Does the “Obesity Paradox” Have an Expiration Date? A Retrospective Cohort Study

Abstract

(1) Background: The “obesity paradox” refers to a protective effect of higher body mass index (BMI) on mortality in acute infectious disease patients. However, the long-term impact of this paradox remains uncertain. (2) Methods: A retrospective study of patients diagnosed with community-acquired acute infectious diseases at Shamir Medical Center, Israel (2010–2020) was conducted. Patients were grouped by BMI: underweight, normal weight, overweight, and obesity classes I–III. Short- and long-term mortality rates were compared across these groups. (3) Results: Of the 25,226 patients, diverse demographics and comorbidities were observed across BMI categories. Short-term (90-day) and long-term (one-year) mortality rates were notably higher in underweight and normal-weight groups compared to others. Specifically, 90-day mortality was 22% and 13.2% for underweight and normal weight respectively, versus 7–9% for others (p < 0.001). Multivariate time series analysis revealed underweight individuals had a significantly higher 5-year mortality risk (HR 1.41 (95% CI 1.27–1.58, p < 0.001)), while overweight and obese categories had a reduced risk (overweight—HR 0.76 (95% CI 0.72–0.80, p < 0.001), obesity class I—HR 0.71 (95% CI 0.66–0.76, p < 0.001), obesity class II—HR 0.77 (95% CI 0.70–0.85, p < 0.001), and obesity class III—HR 0.79 (95% CI 0.67–0.92, p = 0.003)). (4) Conclusions: In this comprehensive study, obesity was independently associated with decreased short- and long-term mortality. These unexpected results prompt further exploration of this counterintuitive phenomenon.

Weight loss-induced adipose macrophage memory improves localStaphylococcus aureusclearance in male mice

“…Thus, there is an interesting relationship between weight and response to infection that is also supported in the literature. In humans, some report an obesity paradox, in which sepsis patients who meet the criteria for overweight and obese have lower mortality than lean individuals [32][33][34] . This may be due to patients with higher adiposity having higher metabolic reserves, higher secretion of anti-inflammatory mediators by adipose tissue, and higher lipoprotein concentrations to bind to bacterial LPS to dampen the early cytokine storm 35,36 .…”