Non-invasive methods for epidemiological screening of children with clustered risk for later development of lifestyle related diseases

Transcription

1 Non-invasive methods for epidemiological screening of children with clustered risk for later development of lifestyle related diseases Bianca El-Naaman, PhD-student Centre for Research in Childhood Health (RICH), Department of Exercise Epidemiology, Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark and Centre for Intervention Research in Health Promotion and Disease Prevention, University of Southern Denmark Supervisor: Prof. Lars Bo Andersen Funded by Trygfonden, Denmark

2 The need for a screening tool: Healthy population. The children is not sick yet! Screening for obesity does not necessarily find the children at risk Cluster of risk factors at childhood enhanced risk of later development of type-2-diabetes and cardio-vascular diseases. Clinically MetS is diagnosed by looking at CVD riskfactors

3 Children and MetS: Use of current diagnostical tools is problematic in preventive work on an epidemiological prospective with children - mostly since all methods includes a bloodsample - Furthermore since we do not have arbitrary cut-points for children MetS in children is a condition where the risk factors tends to accumulate in some children compared to the rest of the population => more correct not to use arbitrary cut-points for children, but instead look at a condition where the CVD riskfactors is not independently distrubuted throughout the population

4 Children and MetS: A screening tool that includes lifestyle related factors would be useful MetS can mostly be reversed by lifestyle changes on diet and exercise Important! - Since MetS often is the predecessor of later CVD and Type 2 diabetes. Behavior is a difficult parameter to include as a measurement, therefor fatnesslevels (BMI, skinfold, waist) and physical fitness more usable as a screening tool. IR highly associated to MetS and is highly correlated to diet, fatness and fitness levels.

5 Aim: The aim of this study is: to look at physical fitness and three different fat measurements and investigate their relation to IR. Furthermore to look at their sensitivity and specificity as screening tools for insulin resistance/ MetS. to develope a simple screening method to find the children at risk of developing MetS, by constructing a combinationscore of these 4 variables.

6 Importance The importance for these surrogate measurements of body fat and fitness lies in the non-invasive way for epidemiological screening of children at risk of having a impaired insulin sensitivity. Necessary with a simple screening method that goes beyond finding the obese children Useful both as a preventive method but also a easy way to monitor changes in the population

7 Methods: Observational study based on the cohort of CoSCIS. Baseline 2001/2002 Mean age: 6.74 years 1. Follow-up (3 rd grade) 2003/2004 Mean age: 9.45 years 2. Follow-up (7 th grade) 2008/2009 Mean age: years n= 695 Fasting blodsample Antropometric measurements Treadmill test n= 606 Fasting blodsample Antropometric measurements Treadmill test n= 513 Fasting blodsample Antropometric measurements Treadmill test

8 Methods: Intravenous blood samples assessed after an overnight fast. Glucose and Insulin used to calculate HOMA-IR Sum-of-4-skinfolds, waist circumference and BMI were used as surrogate measurements of subcutaneous, intra-abdominal and whole body fat Cardio-respiratory fitness (VO 2 - max) was directly measured on a progressive treadmill test.

9 Methods: Cross-sectional associations between outcome and the different measurements of body fat and fitness on all 3 test periods Includes simpel associations, regressions, OR and a calculation of specificity and sensitivity as screening tool Combined Z-scores of the 3 fat-measures and the inverse fitness component as exposure Outcome: HOMA-IR MetS (HOMA-IR, sum4skin, systolic BP, Total/HDL, VO2-max)

10 Questions Bias in constructing 2 combined scores for exposure/outcome that holds some of the same variables? The need to include all 3 test periods? Composite scores or z-scores? More appropriate to use composite score based on a continious variable. Provides us with more information of the childs placement in the population.

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