OBJECTIVE To estimate the prevalence of diagnosed arthritis among U.S. adults and the proportion of arthritis-attributable activity limitation (AAAL) among those with arthritis by diagnosed diabetes mellitus (DM) status.

RESEARCH DESIGN AND METHODS We estimated prevalences and their ratios using 2008–2010 U.S. National Health Interview Survey of noninstitutionalized U.S. adults aged ≥18 years. Respondents’ arthritis and DM status were both based on whether they reported a diagnosis of these diseases. Other characteristics used for stratification or adjustment included age, sex, race/ethnicity, education level, BMI, and physical activity level.

RESULTS Among adults with DM, the unadjusted prevalences of arthritis and proportion of AAAL among adults with arthritis (national estimated cases in parentheses) were 48.1% (9.6 million) and 55.0% (5.3 million), respectively. After adjusting for other characteristics, the prevalence ratios of arthritis and of AAAL among arthritic adults with versus without DM (95% CI) were 1.44 (1.35–1.52) and 1.21 (1.15–1.28), respectively. The prevalence of arthritis increased with age and BMI and was higher for women, non-Hispanic whites, and inactive adults compared with their counterparts both among adults with and without DM (all P values < 0.05). Among adults with diagnosed DM and arthritis, the proportion of AAAL was associated with being obese, but was not significantly associated with age, sex, and race/ethnicity.

CONCLUSIONS Among U.S. adults with diagnosed DM, nearly half also have diagnosed arthritis; moreover, more than half of those with both diseases had AAAL. Arthritis can be a barrier to physical activity among adults with diagnosed DM.

Physical activity is a key component of diabetes mellitus (DM) and arthritis management (1–3). Arthritis, which is a barrier to physical activity (4), is the most common cause of disability in the United States (5). DM and arthritis each produce large burdens in the United States (6–8); they also share some risk factors including age and obesity (9,10). The mechanism of this comorbidity remains uncertain; these co-occurring conditions have been associated with a significant reduction in quality of life and increased risk for other severe complications (11). Understanding the extent to which arthritis produces activity limitation among adults with DM will help raise awareness of the conjoint burden of these two diseases as well as the need for efforts to promote the benefits of physical activity in managing DM and arthritis.

In this study, we estimated the prevalences of arthritis and the proportion of arthritis-attributable activity limitation (AAAL) among U.S. adults with arthritis aged ≥18 years according to diagnosed DM status using 2008–2010 data from the U.S. National Health Interview Survey (NHIS).