# Frozen Shoulder as a Metabolic Signal: Advocating Routine HbA1c Screening in Atraumatic Cases

## TL;DR

Frozen shoulder may signal hidden diabetes or prediabetes, suggesting the need for routine HbA1c screening in patients with unexplained shoulder stiffness.

## Contribution

Proposes frozen shoulder as a metabolic indicator and advocates for HbA1c screening in atraumatic cases to detect dysglycemia early.

## Key findings

- Frozen shoulder patients often have elevated HbA1c despite normal glucose tests.
- Metabolic changes like collagen glycation may cause capsular fibrosis in frozen shoulder.
- Routine HbA1c screening could improve diabetes detection and shoulder outcomes.

## Abstract

Frozen shoulder, also known as adhesive capsulitis, is often regarded as a localized musculoskeletal disorder. However, it may also be an early indicator of underlying metabolic dysfunction, particularly diabetes or prediabetes. Many patients presenting with atraumatic, progressive shoulder stiffness are found to have elevated HbA1c levels despite normal fasting and postprandial glucose values. Diabetes-related tissue changes, such as collagen glycation and microvascular compromise, may contribute to the development of capsular fibrosis. Recognizing this, routine HbA1c screening in such presentations can aid early diagnosis of dysglycemia and enable timely intervention. This approach may promote interdisciplinary care and improve both systemic and shoulder outcomes. Clinicians should consider frozen shoulder within a broader metabolic-inflammatory framework, especially in middle-aged patients with persistent symptoms and no clear alternative diagnosis.