Trends in resting pulse rates in 9-11-year-old children in the UK 1980-2008.
OBJECTIVE
Little is known about whether levels of physical fitness, which is related to adiposity and physical activity (PA), have changed in children, particularly the progressive increase in childhood obesity levels. We aimed to examine the time trends in resting pulse rate (a marker of physical fitness) among UK children, in order to better understand the trends in levels of physical fitness in recent decades.


METHODS
We used a cross-sectional study design and included data on over 22 000 children aged 9-11 years (mean 10.3 years) from five population-based studies conducted in the UK between 1980 and 2008.


METHODS
Resting pulse rate (bpm).


RESULTS
Observed mean resting pulse rate was higher for girls than boys (82.2 bpm vs 78.7 bpm). During the study period mean pulse rate increased by 0.07 bpm/year (95% CI 0.04 to 0.09) among boys and to a lesser extent among girls, by 0.04 bpm/year (0.01 to 0.06) (p<0.05 for gender interaction). For boys, there was an indication that the trend was steeper after the mid-1990 s, compared to that prior to 1994 (annual increase 0.14 vs 0.04 bpm). The trends for Body Mass Index (BMI) accounted for only 13.8% (11.3% to 16.3%) of increase in pulse rate for boys and 17.2% (9.4% to 24.9%) for girls.


CONCLUSIONS
Increases in mean resting pulse rate have occurred during the period 1980-2008 in girls and especially in boys. The increase was not explained by increased BMI. The observed trends in children, though modest, could have important public health implications for future cardiovascular risk.
MRC Centre of Epidemiology for Child Health/Centre for Paediatric Epidemiology & Biostatistics, UCL Institute of Child Health, , London, UK.
Helen
H
Peters
Peter H
PH
Whincup
Derek G
DG
Cook
Catherine
C
Law
Leah
L
Li
D001827:Body Height; D015992:Body Mass Index; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006306:Health Surveys; D006339:Heart Rate; D006801:Humans; D008297:Male; D009765:Obesity / Q000453:epidemiology; D050177:Overweight / Q000453:epidemiology* / Q000503:physiopathology; D010809:Physical Fitness / Q000502:physiology*; D012737:Sex Factors; D006113:United Kingdom / Q000453:epidemiology
Adolescent Health; Comm Child Health; Epidemiology; Obesity