Supraspinatus Tendon Thickness in Type 2 Diabetes Patients With Shoulder Pain: Correlations With HbA1c and Advanced Glycation End Product Accumulation

• Grant number: 25/14459-2
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: November 01, 2025
• End date: February 28, 2026
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Paula Rezende Camargo
• Grantee: Luísa de Paula Castanheira
• Supervisor: Fernanda Assis Paes Habechian Zamuner
• Host Institution: Centro de Ciências Humanas e Biológicas (CCHB). Universidade Federal de São Carlos (UFSCAR). Sorocaba , SP, Brazil
• Institution abroad: Universidad Católica Del Maule Talca, Chile
• Associated to the scholarship: 24/16213-8 - Perceptions of individuals with Diabetes Mellitus on sensory, motor and functional alterations in the upper limbs: a qualitative study., BP.IC

Abstract

Diabetes mellitus (DM) is a chronic metabolic disorder characterized by persistent hyperglycemia, currently affecting over 588¿million people worldwide. One biochemical consequence of sustained hyperglycemia is the accumulation of advanced glycation end-products (AGEs), which are implicated in various diabetic complications, including musculoskeletal disorders. Despite their high prevalence, musculoskeletal complications in DM-particularly those affecting the upper limbs-remain underrecognized. Recent evidence suggests that AGEs may contribute to tendon degeneration by altering collagen structure and disrupting tendon homeostasis. Among the tendons affected, the supraspinatus tendon is of particular interest due to its key role in shoulder pain and functional impairment. This study aims to investigate the association between supraspinatus tendon thickness and glycemic biomarkers-specifically HbA1c levels and AGE accumulation-in individuals with type¿2 DM and shoulder pain. We will perform a secondary analysis of baseline data from a randomized controlled trial conducted in Chile, which enrolled participants aged 40-75¿years with type¿2 DM and chronic shoulder pain. Supraspinatus tendon thickness will be measured using musculoskeletal ultrasound; AGE accumulation assessed via skin autofluorescence; and HbA1c quantified through standard blood tests. Depending on data distribution, we will use Pearson's or Spearman's correlation to examine the relationships between variables. Linear regression analyses will assess whether HbA1c and AGE accumulation can predict supraspinatus tendon thickness, adjusting for possible confounders. A p-value of < 0.05 will be considered statistically significant. We hypothesize that higher HbA1c levels and greater AGE accumulation will be associated with increased supraspinatus tendon thickness. The findings of this study are expected to enhance understanding of upper limb complications in DM and elucidate the musculoskeletal impact of poor glycemic control, ultimately informing the development of targeted preventive and therapeutic strategies for this population.