Impact of the Obesity Paradox Between Sexes on In‐Hospital Mortality in Cardiogenic Shock: A Retrospective Cohort Study

Abstract

Background Several studies have shown that obesity is associated with better outcomes in patients with cardiogenic shock (CS). Although this phenomenon, the “obesity paradox,” reportedly manifests differently based on sex in other disease entities, it has not yet been investigated in patients with CS. Methods and Results A total of 1227 patients with CS from the RESCUE (Retrospective and Prospective Observational Study to Investigate Clinical Outcomes and Efficacy of Left Ventricular Assist Device for Korean Patients With Cardiogenic Shock) registry in Korea were analyzed. The study population was classified into obese and nonobese groups according to Asian Pacific criteria (BMI ≥25.0 kg/m 2 for obese). The clinical impact of obesity on in‐hospital mortality according to sex was analyzed using logistic regression analysis and restricted cubic spline curves. The in‐hospital mortality rate was significantly lower in obese men than nonobese men (34.2% versus 24.1%, respectively; P =0.004), while the difference was not significant in women (37.3% versus 35.8%, respectively; P =0.884). As a continuous variable, higher BMI showed a protective effect in men; conversely, BMI was not associated with clinical outcomes in women. Compared with patients with normal weight, obesity was associated with a decreased risk of in‐hospital death in men (multivariable‐adjusted odds ratio [OR], 0.63; CI, 0.43–0.92 [ P =0.016]), but not in women (multivariable‐adjusted OR, 0.94; 95% CI, 0.55–1.61 [ P =0.828]). The interaction P value for the association between BMI and sex was 0.023. Conclusions The obesity paradox exists and apparently occurs in men among patients with CS. The differential effect of BMI on in‐hospital mortality was observed according to sex. Registration URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02985008.

Is There an Obesity Paradox in Cardiogenic Shock?

“…In their multivariate‐adjusted model, mortality was 37% lower in the men who were obese, but obesity did not affect mortality in women, with evidence of significant interaction ( P value for the association between BMI and sex 0.023). The results in the present study by Kwon et al 15 appear to differ from the recent publications, 13 , 14 which did not find an obesity paradox in CS. There are significant methodological differences between prior evaluations and the Kwon study that may shed light on these observations.…”

“…In this issue of the Journal of the American Heart Association (JAHA) , Kwon and colleagues 15 studied 1227 patients with CS from a South Korean registry and classified patients as obese (BMI ≥25 kg/m 2 based on the Asian‐Pacific criteria) and nonobese. In‐hospital mortality was considerably higher in the men who were not obese compared with their counterparts who were obese, whereas BMI was not significantly associated with mortality in women.…”

“…First, Kwon and colleagues 15 used the Asian‐Pacific BMI criteria for obesity (BMI ≥25 kg/m 2 ), and their average BMI in the obese group was only in the 27 to 28 range with very few (n=50) patients with a BMI ≥30 kg/m 2 . The Asian‐Pacific cut‐point for obesity is different because at lower levels of BMI, Asian people have greater body fat and risk of cardiometabolic disease compared with the US and European populations at a similar level of BMI.…”

“… 16 , 17 There are differences among the various Asian populations in cardiometabolic risk, including metabolic syndrome and risk of diabetes at various BMI levels, making it difficult to generalize these results to populations outside of Korea, especially if the Asian people or Asian descendants live in different countries with different environmental factor exposures. Next, the Kwon study 15 curiously found an obesity paradox only in men who were obese, who appeared to be vastly different as a group, including lower age and greater prevalence of ischemic etiology of CS that may be associated with better prognosis (than those with HF and CS) in some studies. In general, CS in the setting of a coronary heart disease event may be associated with recovery and stabilization more often (perhaps facilitated by revascularization) than in situations of severe decompensated HF.…”

Obesity and Critical Illness-Associated Mortality: Paradox, Persistence and Progress*

“…This contrary finding has been referred to as the “obesity paradox” (OP). Since the term OP was first coined 20 years ago (2), it has been reported in diverse populations of critically ill patients including obese patients with sepsis (3), acute respiratory distress syndrome (4), stroke (5), cardiogenic shock (6), pulmonary embolism (7), and acute kidney injury (8) as well as among ICU survivors (9). A number of biological and physiologic mechanisms have been postulated to explain the OP in critical illness including greater energy reserves that may protect against an increased catabolic state and nutritional compromise, increased serum lipid levels which bind and detoxify endotoxin-lipoproteins and block the release of inflammatory cytokines, antioncogenic and immunomodulatory properties of adipose tissue, as well as an increased renin-angiotensin system activation which may confer hemodynamic advantages (10).…”