Idiopathic Frozen Shoulder in Individuals with Diabetes: Association with Metabolic Control, Obesity, Antidiabetic Treatment and Demographic Characteristics in Adults with Type 1 or 2 Diabetes from the DPV Registry.

AIMS: To examine the association of frozen shoulder (FS) with demographic and diabetes-related outcomes in individuals with type 1 (T1D) or type 2 (T2D) diabetes aged ≥30 years. MATERIALS AND METHODS: Multivariable logistic regression models, adjusted for demographics were used to calculate the proportion of FS in association with age, gender, diabetes duration, body mass index (BMI), haemoglobin A1C (HbA1c) and diabetes treatment. RESULTS: The unadjusted percentage of FS was higher in T1D compared to T2D (0.22% vs. 0.06%). In T1D, adjusted regression models revealed higher prevalence of FS in women than men (0.26 [0.20-0.34] % vs. 0.15 [0.11-0.21] %, p=0.010). No significant relationship of age and BMI with FS was found in both diabetes types. Longer diabetes duration was associated with a higher proportion of FS in T1D (p<0.001) and T2D (p=0.004). In T1D, HbA1c >7% was related to a higher proportion of FS compared to HbA1c ≤7% (0.25 [0.19-0.32] vs. 0.12 [0.08-0.20] %, p=0.007), while an inverse relationship was found in T2D (HbA1c ≤7%: 0.08 [0.07-0.10] vs. HbA1c >7%: 0.05 [0.04-0.06] %, p=0.001). CONCLUSIONS: Different associations of FS with gender and HbA1c were observed for T1D and T2D; however, longer diabetes duration increases the risk for FS independent of diabetes type. Musculoskeletal diseases are still underreported in individuals with diabetes and awareness should be raised for FS as a specific diabetes complication.