Obesity-related index predicts risk of death in overweight/obese patients
MedWire News: Increased scores on a novel obesity-related health index are associated with an higher mortality risk, Canadian research suggests.
The association remained statistically significant even after adjusting for body mass index (BMI) and metabolic syndrome or hypertriglyceridemic waist, report Raj Padwal (University of Alberta, Edmonton) and colleagues in the Canadian Medical Association Journal.
The obesity index, known as the Edmonton obesity staging system, is a five point classification system that considers comorbidities and functional status.
The novel obesity staging system is intended to complement anthropometric measures and to tackle some of the limitations of using BMI to assessed risk.
BMI, for example, is able to classify adiposity and estimate its prevalence, but it does not reflect the presence of underlying obesity-related comorbidity, including hypertension, diabetes, and dyslipidemia, reduced quality of life, or diminished functional status.
These measures, investigators say, are "critically important to the clinical assessment of patients with excess body weight."
In the current study, Padwal and colleagues used the Edmonton obesity staging system to predict mortality in a nationally representative sample of US subjects.
Adults 20 years of age and older who were considered overweight or obese were scored using the new staging system.
Over 75% of the cohort received a score of 1 or 2. Patients with scores of 1 typically had obesity-related subclinical risk factors, such as borderline hypertension, or mild physical symptoms, as well as mild impairment of well being. Scores of 2 reflected the presence of established obesity-related chronic disease, such as hypertension or diabetes.
After adjusting for BMI and metabolic syndrome, scores of 2 on the Edmonton index increased the risk for mortality 1.57-fold when compared with individuals with scores of zero or 1.
Scores of 3 increased the risk for mortality 2.69-fold.
"Even within strata of BMI categories, there was clear separation of survival curves according to Edmonton obesity staging system scores," the researchers report.
Lack of sufficient data prohibited the researchers from assigning any patients with scores of 4 on the Edmonton index.
In a cohort of patients eligible for bariatric surgery, a score of 2 was also associated with an increased risk of death (odds ratio [OR]=3.86) as was a score of 3 (OR=12.29).
The risks in both cohorts remained statistically significant even after adjusting for the presence of hypertriglyceridemic waist.
An enhanced risk assessment of overweight and obese patients might enable a better understanding of obesity-related prognoses, according to Padwal and colleagues.
Most importantly, enhanced risk assessment tools might assist in determining the urgency of intervention.
"This may be particularly useful as a means for prioritizing patients for bariatric surgery," they conclude.
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