CHOLESTEROL IN THE BLOOD 373 



tion in blood cholesterol. According to Gordon and Cohn/"' the level of 

 this component was only 89 mg. % at birth in human infants; it increased 

 to an average of 136 mg. % in the five- to twelve-month group, and leveled 

 off at the value noted in adults by the age of five to six years. There is 

 some disagreement in the literature as to whether or not hypercholesterol- 

 emia is associated with advanced age. According to Page and co-work- 

 ers/"* who examined sixty -six male subjects with ages ranging from 

 twenty to one-hundred-one years, there was no change in the blood choles- 

 terol value which could be ascribed to age. Sperry and Webb^°^ were also 

 unable to prove a direct relationship between age and the level of blood 

 cholesterol in the case of twenty-two subjects who were kept under obser- 

 vation over a period of fifteen years. On the other hand. Keys and as- 

 sociates^"^ concluded that a pronounced curvilinear relation exists between 

 age and serum cholesterol in men, the maximum concentration being 

 reached in the sixth decade. Average normal blood cholesterol levels are 

 given as 173 mg. % for the nineteen-year-old subjects, and 252 mg. % for 

 those who had reached the age of fifty-two years. Until further research 

 is completed, it is impossible to say with certainty to what extent age in- 

 fluences the level of blood cholesterol. 



Although the values for blood cholesterol reported by Bose and De^"^ 

 and by Boyd and Roy^°^ for Indians do appear to be somewhat less than 

 the corresponding values for occidentals, there is no compelling evidence 

 that race has an appreciable effect on the level of blood cholesterol. More- 

 over, blood cholesterol shows no diurnal variation. ^"^ 



A decrease in the level of blood cholesterol has been noted in women 

 prior to the onset of the menstrual period. ^^"'^^^ Parhon and Parhon^^^ 

 noted that higher than normal blood cholesterol occurs in hens during the 

 egg-laying period. The most striking changes in blood cholesterol have 

 been observed in women during pregnancy; thus, the increase in choles- 



"" M. B. Gordon and D. J. Cohn, Am. J. Diseases Children, 85, 193-200 (1928). 



'0^ I. H. Page, E. Kirk, W. H. Lewis, Jr., W. R. Thompson, and D. D. Van Slyke, 

 J. Biol. Chem., Ill, 613-639 (1935). 



105 W. M. Sperry and M. Webb, /. Biol. Chem., 187, 107-110 (1950). 



lo^ A. Keys, 0. Mickelsen, E. 0. Miller, E. R. Hayes, and R. L. Todd, /. Clin. Invest., 

 29, 1347-1353 (1950). 



'" J. P. Bose and U. N. De, Indian J. Med. Research, 24, 489-508 (1936). 



108 T. C. Boyd and A. C. Roy, Indian J. Med. Research, 15, 643-651 (1928). 



109 C. W. McChire and M. E. Huntsinger, /. Biol. Chem., 76, 1-18 (1928). 

 "« R. Okey and R. E. Bovden, J. Biol. Chem., 72, 261-281 (1927). 



1" C. Kaufmann and B. Muhlbock, Arch. Gynakol., 136, 478-502 (1929). 

 "* C. J. Parhon and M. Parhon, Compt. rend. sac. biol, 89, 349-353 (1923); 00, 150- 

 152(1924). 



