Prevalence of prediabetes in patients with idiopathic frozen shoulder: a prospective study

Background: The association between diabetes and frozen shoulder is well established. However, the data regarding prediabetes and primary frozen shoulder (PFS) are still lacking. Methods: In a prospective study, 158 patients with PFS were included. The prediabetes status was ascertained by estimating serum hemoglobin A1c (HbA1c) levels in patients with PFS. According to the level of HbA1c, patients were classified into normoglycemic, prediabetic, and diabetic. In addition, random blood sugar (RBS) was also performed. Results: Out of 158 participants, 84 (53.2%) were male and 74 (46.8%) were female. Nine patients had bilateral shoulder involvement, and all were diabetics; 47.5% (n = 75) of the patients were in the age group of 51-60 years, 16.5% (n = 26) of the participants were normoglycemic, 37.3% (n = 59) were prediabetics, and 46.2% (n = 73) were diabetics. The difference in mean HbA1c values between the 3 groups was statistically significant (P <.001). However, there was no statistical difference in various age groups (P =.86) or gender (P =.68) between normoglycemics, prediabetics, and diabetics. The difference in mean RBS values between diabetic-nondiabetic and diabetic-prediabetic groups were statistically significant (P <.001), whereas no significant difference was detected between nondiabetic and prediabetic (P =.355). Conclusion: The prevalence of prediabetes is 37.5% in patients with PFS. Single-point HbA1c estimation is an acceptable tool to detect prediabetes, whereas RBS estimation should not be used to detect prediabetes.