Socio-economic status and lifestyle factors are associated with achalasia risk: a population-based case-control study

Authors

Coleman HG, Gray RT, Lau KW, McCaughey C, Coyle PV, Murray LJ, Johnston BT.

Departments / Institutions

Cancer Epidemiology and Health Services Research Group, Centre for Public Health, Queen’s University Belfast

Publication Date

Autumn 2015

Introduction

Achalasia is a neurodegenerative motility disorder of the oesophagus that results in loss of normal lower oesophageal sphincter function. The aetiology of achalasia is poorly understood. The aim of this study was to evaluate the association between various lifestyle factors and achalasia risk.

Methods

A population-based case-control study was conducted in Northern Ireland, including n=151 achalasia cases and n=117 age- and sex-matched controls. Lifestyle factors were assessed via a face-to-face structured interview. The association between achalasia and lifestyle factors was assessed by unconditional logistic regression, to produce odds ratios (OR) and 95% confidence intervals (CI).

Results

Individuals who had low-class occupations were at the highest risk of achalasia (OR 1.88; 95% CI: 1.02-3.45), inferring that high-class occupation holders have a reduced risk of achalasia. A history of foreign travel, a lifestyle factor linked to upper socio-economic class, was also associated with a reduced risk of achalasia (OR 0.59; 95% CI: 0.35-0.99). Smoking and alcohol consumption carried significantly reduced risks of achalasia, even after adjustment for socio-economic status. The presence of pets in the house was associated with a two-fold increased risk of achalasia (OR 2.00; 95% CI 1.17-3.42). No childhood household factors were associated with achalasia risk. Conclusions: Achalasia is a disease of inequality, and individuals from low socio-economic backgrounds are at highest risk. This does not appear to be due to corresponding alcohol and smoking behaviours. An observed positive association between pet ownership and achalasia risk suggests an interaction between endotoxin and viral infection exposure in achalasia aetiology.