Metabolic Disease

Chapter 15 Metabolic Disease Megan B. Brickley1 and Simon Mays2 1Department of Anthropology, McMaster University, Hamilton, ON, Canada, 2Historic England, Portsmouth, United Kingdom INTRODUCTION often a tendency toward collection of the spectacular or unusual (Alberti, 2011; Stephens, 2011). This bias in the Metabolic bone diseases are conditions that cause an reference group may mean that the manifestations of dis- alteration in normal bone formation, resorption, or miner- ease may differ from those likely to be encountered in an alization, or a combination of these; in most conditions archeological target group. In addition, specimens gath- these alterations are systemic. Metabolic bone disease ered for medical pathology museum collections may have may arise due to nutritional problems, hormonal imbal- come from individuals who suffered from multiple condi- ance, or other causes. In this section we consider disease tions, some of which may have affected the skeleton and associated with vitamin C deficiency (scurvy) and vitamin only one of which was diagnosed by physicians. These D deficiency (rickets and osteomalacia), osteoporosis considerations should always be borne in mind when (which normally arises from age-related hormonal using reference material in paleopathology, but are espe- changes), together with certain other conditions arising cially to the fore in metabolic bone disease. For example, from imbalances in bone metabolism. most pathology museum specimens showing vitamin C The classical approach to diagnosis of disease in and vitamin D deficiency show much more severe bony paleopathology is essentially to use lesions in a reference alteration than will usually be encountered in archeologi- group or groups to help us interpret lesions in a target cal material (Brickley and Ives, 2008: 118; Mays, 2008a). individual or population. The target group is archeological It has long been recognized (e.g., Barlow, 1883) that, remains showing pathological lesions. The reference especially in infants, deficiencies of vitamin C and vita- group comprises individuals showing skeletal lesions and min D may often coexist, and some medical museum spe- with independent evidence concerning which disease was cimens diagnosed with rickets also appear to show lesions present. Reference materials comprise specimens from due to scurvy (Brickley and Ives, 2008: 11). Recent medical pathology museums; radiographic and other paleopathological work directed at identification of vita- imaging studies of living individuals also contribute. min C and vitamin D deficiencies has emphasized an Whilst having clear strengths, using lesions observed in a alternative approach, involving careful reading of primary reference population to interpret alterations in a target clinical sources coupled with a close understanding of the group or individual also has limitations. Ideally, we would pathophysiology of the bony alterations, as a means of wish a reference group to be representative of the full augmenting and refining our diagnostic criteria (Ortner, range of skeletal expression of the disease of interest. 2011; Crandall and Klaus, 2014). We therefore use not Medical pathology museum specimens collected prior to only documented cases, but also archeological material to the mid-20th century predate the advent of effective drug illustrate pathology typical of these diseases. For another and other treatments which radically altered the natural major condition discussed in this section, osteoporosis, history of many diseases, an advantage when acting as we are forced to step away from the reference/target pop- reference material for archeological target groups. ulation, lesion-based approach. Osteoporosis is a condition, However, pathology museum collections were assembled often age-related, that involves a decline in bone mass and for a variety of didactic and other purposes, none of in microstructural integrity of bone. Osteoporosis is identi- which were concerned with facilitating paleopathological fied in skeletal remains by direct measures of bone mass or Copyright © 2019. Elsevier Science & Technology. All rights reserved. & Technology. © 2019. Elsevier Science Copyright diagnosis. Accessioning and deaccessioning policies were microstructural integrity; in our discussion we emphasize often rather idiosyncratic, and heavily dependent upon the the strengths and weaknesses of applying various methods interests of individual curators (Arnold, 1999). There was to assess these parameters in ancient remains. Ortner’s Identification of Pathological Conditions in Human Skeletal Remains. DOI: https://doi.org/10.1016/B978-0-12-809738-0.00015-6 © 2019 Elsevier Inc. All rights reserved. 