Association between the body roundness index and osteoarthritis: evidence from NHANES

Approximately 80% of US adults and adolescents are insufficiently active. Physical activity fosters normal growth and development and can make people feel, function, and sleep better and reduce risk of many chronic diseases.

Osteoarthritis (OA) is one of the most common joint disorders worldwide. Its prevalence is increasing because of the growing aging of the population in developed and developing countries as well as an increase in risk factors leading to OA, particularly obesity and a sedentary lifestyle. Risk factors of OA can be divided into person-level factors (age, gender, obesity, genetics and diet) and joint-level factors (injury, malalignment and abnormal loading of the joints) that interact in a complex manner. OA is the 11th cause of disability in the world. It is responsible for activity limitations, particularly walking, and affects participation and quality of life. Patients with OA are at greater risk of all-cause mortality, particularly for cardiovascular diseases, than the general population. This excess mortality is closely associated with disability level. Consequently, strategies to reduce burden through primary and secondary prevention programs are increasingly important. Show more

Objective To develop a new geometrical index that combines height, waist circumference (WC), and hip circumference (HC) and relate this index to total and visceral body fat. Design and Methods Subject data were pooled from three databases that contained demographic, anthropometric, dual energy X-ray absorptiometry (DXA) measured fat mass, and magnetic resonance imaging measured visceral adipose tissue (VAT) volume. Two elliptical models of the human body were developed. Body roundness was calculated from the model using a well-established constant arising from the theory. Regression models based on eccentricity and other variables were used to predict % body fat and % VAT. Results A body roundness index (BRI) was derived to quantify the individual body shape in a height-independent manner. Body roundness slightly improved predictions of % body fat and % VAT compared to the traditional metrics of body mass index (BMI), WC, or HC. On this basis, healthy body roundness ranges were established. An automated graphical program simulating study results was placed at http://www.pbrc.edu/bodyroundness. Conclusions Body roundness index, a new shape measure, is a predictor of % body fat and % VAT and can be applied as a visual tool for health status evaluations. Show more