Original ContributionDoes the obesity paradox apply to early postoperative complications after hip surgery? A retrospective chart review☆,☆☆,★,★★,☆☆☆,☆☆☆☆,★★★,★★★★,☆☆☆☆☆,☆☆☆☆☆☆,★★★★★,★★★★★★
Introduction
The prevalence of overweight and obesity in the American population has increased steadily over the last 25 years [1]. According to the Centers for Disease Control and Prevention, 68.8% of Americans are now classified as overweight (body mass index [BMI] 25-29.9 kg/m2) [1] or obese (BMI > 30 kg/m2) [2], with more than half these patients falling into the obese category. Elevated BMI is associated with comorbidities such as ischemic heart disease [3], type 2 diabetes [4], stroke [5], and hypertension [6], and BMI is positively correlated with all-cause mortality in the general population [7]. The average BMI is increasing in many populations around the world, mounting concern about the public health effects of this obesity epidemic [8].
Recent literature, however, has shown that obesity is associated with better outcomes in certain chronic disease states. This phenomenon was initially termed “reverse epidemiology” in a 2003 review by Kalantar-Zadeh et al [9] proclaiming the protective effect of obesity on survival among dialysis patients. Furthermore, Leavey et al [10] found that in patients undergoing hemodialysis, overweight patients have a lower relative risk of mortality compared with patients with BMIs in the normal, class I obesity, and class II obesity categories. Reverse epidemiology, also known as the “obesity paradox,” is seen in patients with established heart failure as well. A meta-analysis conducted by Oreopoulos et al [11] in 2007 showed that compared with normal BMI, overweight and obesity are associated with lower all-cause mortality in patients with heart failure. On the other hand, the study shows that underweight and low-normal weights compared with normal weight are associated with a higher risk of cardiovascular mortality.
The incidence of hip fracture and its surgical repair are increasing every year [12]. Studies have reported a positive correlation of postoperative complications rates and 1-year mortality rates after the hip replacement surgeries [13].The effect of increased BMI on the rate of complications in patients undergoing surgery, specifically total hip arthroplasty, is not as well described. There is some evidence that morbidly obese patients (BMI > 40 kg/m2) undergoing hip replacement have longer average hospital stays, as well as higher rates of complications and readmission when compared with patients with normal BMI [14]. However, there are few data describing how overweight and obese patients fare in the period directly after hip replacement surgery when compared with patients with low or normal BMI. The goal of this retrospective study was to explore the association, if any, of BMI and immediate postoperative complications in patients undergoing total hip arthroplasty.
Section snippets
Methods
This retrospective study was approved by our institutional review board. Patient data included hospital records from outpatient, inpatient, and emergency department visits. All diagnostic and surgical procedures entered into these records are indexed in a computer database, allowing the retrieval of all records of interest. We queried the Montefiore Medical Center database using a patented hospital software program, Clinical Looking Glass (CLG). The CLG database allows users to create lists of
Results
In total, 142 charts were reviewed. Of these, 46 patients were further excluded from the final analysis, as the only reason for extended stay was receiving blood transfusions and no other medical issues were identified. Demographic data and medical information for all the patients entered into the analysis are listed in Table 1. Age, American Society of Anesthesiologist Physical Status Classification System, length of surgery, and hematocrit before and after surgery were not similar among the
Discussion
In this retrospective review of hip replacement surgery patients, BMI classification was a predictor of early postoperative complications. However, the predictions did not follow a linear pattern. The poorest outcomes were found to be in the underweight, normal, and morbidly obese groups. The phenomenon in which overweight and obese patients exhibit decreased morbidity and mortality rates compared with normal-weight and underweight patients has been termed the “obesity paradox” [16], [17], [18]
References (41)
- et al.
Reverse epidemiology of cardiovascular risk factors in maintenance dialysis patients
Kidney Int
(2003) - et al.
Hip fractures among the elderly: causes, consequences and control
Ageing Res Rev
(2003) - et al.
A new method of classifying prognostic comorbidity in longitudinal studies: development and validation
J Chronic Dis
(1987) - et al.
Undernutrition, hypothermia, and injury in elderly women with fractured femur: an injury response to altered metabolism?
Lancet
(1983) Keeping the young-elderly healthy: is it too late to improve our health through nutrition?
Am J Clin Nutr
(2007)- et al.
The obesity paradox, cardiorespiratory fitness, and coronary heart disease
Mayo Clin Proc
(2012) - et al.
The endotoxin-lipoprotein hypothesis
Lancet
(2000) - et al.
Obesity and suppressed B-type natriuretic peptide levels in heart failure
J Am Coll Cardiol
(2004) - et al.
Higher body mass index leads to longer operative time in total knee arthroplasty
J Arthroplast
(2013) - et al.
ESPEN guidelines on parenteral nutrition: surgery
Clin Nutr
(2009)
Prevalence of overweight and obesity in the United States, 1999–2004
Jama
Prevalence of obesity among adults: United States, 2011-2012
NCHS Data Brief
A prospective study of obesity and risk of coronary heart disease in women
N Engl J Med
Obesity, fat distribution, and weight gain as risk factors for clinical diabetes in men
Diabetes Care
Body mass index and ischemic and hemorrhagic stroke: a prospective study in Korean men
Stroke
Pathophysiology of obesity hypertension
Curr Hypertens Rep
Body-mass index and mortality in a prospective cohort of U.S. adults
N Engl J Med
WHO Global InfoBase team
The SuRF Report 2. Surveillance of chronic disease risk factors: country-level data and comparable estimates
Body mass index and mortality in ‘healthier’ as compared with ‘sicker’ haemodialysis patients: results from the Dialysis Outcomes and Practice Patterns Study (DOPPS)
Nephrol Dial Transplant
The relationship between body mass index, treatment, and mortality in patients with established coronary artery disease: a report from APPROACH
Eur Heart J
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Funding: Departmental funds.
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Information for LWW regarding depositing manuscript into PubMed Central: This paper does not need to be deposited in PubMed Central.
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Submitted as a research report.
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This report describes human research. IRB contact information: Montefiore Medical Center/Albert Einstein College of Medicine IRB, David Wallach, CIP, 3308 Rochambeau Ave, Bronx, NY 10467; Tel.: 718-430-2237.
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The requirement for written informed consent was waived by the institutional review board.
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The study was not registered prior to patient enrollment.
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This was not an observational clinical study.
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This manuscript was screened for plagiarism using CrossRefMe.
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Link to Title Page: http://www.aaauthor.org/pages/8533-2014-Feb-06.
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Role: N.S., J.W., S.N., I.K., and E.D. helped design the study, conduct the study, analyze the data, and write the manuscript. D.G. helped write the manuscript and is the study adviser.
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Conflicts of interest: N.S., J.W., S.N., I.K., D.G., and E.D. reported no conflicts of interest.
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Attestation: N.S., J.W., I.K., and E.D. have seen the original study data, reviewed the analysis of the data, and approved the final manuscript. S.N. has seen the original study data, reviewed the analysis of the data,approved the final manuscript, and is the author responsible for archiving the study files. D.G. approved the final manuscript.