Splenectomy and the subsequent development of type 2 diabetes: a 9-year nationwide retrospective cohort study

Although the spleen plays a vital role in immune modulation and metabolic regulation, its long-term metabolic consequences, including the risk of type 2 diabetes, remain unclear. We aimed to investigate the association between splenectomy and the risk of developing type 2 diabetes using a large-scale nationwide cohort in Korea.

This retrospective cohort study utilized data from the Korean National Health Insurance Service and included 4,132,510 adults aged ≥20 years who underwent health screenings in 2012. Of these, 698 individuals had undergone splenectomy. Splenectomy status was identified via procedure codes P2091, and the underlying causes were classified into trauma, cancer, and other medical conditions. Cox proportional hazards models were used to evaluate the risk of type 2 diabetes according to splenectomy status, adjusting for sociodemographics, lifestyles, and comorbidities.

The mean age of participants was 47.1 years, and 53.2% were male. During a median follow-up of 10.3 years, the incidence rate of type 2 diabetes was higher in the splenectomy group than in the non-splenectomy group (19.5 vs. 9.5 per 1,000 person-years). Splenectomy was associated with an increased risk of type 2 diabetes (adjusted hazard ratio [HR] 2.35, 95% confidence interval [CI] 1.96-2.81), particularly among individuals who underwent non-traumatic splenectomy (HR 2.54, 95% CI 2.11-3.06). Among the non-traumatic splenectomy causes, cancer-related splenectomy (HR 3.96, 95% CI 3.05-5.17) and other medical conditions (HR 1.91, 95% CI 1.47-2.46) showed higher risks of type 2 diabetes. This association was more pronounced among older adults and remained robust across stratified and sensitivity analyses.

This large-scale cohort study demonstrated a significant association between splenectomy and an increased risk of type 2 diabetes, particularly in non-traumatic cases due to cancer. These findings highlight the importance of metabolic monitoring and targeted preventive strategies in post-splenectomy patients to mitigate future diabetes risk.