Objective: This study estimated the economic burden of obesity-related comorbidities (ORCs) in the US, at both the person and population levels.

Methods: The Geisinger Health System provided electronic medical records and claims between January 2004 and May 2013 for a sample of 153,561 adults (50% males and 97% white). Adults with < 2 years of data, who were underweight (body mass index (BMI) < 18.5 kg/m(2)), or had diseases causing major weight change (e.g., malignancy) during the study period (i.e., continuous enrollment in health plans) were excluded. A total of 21 chronic conditions, with established association with obesity in the literature, were identified by diagnosis codes and/or lab test results. The total healthcare costs were measured in each year. The association between annual costs and ORCs was assessed by a regression, which jointly considered all the ORCs. The per-person incremental costs of a single comorbidity, without any of the other ORCs, were calculated. The population-level economic burden was the product of each ORC's incremental costs and the annual prevalence of the ORC among 100,000 individuals. The prevalence of ORCs was stratified by obesity status to estimate the economic burden among 100,000 individuals with obesity and among those without.

Results: This study identified 56,895 adults (mean age = 47 years; mean BMI = 29.6 kg/m(2)). The annual prevalence of ORCs ranged from 0.5% for pulmonary embolism (PE) to 41.8% for dyslipidemia. The per-person annual incremental costs of a single ORC ranged from $120 for angina to $1665 for PE. Hypertensive diseases (HTND), dyslipidemia, and osteoarthritis were the three most expensive ORCs at the population level; each responsible for ≥$18 million annually among 100,000 individuals. HTND and osteoarthritis were much more costly among individuals with obesity than those without obesity.

Limitations: Data were from a small geographic region.

Conclusions: ORCs are associated with substantial economic burden, especially for those requiring continuous treatments.