University found that the waist-to-height ratio (WHtR) is a better predictor of likely hypertension than body mass index (BMI).
To calculate BMI, divide weight in kilograms by height in meters squared.
WHtR, like BMI, is used to assess body fat and . Obesity is generally considered a complex chronic disease characterized by an excessive amount of body fat. It increases the risk of:
- hypertension
- ischemic heart disease
- deep vein thrombosis and varicose veins
- musculoskeletal disorders
- respiratory problems
- digestive system diseases
BMI has long been the accepted standard for diagnosing obesity. But it has several limitations, Medical Xpress reports. For example, BMI doesn’t distinguish between fat and muscle mass. Studies show that increased muscle mass lowers the risk of diseases such as and .
In recent years, the waist-to-height ratio has attracted attention as an alternative or additional measure of body fat and obesity.
Last year, the U.K. National Institute for Health and Care Excellence (NICE) recommended using a WHtR threshold of 0.5 to diagnose obesity. That means an adult’s waist circumference should not exceed half their height to reduce health risks.
Every additional 4.5 kg of body weight raises blood pressure by 4.2–4.4 mm Hg.
New study finds waist-to-height ratio outperforms BMI for predicting high blood pressure
The team used data on 19,124 people aged 12 and older from the U.S. National Health and Nutrition Examination Survey (NHANES) for 2015–2023.
During the analysis, the researchers applied WHtR threshold values to identify normal, high, and excess body fat (depending on sex). They defined elevated as ≥120/70 mm Hg and hypertension as ≥140/90 mm Hg.
In the last cycle of the study, which included 7,243 participants with an average age of 44.8 years, the prevalence of elevated blood pressure was 63.5 percent and the prevalence of hypertension was 14.4 percent.
The study showed that participants with a high WHtR had a 50 percent higher likelihood of elevated blood pressure and an 82 percent higher likelihood of hypertension. Those with excess body fat had a 91 percent higher likelihood of elevated blood pressure and a 161 percent higher likelihood of hypertension, respectively. Excess body fat had a particularly strong effect on raising blood pressure in adults aged 25–65.
“BMI failed to detect an independent effect of obesity, probably because it doesn’t isolate the confounding influence of muscle mass, which can inflate its association with blood pressure at early stages and hide its link with established hypertension.” Махідере Алі, провідна авторка дослідження.
Meanwhile, among young people under 25, high and excess body fat measured by WHtR increased the likelihood of elevated blood pressure by 66 and 98 percent, respectively. The association with hypertension in this age group was not statistically significant.
“Assessing body fat using WHtR provides a more accurate and clinically meaningful indicator of hypertension risk. WHtR is a simple, scalable tool that can improve detection of cardiovascular risk related to obesity,” Dr. Mahidere Ali concluded.
What waist measurements doctors call healthy — and what’s risky
Normal: women — up to 80 cm, men — up to 94 cm.
Risky values (linked to premature death and metabolic disorders): women — over 88 cm, men — over 102 cm.
Healthy BMI range
A healthy BMI is 18.5–24.9.
Photo: Unsplash
