This 1972 study examined whether adhesive capsulitis (frozen shoulder) is associated with diabetes mellitus. It compared the incidence of periarthritis of the shoulder in 800 diabetic out-patients against 600 non-diabetic medical controls of similar age. It also assessed whether neuropathy, immobilization, or diabetes severity explained the link.
When a patient presents with a stiff, painful shoulder and progressive loss of passive external rotation, diabetes should be on your radar, particularly if both shoulders are affected. This paper quantified what clinicians suspected: frozen shoulder is about 5x more common in diabetics (10.8% vs 2.3%), and the risk rises with insulin dependence and disease duration.
The practical decision rule flows directly from the bilateral finding. Bilateral frozen shoulder in an undiagnosed patient warrants screening for diabetes. The authors also cleared away competing explanations. Neuropathy rates were identical in diabetics with and without shoulder disease, and patients were fully ambulant, so neither immobilization nor peripheral nerve damage accounts for the link.
For a trainee, the takeaway is a mental model: frozen shoulder is a fibrotic capsular condition, not an inflammatory one. Normal ESR, uric acid, and rheumatoid factor are expected and help exclude mimics like rheumatoid arthritis and gout.
This 1972 study examined whether adhesive capsulitis (frozen shoulder) is associated with diabetes mellitus. It compared the incidence of periarthritis of the shoulder in 800 diabetic out-patients against 600 non-diabetic medical controls of similar age. It also assessed whether neuropathy, immobilization, or diabetes severity explained the link.
When a patient presents with a stiff, painful shoulder and progressive loss of passive external rotation, diabetes should be on your radar, particularly if both shoulders are affected. This paper quantified what clinicians suspected: frozen shoulder is about 5x more common in diabetics (10.8% vs 2.3%), and the risk rises with insulin dependence and disease duration.
The practical decision rule flows directly from the bilateral finding. Bilateral frozen shoulder in an undiagnosed patient warrants screening for diabetes. The authors also cleared away competing explanations. Neuropathy rates were identical in diabetics with and without shoulder disease, and patients were fully ambulant, so neither immobilization nor peripheral nerve damage accounts for the link.
For a trainee, the takeaway is a mental model: frozen shoulder is a fibrotic capsular condition, not an inflammatory one. Normal ESR, uric acid, and rheumatoid factor are expected and help exclude mimics like rheumatoid arthritis and gout.