ABSTRACT
As shown in 744 adult men and women aged 30-49 at entry and followed for 21.4 ± 0.9 years there is continuing subperiosteal expansion in both sexes as well as continuing and increasing endosteal surface resorption. In this longitudinal study, bone loss (as shown by medullary cavity expansion) begins by the 5th decade and increases thereafter. The smaller gains at the outer bone surface are essentially independent of the larger losses at the inner (endosteal) surface and neither functionally nor causally related. Though bone loss and net bone loss is nearly as great in men as in women, absolutely speaking, two-decade bone loss constitutes a larger percentage of the initially smaller bone mass in the female. In both sexes subperiosteal apposition (delta TA) and endosteal resorption (delta MA) are bone-size dependent though in diametrically opposite directions. These trends in two-decade bone change are not affected by smoking behavior, alcoholic beverage usage, antihypertensive usage, or early menopausal age. Similarly, the long-term bone changes prove to be independent of energy and mineral intakes and to long-term changes in calcium, phosphorus, magnesium, and vitamin D intake. Though dietary intakes do not predict long-term bone changes, the amount of tissue bone present at entry is highly correlated (> 0.93) with tissue bone 21.4 years later in men and women alike. Accordingly, only a small amount of intraindividual cortical variance in the later years still remains to be explained by life-style, dietary, medication, and error variables.
ABSTRACT
As shown in 702 wives with 9-12 years of education and 612 husbands similarly educated, the summed skinfolds of one spouse are influenced by the educational level of the other spouse, considerably so for the husbands. Women with 9-12 years of education married to men of lower educational attainment are higher in the sum of four skinfolds while women of similar years of schooling married to men of college education and beyond are leaner (P=0.001). Possible explanations for the effect of the education of one spouse on the fatness level of the other spouse include selective mating in the direction set by the husband's socioeconomic milieu and fatness "drift" on the part of the wives, again in the direction of the husband's socioeconomic status (SES). While these findings do not lend themselves to a simple biological explanation, they do reiterate the effects of socioeconomic variables on fatness level within populations and even within families.
