# Obesity as a Risk Factor for Carpal Tunnel Syndrome Independent of Diabetes Mellitus: A Nationwide Study

## TL;DR

This study shows that obesity significantly increases the risk of carpal tunnel syndrome, even when diabetes is not present.

## Contribution

The study identifies obesity as an independent risk factor for CTS at a population level, separate from diabetes.

## Key findings

- Obese adults had nearly six times higher CTS prevalence than nonobese adults.
- Obese adults without diabetes still had five times higher CTS prevalence than nonobese adults without diabetes.
- Obese adults without diabetes had higher CTS rates than nonobese adults with diabetes.

## Abstract

Although the relationship between diabetes mellitus (DM) and carpal tunnel syndrome (CTS) is well documented because of diabetic neuropathic complications, a relationship specific to CTS and obesity has not yet been identified on a population level. The current study seeks to compare CTS prevalence between obese and nonobese patients and examine relationships among obesity, DM, and CTS.

Data used in this study came from Epic Cosmos, a community collaboration of health systems representing over 227,000,000 patient records from over 1,301 hospitals and 28,600 clinics. All patients at least 18 years of age with an encounter between December 2013 and December 2023 were included and grouped based on presence or absence of International Classification of Diseases-10 codes for CTS, obesity, and DM as well as Current Procedural Terminology codes for EMG and nerve conduction studies. Here, 99% confidence intervals were recorded, and odds ratios (OR) were calculated for group comparison using P < .01 for significance.

All adult patients with a documented obesity diagnosis showed a near six-fold increase in CTS prevalence compared with nonobese adult patients. When excluding those with a documented DM diagnosis, this relationship was largely maintained with a five-fold increased prevalence in obese adults without DM compared with nonobese adults without DM. Additionally, obese adults without DM had a higher rate of CTS compared to nonobese, diabetic adults.

Although DM patients are classically associated with CTS presentation, obesity even without DM may possess a similar or more powerful relationship. Additionally, comorbidity of obesity and DM suggests an additive effect between the two diagnoses on increased CTS prevalence. However, further research must be performed to evaluate the anatomic and pathologic mechanism of this relationship.

Differential Diagnosis/Symptom Prevalence Study, Level 2b.