The Predictive Value of Serum Sodium Levels and Inflammatory Markers in Differentiating Complicated and Uncomplicated Acute Diverticulitis: A Retrospective Cohort Study

<i>Background and Objectives</i>: This study aimed to investigate the role of serum sodium levels as an independent predictor of complications in acute diverticulitis and to evaluate their diagnostic value alongside inflammatory markers. <i>Materials and Methods</i>: A total of 134 patients diagnosed with acute diverticulitis between June 2018 and January 2024 at the Erol Olçok Training and Research Hospital were retrospectively analyzed. Complicated diverticulitis was defined based on the presence of an abscess, perforation, fistula, or obstruction classified as Hinchey stage II-IV. Serum sodium, CRP, and WBC levels were assessed for their predictive value. Statistical analyses included ROC analysis to determine optimal thresholds and logistic regression to evaluate independent predictors. <i>Results</i>: A total of 29.1% of the patients were classified as having complicated diverticulitis. Serum sodium levels were significantly lower in the complicated group (median: 133 mmol/L, <i>p</i> < 0.001), whereas CRP (median: 86.5 mg/L, <i>p</i> < 0.001) and WBC levels (median: 11.62 × 10³/µL, <i>p</i> = 0.001) were higher. The ROC analysis identified <135.5 mmol/L as the optimal threshold for serum sodium, with a 94.9% sensitivity and 94.7% specificity, making it the strongest predictor. The logistic regression revealed that each unit decrease in serum sodium increased the risk of complications by 5.7 times (<i>p</i> < 0.001). <i>Conclusions</i>: Serum sodium levels are an independent and strong predictor of complications in acute diverticulitis. When used alongside CRP and WBC levels, diagnostic accuracy can be enhanced, leading to improved patient management.