The chart below is what we typically use, for adults, to get a rough estimate of risk for heart disease (e.g., increased, high, very high, extremely high). First, we calculate someone's Body Mass Index (BMI) and measure their waist circumference (WC). Then, we look at the chart to determine risk. For example, a 5'4" female who weighs 155 pounds (BMI=26.6) and has a WC of 36 is predicted to have a "high risk" for heart disease.

*relative to normal weight and normal waist circumference

But in children, determining risk is a bit more difficult. While excess fat in children has been correlated with high blood pressure, high cholesterol, and insulin resistance (when the body makes insulin but can't use it efficiently; a risk factor for diabetes and heart disease), accurately measuring body fat in children's rapidly changing bodies is problematic. Therefore, researchers at "Sapienza" University in Rome, Italy recently tested a new way for doctors to identify children at greatest risk for heart disease - wrist circumference measurement.¹ They enrolled 477 overweight/obese children and adolescents into a study, measuring their wrist circumference with a cloth tape measure. They also took 51 of those children/adolescents and precisely measured their wrist bony area vs. fatty area with MRI. All of the children/adolescents also underwent blood tests to measure their insulin levels.

Results showed that wrist circumference accounted for 12-17% of the variance in insulin resistance and that insulin resistance was explained by the size of the wrist's bony tissue and not by the fatty tissue. Thus, researchers concluded that there is a close relationship between wrist circumference, its bony component, and insulin resistance in overweight/obese children and adolescents; a much stronger correlation than BMI and insulin resistance.

What's the likely link? Recent studies have shown that high blood insulin levels are associated with increased bone mass. In other words, insulin may act as a growth factor to increase bone cell production. And wrist circumference could be a marker for increased bone growth when insulin levels are high.

The bottom line is that wrist circumference, a very simple measurement for doctors (or maybe even parents!) to take may provide a good estimate of heart disease risk in children/adolescents. The hard part, though, are the steps that need to be taken (or behaviors that need to be changed) after increased risk is identified!

¹Capizzi, M., Leto, G., & Petrone, A. (2011). Wrist circumference is a clinical marker of insulin resistance in overweight and obese children and adolescents. Circulation, 123, 1757-1762.