Effects of gender and altitude on short-term heart rate variability in children.
OBJECTIVE
We aimed to study short-term heart rate variability (HRV) in 113 apparently healthy children permanent residents of moderate altitudes, the effects of gender and altitude.


METHODS
Children were assigned into 3 groups according with altitude of residence: Group 1--1650 m/a/s/l (n=38), Group 2--1740 m/a/s/l (n=36) and Group 3--2030 m/a/s/l (n=39). All children underwent short-term electrocardiographic recordings with spectral analysis of HRV at rest and during standing. Statistical analysis was performed using multivariate ANOVA analysis.


RESULTS
Heart rate variability analysis showed significant increase in SDNN, high frequency and total powers in parallel with increase of the altitude of residence (p<0.0001, p<0.03 and p<0.01, respectively). The magnitude of the HRV response to posture did not differ between groups except index of sympathetic modulation, LFNU, which rose to a significantly lesser degree (F=3.45, p<0.03) in Group 3, as compared with Group 1 and 2. Girls had lower HRV as compared with boys.


CONCLUSIONS
Thus, in apparently healthy children, residents of moderate altitudes, increase in altitude levels is accompanied by higher overall variability and parasympathetic modulation of the sinus node and lower sympathetic response to posture. Heart rate variability in children, residents of moderate altitudes is also dependent of gender, resembling similar relationship in inhabitants of sea level.
Sharshenova
Ainash A
AA
Scientific and Production Center of Preventive Medicine, Bishkek, Kyrgyzstan. asharshenova@yahoo.com
Majikova
Elvira J
EJ
Kasimov
Omor T
OT
Kudaiberdieva
Gulmira
G
D000222:Adaptation, Physiological; D000531:Altitude; D002648:Child; D004562:Electrocardiography; D005260:Female; D005783:Gender Identity; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D011187:Posture; D012016:Reference Values