Evaluation of the relationship between Body Mass Index (BMI) and healthcare cost, utilization and health-related quality of life in adult diabetic patients

The present study assessed the relationship between Body Mass Index (BMI) and healthcare cost, utilization and health-related quality of life (HRQoL) of type 2 diabetes patients using the Medical Expenditure Panel Survey (MEPS) database. Study subjects were at least 18 years of age, diagnosed with diabetes and taking ≥1 oral antidiabetic medication. Data were extracted over a 5-year period (01/01/2006-12/31/2010). The main study outcomes were healthcare costs and utilization and HRQoL. The study covariates were age, gender, race, smoking status, census region of residence, marital status, insurance status, Charlson comorbidity index score and additional bed days. Study objectives were addressed using generalized linear model, negative binomial and multivariate regression analyses. A final un-weighted sample size of 7,003 patients was obtained. Mean age (±SE) was 61.2 (±0.24) years, mean BMI (±SE) was 32.2 (±0.12), and 50.4% were males. The majority was white (77.4%), did not smoke (84.5%), and were married (60.4%). Based on BMI categories, 12.6% had normal weight (BMI: 18.0-24.9); 29.2% were overweight (BMI: 25.0-29.9); 45.6% were obese (BMI: 30.0-39.9), and 12.6% were morbidly obese (BMI≥ 40.0). Compared to normal-weight patients; overweight, obese or morbidly obese patients had significantly higher (p<0.05) diabetes-related direct medical costs. However, overweight patients had significantly lower (p=0.021) all-cause direct medical costs. Furthermore, compared to normal weight patients, obese patients had a significantly higher (p=0.009) number of ambulatory care visits, while overweight patients had a significantly lower (p=0.035) number of emergency department visits. In addition, being obese or morbidly obese was associated with a significantly higher (p<0.0001) number of prescribed medicines compared to normal-weight patients. Compared to normal-weight patients; being obese or morbidly obese was also significantly (p<0.0001) associated with lower physical component summary (PCS-12) scores (i.e., worse quality of life) while being overweight was significantly (p=0.038) associated with higher mental component summary (MCS-12) scores (i.e., better quality of life). In conclusion, the present study suggests that among type 2 diabetes patients, being obese may be associated with negative consequences (in terms of healthcare costs, utilization and outcomes). Hence, there is the need to address obesity among type 2 diabetes patients in order to improve their health outcomes and significantly reduce healthcare costs and resource utilization.