長期疼痛會引起類似與早期老化有關的失能
作者：Laurie Barclay, MD
出處：WebMD醫學新聞
September 29, 2009 — 根據發表於9月美國老年醫學會期刊中的一篇橫斷面研究結果，有疼痛的年輕人發生的失能情況類似於年長20到30歲但沒有疼痛者。
第一作者、加州大學舊金山分校的Kenneth E. Covinsky醫師在新聞稿中表示，我們發現，50至59歲有疼痛者的能力狀態就像80至89歲無疼痛者，其中4%可以慢跑1英里、55%可以散步幾條街，這些遭受疼痛之苦者的狀態就像比其年長20到30歲但無疼痛者。
校正人口統計學特徵、社會經濟狀態、共病症、憂鬱、肥胖與健康習慣之後，綜合全部四種測量，有明顯疼痛者發生功能性限制的風險高出許多。如果同時評估和治療疼痛與失能，對病患的結果會比分開治療還要好。
本研究的目標是評估2004年「Health and Retirement Study」研究中，18,531名研究對象從中年到老年，其功能性限制和疼痛之間的關係，「Health and Retirement Study」研究是一個有全國代表性之50歲以上社區居民的研究。明顯疼痛的定義是多數時間有中到嚴重的疼痛，且經常令發生疼痛者感到困擾。
根據研究對象在移動性、爬樓梯、上肢任務、日常生活功能活動等四種功能面的限制程度進行分類。50至59歲的參與者有24%報告有明顯疼痛。在前述的四種功能面中，有疼痛者發生功能性限制的比率，遠高於沒有疼痛者。
在功能性限制中，有疼痛者的狀態相當於比其年長20至30歲者。在移動性這一項，50至59歲、沒有疼痛的參與者，有37%可以慢跑1英里、91%可以散步幾條街、96%可以毫無困難的走一個街區。不過，50至59歲、有疼痛者中，只有9%可以慢跑1英里、50%可以散步幾條街、69%可以毫無困難的走一個街區。這一組的移動性限制類似80至89歲而無疼痛的研究對象：4%可以慢跑1英里、55%可以散步幾條街、72%可以毫無困難的走一個街區。
校正人口統計學特徵、社會經濟狀態、共病症、憂鬱、肥胖與健康習慣之後，在這四種功能面中，明顯疼痛的研究對象發生功能性限制的風險高出許多。移動性的校正勝算比為2.85(95%信心區間[CI]為2.20 - 3.69)、爬樓梯為2.84(95% CI，2.48 - 3.26)、上肢任務為3.96 (95% CI，3.43- 4.58)、日常生活功能活動為4.33 (95% CI，3.71 - 5.06)。
研究者結論表示，有疼痛經驗的年輕人，更容易發生與老化有關的功能性限制。
Covinsky醫師表示，我們的研究無法確認是否因疼痛引起失能或者失能引起疼痛；我們認為兩者都有可能，疼痛和失能可能一起惡性循環而產生一些問題；我們的研究涵義之一是，疼痛和失能兩者或許無法完全切割，可能有部份的相同原因。
研究限制包括，橫斷面設計，疼痛測量上有其既有難度。
美國老年醫學會期刊編輯Thomas Yoshikawa醫師表示，劇痛產生的影響會令人難以進行日常生活的工作，這顯示出有效處置與治療疼痛的重要性。上個月，我們出版今年度有關年長者持續疼痛之藥物處置指引，本研究的確讓健康照護者瞭解，透過最佳治療來改善病患生活品質的重要性。
國家關節炎與肌肉骨骼和皮膚疾病研究中心資助「Health and Retirement Study」研究。Covinsky醫師的部份資助來自國家老化研究中心的中年生涯研究獎。其他研究作者宣告沒有相關財務關係。
Chronic Pain May Cause Similar Disability Linked With Aging at Earlier Ages
By Laurie Barclay, MD
Medscape Medical News
September 29, 2009 — Younger people with pain have disability similar to that of people who are 2 to 3 decades older without pain, according to the results of a cross-sectional study published in the September issue of the Journal of the American Geriatrics Society.
"We found that the abilities of those aged 50 to 59 with pain were far more comparable to subjects aged 80 to 89 without pain, of whom 4% were able to jog 1 mile and 55% were able to walk several blocks, making pain sufferers appear 20 to 30 years older than non-pain sufferers," lead author Kenneth E. Covinsky, MD, MPH, from the University of California, San Francisco, said in a news release.
"After adjustment for demographic characteristics, socioeconomic status, comorbid conditions, depression, obesity, and health habits, across all four measures, participants with significant pain were at much higher risk for having functional limitations....Patients may be better served if pain and disability are evaluated and treated jointly rather than treated as separate issues."
The goal of this study was to evaluate the relationship between functional limitations and pain across a spectrum of age, ranging from mid life to advanced old age, among 18,531 participants in the 2004 Health and Retirement Study, a nationally representative study of community-dwelling persons 50 years and older. Significant pain was defined as pain that was moderate or severe most of the time and that often troubled the person reporting the pain.
Participants were classified based on their degree of functional limitation in each of 4 functional domains: mobility, stair climbing, upper extremity tasks, and activities of daily living function. Significant pain was reported by 24% of participants aged 50 to 59 years. In all 4 domains, rates of functional limitations were much higher in participants with pain vs those without pain.
In functional limitation, participants with pain were similar to participants 2 to 3 decades older. In the mobility domain, 37% of participants aged 50 to 59 years without pain could jog 1 mile, 91% could walk several blocks, and 96% could walk 1 block without difficulty. However, of participants aged 50 to 59 years with pain, only 9% could jog 1 mile, 50% could walk several blocks, and 69% could walk 1 block without difficulty. Mobility limitations in this group were similar to those in participants aged 80 to 89 years without pain, of whom 4% could jog 1 mile, 55% could walk several blocks, and 72% could walk 1 block without difficulty.
Participants with significant pain were at much higher risk of having functional limitations across all 4 measures, after adjustment for demographic and socioeconomic factors, comorbid conditions, depression, obesity, and health habits. Adjusted odds ratio was 2.85 for mobility (95% confidence interval [CI], 2.20 - 3.69), 2.84 for stair climbing (95% CI, 2.48 - 3.26), 3.96 for upper extremity tasks (95% CI, 3.43 - 4.58), and 4.33 for activities of daily living function (95% CI, 3.71 - 5.06).
The investigators concluded that younger subjects with pain experience functional limitations classically associated with aging.
"Our study cannot determine whether pain causes disability or whether disability causes pain," Dr. Covinsky said. "We think it is likely that both are true and that pain and disability probably can act together in ways that make both problems worsen in a downward spiral. One implication of our study is that pain and disability may not be fully separate processes, but may often be part of the same underlying process."
Limitations of this study include cross-sectional design and difficulties inherent in pain measurement.
"The drastic effect that pain can have on sufferers' abilities to carry out everyday tasks in their lives highlights the importance of managing pain and treating it effectively," said Thomas Yoshikawa, MD, editor of the Journal of the American Geriatrics Society, "Last month, we published our annual guidelines on the pharmacological management of persistent pain in older persons, and this study really brings home how essential it is for healthcare providers to be able to improve quality of life through awareness of the best treatments."
The National Institute of Arthritis and Musculoskeletal and Skin Diseases funded the Health and Retirement Study. Dr. Covinsky is supported in part by a midcareer investigator award from the National Institute on Aging. The other study authors have disclosed no relevant financial relationships.
J Am Geriatr Soc. 2009;57:1556-1561.
