降血脂药与睡眠紊乱有关
From 自明知识
降血脂药与睡眠紊乱有关?
研究人员在2007年美国的心脏病协会的科学大会上报告称，降血脂药可能会影响某些患者的睡眠。论文第一作者，加州州立大学圣地亚哥医学院家庭预防医学的医学助理教授Beatrice Golomb医学博士称，该发现很重要，因为睡眠问题会影响生活质量，还可能会导致不良的健康问题，例如刺激体重增加及胰岛素抵抗。
在最大的一项此类研究中，研究人员比较了两种他汀类降血脂药物，亲脂的辛伐他汀（溶于脂类）和亲水的帕伐他汀（溶于水）。因为辛伐他汀为脂溶性，所以更容易透过细胞膜及穿越血脑屏障进入大脑。大脑控制睡眠，且很多脑神经细胞外包有称为髓磷脂的绝缘脂质鞘。研究结果显示，服用辛伐他汀的患者伴有严重的睡眠质量降低，而且服用辛伐他汀的患者出现睡眠问题显著高于服用帕伐他汀或服用安慰剂的患者。因此平均起来，亲脂类药物对睡眠质量的不良影响更强。在过去的研究及病例报告中，某些服用他汀药物的患者报告出现失眠或梦魇。
Golomb称，早期曾进行过几项小型研究，其中包括集中比较亲脂性他汀与亲水性他汀的研究。但可能因为随访时间较短，且仅对小部分患者进行（通常少于20人-如此小的患者量不足以观察这种区别），大部分研究人员并未注意到影响睡眠方面的区别。而其中一项研究确实报告了帕伐他汀和辛伐他汀间的某种显著差别。但因未做更多及更大型的研究，所以并未确定这种影响。
在该项研究中，研究人员对1016名健康成年男女进行6个月的随机双盲安慰剂对照实验，受试者随机分成三组，辛伐他汀组（20mg），帕伐他汀组（40mg）及安慰剂对照组。然后在治疗前及治疗期间用利兹睡眠评估量表（一种睡眠质量直观类比标度）及睡眠障碍等级量表对结果进行评估。结果发现，与其他患者相比，那些报告称试验药物治疗严重损害睡眠的患者，在攻击指数方面也出现明显的不良变化。另外Golomb还指出，虽然辛伐他汀对睡眠的平均影响是有害的，但这并不意味着每位服用辛伐他汀的患者都会出现睡眠质量变坏。
考虑到随机试验中可能会将患者分配进安慰剂组，所以研究人员没有纳入有心脏病或糖尿病的患者。Golomb建议，服用辛伐他汀出现睡眠问题的患者应该咨询医生，对于小部分人而言，睡眠不足是个大问题。
Cholesterol-lowering drug linked to sleep disruptions
A cholesterol-lowering drug appears to disrupt sleep patterns of some patients, researchers reported at the American Heart Association’s Scientific Sessions 2007.
“The findings are significant because sleep problems can affect quality of life and may have adverse health consequences, such as promoting weight gain and insulin resistance,” said Beatrice Golomb, M. D., lead author of the study and an associate professor of medicine and family and preventive medicine at the University of California at San Diego School of Medicine.
In the largest study of its kind, researchers compared two types of cholesterol-lowering drugs called statins — simvastatin, which is lipophilic (soluble in fats), and pravastatin, which is hydrophilic (soluble in water).
Because simvastatin is fat soluble it can more readily penetrate cell membranes and cross the blood brain barrier into the brain. The brain controls sleep, and many of the brain’s nerve cells are wrapped in a fatty insulating sheath called myelin.
“The results showed that simvastain use was associated with significantly worse sleep quality. A significantly greater number of individuals taking simvastatin reported sleep problems than those taking either pravastain or the placebo,” Golomb said. “On average, the lipophilic statin had a greater adverse effect on sleep quality.”
In past studies and case reports, some people on statins reported having insomnia or nightmares.
“Several small studies were done early on, including those focused on lipophilic versus hydrophilic statins,” Golomb said. “Most (researchers) didn’t see a difference in sleep, but they had short durations of follow-up and enrolled just a handful of people — often fewer than 20, which was not enough to see a difference unless it was very large.
“One of these studies did report a significant difference between pravastatin and simvastatin. But without more and bigger studies, an effect was not considered to be established.”
In this study, researchers tested 1,016 healthy adult men and women for six months in a randomized, double-blind, placebo-controlled trial using simvastatin, given at 20 milligrams (mg), pravastatin at 40 mg, or a placebo. They assessed outcomes with the Leeds sleep scale, a visual analog scale of sleep quality, and a rating scale of sleep problems. Both scales were measured before and during treatment.
“Those who reported developing much worse sleep on study medication also showed a significant adverse change in aggression scores compared to others,” Golomb said “We should also point out that although the average effect on sleep was detrimental on simvastatin, this does not mean that everyone on simvastatin will experience worse sleep.”
Researchers did not include patients with heart disease or diabetes due to concerns about assigning these people to placebos.
“Patients taking simvastatin who are having sleep problems should consult with their doctor,” Golomb said. “Sleep deprivation is a major problem in a minor number of people.”
The National Heart, Lung, and Blood Institute of the National Institutes of Health funded the study.
Co-authors are Edwin K. Kwon, B.A.; Michael H. Criqui, M.D., M.P.H.; and Joel E. Dimsdale, M.D.
Statements and conclusions of study authors presented at American Heart Association scientific meetings are solely those of the study authors and do not necessarily reflect association policy or position. The American Heart Association makes no representation or warranty as to their accuracy or reliability.