The relationship between physical fitness and clustered risk, and tracking of clustered risk from adolescence to young adulthood: eight years follow-up in the Danish Youth and Sport Study

Abstract

IntroductionCardiovascular disease (CVD) is usually caused by high levels of many risk factors simultaneously over many years. Therefore, it is of great interest to study if subjects stay within rank order over time in both the biological risk factors and the behaviour that influences these risk factors. Many studies have described stability (tracking) in single risk factors, especially in children where hard endpoints are lacking, but few have analysed tracking in clustered risk.MethodsTwo examinations were conducted 8 years apart. The first time, 133 males and 172 females were 16–19 years of age. Eight years later, 98 males and 137 females participated. They were each time ranked into quartiles by sex in four CVD risk factors all related to the metabolic syndrome. Risk factors were the ratio between total cholesterol and HDL, triglyceride, systolic BP and body fat. The upper quartile was defined as being at risk, and if a subject had two or more risk factors, he/she was defined as a case (15–20 % of the subjects). Odds ratios (OR) for being a case was calculated between quartiles of fitness in both cross-sectional studies. The stability of combined risk was calculated as the OR between cases and non-cases at the first examination to be a case at the second examination.ResultsORs for having two or more risk factors between quartiles of fitness were 3.1, 3.8 and 4.9 for quartiles two to four, respectively. At the second examination, OR were 0.7, 3.5 and 4.9, respectively. The probability for "a case" at the first examination to be "a case" at the second was 6.0.ConclusionsThe relationship between an exposure like physical fitness and CVD risk factors is much stronger when clustering of risk factors are analysed compared to the relationship to single risk factors. The stability over time in multiple risk factors analysed together is strong. This relationship should be seen in the light of moderate or weak tracking of single risk factors, and is strong evidence for early intervention in children where risk factors cluster.

Tracking of clustered metabolic syndrome risk factor in Japanese children: 3-year follow-up study

“…Correlation coefficients in- fatness determined by waist circumference and aerobic fitness were higher than other variables, similar to previous studies 23,36) . Also, moderate tracking of TG and blood pressure was consistent with previous studies 23,24,26,36) . Although it is difficult to explain these phenomena in detail, we suggest that single risk factors in the short-term were moderate to high stable from childhood to adolescence in Japanese children.…”

“…Although these clustering risk factors did not have the same parameters, the studies did show that tracked clustering risk factors had a correlation coefficient between 0.42 and 0.67 20,23,24,[26][27][28]30) . To the best of our knowledge, only Bugge et al 23) investigated short-term tracking (<6 years) and the clustering risk factor included fitness.…”

“…In previous studies, clustered risk factors have been reported by longitudinal studies in children and adolescents 20,[23][24][25][26][27][28][29][30] . Although these clustering risk factors did not have the same parameters, the studies did show that tracked clustering risk factors had a correlation coefficient between 0.42 and 0.67 20,23,24,[26][27][28]30) .…”

“…They reported that tracking was higher for lower fitness children, and there was a weak relationship with fatness. In addition, in longitudinal studies, the participants were European [23][24][25][26] , American [27][28][29] , and Canadian 30) ; there were no data for Asian children.…”

Prospective Associations Between Physical Activity Level and Body Composition in Adolescence: 1993 Pelotas (Brazil) Birth Cohort

“…1 Likewise, there is evidence that physical activity may improve mental health and cognitive function in children and adolescents. [2][3][4][5] Low levels of physical activity, along with inadequate diet, are usually considered the main causes of such a rise.…”