Bone Density of an Aging Population

Abstract

The x-ray density coefficients of the left os calcis and of the second phalanx of the left fifth finger of 524 men and women from forty-nine to more than eighty years of age, and of thirty-eight men and women twenty-five to forty-nine years of age, were determined by a standardized technic. The subjects resided in California, Colorado and Utah; the study was part of a regional cooperative study of nutritional status. The density of the soft tissue covering the centers and ends of the finger bone was calculated as was the total density of os calcis and covering soft tissue. Mean bone and soft tissue density coefficients were calculated for men and women at five year intervals from forty-nine to past eighty years of age. Little difference after sixty-five years of age due to location or sex was found in the bone density of the phalanx 5-2 ends, but a definite decrease with age was found in women from fifty to sixty-five years but not in men from California. The phalanx 5-2 centers showed marked differences in bone density due to location, all subjects from Colorado and Utah having higher mean values than those from California. There was no variation in the bone density of the os calcis of the men due to age or location, but the women from California had significantly lower values at every age than the men from California or Colorado and lower than the women from Colorado (p < 0.01) in the decade forty-nine to fifty-nine years. The mean bone density coefficients of twenty-seven men over sixty years of age living in a county home in California were significantly lower than those of the men of the same age living in their own homes. This was in accord with the lower levels of serum ascorbic acid, vitamin A, carotene and cholesterol also observed in these men. Significant correlations between bone density coefficients and blood levels or nutrient intakes were found only in the women from California. These were plus 0.53 for ascorbic acid intake versus os calcis, plus 0.100 for serum vitamin A versus finger bone ends, plus 0.140 for serum vitamin A versus finger bone centers, and plus 0.246 for serum cholesterol versus finger bone centers. The possible physiologic significance of these correlations is discussed.