Enlarged waist circumference is associated with a syndrome of lipid over-accumulation and increased mortality.
The information comes from the results of a cross-sectional study published in the November issue of the American Journal of Clinical Nutrition. An accompanying editorial suggests that all physicians should routinely measure waist circumference.
“Abdominal fat and circulating triacylglycerols increase with age, which indicates lipid over- accumulation,” write Henry S. Kahn and Rodolfo Valdez from the National Center for Chronic Disease Prevention and Health Promotion, at the Centers for Disease Control and Prevention, in Atlanta, Georgia. “Enlarged waist with elevated triacylglycerols (EWET) could identify adults at metabolic risk.”
In a cross-sectional, weighted sample of 9,183 adults, two-dimensional displays provided thresholds for enlarged waist of at least 95 cm in men and 88 cm in women. Threshold for elevated fasting triacylglycerols was at least 1.45 mmol/L.
The population prevalence of EWET was 6% in persons aged 18 to 24 years; it increased with advancing age until age 55 to 74 years, when prevalence was 43%; and it then decreased with advancing age beyond 75 years.
Relative risk of diabetes was 3.2 for persons with EWET compared with persons without EWET. After adjustment for other clinical variables, individuals with EWET had significantly worse (P < .0001) mean values for metabolic risk factors including fasting insulin (43 ± 3 pmol/L), high-density lipoprotein cholesterol (-0.27 ± 0.02 mmol/L), apolipoprotein B (0.20 ± 0.01 g/L), fasting glucose (0.71 ± 0.07 mmol/L), and uric acid (50 ± 2 µmol/L).
Compared with a subgroup of individuals with high body mass index, those with EWET were older and had more dyslipidemia, hyperglycemia, and hyperuricemia. Compared with individuals with “metabolic syndrome,” those with EWET were younger and had higher concentrations of low-density lipoprotein cholesterol and apolipoprotein B. Compared with persons with “prediabetes,” those with EWET had more hyperinsulinemia, dyslipidemia, and hyperuricemia.
“EWET identifies a syndrome of lipid over-accumulation associated with metabolic risk and accelerated mortality after middle age,” the authors write. ”
In an accompanying editorial, Jack Wang, from St. Luke’s–Roosevelt Hospital at Columbia University in New York City, notes that these results “provide the first irrefutable evidence that waist circumference is a reliable risk indicator for the syndrome of lipid over-accumulation, as documented by elevated fasting triacylglycerol concentrations and by accelerated mortality after middle age in a large population with wide age and [body mass index] ranges.”
Dr. Wang encourages clinicians to measure waist circumference routinely. Reasons that few clinicians currently use this marker include lack of systematic and continuous effort from any organization to inform practicing physicians about the potential usefulness of waist circumference measurement; lack of standardized and calibrated normal ranges; varying cutoffs based on age, sex, and ethnicity; and lack of a standardized measuring protocol.
“In light of experts’ warnings about the health risks related to greater waist circumference, the few minutes needed with a tape measure to obtain this useful variable could be cost-effective, especially when a patient’s visit to his or her doctor’s office is for evaluation of overweight and obesity,” Dr. Wang writes. “Any reduction in waist circumference would most likely result in a decrease in trunk fat content, regardless of the type of treatment or intervention, and this reduction may have greater clinical implication than does a reduction in body weight.” Am J Clin Nutr. 2003;78:928-934, 902-903.