DIABETES AS A RISK FACTOR FOR THE ONSET OF FROZEN SHOULDER: A SYSTEMATIC REVIEW AND META-ANALYSIS

Abstract

Objective:  The objective of this study was systematic review and meta-analysis, with diabetes as a risk factor for the onset of frozen shoulder.

Study design: Systematic review and meta-analysis

Place and duration of study: Department of Medicine, Tertiary Care Hospital, Lahore from December 2024- May 2025.

Methodology: This systematic review and meta-analysis was conducted according to PRISMA guidelines to evaluate diabetes mellitus as a risk factor for frozen shoulder. Electronic databases including PubMed, Scopus, Embase, Web of Science, and Google Scholar were searched for studies published between 2000 and 2024 using keywords related to “diabetes mellitus” and “frozen shoulder” or “adhesive capsulitis.” Observational studies involving adult participants and reporting quantitative associations between diabetes and frozen shoulder were included. Case reports, reviews, conference abstracts, pediatric studies, and non-English articles were excluded. Two independent reviewers screened articles, extracted data, and assessed study quality using the Newcastle–Ottawa Scale. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using a random-effects model, while heterogeneity was assessed using the I² statistic.

Results: A total of 18 observational studies involving 42,735 participants were included in the meta-analysis. Among these, 16,482 participants had diabetes mellitus. The pooled analysis demonstrated that diabetic individuals had a significantly greater risk of developing frozen shoulder compared with non-diabetic individuals (OR = 3.12; 95% CI: 2.45–3.97; p < 0.001). Moderate heterogeneity was observed among studies (I² = 58%). Subgroup analysis indicated a stronger association in type 2 diabetes compared with type 1 diabetes. Studies with poor glycemic control and longer diabetes duration reported higher prevalence and severity of frozen shoulder. Most included studies were of moderate-to-high methodological quality.

Conclusion: Diabetes mellitus is strongly associated with an increased risk of developing frozen shoulder, particularly among patients with poor glycemic control and longer disease duration.