Cortical and trabecular bone microstructural parameters and dietary stable isotopes throughout ontogeny

Abstract

IntroductionRecent research has revealed correlations between δ15N, an indicator of dietary protein sources, and measures of intracortical and endosteal bone remodeling in adults. Given that these isotopes are used to infer the prevalence and duration of breastfeeding in past populations, it may be possible to specifically target bone microstructural variation associated with early life nutrition. It is critical to develop a more robust understanding of skeletal responses to weaning and infant diet, as they ultimately influence final body size proportions, skeletal fragility, and osteoporosis risk.Materials and MethodsThe sample is 27 mid‐sternal rib bone sections, each representing one child (0–16 years of age) from the Wesleyan Methodist cemetery of Prospect Hill, Newmarket, ON (1824–1879 AD). All specimens were scanned using the SkyScan 1174 Micro‐CT system at the Lunenfeld‐Tanenbaum Research Institute, Toronto, ON. Quantitative parameters were derived using SkyScan CT‐analyser software. Carbon and nitrogen stable isotope ratios from bone collagen were previously reported (Katzenberg and Pfeiffer1995).Spearman’s rank order correlation coefficients were calculated to explore relationships between each bone microstructural variable and age‐at‐death. Partial corrections, controlling for age, were used to examine the relationships between bone microstructural variables and δ13C and δ15N.ResultsCortical bone variables relating to cross‐sectional size increase from birth to late adolescence. With age, bone volume fraction (BV/TV), trabecular number (Tb.N) and connectivity density (Conn.Dn) decrease, while trabecular spacing (Tb.Sp) increases. Relationships between bone microstructural variables and δ13C or δ15N values are not straightforward.Discussion and ConclusionOntogenetic patterns of microstructural variation in the rib are similar to those of other bones undergoing endochondral ossification. Linkage to characteristics of infant and childhood dietary protein may be mitigated by causes of death.