Aerobic fitness is associated with low cardiovascular disease risk: the impact of lifestyle on early risk factors for atherosclerosis in young healthy Swedish individuals – the Lifestyle, Biomarker, and Atherosclerosis study

BACKGROUND The progression of cardiovascular disease (CVD) and atherosclerosis is slow and develops over decades. In the cross-sectional Swedish Lifestyle, Biomarker, and Atherosclerosis study, 834 young, self-reported healthy adults aged 18.0-25.9 years have been studied to identify early risk factors for atherosclerosis. PURPOSE The aims of this study were to 1) assess selected cardiometabolic biomarkers, carotid intima-media thickness (cIMT) as a marker of subclinical atherosclerosis, and lifestyle-related indicators (food habits, handgrip strength, and oxygen uptake, VO2 max); 2) analyze the associations between cIMT and lifestyle factors; and 3) identify subjects at risk of CVD using a risk score and to compare the characteristics of subjects with and without risk of CVD. METHOD Blood samples were taken in a fasting state, and food habits were reported through a questionnaire. cIMT was measured by ultrasound, and VO2 max was measured by ergometer bike test. The risk score was calculated according to Wildman. RESULT cIMT (mean ± standard deviation) was 0.50±0.06 mm, and VO2 max values were 37.8±8.5 and 42.9±9.9 mL/kg/min, in women and men, respectively. No correlation was found between aerobic fitness expressed as VO2 max (mL/kg/min) and cIMT. Using Wildman's definition, 12% of the subjects were classified as being at risk of CVD, and 15% had homeostasis model assessment of insulin resistance. A total of 35% of women and 25% of men had lower high-density lipoprotein cholesterol than recommended. Food habits did not differ between those at risk and those not at risk. However, aerobic fitness measured as VO2 max (mL/kg/min) differed; 47% of the subjects at risk had low aerobic fitness compared to 23% of the nonrisk subjects (P<0.001). CONCLUSION High aerobic fitness is associated with low CVD risk in Swedish young adults. The high prevalence of young adults observed with unfavorable levels of high-density lipoprotein cholesterol and homeostasis model assessment of insulin resistance raises concerns about future CVD risk.