Even small amounts of exercise improve lipid profiles in youth
MedWire News: There is a dose-response relationship between physical activity and dyslipidemia in young people, Canadian researchers have discovered.
Their data underline the cardiovascular benefits associated with engaging in moderate-to-vigorous physical activity (MVPA), even at levels below the current target of 60 minutes per day.
“Lower MVPA targets may act as an incentive for currently sedentary youth,” note Ian Janssen (Queen’s University, Kingston, Ontario) and co-authors in the CanadianJournal ofCardiology .
For their study, Janssen’s team analyzed data on 1235 individuals, aged 12–19 years, who were assessed as part of the 2003–4 and 2005–6 cycles of the US National Health and Nutrition Examination Survey.
The survey included 7-day objective assessments of MVPA using accelerometers, with MVPA defined as periods of at least 5 minutes spent at 3000 counts/minute or more.
The median value for MVPA was 15.7 minutes/day (29.4 minutes/day in boys and 12.7 minutes/day in girls). Just 4.1% of participants met the guideline-recommended daily MVPA target of 60 minutes/day.
The researchers found that the likelihood of having raised triglycerides or reduced high-density lipoprotein (HDL) cholesterol levels fell in a curvilinear manner with increasing daily minutes of MVPA.
At 15, 30, and 50 minutes/day of MVPA, the odds ratios for having high-risk HDL cholesterol were 0.29, 0.24, and 0.21, respectively, compared with 1 minute/day of MVPA.
For the same MVPA values, the odds ratios for having high-risk triglycerides were 0.40, 0.22, and 0.10, respectively.
There was no association between MVPA and levels of low-density lipoprotein cholesterol, however.
“A curvilinear dose-response relationship was observed with high-risk HDL cholesterol and triglyceride values such that most of the effect was observed within the first 15 to 30 minutes per day of MVPA,” Janssen and team write.
They conclude: “Because youth can achieve significant cardiovascular health benefits with even modest amount of MVPA, physical activity guidelines for youth may need to recognize that getting young people to engage in less than the currently recommended 60 minutes/day or more of MVPA is beneficial.”
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By Joanna Lyford