歯の喪失とがんでの死亡の関連

高齢者における歯の喪失とがんでの死亡の関連をまとめた書籍の1章を紹介します。

Toshihiro Ansai and Yutaka Takata: Association Between Tooth Loss and Cancer Mortality in Elderly Individuals

下記のHPで全文見ることができます。

http://cdn.intechopen.com/pdfs/29454/InTech-Association_between_tooth_loss_and_cancer_mortality_in_elderly_individuals.pdf

結論として、歯の喪失と胃がん、肺がん、膵がんの関連を認めるという報告もありますが、全体的には、曖昧な状況です。関連を認める可能性がある要因として、慢性炎症、栄養、サルコペニア、脳活動、QOL、社会経済状況があげれらています。個人的には年齢の要素が大きい気もしますが。

サルコペニアに関する記載の部分だけ引用させていただきます。仮説レベルではありますが、口腔・咀嚼のサルコペニアによって、食欲、食事摂取量、ADLが低下する可能性はあります。以下、引用です。

Sarcopenia is defined as muscle power decline or decreased muscular volume with aging,
leading to decreased levels of basal metabolism and energy consumption by the whole
body, which results in lower energy intake and a decrease in synthesis of proteins in the
body. To the best of our knowledge, no study concerning the association between chewing
ability (tooth loss) and sarcopenia has been presented, though it is considered that elderly
individuals with sarcopenia may also develop the condition in the oral cavity region, which
has been supported by several reports. For example, subjects with stable occlusion, eg.,
Eichner index (EI; Eichner, 1955) Class A were shown unlikely to stumble (Yoshida, 2005).
EI, long used as an indicator of occlusal condition, are based on existing natural tooth
contacts between the maxilla and mandible in the bilateral premolar and molar regions.
Class A represents contact in all 4 support zones. Some reports have been presented
regarding associations between stable occlusion and physical fitness ability (Yamaga et al.,
2002), chewing ability and physical fitness (Takata et al., 2004), and walking speed and oral
function (Okada et al., 2011). In a recent longitudinal study of Japanese elderly subjects,
partial or complete loss of occlusion was associated with a decline in leg extensor power or
decrease in one-leg standing time with eyes open (Okuyama et al., 2011). Sarcopenia may
have a negative influence on both chewing ability and oral function. A Japanese survey of
elderly individuals (60 to 87 years old) reported that significant factors related to occlusal
power were handgrip strength in males, walking speed for 5 m in both genders, and body
muscle volume in females (Kono, 2009). These findings suggest the possibility that oral
sarcopenia induces a negative spiral of systemic health conditions including decreased levels
of appetite and activities of daily living, as well as deterioration of psychosomatic health
conditions, such as occurrence of depression, though the causal relationship remains unclear.