[Body composition, aerobic fitness, physical activity and metabolic profile among 18 year old Icelandic high-school students].

OBJECTIVE

The purpose of the study was to examine metabolic risk factors among 18 year old high-school students and compare students attending vocational and traditional schools.

MATERIAL AND METHODS

Participants (147 boys and 130 girls) were randomly selected. Physical activity (PA) was measured with pedometers and aerobic fitness (fitness) with maximal oxygen uptake test on a treadmill. Height, weight, waist circumference (WC), and body mass index (BMI) were measured and percentage body fat (%Fat) assessed with dual energy X-ray absorptiometry. Resting blood pressure (BP) and serum lipids and glucose were measured.

RESULTS

According to BMI, 23% of the students were overweight/obese, 20% had elevated WC, and 51% increased %Fat. In addition, 11% of the students had high-density lipoprotein below recommended levels, and 8% had low-density lipoprotein and 9% triglycerides above advised values. Finally, 10% had borderline or high systolic BP. In contrast, 84% of the students had fair or higher levels of fitness, although only 34% reached recommended levels of daily PA. According to %Fat, a higher proportion of boys (33%) than girls (22%) were classified as obese (p=0.042) but a higher proportion of boys (57%) were very fit (57 vs. 24%, p<<0.001). Vocational students had lower levels of fitness (Cohen´s d (Cd)=0.7) and PA (Cd=0.7), and higher %Fat (Cd=0.5), WC (Cd=0.6), and BP (Cd=0.3, p<0.05).

CONCLUSION

Although fitness among 18 year old Icelandic high-school students seems generally good, their PA is low and %Fat elevated. Serum lipids and systolic BP are also increased in about 10% of the teenagers. Vocational students measure worse on most metabolic risk factors than traditional students.