Susceptibility to Exacerbation in Chronic Obstructive Pulmonary Disease
COPD(慢性拘束性肺疾患)における増悪感受性
Background Although we know that exacerbations are key events in chronic
obstructive pulmonary disease (COPD), our understanding of their
frequency, determinants, and effects is incomplete. In a large
observational cohort, we tested the hypothesis that there is a
frequent-exacerbation phenotype of COPD that is independent of disease
severity.
背景：COPDにおいて増悪は重要事象であることは知っているが，増悪頻度・決定因子・影響について完全には理解していない．大規模観察コホート研究において，COPDの頻繁増悪型は疾患重症度と独立であるという仮説を検証した．
Methods We analyzed the frequency and associations of exacerbation in
2138 patients enrolled in the Evaluation of COPD Longitudinally to
Identify Predictive Surrogate Endpoints (ECLIPSE) study. Exacerbations
were defined as events that led a care provider to prescribe antibiotics
or corticosteroids (or both) or that led to hospitalization (severe
exacerbations). Exacerbation frequency was observed over a period of 3
years.
方法： ECLIPSE研究(予測代替エンドポイントを同定するためのCOPD長期的評価研究)に登録された2138症例において，増悪の頻度と関連を解析した．増悪は抗生物質か糖質コルチコイドのいずれか(もしくはその両方)を処方するか，入院することと定義した．増悪頻度は3年以上にわたり観察した．
Results Exacerbations became more frequent (and more severe) as the
severity of COPD increased; exacerbation rates in the first year of
follow-up were 0.85 per person for patients with stage 2 COPD (with
stage defined in accordance with Global Initiative for Chronic
Obstructive Lung Disease [GOLD] stages), 1.34 for patients with stage 3,
and 2.00 for patients with stage 4. Overall, 22% of patients with stage
2 disease, 33% with stage 3, and 47% with stage 4 had frequent
exacerbations (two or more in the first year of follow-up). The single
best predictor of exacerbations, across all GOLD stages, was a history
of exacerbations. The frequent-exacerbation phenotype appeared to be
relatively stable over a period of 3 years and could be predicted on the
basis of the patient's recall of previous treated events. In addition
to its association with more severe disease and prior exacerbations, the
phenotype was independently associated with a history of
gastroesophageal reflux or heartburn, poorer quality of life, and
elevated white-cell count.
結果： COPDの重症度が高まると，増悪はより頻回に起こり，より重症になった．追跡期間1年目の1人当たりの増悪発生率は，ステージⅡのCOPD患者で0.85回/人年，ステージⅢのCOPD患者で1.34回/人年，ステージⅣのCOPD患者で2.00回/人年であった(慢性拘束性肺疾患に対するグローバルステージ分類[GOLD分類]で定義した)．全体でステージⅡの22%，ステージⅢの33%，ステージⅣの47%の患者が頻回に増悪を起こした(追跡期間1年目に2回以上)．GOLDステージ分類の全てにおける増悪の最も良い単一予測因子は，増悪の既往であった．頻回増悪型は，3年以上に渡って比較的安定しているようであり，患者が過去の治療経験を思い出すというバイアス(偏り)により予測されるのかもしれない．頻回増悪型において，疾患重症度と増悪の既往の相関に加えて，胃食道逆流症(GERD)の既往・胸やけ・QOL不良・白血球数増加とも独立して相関がみられた．
・ 臨床試験登録前の1年間の増悪治療既往のオッズ比は
4.30，95%信頼区間は3.58～5.17，P値<0.001であった．
・ 他の増悪関連因子は，気管支拡張薬投与後のFEV1による肺機能低下
健康状態(QOL)の低下・胃食道逆流・白血球増加である．
Conclusions Although exacerbations become more frequent and more severe
as COPD progresses, the rate at which they occur appears to reflect an
independent susceptibility phenotype. This has implications for the
targeting of exacerbation-prevention strategies across the spectrum of
disease severity. (Funded by GlaxoSmithKline; ClinicalTrials.gov number,
NCT00292552.)
結論： COPDの進行とともに，増悪はより頻回に，より重症になったが，増悪頻度は独立した感受性表現型を反映しているようであった．このことは，疾患重症度の幅を越えて増悪予防法を特定の患者に絞ることを意味している．
COPD Exacerbations COPD増悪
The natural history of chronic obstructive pulmonary disease (COPD) is punctuated by exacerbations -- acute increases in the severity of symptoms.
慢性拘束性肺疾患(COPD)の自然経過は，増悪(症状が急激に悪化すること)が時々おこる．
What is the effect of COPD exacerbations on patients?
COPD増悪は患者にどのような影響をもたらすか？
Exacerbations appear to accelerate the decline in lung function that characterizes COPD, resulting in reduced physical activity, poorer quality of life, and an increased risk of death. Exacerbations are also responsible for a large proportion of the health care costs attributable to this prevalent condition.
COPDの特徴的である増悪は，肺機能の低下を促進させ，身体活動・QOL(生活の質)を低下させ，死亡リスクを増加させる．さらに，増悪が頻繁に発症することによる医療費は，かなりの割合を占める．
How is COPD severity associated with exacerbation frequency and severity?
COPD重症度は増悪頻度と増悪重症度とどのような関連があるか？
As the severity increased, exacerbations were both more frequent and more severe. The severity of disease also affected hospitalization in year 1, with the proportion of patients who were hospitalized increasing with the severity of disease: moderate disease, 7%; severe disease, 18%; and very severe disease, 33%.
重症度が増加すると，増悪はより頻回に起こり，より重症化する．疾患重症度も1年間の入院に影響し，入院患者の割合は疾患が重症になるほど増加し，重症の7%，最重症の33%が入院する．
皆さん！タバコは止めようね！(喫煙がCOPDの最も重要な原因と言われています)
自分の健康の為にも，国民の医療費の為にも，Stop Smoking！