POPULATION BIOLOGY OF HUMAN AGING - METHODS OF ASSESSMENT AND SEX VARIATION

Biological age, as assessed by osteographic measurements of hand banes from radiograms, was estimated in about 7000 individuals belonging to 32 ethnic groups and samples and to 2 major human groups (Europeans a nd Asians). Individual ages in the total group varied between 16 and 9 9 years old. Our biological age measure is strongly correlated with ch ronological age of the individual (Pearson's r = 0.78-0.80, p < 0.001) , which renders the correlation amenable to fitting with a two-stage s tochastic model. The following parameters of the model were estimated accordingly: t(o) is the minimal age at which initial bone changes occ urred, q is the probability that an individual will first develop invo lutive bone change at age t(i) > t(o), and B is the rate of aging (bon e change) per unit time. The parameters varied considerably within dif ferent populations, but only a few samples showed statistically signif icant sex differences for all three parameters. However, B was consist ently higher among women than among men. Apart from that, the distribu tions of the observed biological age estimates adjusted on the expecte d biological age values reveal no differences between men and women in any of the studied samples or in the total population.