How Does Body Mass Index Affect Health Conditions among Elders? An Analysis Using IHIS Data

Studies have demonstrated the burden overweight elders have on our health care system (Flegal, Carroll, Kuczmarski, & Johnson, 1998; Wolf, Manson, & Colditz, 2002; Wolf & Colditz, 1998). Having a chronic disease places elder adults in a position to have greater access to medical services usage and costs. More importantly, an increased body mass index (BMI) among elder populations has been associated with an increased risk for severe and significant health conditions. Being underweight, overweight, or obese is associated with being at risk for chronic diseases (Flegal, Graubard, Williamson, & Gail, 2005). The impact of BMI in relation to health conditions needs to be examined so interventions may be developed that properly address the weight problems among the elderly.

Using data from the Integrated Health Interview Survey (IHIS) data set, the body mass index (BMI) was calculated for 31,814 elders (individuals equal to or greater than 65 years old) using the height (in inches) and weight (in pounds) of each individual. BMI was then grouped into five categories: underweight (n=422, 1.3%), normal weight (n=12,508, 39.3%), overweight (n=12,270, 38.6%), obese (n=4,888, 15.4%, and very obese (n=1,726, 5.4%). The BMI groupings were compared to condition and health variables to identify associations between BMI and overall health. There was a significant association between BMI and health status (X2 = 546.56, p=.000) and health status compared to one year ago (X2 = 118.01, p=.000). There was also a significant association between BMI and various health conditions including: high cholesterol (X2 = 129.92, p=.000), coronary heart disease (X2 = 84.57, p=.000), heart attack(X2 = 62.00, p=.000), hypertension (X2 = 906.04, p=.000), weak/failing kidneys (X2 = 44.76, p=.000), and low back pain (X2 = 359.02, p=.000).

Elders grouped into the morbidly obese category were three times more likely to suffer from arthritis (AOR=3.37, CI=2.51-4.51, p=.000). However, rates were similar for the obese (AOR=1.42, CI=1.26-1.60, p=.000) and overweight (AOR=1.49, CI=1.26-1.75, p=.000) groups. Rates of diabetes were also significant for each of the BMI groupings: overweight (AOR=1.75, CI=1.62-1.89, p=.000), obese (AOR=3.27, CI=2.99-3.57, p=.000) and the morbidly obese (AOR=5.21, CI=4.63-5.86, p=.000). In addition, being underweight was a protective factor against developing diabetes (AOR=.662, CI=.443-.990, p=.045). Elders in the morbidly obese groups also had higher rates of heart conditions (AOR=1.28, CI=1.12-1.45, p=.000) and of having a health status worse than one year ago (AOR=1.41, CI=1.24-1.61, p=.000).

These findings demonstrate how important weight loss is to the overall wellbeing of elders. Elders who fell into the morbidly obese category were three times more likely to have arthritis and five times more likely to have diabetes. In addition, elders in each of the higher weight groupings were at greater risk for disease with those in the morbidly obese category at the greatest risk. Encouraging enough weight loss to move an elderly client into the lighter weight grouping will significantly reduce the odds of the elder developing certain significant health conditions. Interventions that focus on reducing BMI among the elderly should be developed to reduce the overall risk of significant health conditions.