A new study finds that women who are obese or overweight, particularly those with a large waist circumference, are more likely to fracture than women who are normal weight.
According to research presented at the European Congress on Obesity (ECO) in the Netherlands, being underweight rather than overweight is associated with a higher risk of broken bones in men.
Obesity has long been thought to aid in fracture prevention. This is due to the fact that mechanical loading on bones, which increases with body weight, aids in the increase of bone mineral density, which is an important determinant of bone strength.
Recent research, however, suggests that the relationship between obesity and fracture risk differs depending on gender, the skeletal site studied, and the definition of obesity used (body mass index BMI vs. waist circumference).
To learn more, a team from the CHU de Quebec Research Center in Canada analyzed data from nearly 20,000 Quebec residents aged 40 to 70. The BMI and waist circumference (a measure of abdominal obesity) of the participants were measured.
497 women and 323 men fractured during a median follow-up of 5.8 years
Greater waist circumference was associated with an increased risk of fracture in women. The risk of fracture at any site increased by 3% for every 5cm (two inch) increase in waist circumference, and the risk of a distal lower limb fracture (the part of the leg below the knee) increased by 7%.
The link between waist circumference and ankle fractures was especially strong.
“In women, waist circumference was more strongly associated with fractures than BMI.” This could be due to visceral fat, “fat that is very metabolically active and stored deep within the abdomen, wrapped around the organs, secreting compounds that negatively affect bone strength,” said Dr. Anne-Frederique Turcotte of the Centre’s Endocrinology and Nephrology Unit.
Furthermore, women with a higher BMI had a higher risk of distal lower limb fractures. Compared to women with a BMI of 25 kg/m2,A the risk increased linearly from 5% in those with a BMI of 27.5 kg/mA to 40% in those with a BMI of 40 kg/mA.
While the link between obesity and a higher risk of fractures in women is unknown, the researchers stated that most fractures are the result of a fall, and falls are more common in obese people. The ankle, unlike the hip and thigh bone, is not protected by soft tissue, making it more likely to break during a fall.
