Visceral Fat Quantified by a Fully Automated Deep-Learning Algorithm and Risk of Incident and Recurrent Diverticulitis

Dis Colon Rectum. 2025 Mar 4. doi: 10.1097/DCR.0000000000003677. Online ahead of print.

ABSTRACT

BACKGROUND: Obesity is a risk factor for diverticulitis. However, it remains unclear whether visceral fat area, a more precise measurement of abdominal fat, is associated with the risk of diverticulitis.

OBJECTIVE: To estimate the risk of incident and recurrent diverticulitis according to visceral fat area.

DESIGN: A retrospective cohort study.

SETTINGS: The Mass General Brigham Biobank.

PATIENTS: 6,654 patients who underwent abdominal CT for clinical indications and had no diagnosis of diverticulitis, inflammatory bowel disease, or cancer before the scan.

MAIN OUTCOME MEASURES: Visceral fat area, subcutaneous fat area, and skeletal muscle area were quantified using a deep-learning model applied to abdominal CT. The main exposures were z-scores of body composition metrics, normalized by age, sex, and race. Diverticulitis cases were defined with the ICD codes for the primary or admitting diagnosis from the electronic health records. The risks of incident diverticulitis, complicated diverticulitis, and recurrent diverticulitis requiring hospitalization according to quartiles of body composition metrics z-scores were estimated.

RESULTS: A higher visceral fat area z-score was associated with an increased risk of incident diverticulitis (multivariable HR comparing the highest versus lowest quartile, 2.09; 95% CI, 1.48-2.95; P for trend <.0001), complicated diverticulitis (HR, 2.56; 95% CI, 1.10-5.99; P for trend = .02), and recurrence requiring hospitalization (HR, 2.76; 95% CI, 1.15-6.62; P for trend = .03). The association between visceral fat area and diverticulitis was not materially different among different strata of body mass index. Subcutaneous fat area and skeletal muscle area were not significantly associated with diverticulitis.

LIMITATIONS: The study population was limited to individuals who underwent CT scans for medical indication.

CONCLUSION: Higher visceral fat area derived from CT was associated with incident and recurrent diverticulitis. Our findings provide insight into the underlying pathophysiology of diverticulitis and may have implications for preventive strategies. See Video Abstract.

PMID:40272787 | DOI:10.1097/DCR.0000000000003677