Caffeine had shown promise in a small (61 patients), short (6 weeks), randomized study¹ for improving motor function in patients with Parkinson disease. Caffeine holds appeal as an inexpensive intervention that is well-tolerated in most individuals. The investigators for that small study now report the results of a multicenter randomized study² using the same outcome. They designed the study to have approximately 4 times as many participants, an extended follow-up to evaluate the persistence of any effects, and adequate power to detect a similar effect size as observed in the smaller study. The study focused on symptomatic improvement and not disease progression given the lack of any biological model in which caffeine would affect the latter.

一項(xiàng)持續(xù)6周的短期隨機(jī)對(duì)照研究（61例病例）表明,，咖啡因可改善帕金森病患者的運(yùn)動(dòng)功能¹,。咖啡因作為一種廉價(jià)的干預(yù)手段,，對(duì)大多數(shù)人來說有著良好的耐受性,。該小規(guī)模研究的調(diào)查者還報(bào)道了一項(xiàng)多中心隨機(jī)對(duì)照研究²，其結(jié)果和上述結(jié)果相似,。這項(xiàng)研究有大約 4倍的參與者,，持續(xù)隨訪其所有作用，其充足的證據(jù)預(yù)期檢測(cè)出與上述小規(guī)模研究相似的效果,。由于缺少生物學(xué)模型,，研究致力于癥狀的改善而不是疾病的進(jìn)展，因?yàn)榭Х纫驎?huì)影響后者結(jié)果,。

The study appears well-run and not biased by differential compliance or loss to follow-up. Disappointingly, caffeine showed no benefit compared to placebo on the primary outcome or on important secondary outcomes. Terminated early for lack of efficacy, the study only enrolled approximately half the intended total and completed only 18 months of follow-up. Although the small number of participants (n =121) resulted in a wide confidence interval and cannot exclude a small effect, this trial suggests that caffeine does not significantly improve Parkinson disease symptoms and that it should not be a priority for future Parkinson disease intervention studies.

此研究順利進(jìn)行,，無統(tǒng)計(jì)學(xué)差異和隨訪的缺失。令人失望的是,，與安慰劑相比,，咖啡因在主要結(jié)果和重要次要結(jié)果上沒有優(yōu)勢(shì)。因缺乏有效性，研究提前終止,。研究?jī)H納入大約預(yù)期一半的人數(shù),，且僅完成了18個(gè)月的隨訪。雖然這組參與者（n=121）的置信區(qū)間較寬,，且不能排除任一小的影響,，本次實(shí)驗(yàn)表明咖啡因并不能顯著改善帕金森病的癥狀，其不應(yīng)該成為未來帕金森病的優(yōu)先干預(yù)措施,。

Promising leads must be studied, and disappointing findings be disseminated to the research and clinical communities. Researchers can now focus on more promising intervention targets and clinicians now know that any effects of caffeine are likely small and not better than placebo. Hopefully future studies will find more effective interventions.

令人失望的研究結(jié)果已傳播至研究和臨床團(tuán)體,，必須研究有前途的線索。研究人員現(xiàn)在致力于更有希望的干預(yù)目標(biāo),，而臨床醫(yī)生現(xiàn)已了解咖啡因的作用微乎其微,，并不比安慰劑作用好。希望未來研究能發(fā)現(xiàn)更有效的干預(yù)措施,。

1. Postuma RB, Lang AE, Munhoz RP, et al. Caffeine for treatment of Parkinson disease: a randomized controlled trial. Neurology 2012;79:651–658.

2. Postuma RB, Anang J, Pelletier A, et al. Caffeine as symptomatic treatment for Parkinson disease (Café-PD): a randomized trial. Neurology 2017;89:xx–xxx.