Findings of a new study suggest early intervention and prevention strategies targeting youth cardiorespiratory fitness may be associated with maintaining better health later in life.

The findings indicated prevention strategies targeting youth physical fitness may be associated with improved health parameters later in life.

Antonio Garcia-Hermoso, PhD, and colleagues examined the association between cardiorespiratory fitness in childhood and adolescence and future health status. They also assessed whether changes in cardiorespiratory fitness were associated with future health status at least 1 year later. To do this, the team conducted a systematic review and meta-analysis of MEDLINE, Embase, and SPORTDiscus electronic databases. The databases were searched for relevant articles published from inception to January 30, 2020.

Eligibility criteria included cardiorespiratory fitness measured using a validated test and assessed at baseline and/or its change from baseline to the last point of follow-up, generally healthy population with a mean age of 3-18 years old at baseline, and prospective cohort design with a follow-up period of at least 1 year. The investigators extracted study characteristics, exposure details, and analysis and results. Included endpoints were anthropometric and adiposity parameters and cardiometabolic parameters.

Overall, 55 studies were included in the systematic review with sample sizes ranging from 48-6297 and a length of follow-up ranging from 1 year to 27 years. There was a total of 37,563 youths included, 46% female. Laboratory and field tests were used most often to assess cardiorespiratory fitness.

The team found weak-moderate associations between cardiorespiratory fitness at baseline and body mass index (BMI) (correlations coefficient [r]=-.11; 95% CI, -.18 to -.04; inconsistency index [I2]=59.03), waist circumference (r=-.29; 95% CI, -.42 to -.14; I2=69.42), skinfold thickness (r=-.34; 95% CI, -.41 to -.26; I2=83.87), obesity (r=-.15; 95% CI, -.23 to -.06; I2=86.75), and total cholesterol level (r=-.12; 95% CI, -.19 to -.05; I2=75.81). Further, there were weak-moderate associations between high-density lipoprotein cholesterol (HDL-C) level (r=.11; 95% CI, .05-.18; I2=69.06), total cholesterol to HDL-C ratio (r=-.19; 95% CI, -.26 to -.13; I2=67.07), triglyceride levels (r=-.10; 95% CI, -.18 to -.02; I2=73.43), homeostasis model assessment for insulin resistance (r=-.12; 95% CI, -.18 to -.06; I2=68.26), fasting insulin level (r=-.07; 95% CI, -.11 to -.03; I2=0), and cardiometabolic risk (r=-.18; 95% CI, -.29 to -.07; I2=90.61) at follow-up.

During meta-regression analyses, the team found early associations in waist circumference (regression coefficients [β]=.014; 95% CI, .002-.026), skinfold thickness (β=.006; 95% CI, .002-.011), HDL-C level (β=-.006; 95% CI, -.011 to -.001), triglyceride levels (β=.009; 95% CI, .004-.014), and cardiometabolic risk (β=.007; 95% CI, .003-.011) from baseline to follow-up over time.

There were weak-moderate association between change in cardiorespiratory fitness and BMI (r=-.17; 95% CI, -.24 to -.11; I2=39.65), skinfold thickness (r=-.36; 95% CI, -.58 to -.09; I2=96.84), obesity (r=-.21; 95% CI, -.35 to -.06; I2=91.08), HDL-C level (r=.05; 95% CI, .02-.08; I2=0), low-density lipoprotein cholesterol level (r=-.06; 95% CI, -.11 to -.01; I2=58.94), and cardiometabolic risk (r=-.08; 95% CI, -.15 to -.02; I2=69.53) later in life.

The findings from Garcia-Hermoso and the team supported the association between cardiorespiratory fitness at baseline and anthropometric, serum lipid, insulin sensitivity, and cardiometabolic risk parameters later in life. Early associations from baseline to follow-up went away over time.

The study, “Association of Cardiorespiratory Fitness Levels During Youth With Health Risk Later in Life,” was published online in JAMA Pediatrics.