Hyperostosis frontalis interna in female historic skeletal populations: Age, sex hormones and the impact of industrialization

Objectives This analysis aims to investigate the impact of industrialization on the prevalence of Hyperostosis Frontalis Interna (HFI), focusing on the roles of age and parity to examine the claim that longevity and changing reproductive patterns have led to increased rates in modern populations. Materials and methods A total of 138 individuals from two documented London skeletal assemblages of the Industrial period were analyzed employing macroscopic observation, digital radiography and MicroCT scanning to establish the prevalence rates of HFI according to modern clinical standards. Statistical analysis was also undertaken on a sub‐sample of 51 females of post‐menopausal age to identify any relationship between parity and HFI. Results The majority of cases of HFI were found in older females, reflecting clinical observations. The prevalence rates of HFI corresponded well to those predicted from the proportion of old age females present within populations. Age was therefore shown to be a predominant factor in HFI presence. A plateau in HFI prevalence was noted from the age of 50–59 years onwards. No statistically significant relationship was found between parity and HFI. Discussion When recorded consistently, HFI was positively correlated with age and longevity but had also increased among old age females over time. Our results suggest that nulliparity co‐occurs with HFI but is not a primary factor in its pathogenesis. Key factors in HFI presence in females are likely to be increased androgens and the dysregulation of insulin and insulin‐like growth factor‐1.