Association of Exfoliation Syndrome With Risk of Indirect Inguinal Hernia: The Utah Project on Exfoliation Syndrome.

Importance: Exfoliation syndrome (XFS) is a systemic connective tissue disease, and abnormal connective tissue metabolism is implicated in inguinal hernias (IH). Associating XFS with comorbid conditions may illuminate their underlying pathophysiology and affect clinical screening and treatment. Exfoliation syndrome involves altered systemic extracellular matrix (ECM) homeostasis involving elastin metabolism. Hernias occur owing to abnormal ECM synthesis, metabolism, or repair. Inguinal hernias involve weakening or rupture of the abdominal/groin wall.

Objective: To determine an association between patients with XFS and patients with IH in Utah, possibly differing between direct or indirect hernia.

Design, Setting, and Participants: Cross-sectional study in a large health care system of Utah hospitals and clinics. Conditional logistic regression odds ratios were used to estimate risk of XFS in patients with IH overall and by subtype (direct or indirect) compared with control individuals. Codes specific to direct and indirect IH with additional medical records review of 186 procedures were used to classify IH subtypes that were not prespecified. Bootstrap resampling with jackknife estimation used to calculate 95% confidence intervals. The model accounted for matching on sex and age and adjusted for body mass index and tobacco use. Population-based sample using medical records from 1996 to 2015 that identified 2594 patients 40 years or older on January 1, 1996, with surgical IH repair and 12 966 random control patients with no IH history matched 5:1 on sex and birth year. Data were analyzed between September 10, 2017, and October 23, 2017.

Main Outcomes and Measures: Exfoliation syndrome outcome defined by diagnosis codes for XFS or exfoliation glaucoma from 1996 to 2015.

Results: Participants were primarily white (2532 of 2594 patients, [96.1%]; 12 454 of 12 966 control individuals [97.6%]) and non-Hispanic (2396 of 2594 patients [92.4%]); 250 participants were women (9.6%). Of study participants, 22 patients with IH and 43 control individuals were diagnosed as having XFS, respectively. Patients with IH had a 2.3-fold risk for an XFS diagnosis compared with control individuals (95% CI, 1.4-3.5; P = .03), and XFS risk with indirect IH appeared especially pronounced.

Conclusions and Relevance: Inguinal hernia was associated with an increased risk of XFS in this Utah population. Further work is needed to understand the pathophysiology, genetics, and environmental factors contributing to both diseases.