著者

野上 絵理子 宮井 信行 張 岩 阪口 将登 早川 博子 服部 園美 内海 みよ子 上松 右二 有田 幹雄

出版者

一般社団法人日本衛生学会

雑誌

日本衛生学雑誌 (ISSN:00215082)

巻号頁・発行日

vol.76, pp.21003, 2021 (Released:2021-07-10)

参考文献数

35

被引用文献数

3

---

Objectives: Recently, attention has been paid to the impact of cigarette smoking on skeletal muscles, as its underlying pathophysiological mechanism has been gradually elucidated. In this study, we aimed to examine whether cigarette smoking is associated with muscle mass reduction and low muscle strength in elderly men.Methods: The study participants comprised 417 community-dwelling elderly men (aged 73±6 years) without severe glucose intolerance, chronic kidney disease, or liver disease. Bioelectrical impedance analysis was performed to estimate appendicular skeletal muscle mass (ASM), which was normalized for height (ASM index, kg/m2). Handgrip strength (HGS) was measured using a Smedley grip dynamometer. Cumulative smoking exposure level during a lifetime was expressed in pack-years, which is a product of the average number of packs of cigarettes smoked per day and smoking duration in years.Results: When the participants were stratified on the basis of cumulative smoking exposure (<10 pack-years, 10–39 pack-years, ≥40 pack-years), the ASM index and HGS progressively decreased with increasing exposure level (P for trend <0.01). In multiple regression analysis, heavy smoking (defined as ≥40 pack-years) was found to be a significant determinant of the ASM index and HGS, independent of potential confounding factors. Among former smokers, the subgroup that quit smoking for ≥20 years had a significantly higher ASM index and HGS than the subgroup that quit smoking for <10 years. The duration of smoking cessation was significantly associated with the ASM index and HGS, even after adjusting for cumulative smoking exposure.Conclusions: These findings suggest that cigarette smoking contributes to the loss of muscle mass and function in elderly men and that smoking cessation could reverse the impact of cigarette smoking on skeletal muscles.

著者

張 岩 今井 清博 小林 道頼

出版者

一般社団法人日本生物物理学会

雑誌

生物物理 (ISSN:05824052)

巻号頁・発行日

vol.47, no.3, pp.167-173, 2007-05-25

参考文献数

13

---

The slope of the oxygen equilibrium curve (OEC) of mammalian-hemoglobin (Hb) is maximized at <i>S</i> (oxygen saturation) value of 0.38, and the slope of the <i>S</i> vs. <i>P</i>/<i>P</i>₅₀ (<i>P</i> is partial oxygen pressure; <i>P</i>₅₀ is <i>P</i> at <i>S</i> = 1/2) plot at a <i>P</i>/<i>P</i>₅₀ value of 1 is one-forth that of the Hill-coefficient (<i>n</i>). OECs of mammalian Hbs are designed to have an identical optimal <i>P</i>₅₀ value for O₂ delivery and the effectiveness of the Bohr shift (shift of OEC upon pH changes) at O₂ loading site. This fact is favorable for uptake and delivery of maximum amount of O₂ for fetal blood. To have the identical optimal <i>P</i>₅₀ value for O₂ delivery and for the efficiency of the Bohr shift, the relationship, <i>P</i>aO₂/<i>P</i>vO₂ = ((<i>n</i> + 1)/(<i>n</i> &minus; 1))^2/n, is required to hold, where <i>P</i>aO₂ and <i>P</i>vO₂ are <i>P</i> for arterial and venous bloods, respectively.<br>