Diabetes and risk of physical disability in adults: a systematic review and meta-analysis

Background
According to previous reports, the risk of disability as a result of diabetes varies from none to double. Disability is an important measure of health and an estimate of the risk of disability as a result of diabetes is crucial in view of the global diabetes epidemic. We did a systematic review and meta-analysis to estimate this risk.

Methods
We searched Ovid, Medline, Embase, Cochrane Library, and Cumulative Index to Nursing and Allied Health Literature up to Aug 8, 2012. We included studies of adults that compared the risk of disability—as measured by activities of daily living (ADL), instrumental activities of daily living (IADL), or mobility—in people with and without any type of diabetes. We excluded studies of subpopulations with specific illnesses or of people in nursing homes. From the studies, we recorded population characteristics, how diabetes was diagnosed (by doctor or self-reported), domain and definition of disability, and risk estimates for disability. We calculated pooled estimates by disability type and type of risk estimate (odds ratio [OR] or risk ratio [RR]).

Results
Our systematic review returned 3224 results, from which 26 studies were included in our meta-analyses. Diabetes increased the risk of mobility disability (15 studies; OR 1·71, 95% CI 1·53—1·91; RR 1·51, 95% CI 1·38—1·64), of IADL disability (ten studies; OR 1·65, 95% CI 1·55—1·74), and of ADL disability (16 studies; OR 1·82, 95% CI 1·63—2·04; RR 1·82, 95% CI 1·40—2·36).

Interpretation
Diabetes is associated with a strong increase in the risk of physical disability. Efforts to promote healthy ageing should account for this risk through prevention and management of diabetes.

Funding
Monash University, Baker IDI Bright Sparks Foundation, Australian Postgraduate Award, VicHealth, National Health and Medical Research Council, Australian Research Council, Victorian Government.