Henje Blom E;
Olsson EM; Serlachius E; Ericson M; Ingvar M
Department of Clinical Neuroscience, Osher Center for
Integrative Medicine, Karolinska Institutet,
171 76, Stockholm, Sweden. eva.henjeblom@ki.se
This study investigated whether
there is a relationship between heart rate variability (HRV) versus lifestyle
and risk factors for cardiovascular disease in a population of healthy
adolescents. HRV is as an index of tonic autonomic activity and in adults HRV is
related to lifestyle and risk factors for cardiovascular disease, but it is not
known if this is the case in adolescents. HRV was registered for 4 min in
sitting position in 99 healthy adolescents (age range 15 years 11 months-17
years 7 months) and repeated after 6 months. On both occasions there were
significant correlations (P < 0.05) between physical activity and HRV, with
respective r values: high frequency (HF) 0.26, 0.30; low frequency power (LF)
0.35, 0.29 and the standard deviation of inter-beat intervals (SDNN) 0.28,
0.37. There was no significant interaction between first and second
measurements. In contrast, there were no correlations to sleeping patterns,
eating habits and smoking. Risk factors for cardiovascular disease [body mass
index (BMI = weight (kg)/length in m(2)), systolic
blood pressure and p-glucose] did not show any repeatable significant
correlations to HRV. Multiple regression models showed that physical activity
was a predictor for HF, LF and SDNN in both measurements. In conclusion HF, LF
and SDNN were reproducible after 6 months and were related to physical activity
on both occasions.