Collagen turnover in the adult femoral mid‐shaft: Modeled from anthropogenic radiocarbon tracer measurements

TLDR

Human femoral bone collagen isotopically reflects an individual's diet over a period longer than 10 years, including a substantial portion synthesized during adolescence. The study measures 14C content of femoral mid‑shaft collagen to determine adult collagen turnover dynamics using the atmospheric 14C bomb spike as a tracer. The authors measured 14C in collagen from 67 Australian adults (ages 40–97) and compared the results to an age‑dependent turnover model. The analysis shows that female collagen turnover decreases from ~4 %/yr to ~3 %/yr between ages 20 and 80, male rates average 1.5–3 %/yr, adolescent turnover is 5–15 %/yr with males up to twice as high, and individual variation explains up to ~30 % of residual bomb 14C. © 2007 Wiley‑Liss, Inc.

Abstract

Abstract We have measured the 14 C content of human femoral mid‐shaft collagen to determine the dynamics of adult collagen turnover, using the sudden doubling and subsequent slow relaxation of global atmospheric 14 C content due to nuclear bomb testing in the 1960s and 1970s as a tracer. 14 C measurements were made on bone collagen from 67 individuals of both sexes who died in Australia in 1990‐1993, spanning a range of ages at death from 40 to 97, and these measurements were compared with values predicted by an age‐dependent turnover model. We found that the dataset could constrain models of collagen turnover, with the following outcomes: 1) Collagen turnover rate of females decreases, on average, from 4%/yr to 3%/yr from 20 to 80 years. Male collagen turnover rates average 1.5–3%/yr over the same period. 2) For both sexes the collagen turnover rate during adolescent growth is much higher (5–15%/yr at age 10–15 years), with males having a significantly higher turnover rate than have females, by up to a factor of 2. 3) Much of the variation in residual bomb 14 C in a person's bone can be attributed to individual variation in turnover rate, but of no more than about 30% of the average values for adults. 4) Human femoral bone collagen isotopically reflects an individual's diet over a much longer period of time than 10 years, including a substantial portion of collagen synthesised during adolescence Am J Phys Anthropol, 2007. © 2007 Wiley‐Liss, Inc.