The intimate relation between pulse-rate and metabolism, shown with the same individual in the large majority of observations in this laboratory, makes a careful examination of pulse-rate with respect to sex of special importance. The analysis of data for the basal metabolism of men and women has shown that women as a class have a lower metabolism than men, not only per individual, but per unit of weight. On the other hand, the pulse-rate of women as a class was shown to be higher than that of men, as measurements for 90 women and 121 men in our series gave an average of 68.67 for women and 61.26 for men. These differences are substantiated by the fact that with men three different groups of 28, 116, and 50 men showed average pulse-rates of 62.5, 61.3, and 61.3, respectively. Two groups of women, one of 68 and the other of 22, showed pulse-rates of 69.1 and 67.3, respectively. In other words, it seems thoroughly established that the women as a class have a pulse-rate somewhat higher than men, in spite of the fact that their metabolism is distinctly lower. This supplies very clear evidence that while pulse-rate and heat production may be closely correlated in the same individual, in groups of individuals the pulse-rate may vary enormously and "average" pulse-rate may have little, if any, connection with "average" heat production.
Since the pulse-rates of men and women show a difference, it becomes extremely important, in studying our groups of children, to note at what point, if any, there is a definite change in the pulse-rate, and further comparisons of values for males and females will be of special interest in this connection. Such comparison may be made from the pulse-rate data for boys and girls in table 20, which gives an opportunity of noting the differentiation, if any, due to sex. To this end, wherever values for both boys and girls are recorded at the same age, the higher of the two values has been italicized. Thus, for children I day old, 29 boys gave an average minimum pulse-rate of 113, while 21 girls had a pulse-rate of 110. On the next day the conditions for very nearly the same number of boys as girls were reversed, the girls showing a pulse-rate 4 beats higher than the boys.
Pursuing this method of analysis for the entire group of data in table 20, and passing over those ages for which records are available for only one of the two sexes, we find that at 11 age-periods the boys have a higher pulse-rate than the girls of the same age, while at 15 age-periods the girls have a higher pulse-rate than boys of like age. On this basis, therefore, it would appear that the pulse-rate of the girls was, on the whole, somewhat higher than that of boys. The italicized figures in the table show no great regularity in the appearance of these high values with either sex. The most consistent record is that from 1½ months to 10 months, the only ages at which the girls are not higher being that of 4 months, and again of 5 months, when the average pulse-rate for both sexes is the same. After 10 months the italicized figures indicate but little regularity as to sex.
On the whole, the picture can not be said to speak pronouncedly for a higher pulse-rate with girls than with boys. In making this general conclusion, however, it is important to note that the data under consideration are at best somewhat meager, although they may be relied upon as far as they go. But many observations of the minimum resting pulse-rate of boys and girls are necessary before final conclusions can be drawn, for obviously the pulse-rate at other ages should be studied and supplementary data should be obtained for the higher ages included in our observations.
Showing posts with label pulse-rates. Show all posts
Showing posts with label pulse-rates. Show all posts
Wednesday, October 10, 2007
Average pulse-rate of children
The second important factor to which our data contribute is the average pulse-rate of children of the same age, both as to its absolute value and as to the deviation therefrom which can be expected for children in repose. With boys, one of the most extensive series numerically that we have for any age represented is that for the group 7 months old, in which the basal pulse-rate for the 13 boys ranged from 107 to 127. The average for this group is found to be 117. It is clear, therefore, that it is only with a great deal of reserve that one may speak of the pulse-rate of a boy of 7 months as being 117. Even wider differences are observed with the 4 boys of 20 months, the lowest being 92 and the highest 127, with an average of 111.
From the foregoing discussion of the considerable variation to be found with an individual in the earlier years, one would naturally expect similar large differences between groups of older children of the same age. Thus, for the 7 boys 7 years of age, the lowest is 74 and the highest 99. With the 5 boys 9 years of age, the lowest record is 71 and the highest 86, while the 9 boys 11 years of age show a maximum difference in their basal pulse-rates of 22 beats.
With girls, one of the largest groups at the earlier ages is that for 6 months, but the pulse-rates for these 8 girls range only from 118 to 132, with an average of 124. This approach to uniformity, which is much closer than that noted for boys, does not by any means hold for all ages, since at 16 and 18 months differences amounting to 40 and 32 beats, respectively, are observed. Bearing in mind the irregularities seen in the careful examination of the data for these several age-groups, we may average these pulse data and attempt to portray the general trend of the minimum or basal pulse-rate of boys and girls from birth to 13 years of age. In so doing we have left out of the averaging all age-ranges represented by less than three individuals.
The average values shown for boys indicate a reasonably constant pulse-rate for the first 14 months of life, ranging from 113 to 125, if we exclude the first 5 days, and from 105 to 125 if these earlier values are included. Thereafter the picture is a gradual decrease, persisting throughout the second and much of the third year. The data between 3 and 6 years are lacking. During this period there has been a very considerable fall, the tendency to a decrease continuing subsequent to 7 years. The lowest value is 69 at the age of 12 years. With girls, the averages show that after the first 11 days there is a distinct tendency for a rise in pulse-rate, the return to the rate of the first week not taking place until shortly after the end of the first year. There is then a continued decrease, the lowest record being 74 at the age of 7 years.
From the foregoing discussion of the considerable variation to be found with an individual in the earlier years, one would naturally expect similar large differences between groups of older children of the same age. Thus, for the 7 boys 7 years of age, the lowest is 74 and the highest 99. With the 5 boys 9 years of age, the lowest record is 71 and the highest 86, while the 9 boys 11 years of age show a maximum difference in their basal pulse-rates of 22 beats.
With girls, one of the largest groups at the earlier ages is that for 6 months, but the pulse-rates for these 8 girls range only from 118 to 132, with an average of 124. This approach to uniformity, which is much closer than that noted for boys, does not by any means hold for all ages, since at 16 and 18 months differences amounting to 40 and 32 beats, respectively, are observed. Bearing in mind the irregularities seen in the careful examination of the data for these several age-groups, we may average these pulse data and attempt to portray the general trend of the minimum or basal pulse-rate of boys and girls from birth to 13 years of age. In so doing we have left out of the averaging all age-ranges represented by less than three individuals.
The average values shown for boys indicate a reasonably constant pulse-rate for the first 14 months of life, ranging from 113 to 125, if we exclude the first 5 days, and from 105 to 125 if these earlier values are included. Thereafter the picture is a gradual decrease, persisting throughout the second and much of the third year. The data between 3 and 6 years are lacking. During this period there has been a very considerable fall, the tendency to a decrease continuing subsequent to 7 years. The lowest value is 69 at the age of 12 years. With girls, the averages show that after the first 11 days there is a distinct tendency for a rise in pulse-rate, the return to the rate of the first week not taking place until shortly after the end of the first year. There is then a continued decrease, the lowest record being 74 at the age of 7 years.
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