‘Narrowest point of waist’ best measure for predicting CV risk factors in children
MedWire News: Measuring the narrowest point of the waist, between the iliac crest and the ribs, is the most accurate waist circumference (WC) measurement site for the prediction of cardiovascular (CV) risk factors and the metabolic syndrome in children, study findings suggest.
"There is a lack of consensus regarding specific criteria and cut-off values for components of the metabolic syndrome, particularly in children," write Alynne Christian Ribeiro Andaki (Viçosa Federal University, Brazil) and co-authors in the journal Obesity Research and Clinical Practice.
However, if a "standardized" measurement site is to be used across different countries, it should be based on studies designed to elucidate the anatomic site that best predicts CV risk factors, they say.
The team therefore compared the effectiveness of measurements at three anatomic sites: the midpoint between the iliac crest and the lower rib (WC1); at the level of the umbilicus (WC2); and at the narrowest point of the waist (WC3), in the prediction of CV risk factors and the metabolic syndrome in children.
A total of 187 children (mean age 9.9 years) were evaluated for weight, height, WC, skinfolds (triceps and subscapular), and blood pressure. Levels of triglycerides, high-density lipoprotein (HDL) cholesterol, and glucose were also assessed in 141 of the children.
Area under the receiver operating characteristic curve (AUC) analysis revealed that, for boys, WC3 was the most accurate predictor of overweight and obesity (defined by the International Obesity Task Force) and low levels of HDL cholesterol (<50 mg/dl [1.30 mmol/l]), with respective AUC values of 0.952 and 0.751.
WC1 achieved the highest AUC for the prediction of excess body fat (AUC=0.912), while no WC measurement site accurately predicted hypertriglyceridemia (triglycerides ≥100mg/dl [1.13 mmol/l]), high blood pressure (>90th percentile adjusted for age, height, and gender) or the metabolic syndrome in boys.
For girls, WC3 achieved the highest discriminatory power for the diagnosis of overweight/obesity, excess body fat, and low HDL cholesterol levels (AUC=0.970, 0.939, and 0.642, respectively). In contrast, WC2 was the best predictor of hypertriglyceridemia and the metabolic syndrome (AUC=0.623 and 0.616, respectively), while WC1 was the best predictor of high blood pressure (AUC=0.705).
The researchers say that, although all three WC measurement sites accurately predicted CV risk factors and the metabolic syndrome in children, overall, WC3 presents the best predictive ability, as well as being an easily performed WC measurement.
They also note that, despite being recommended by the World Health Organization and widely used in the scientific literature, WC1 was only accurate for the prediction of high blood pressure in girls.
"Further studies are required to assess the wider generalizability of these reference values," concludes the team.
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By Nikki Withers