Body Mass Index and Quality of Well-being in a Community of Older Adults

Background: The impact of obesity and associated conditions on health has not been assessed in older adults using a generic, utility-based measure of health-related quality of life (HRQOL). This study evaluates the relationship between body mass index (BMI) and HRQOL scores and gives estimates of quality-adjusted life years (QALYs) lost to overweight, obesity, and associated conditions.

Methods: A total of 1326 adults from the Rancho Bernardo longitudinal cohort study, with a mean age of 72 years, completed the Quality of Well-Being Scale (QWB), a generic health-related quality of life measure. Height, weight, exercise, and smoking status were also assessed. Differences in QWB scores between obese adults and those with a normal BMI were used to estimate the QALYs lost due to obesity and associated conditions.

Results: Participants were divided into four groups based on BMI: <20 (underweight); 20 to 24.9 (normal); 25 to 29.9 (overweight); >30 kg/m(2) (obese). Analysis of covariance controlling for age, gender, smoking history, and exercise showed a significant difference between group means (F(7,1310)=30.79; p <0.001). The normal BMI group had the highest QWB score (0.709), followed by the underweight (0.698), overweight (0.695), and obese (0.663) groups. The QWB score for the obese group was significantly lower than that for the normal and overweight groups. An estimated 2.93 million QALYs are lost in this country each year from obesity and associated conditions.

Conclusions: Obese older adults tend to have lower HRQOL than those who are overweight or of normal BMI. The lower QWB scores associated with obesity translate into millions of QALYs lost each year. Being overweight but not obese did not have a significant impact on HRQOL in this population.