531 Ortner's Identification of Pathological Conditions in Human Skeletal Remains, edited by Jane E. Buikstra, Elsevier Science & Technology, 2019. ProQuest Ebook Central, http://ebookcentral.proquest.com/lib/harvard-ebooks/detail.action?docID=5673624. Created from harvard-ebooks on 2020-11-08 16:07:31. 532 Ortner’s Identification of Pathological Conditions in Human Skeletal Remains VITAMIN C DEFICIENCY long bone. There may also be osteopenia of the trabecular bone of the epiphysis. Mineralization in the provisional Scurvy is a disease caused by inadequate vitamin C. zone of calcification at the growth plate margin is main- Unlike most other animals, humans are unable to synthe- tained and is visible as a thin, more radiodense line at the size their own vitamin C, so are reliant on dietary intake. metaphyseal surface immediately beneath the growth Fresh fruit and vegetables are rich in vitamin C, and smal- plate. This is known as the white line of Fra¨nkel. ler amounts are available in meat, fish, and dairy pro- Similarly, the radiolucent epiphyseal spongiosa tends to ducts. Vitamin C content of foods is diminished by be surrounded by a thin, more radiodense line termed heating (Igwemmar et al., 2013) and, unless air is Wimberger’s ring (Noordin et al., 2012; Agarwal et al., excluded, by prolonged storage (Montan˜o et al., 2006). 2015). The poorly mineralized growing end of the bone Vitamin C deficiency principally reflects faulty diet, food may yield to mechanical forces, resulting in microfracture preparation, or storage. of the spongiosa beneath the growth plate. This may be evident as irregularity or concavity (“cupping”) of the growing end of the bone (Duggan et al., 2007). Repair of SUBADULT SCURVY microfractures may lead to bony spur formation at meta- Neonatal levels of vitamin C are related to maternal physeal margins (Pelkan’s spurs) (McCann, 1962; Tamura levels, and vitamin C is present in breast milk (Agarwal et al., 2000). Some of these alterations are shown dia- et al., 2015). Scurvy is rarely observed before age 4 grammatically in Fig. 15.1, and radiographically in months (unless the mother is deficient in the vitamin) and Fig. 15.2. The most frequent of the bony alterations asso- is most frequent in later infancy and early childhood, ciated with the direct effects of vitamin C deficiency is although it can occur at any age (Gulko et al., 2015). generalized osteopenia (Weinstein et al., 2001), which is Prolonged deficiency is necessary to produce scurvy, per- too nonspecific to aid diagnosis. The other changes are haps for a matter of months, although research in humans less frequent and may not form at all, even in advanced on this point relates to adult rather than subadult cases disease (Tamura et al., 2000; Weinstein et al., 2001; (e.g., Hodges et al., 1971). Akikusa et al., 2003). Most of the above alterations are Historical sources mainly discuss adult scurvy. The removed by remodeling following restoration of adequate first good description of subadult scurvy dates from 17th- vitamin C, but metaphyseal deformity may persist in century England (Still, 1935). It only began to be noted as severe cases (Sprague, 1976). In buried bone, care is a widespread problem in the 1870s when the wealthy began to feed their infants on bread and milk sterilized by heating, which destroyed the vitamin C (Carpenter, 1986: 158À172). In 1914, Hess demonstrated that scurvy could be cured by including raw milk, or fresh fruit and vegetables, in the diet, and as the benefits of these dietary com- ponents became more widely known, the frequency of the disease fell (Carpenter, 1986: 172). Vitamin C is a critical modulator of the production of collagen, the main structural protein of bone and other connective tissue. In bone, the effects of vitamin C are complex and incompletely understood, but as well as pro- moting collagen matrix formation, it also (inter alia) pro- motes osteoblastic differentiation and proliferation in osteogenic cells (Aghajanian et al., 2015). Deficient vitamin C results in reduced bone formation, with consequent rarification of trabecular bone and cortical thinning. Although the metabolic effects of scurvy are systemic, in the growing skeleton, alterations are most pronounced at rapidly growing long-bone ends, particularly the distal femur, and at the sternal rib ends. These alterations, most of which are best visualized using radiographic or other medical imaging techniques, are described below. Copyright © 2019. Elsevier Science & Technology. All rights reserved. & Technology. © 2019. Elsevier Science Copyright There may be a transverse band of decreased density, visible as a radiolucent line (termed a scurvy line or FIGURE 15.1 Radiographic alterations that may be observed in sub- Tru¨mmerfeld zone) adjacent to the metaphyseal end of a adult scurvy

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