Cholesterol distribution in the bulk tissues of man: variation with age

Lacking reliable data on cholesterol concentrations in muscle, adipose tissue, skin, and connective tissues (i.e., the "bulk tissues") in "normal" man, we have completed these analyses in 21 men and 8 women who died suddenly and unexpectedly; their ages ranged from 23 to 78 yr. In 11 of these subjects aged 20-40 yr, the mean cholesterol concentrations ranged from 180-440 mg/100 g dry tissue. In contrast, in 13 subjects aged 60-80 yr the values were 23-28% higher in muscle, adipose, and skin, while in dura mater, biceps, and psoas tendons the concentrations were 130, 260, and 460% higher (respectively). Esterified cholesterol in these connective tissues was found to be the major contributor, increasing 5- to 10-fold in the older group as opposed to a less than 5-fold rise in free cholesterol. In view of the large proportion of total body weight represented by these tissues, it is clear that large amounts of cholesterol can be accumulated there over a lifetime; indeed, the dense connective tissues appear to act uniquely as a trap for cholesterol, especially in the esterified form. Whether analyses of tendinous tissues in man, accessible during life, mirror the pattern of cholesterol deposition in arterial connective tissue remains to be determined.