Arthritis as a Potential Barrier to Physical Activity Among Adults with Diabetes --- United States, 2005 and 2007

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The American Diabetes Association and the American College of Sports Medicine agree that increasing physical activity among persons with diabetes is an important public health goal to 1) reduce blood glucose and risk factors for complications (e.g., obesity and hypertension) in persons with diabetes and 2) improve cardiovascular disease outcomes (1,2). Among adults with diabetes, co-occurring arthritis might present an underrecognized barrier to increasing physical activity, but to date this has not been directly studied. To estimate the prevalence of 1) diagnosed arthritis among adults with diabetes and 2) physical inactivity among adults with diabetes by arthritis status, CDC analyzed combined 2005 and 2007 data from the Behavioral Risk Factor Surveillance System (BRFSS). This report describes the results of that analysis, which indicated that 1) arthritis prevalence was 52.0% among adults with diagnosed diabetes and 2) the prevalence of physical inactivity was higher among adults with diabetes and arthritis (29.8%) compared with adults with diabetes alone (21.0%), an association that was independent of age, sex, or body mass index (BMI). The higher prevalence of physical inactivity among adults who have both diabetes and arthritis suggests that arthritis might be an additional barrier to increasing physical activity. Health-care providers and public health agencies should consider addressing this barrier with arthritis-specific or general evidence-based self-management and exercise programs.

The BRFSS survey is a state-based, random-digit--dialed telephone survey of the civilian, noninstitutionalized U.S. adult population aged >18 years and is conducted in all 50 states, the District of Columbia (DC), Guam, Puerto Rico, and the U.S. Virgin Islands. Diabetes was defined as a "yes" response to the question, "Have you ever been told by a doctor that you have diabetes?" Doctor-diagnosed arthritis was defined as a "yes" response to the question, "Have you ever been told by a doctor or other health professional that you have some form of arthritis, rheumatoid arthritis, gout, lupus, or fibromyalgia?" This question is included in the BRFSS core questionnaire in odd-numbered years only. Physical activity level of respondents was determined from six questions* that asked about frequency and duration of participation in nonoccupational activities (i.e., lifestyle activities) of moderate and vigorous intensity; those reporting no participation in such activities were classified as inactive (i.e., engaged in no nonoccupational physical activity), and all others as active. BMI was calculated from self-reported height and weight.

To obtain adequate sample sizes for greater statistical power, CDC combined data for the 50 states and DC from 2005 and 2007, calculated estimates, and applied an annual average weighting; 95% confidence intervals (CIs) were calculated using sample design factors to account for the multistage probability sample. To assess factors potentially confounding an association between doctor-diagnosed arthritis and physical inactivity among those with diabetes, data were combined across states/areas in unadjusted and adjusted (by age, sex, and BMI) logistic regression models. Age groups were 18--44 years, 45--64 years, and >65 years. BMI groups were underweight/normal weight (BMI <25.0), overweight (BMI 25.0 to <30.0), and obese (BMI >30). Statistical significance was determined by nonoverlapping CIs. State-level estimates then were calculated for the 50 states and DC (reported medians were based on these areas) and for Guam, Puerto Rico, and the U.S. Virgin Islands. Council of American Survey Organizations (CASRO) response rates among the 50 states, DC, and the three territories for 2005 ranged from 34.6% (New Jersey) to 67.4% (Alaska) (median: 51.1%), and cooperation rates ranged from 58.7% (California) to 85.3% (Minnesota) (median: 75.1%). CASRO response rates for 2007 ranged from 26.9% (New Jersey) to 65.4% (Nebraska) (median: 50.6%), and cooperation rates ranged from 49.6% (New Jersey) to 84.6% (Minnesota) (median: 72.1%).^§

During 2005 and 2007, the prevalence of arthritis among adults with diabetes was 52.0% (CI = 51.3%--52.7%), compared with 26.9% (CI = 26.7%--27.1%) for all adults aged >18 years. The prevalence of arthritis among persons with diabetes was higher than in the general population for both sexes: males (45.9% [CI = 44.8%--47.1%] versus 22.6 [CI = 22.3%--22.9%]); females (58.0% [CI = 57.1%--59.0%] versus 30.9% [CI = 30.7%--31.2%]), respectively. In addition, arthritis prevalence among persons with diabetes was higher than in the general population for all age groups (i.e., 18--44 years, 45--64 years, and >65 years): 27.6% (CI = 25.7%--29.7%) versus 11.0% (CI = 10.8%--11.2%), 51.8% (CI = 50.8%--52.9%) versus 36.4% (CI = 36.1%--36.8%), and 62.4% (CI = 61.3%--63.5%) versus 56.2% (CI = 55.8%--56.6%), respectively. Prevalence of physical inactivity was lowest among adults without arthritis or diabetes (10.9% [CI = 10.7%--11.1%]), higher among adults with arthritis alone (17.3% [CI = 17.0%--17.6%]) and diabetes alone (21.0% [CI = 20.0%--22.1%]), and highest among adults with both conditions (29.8% [CI = 29.0%--30.7%]) (Figure). In logistic regression analyses, the unadjusted odds ratio (OR) for the association between doctor-diagnosed arthritis and physical inactivity among adults with doctor-diagnosed diabetes was 1.6 (CI = 1.3--1.7); adjusted for age and sex, the OR was 1.4 (CI = 1.3--1.5); and adjusted for age, sex, and BMI, the OR was 1.3 (CI = 1.2--1.4). In state-specific analyses, the state median prevalence estimate of physical inactivity among adults with diabetes and arthritis was 28.9% (range: 20.2% in California to 46.4% in Tennessee). The state median prevalence estimate of physical inactivity among adults who had diabetes and no arthritis was 19.5% (range: 9.0% in Alaska to 30.2% in West Virginia) (Table).

