What is the problem and what is known about it so far?

Parkinson disease is a chronic neurologic condition that affects movement and often leads to disability and decreased quality of life. Currently, no treatment is able to slow the progression (or worsening) of Parkinson disease. Some studies suggest that a certain type of blood pressure medication—a dihydropyridine calcium-channel blocker—may decrease the risk for Parkinson disease.

Why did the researchers do this particular study?

To determine whether treatment with isradipine, a dihydropyridine calcium-channel blocker, could slow down the progression of Parkinson disease symptoms.

Who was studied?

Adults aged 30 years or older who had a new diagnosis of Parkinson disease (diagnosed within the past 3 years) and were not treated with dopaminergic antiparkinson drugs at the time of enrollment or within 3 months of the baseline visit. The study participants were enrolled in 57 clinical sites in the United States and Canada.

How was the study done?

The study participants were randomly assigned to receive either 5 mg of isradipine twice a day or placebo (sugar pill) twice a day for 3 years. They had several follow-up visits during the course of the study (baseline, 14 days, 28 days, and then every 3 months and later every 6 months until 36 months). During these visits, the participants answered questionnaires and completed Unified Parkinson's Disease Rating Scale (UPDRS) assessments. The UPDRS measures mental function, activities of daily living, and motor function and was the main outcome for the study. The participants also told researchers if they were having any side effects from the medication. The researchers compared the change in the UPDRS from baseline to 36 months between the 2 groups.

What did the researchers find?

336 adults with Parkinson disease were enrolled, and 95% completed the study. By the time the study ended, most participants (about 90%) were taking antiparkinson drugs. The researchers found no differences in the UPDRS scores between the isradipine and placebo groups. The most common side effects reported by the isradipine group were dizziness and swelling in the legs and feet.

What were the limitations of the study?

It is possible that the dose of isradipine was not high enough to block the calcium channels in the cells affected by Parkinson pathology.

What are the implications of the study?

Treatment with isradipine was not helpful in slowing down the worsening of Parkinson disease symptoms.

中文翻译：

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早期帕金森病中伊斯拉地平与安慰剂的比较。

问题是什么，到目前为止对此有什么了解？

帕金森病是一种慢性神经系统疾病，会影响运动并经常导致残疾和生活质量下降。目前，没有任何一种治疗方法能够减慢帕金森氏病的进展（或恶化）。一些研究表明，某种类型的降压药（一种二氢吡啶类钙通道阻滞剂）可以降低帕金森氏病的风险。

研究人员为什么要进行这项特殊研究？

要确定用二氢吡啶钙通道阻滞剂伊拉地平治疗是否可以减慢帕金森氏病症状的进展。

谁学的？

入组时或基线访视后3个月内未诊断为帕金森病（在过去3年内诊断）且未接受多巴胺能抗帕金森药物治疗的30岁或30岁以上的成年人。研究参与者被招募到美国和加拿大的57个临床站点。

研究如何完成？

研究参与者被随机分配为每天两次接受5毫克异拉地平或安慰剂（糖丸）两次，共3年。他们在研究过程中进行了几次随访（基线，14天，28天，然后每3个月，然后每6个月直到36个月）。在这些访问期间，参与者回答了问卷，并完成了帕金森病综合评分量表（UPDRS）评估。UPDRS测量精神功能，日常生活活动和运动功能，是该研究的主要结果。参与者还告诉研究人员他们是否从药物中有任何副作用。研究人员比较了两组之间从基线到36个月的UPDRS变化。

研究人员发现了什么？

招募了336名帕金森氏病成人，其中95％完成了研究。到研究结束时，大多数参与者（约90％）正在服用抗帕金森药物。研究人员发现，伊拉地平组和安慰剂组之间的UPDRS评分没有差异。依拉地平组报告的最常见的副作用是头晕和腿脚肿胀。

研究的局限性是什么？

依拉地平的剂量可能不够高，无法阻断受帕金森氏病影响的细胞中的钙通道。

该研究的意义是什么？

用伊拉地平治疗无助于减缓帕金森氏病症状的恶化。