Elevated Fasting Insulin And Crp Levels Are Linked With Obesity And Low Aerobic Fitness In Young Qatari Boys.

Abstract

There is a concern around the world, including the Arabic countries, of young people's lifestyle and its effect on health later in life. Early markers for a possible elevated risk to develop metabolically related chronic diseases are sought for but it is still unknown which of them is the most sensitive. Moreover, the primary life style factor focused on, has been nutrition and overweight with only little attention being paid to physical inactivity and low maximal oxygen uptake. PURPOSE: To screen for a large number of "metabolic" markers in the blood in young Qatari boys with concomitant measures of body composition and maximal oxygen uptake. METHODS: Forty, 10-13 years old boys were studied. A fasting blood sample was taken and in addition to their height and weight a DEXA scan was used to assess body composition. A step test was performed to exhaustion to measure aerobic fitness. RESULTS: The BMI ranged from 14 to 36 kg/m2 with a mean of 22 kg/m2 (median 20) and the aerobic fitness ranged from 14 to 36ml/kg/min with mean value of 30 ml/kg/min (median 32). Equally strong and significant correlations were found for both BMI and aerobic fitness and fasting insulin level with a four fold difference comparing the 20% "worst" and the 20% "best" (4 vs16 microU/ml. The 20% in the middle were in between (8 microU/ml). Also the CRP levels were significantly correlated with BMI and aerobic fitness, with a slightly stronger link to BMI. However the difference in absolute values between those with the highest and lowest BMI and aerobic fitness was 4 fold (2 vs 8 mg/l) and with the middle group being similar to the fit and non-obese boys. The pattern and strength for the correlations were the same for fat % and BMI. No relationships were found for measures of body composition and aerobic fitness to any of the other markers studied (chol, LDL- and HDL-chol, TG, glucose, HbA1c, homocysteine). CONCLUSIONS: Fasting insulin and to some extent CRP may be sensitive early markers of an emerging metabolic deterioration but in this group of boys it is impossible to dissociate between overweight and a low aerobic fitness playing the largest role. Longitudinal studies are needed to track the long term effect of these factors upon metabolic deterioration.