Reported by: J Bolen, PhD, J Hootman, PhD, CG Helmick, MD, L Murphy, PhD, G Langmaid, Div of Adult and Community Health, CJ Caspersen, PhD, Div of Diabetes Translation, National Center for Chronic Disease Prevention and Health Promotion, CDC.

Editorial Note:

In the United States, approximately 20.6 million adults were reported to have diabetes in 2005 (3), with nearly seven in 10 having diabetes diagnosed by a health professional. In addition, during 2003--2005, approximately 46.4 million adults had arthritis (4). Because physical activity is a recommended self-management strategy for both conditions, examining the effect of co-existing arthritis and diabetes on physical activity levels is warranted.

The results of this analysis indicated that, during 2005 and 2007, doctor-diagnosed arthritis affected approximately half of adults with doctor-diagnosed diabetes. The prevalence of self-reported physical inactivity was significantly higher among those with arthritis and diabetes than among those with diabetes alone. This association remained significant after adjustment for age, sex, and BMI, factors that might have otherwise explained the association. State-specific estimates were consistent with the overall findings, with state-to-state differences likely attributable to differences in the distribution of factors associated with both arthritis and physical inactivity in the state population. Because BRFSS data are cross-sectional, they can only demonstrate an association; the temporal sequence of condition onset is unknown.

The associations between arthritis and physical inactivity among adults with diabetes found in this analysis suggest that arthritis might be a barrier to being physically active in this population. Being more physically active (e.g., through aerobic exercise or strength training) can benefit persons with either arthritis or diabetes and those with both conditions (1). Persons with diabetes who are inactive and become more active benefit from improved physical function and glucose tolerance (5), but they face the same common barriers to being more physically active as most adults, such as lack of time, competing responsibilities, lack of motivation, and difficulty finding an enjoyable activity (6). Those who also have arthritis face additional disease-specific barriers, such as concerns about aggravating arthritis pain (6) and causing further joint damage, and they might be unsure about which types and amounts of activity are safe for their joints. Health-care providers interested in improving diabetes management might want to especially consider arthritis-related barriers among persons with diabetes who are physically inactive.

Specially tailored self-management education interventions, such as the Chronic Disease Self Management Program (7) and the arthritis-specific Arthritis Foundation Self-Help Program, help adults learn to manage arthritis pain and discuss how to safely increase physical activity (8). In addition, several exercise programs, including EnhanceFitness (2), the Arthritis Foundation Exercise Program, and the Arthritis Foundation Aquatics Program (8), are available in many communities and are appropriate for adults with diabetes and arthritis. Self-directed physical activities, including joint-friendly activities such as walking, swimming, and biking, also are appropriate for adults with both conditions.^¶

The findings in this report are subject to at least five limitations. First, doctor-diagnosed arthritis, doctor-diagnosed diabetes, and activity level are self-reported in BRFSS and have not been confirmed by a health-care provider or objective monitoring; however, such self-reports have been shown to be valid for surveillance purposes (9,10). Second, BRFSS is a telephone survey and does not include persons without landline telephones, persons in the military, or those residing in institutions. Third, comparisons of tabular data between states should be made with caution because the prevalence estimates are not adjusted for population characteristics (e.g., age) that might explain differences. Unadjusted data are presented in this report to provide actual estimates for state-level program planning. Fourth, BRFSS response rates were low for both survey years. BRFSS weighting procedures partially correct for nonresponse. The effect of low response rates is uncertain. Finally, the findings in this report do not account for persons with undiagnosed diabetes.

In 2007, CDC released a reference guide for planning physical activity interventions for older adults, including those with diabetes (2). This guide suggests different programs sensitive to the medical needs of persons with diabetes and those with chronic disease complications or physical limitations, and promotes active aging among persons not yet limited by complications or limitations of diabetes or arthritis. Because arthritis appears to be an additional barrier to increasing physical activity, state-level diabetes programs whose aim is to increase physical activity among adults with diabetes might meet their own goals more readily by integrating their efforts with arthritis programs.

References

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