Normal-weight central obesity and risk for mortality

M Hamer, G O'Donovan, D Stensel… - Annals of internal …, 2017 - acpjournals.org
Annals of internal medicine, 2017acpjournals.org
Background: The association between obesity, defined in terms of body mass index (BMI),
and mortality in the general population has been controversial (1). Various studies have
examined whether central obesity has greater predictive utility than BMI. In a 2015 study of
15 184 adults, paradoxical results suggested that centrally obese participants defined as
normal weight on the basis of BMI had the worst long-term survival even when compared
with their overweight and obese counterparts (2). Objective: To replicate these analyses in a …
Background: The association between obesity, defined in terms of body mass index (BMI), and mortality in the general population has been controversial (1). Various studies have examined whether central obesity has greater predictive utility than BMI. In a 2015 study of 15 184 adults, paradoxical results suggested that centrally obese participants defined as normal weight on the basis of BMI had the worst long-term survival even when compared with their overweight and obese counterparts (2).
Objective: To replicate these analyses in a larger sample of adults in the general population.
Methods: Participants were recruited from 10 survey years of the Health Survey for England and the Scottish Health Survey, which use a complex survey design (3). Local research ethics committees approved each survey, and all participants gave written informed consent. Trained interviewers measured height and weight to derive BMI, which was categorized as normal weight (BMI of 18.50 to 24.99 kg/m 2), overweight (BMI of 25.00 to 29.99 kg/m 2), and obese (BMI≥ 30.00 kg/m 2). Underweight participants (BMI< 18.50 kg/m 2) and those who died in the first 2 years were excluded as in previous studies to avoid reverse causation (2). Measuring tape was used to record 2 measurements of waist circumference midway between the iliac crest and lower rib, and hip circumference around the widest portion of the buttocks. Central obesity was defined using the World Health Organization criteria of a waist-to-hip ratio of 0.85 or higher in women and 0.90 or higher in men.
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