Caspersen et al. Respond

We thank Arredondo for his interest in our article and his description of the economic burden of diabetes for older adults in Mexico, a middle-income country. Clearly, many countries contribute to a huge and growing worldwide diabetes problem. Projections from 2010 to 2030 estimate that diabetes cases among adults aged 65 years and older will increase by 207% (from 27 to 83 million cases) in developing countries and by 81% (from 26 to 47 million cases) in developed countries.¹

Correspondingly, the global economic burden from 2010 to 2030 is projected to increase dramatically for diabetes and its many complications and comorbid conditions.² Regarding comorbid conditions, which add to costs, diabetes co-occurs with many other chronic conditions more so among those aged 65 years and older than among those who are younger (6.5 vs 2.9 conditions, respectively) in the United Kingdom.³ Governments of poorer countries spend less per capita on diabetes, leaving substantial costs to be paid by other means. Arredondo noted that older adult Mexicans with diabetes incur large out-of-pocket costs. Even in the more affluent United States, Medicare beneficiaries have an annual median out-of-pocket cost of $3241 per person.⁴

We agree with Arredondo concerning the urgent need for diabetes prevention efforts worldwide. We found that in the United States alone, almost 50% of older adults have prediabetes. Each day from January 1, 2011, approximately 10 000 adults turned 65 years old—an anticipated trend for the next 17 years.⁵ The Diabetes Prevention Program⁶ showed impressive declines in diabetes development through lifestyle intervention among older adults, pointing to the value of the National Diabetes Prevention Program led by the Centers for Disease Control and Prevention (http://www.cdc.gov/diabetes/prevention/about.htm) and a specific need to target older adults.

The sad truth is that intensive efforts are required to manage and prevent diabetes and its complications. Such efforts are compounded, for example, when physical activity programs must accommodate participants’ differing physical functional statuses—from being homebound to being unimpaired and having no comorbid conditions—which vary across US states for inactive adults aged 50 years and older.⁷ For this age group, those with prediabetes tend to have better physical function than those with diagnosed diabetes.⁸ Clearly, physical activity programs must accommodate functional status⁷ to help prevent or delay diabetes and its complications.

In all, Arredondo has highlighted the need for intensified public health efforts by all countries dealing with the unique national and individual burdens associated with diabetes management and prevention among older adults.