Waist-To-Hip Ratio vs. Body Mass Index as a Predictor of Total Mortality for People with Normal Weight and Central Obesity

ABSTRACT

Background: Obesity has become one of the greatest health risks in the U.S. Obesity is one of the largest causes of mortality in the country leading to the development of cardiovascular disease, liver disease, and endocrine disorders, to name a few. For decades, the gold standard in predicting a person’s likelihood of developing complications secondary to obesity has been their body mass index (BMI). While BMI succeeds in identifying many who are at risk for developing the complications listed above, there are some individuals who may not receive the proper treatment and preventative measures because they have a normal BMI and excess abdominal adipose tissue. This has lead researchers to investigate whether waist-to-hip ratio or BMI is a better predictor of total mortality in people who have a visceral fat distribution.

Methods:  An exhaustive search of the following databases was performed using MEDLINE (Ovid), Google Scholar, and Web of Science using the key terms: normal weight central obesity, healthy, abdominal obesity, and mortality. Articles which evaluated only human participants and written in the English language were reviewed for quality using the GRADE criteria.

Results:  Searches of published research returned a total of 104 articles, of which three matched the search inclusion criteria and were read in their entirety. Two of these articles were evaluated using the GRADE guidelines. One study was a stratified multistage probability design using NHANES III data while the other study was a prospective cohort study using data from the Dutch EPIC-MORGEN study.

Conclusion:  Studies suggest that while BMI serves as a useful screening tool, it does not sufficiently identify all individuals who may be at risk for developing complications and mortality secondary to obesity. Waist-to-hip ratio may more accurately identify individuals who are at a higher risk of developing obesity related health complications. Some studies have even shown an inverse relationship between BMI and mortality.

Keywords:  Body mass index, waist-to-hip ratio, central obesity, mortality

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REVIEWED STUDIES:

Sahakyan KR, Somers VK, Rodriguez-Escudero JP, Hodge DO, Carter RE, Sochor O, Coutinho T, Jensen MD, Roger VL, Singh P, Lopez-Jimenez F. Normal-Weight Central Obesity: Implications for Total and Cardiovascular Mortality. Annals of Internal Medicine. 163(11):827-35, 2015 Dec 1.

van der A DL, Nooyens AC, van Duijnhoven FJ, Verschuren MM, Boer JM. All-cause Mortality Risk of Metabolically Healthy Abdominal Obese Individuals: The EPIC-MORGEN Study. Obesity. 22(2):557-64, 2014 Feb.

 

AUTHOR: David Smith is currently completing his second year in the School of PA Studies at Pacific University, Oregon.  He will graduate with an MS degree in August, 2016.