The impact of pathological conditions on carbon and nitrogen isotopic values in the bone collagen of individuals with known biographic data and medical history
Abstract
This study aimed to refine our understanding of the extent to which chronic diseases with and without skeletal manifestation affect the isotopic values in bone collagen. Carbon and nitrogen isotopic values were measured in the ribs and femurs of 65 individuals from a documented skeletal collection (19th-21st centuries, Czech Republic).
Statistically significant differences in both carbon and nitrogen isotopic values were found between particular families. There was a notable effect of the year of death on nitrogen isotopic values in ribs.
Neither the presence of chronic disease in general nor the presence of carcinoma, age-related physical debility, or tuberculosis had a significant impact on isotopic values. Cases of cancer with skeletal metastases however showed an increase of 1 parts per thousand-1.5 parts per thousand in nitrogen isotopic values in (i) metastasis tissue, (ii) the healthy areas of bone affected by the metastasis, and (iii) the healthy rib bone.
The results demonstrate that distinct dietary habits in particular families are the main driving force affecting the isotopic values in the sampled individuals. A minor but notable temporal shift in the nitrogen isotopic values of ribs may be linked to environmental and/or societal changes during the studied period.
The observed increase in the nitrogen isotopic values of individuals with bone cancer metastases is in accordance with the state of cachexia and negative nitrogen balance. Despite the low number of cases, this result urges caution, as isotopic changes to the observed degree may significantly affect the dietary interpretation of the isotopic data.