Obesity and 1-Year Outcomes in Older Americans With Severe Sepsis*

Abstract

Objectives While critical care physicians view obesity as an independent poor prognostic marker, growing evidence suggests that obesity is, instead, associated with improved mortality following ICU admission. However, this prior empirical work may be biased by preferential admission of obese patients to ICUs, and little is known about other patient-centered outcomes following critical illness. We sought to determine whether one-year mortality, health care utilization, and functional outcomes following a severe sepsis hospitalization differ by BMI. Design Observational cohort study. Patients We analyzed 1,404 severe sepsis hospitalizations (1999–2005) among Medicare beneficiaries enrolled in the nationally representative Health & Retirement Study, of which 597 (42.5%) were normal weight, 473 (33.7%) were overweight, and 334 (23.8%) were obese or severely obese, as assessed at their survey prior to acute illness. Underweight patients were excluded a priori. Interventions None. Measurements and Main Results Using Medicare claims, we identified severe sepsis hospitalizations and measured inpatient health care facility use and calculated total and itemized Medicare spending in the year following hospital discharge. Using the National Death Index, we determined mortality. We ascertained pre- and post-morbid functional status from survey data. Patients with greater BMIs experienced higher 1-year mortality compared to non-obese patients, and there was a dose response relationship such that obese (OR=0.59, 95%CI 0.39, 0.88) and severely obese patients (OR=0.46, 95%CI 0.26, 0.80) had the lowest mortality. Total days in a health care facility and Medicare expenditures were greater for obese patients (p<0.01 for both comparisons), but average daily utilization (p=0.44) and Medicare spending were similar (p=0.65) among normal, overweight and obese survivors. Total function limitations following severe sepsis did not differ by BMI category (p=0.64). Conclusions Obesity is associated with improved mortality among severe sepsis patients. Due to longer survival, obese sepsis survivors use more health care and result in higher Medicare spending in the year following hospitalization. Median daily health care utilization was similar across BMI categories.

Incidence of high body mass index in critically ill cancer patients

“…The ICU mortality in critically ill patients with a BMI ≥25 kg/m 2 depends primarily on the number of organ failures, especially when two or more organs are affected. The incidence of high BMI in patients enrolled in the present study was higher than those described by other authors, who have report- ed an incidence ranging from 5-25% (5,7,8,14,(25)(26)(27), similar to the data shown in the national health survey of 2012. In the general population, an increase in the incidence of oncologic diseases was observed, which may be associated with the advent of new diagnostic techniques and treatment protocols for oncologic patients, thus allowing an improvement of the survival rate.…”

“…Several authors have described that patients without cancer with certain degrees of obesity have better survival to clinical conditions that endanger life during the ICU stay, which has been defined as paradoxical obesity (15,26,27). In contrast, the results of the present study, which included only critically ill oncologic patients, failed to establish an association between high BMI and better prognosis in ICU; therefore, the ICU mortality of patients with BMI < 25 kg/m 2 and ≥ 25 kg/m 2 was similar.…”

The obesity factor in critical illness

“…Likewise, a recent retrospective study of 792 patients with severe sepsis showed that the survival rate of morbidly obese patients was twofold better than underweight and normal-weight patients. 53 The protective study of Prescott et al 52 examined the association of BMI with mortality rate in 1,404 patients with severe sepsis and showed that obesity was, in fact, associated with improved shortterm (90 days) and long-term (1 year) mortality in older patients. 52 Although unanimous, these investigations performed in ICU setting contradict other findings showing that obesity is a risk factor for increased mortality in pandemic viral infections such as the H1N1 viruses.…”

Impact of body mass index on clinical outcomes in patients with gram-negative bacteria bloodstream infections

“…In a separate analysis by Prescott et al, patients with severe sepsis that were obese (OR ¼ 0.59, 95% CI 0.39e0.88) and severely obese (OR 0.46, 95% CI 0.26e0.88) had a lower risk of death at 1 year than normal weight patients. However, obese patients were noted to have greater Medicare expenditures [24]. Our analysis suggests that patients with excess BMI may be more likely to develop respiratory or renal failure, potentially leading to increased healthcare expenditures.…”