MedicalResearch.com Interview with:
Dr Margaret Ashwell OBE, FAfN, RNutr (Public Health)
Ashwell Associates
Ashwell, Hertfordshire, United Kingdom.
Visiting Research Fellow, Oxford Brookes University
MedicalResearch: What are the main findings from this study?
Dr. Ashwell: In this study, the authors explore the differences in CVD risk factors between overweight and non-overweight people (by BMI) according to their shape (waist-to-height ratio -WHtR) Data for their analysis was taken from the Health Survey for England 2009 (HSE). They found significant differences in levels of total cholesterol (TC) and glycated haemoglobin (HbA1c—a measure of blood sugar control used to diagnose diabetes).
Out of 2917 people aged 16 years and over, 346 classified as ‘normal’ by
BMI, have WHtR exceeding 0.5 (12% of the total,sample, or 34% of normal weight people). These could be called non-overweight ‘apples’, who have a lot of fat around the waist but not a high BMI.
The researchers classified the HSE population into four groups (2×2) using standard boundary values of BMI (above or below 25kg/m2) and WHtR (above or below 0.5). The group with ‘low/normal BMI but high WHtR (non-overweight ‘apples’) had significantly higher mean TC than the group with high BMI but low WHtR (overweight ‘pears’—people with a higher than normal BMI but less fat around the waist): 5.73mmol/L vs. 4.98mmol/L. Similarly, HbA1c levels were higher among non-overweight ‘apples’ than among overweight ‘pears’ (5.62% vs. 5.33%). These differences were similar and also significant in both sexes.
MedicalResearch: Why do you say that piece so string can be used for primary screening?
Dr. Ashwell: Since a good boundary value for waist-to-height ratio is 0.5, you don't even need a tape measure to screen those at risk. It can be done with a piece of string. Measure the height of child with string, fold it in half and see if it fits around his/her waist. If it doesn't, that child should proceed to the next stage of screening.
(more…)