胆固醇是所有动物细胞中
cholesterol is an essential component
基本组成成分
of all animal cells but too much
但是血液中胆固醇太高
cholesterol in the blood is a
将会引起心血管疾病
high risk factor for cardiovascular diseases such
例如心脏病或中风
as heart attacks and strokes cholesterol
血液检测胆固醇含量
levels are measured in a blood test
也叫做血脂测试或血脂分析
known as lipid panel or lipid profile
这项测试能反映总胆固醇含量
this test typically reports total cholesterol
低密度脂蛋白LDL也就是有害胆固醇
low-density lipoprotein LDLalso known as bad cholesterol
高密度脂蛋白HDL也就是有益胆固醇或甘油三酯
high density lipoprotein HDL or goodcholesterol and triglycerides
期待的情况包括每个被测者的总胆固醇含量
a desirable profile include less than 200 milligrams per deciliter total cholesterol
低于200毫升毫克每分升 同时LDL低于100毫升毫克每分升
with less than 100 milligrams per deciliter LDL
并且HDL的含量低于40毫克每分升
and more than 40 milligrams per deciliter of HDL
人体获得胆固醇的途径有两条
the body obtains cholesterol in two ways
一是从食物中获取另一个是自身产出
from foods of animal origin and its ownendogenous production
通常胆固醇含量通过负反馈
usually cholesterol levels are kept in check
时刻检查控制
by negative feedback control
细胞内胆固醇含量低时就刺激生产
low levels of intracellular cholesterol induce its own production levels
高时就抑制生产
while high cholesterol levels inhibited it is noteworthy
然而 这种调节导致了
however that this regulation applies to the
细胞里面的胆固醇聚集
concentration of cholesterol inside the cells not
而对血液里
in the blood the high
高胆固醇没有作用
prevalence of high blood cholesterolworldwide suggests that this control
说明控制机制并不能充分保证胆固醇在健康水平
mechanism is not sufficient to maintainhealthy cholesterol levels when
由许多因素影响而成
challenged by a number
包括不节食 缺乏锻炼
of factors including poor diet lack of exercise
吸烟 肥胖 糖尿病和老龄化
smoking obesity diabetes and aging
另外还有一些人患有遗传性家族疾病
in addition some people have an inherited
叫家族性高胆固醇血症（FH） 这个疾病会造成
condition called familialhypercholesterolemia FH that causes very
在年轻时 LDL也就是有害胆固醇 过高
high levels of LDL the bad cholesterol
病人对此不以为意
at a young age left untreated patients
很容易得心脏病
are likely to have heart attacks
对四五十岁的人来说 LDL就是
in their 40s or 50s LDL is basically a
从肝脏运送胆固醇
vehicle that transports cholesterol
给外部细胞
from the liver to peripheral cells so it can
所以它能用于生成细胞膜
be used in the cell membrane
外围细胞通过细胞内吞来利用LDL
peripheral cells take up LDL by endocytosis using
它们的LDL受体
their LDL receptor which binds to
LDL表面有一个蛋白质配合基
a protein ligand on LDL surface most cases
多数的FH都是由LDL受体基因突变引起
of FH are caused by mutation in the LDLreceptor gene
一个有缺陷的LDL受体降低了LDL摄入
a defective LDL receptor reduces LDL
让更多的LDL在身体循环中
uptake leaving more LDL in the
同时细胞的胆固醇过低
circulation while the cells aredeficient in cholesterol low
细胞内胆固醇水平过低降低了肝内胆固醇转化
intracellular cholesterol levels inducefurther production of endogenous
最终造成肝内LDL更高
cholesterol in the liver eventuallycausing even higher levels of
在循环中
circulating LDL one copy
一个变异的基因就能够引起胆固醇升高
of the mutated gene is enough to cause high cholesterol
这种情况能够遗传
the condition is therefore inherited
在一个显性常染色体中
in an autosomal dominant manner a parent
一对有变异基因的父母就有
with an altered gene has a
50%的几率传给下一代
50 % chance of passing it to a child
如果父母双方都有FH
if both parents have FH each child has
每一个小孩子都有一半的几率得FH
a 50 % chance of having FH a 25 %
25%的几率不得FH
chance of not having FH and a 25 % chance
25%的几率拥有重合的变异基因
of having two copies of the mutated gene
叫做显性重合FH 没有治疗办法这种病人
called homozygous FH without treatmenthomozygous FH patients may have heart
20多岁就得心脏病
attacks in their twenties and may not survive
不会活过30多岁
past the age of thirty
高胆固醇患者的治疗从改变生活方式开始
treatments for high cholesterol muststart with lifestyle changes such as
诸如健康饮食 体育锻炼
healthy diets and physical exercise on top
一些人需要药物治疗去降低胆固醇
of that some people may require
这些药物抑制了胆固醇的
medications to lower cholesterol thesedrugs inhibit cholesterol production
肠道吸收或以胆液形式的再吸收
intestinal absorption or reabsorption inthe form of bile.
重合型FH患者通常需要
Homozygous FH patients usually require more
有力的治疗手段 它包括
drastic treatment measures which include a procedure
一个叫LDL的程序
called LDL apheresis
在这个程序里 血液通过一个过滤装置
in this procedure the blood is diverted through a
过滤掉LDL
filtration device where LDL is removed
血浆和血细胞再回到身体
before the remaining plasma and blood cells are returned to the body
每一周或两周就要来一次
the procedure is repeated weekly or bi-weekly