Bader G, Zuliani G, Kostner G M, Fellin R
2nd Department of Internal Medicine, University of Ferrara, Italy.
Gerontology. 1998;44(5):293-9. doi: 10.1159/000022030.
Apolipoprotein E (apo E) is a protein associated with plasma lipoproteins. Apo E polymorphism has been related to significant modifications of lipoprotein profile, as well as to the incidence of different pathologies including cardiovascular disease, Alzheimer's disease, and vascular dementia. Furthermore, it was proposed that apo E polymorphism might be involved in the aging selection process.
The purposes of the present study were the following: (1) to evaluate apo E polymorphism in 'successful' and 'unsuccessful' aging, defined as the absence or presence of disability and severe chronic diseases (mainly cardiovascular disease and dementia), respectively; (2) to evaluate the impact of apo E polymorphism on plasma lipids in very old individuals free of or affected by disability.
253 Italian subjects including 100 free-living healthy octo- and nonagenarians, 62 disabled octo- and nonagenarians, and 91 healthy adult controls, all matched for origin were studied. Apo E phenotypes were determined by PhastSystem (Pharmacia). Lipoprotein parameters (total cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol, lipoprotein (a), and apoprotein A-I and B) were measured by standardized methods. ADL were evaluated by the Katz index.
The frequency of sigma2, sigma3, and sigma4 alleles was 0.062, 0.887, and 0.051 respectively in the entire sample; no differences in alleles distribution were found between the three groups. When the subjects were divided according to the E type (E2 type: E2/E2 and E2/E3; E3 type: E3/E3; E4 type: E3/E4 and E4/E4), no differences in lipoprotein parameters emerged, but a trend toward higher total and LDL-cholesterol from the E2 to the E4 type was observed. The sigma4 allele had a raising effect, while sigma2 had a lowering effect on total cholesterol levels, but these effects were much less profound in the disabled octo- and nonagenarians.
We conclude that (1) the frequency of the sigma4 allele is very low in this sample of subjects from central Italy; (2) no differences emerged in sigma4 distribution between healthy and disabled octo- and nonagenarians, and adult controls; the very low frequency of sigma4 allele might contribute to this finding; (3) our data do not support the hypothesis of a possible association between apo E polymorphism and longevity or disability in this population.
载脂蛋白E（apo E）是一种与血浆脂蛋白相关的蛋白质。载脂蛋白E多态性与脂蛋白谱的显著改变以及包括心血管疾病、阿尔茨海默病和血管性痴呆在内的不同疾病的发生率有关。此外，有人提出载脂蛋白E多态性可能参与衰老选择过程。
本研究的目的如下：（1）评估分别定义为无残疾和患有严重慢性疾病（主要是心血管疾病和痴呆）的“成功”和“不成功”衰老中的载脂蛋白E多态性；（2）评估载脂蛋白E多态性对无残疾或患有残疾的非常年长者血浆脂质的影响。
研究了253名意大利受试者，包括100名自由生活的健康八旬和九旬老人、62名残疾八旬和九旬老人以及91名健康成人对照，所有受试者均按籍贯匹配。通过PhastSystem（Pharmacia）测定载脂蛋白E表型。通过标准化方法测量脂蛋白参数（总胆固醇、甘油三酯、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇、脂蛋白（a）以及载脂蛋白A-I和B）。通过Katz指数评估日常生活活动能力。
在整个样本中，σ2、σ3和σ4等位基因的频率分别为0.062、0.887和0.051；三组之间未发现等位基因分布存在差异。当根据E型（E2型：E2/E2和E2/E3；E3型：E3/E3；E4型：E3/E4和E4/E4）对受试者进行分组时，脂蛋白参数未出现差异，但观察到从E2型到E4型总胆固醇和低密度脂蛋白胆固醇有升高趋势。σ4等位基因对总胆固醇水平有升高作用，而σ2有降低作用，但在残疾八旬和九旬老人中这些作用要小得多。
我们得出以下结论：（1）在来自意大利中部的这个受试者样本中，σ4等位基因的频率非常低；（2）健康和残疾的八旬和九旬老人以及成人对照之间σ4分布未出现差异；σ4等位基因的极低频率可能导致了这一结果；（3）我们的数据不支持在该人群中载脂蛋白E多态性与长寿或残疾之间可能存在关联的假设。
