Difference in Presentation of Charcot Osteoarthropathy in Type 1 Compared With Type 2 Diabetes

The majority of patients developing Charcot osteoarthropathy (COA) are in their 6th and 7th decades, and 80% of them have had diabetes for over 10 years (1). However, no reports have assessed the differences in the demographic features of patients with type 1 and type 2 diabetes. The purpose of this study was to compare the age of presentation and duration of diabetes at the onset of COA in type 1 and type 2 diabetes.

We reviewed 85 patients presenting with acute COA to the Diabetic Foot Clinic. In agreement with previous studies, their mean age was 51 ± 12.4 years (mean ± SD) and mean duration of diabetes 19 ± 10 years. The patients were divided into two groups according to the type of diabetes: group 1 included 44 patients with type 1 diabetes (17 men, 27 women), and group 2 included 41 patients with type 2 diabetes (22 men, 19 women). The diagnosis of acute COA was based on the recent development of red hot swollen foot, skin foot temperature difference (>2°C) compared with the opposite foot, and typical radiological findings of COA (2).

In patients with type 1 diabetes, the most frequent decade for presentation of COA was the 5th decade (40–49 years), while for patients with type 2 diabetes it was the 6th decade (50–59 years). In type 1 diabetes, the highest rate of presentation was among those with duration of diabetes for 20–24 years, while for type 2 diabetes, the highest rate of presentation was in patients with duration of diabetes of 5–9 years.

At the time of onset of COA, patients with type 1 diabetes had longer duration of diabetes than the patients with type 2 diabetes (24 ± 8.4 vs. 13 ± 8.1 years, P < 0.001) but developed Charcot osteoarthropathy at an earlier age (42 ± 10.2 vs. 59 ± 7.8 years, P < 0.001). There was a significant correlation between age and duration of diabetes in type 1 diabetic patients (r = 0.487, P < 0.01). However, no association was observed between age and duration of diabetes in type 2 diabetic patients (r = 0.28, P > 0.05).

This study has demonstrated that there are type differences in the demographic features of patients with type 1 and type 2 diabetes developing COA. In type 1 diabetes, the age of onset was lower when compared with that of type 2 diabetes. It is thus important to be aware that COA can present at a young age in patients with long-standing type 1 diabetes. There is a striking similarity in the distribution of peak age and duration and a similar reported peak prevalence of autonomic neuropathy in type 1 diabetes (3).

There was a relative preponderance of type 1 diabetes (51.7%) compared with type 2 diabetes in our series, which has not been reported previously, and this requires further study.