Heller D A, de Faire U, Pedersen N L, Dahlén G, McClearn G E
Program in Biobehavioral Health, College of Health and Human Development, Pennsylvania State University, University Park 16802.
N Engl J Med. 1993 Apr 22;328(16):1150-6. doi: 10.1056/NEJM199304223281603.
The extent to which serum lipid levels are affected by genetic and environmental factors remains a point of controversy. We examined both genetic and environmental influences on serum lipid levels in twins reared either together or apart who participated in the Swedish Adoption/Twin Study of Aging.
We studied 302 pairs of twins (mean age, 65.6 years; range, 52 to 86); 146 pairs had been reared apart. We simultaneously compared the twins on the basis of both zygosity and rearing status, which allowed joint estimation of genetic and environmental influences on serum lipid levels. Genetic influence was expressed in terms of heritability, the proportion of the population variation attributable to genetic variation (a value of 1.0 indicates that all of the population variation is attributable to genetic variation). The serum lipids and apolipoproteins measured included total cholesterol, high-density lipoprotein cholesterol, apolipoproteins A-I and B, and triglycerides.
Structural-equation analyses revealed substantial heritability for the serum levels of each lipid measured, ranging from 0.28 to 0.78. Comparisons of the twins reared together with those reared apart suggested that the environment of rearing had a substantial impact on the level of total cholesterol (accounting for 0.15 to 0.36 of the total variance). Sharing the same environment appeared to affect the other lipid measures much less, however, than did genetic factors and unique environmental factors not shared by twins. Comparisons of younger with older twins suggested that heritability for apolipoprotein B and triglyceride levels decreased with age.
The effect of genetic factors on the serum levels of some but not all lipids appears to decrease with age. Early rearing environment appears to remain an important factor in relation to levels of total cholesterol later in life, but it has less effect on other serum lipids and apolipoproteins in the elderly.
血清脂质水平受遗传和环境因素影响的程度仍是一个有争议的问题。我们在参与瑞典收养/双生子老龄化研究的共同抚养或分开抚养的双胞胎中，研究了遗传和环境对血清脂质水平的影响。
我们研究了302对双胞胎（平均年龄65.6岁；范围52至86岁）；其中146对是分开抚养的。我们根据同卵双生或异卵双生以及抚养状况对双胞胎进行了同时比较，这使得能够联合估计遗传和环境对血清脂质水平的影响。遗传影响用遗传度来表示，即群体变异中可归因于遗传变异的比例（值为1.0表示所有群体变异都可归因于遗传变异）。所测量的血清脂质和载脂蛋白包括总胆固醇、高密度脂蛋白胆固醇、载脂蛋白A-I和B以及甘油三酯。
结构方程分析显示，所测量的每种脂质的血清水平都有显著的遗传度，范围从0.28到0.78。共同抚养的双胞胎与分开抚养的双胞胎的比较表明，抚养环境对总胆固醇水平有显著影响（占总方差的0.15至0.36）。然而，共享相同环境对其他脂质指标的影响似乎远小于遗传因素和双胞胎不共享的独特环境因素。年轻双胞胎与年长双胞胎的比较表明，载脂蛋白B和甘油三酯水平的遗传度随年龄下降。
遗传因素对部分而非所有脂质血清水平的影响似乎随年龄降低。早期抚养环境似乎仍是与晚年总胆固醇水平相关的一个重要因素，但对老年人的其他血清脂质和载脂蛋白影响较小。
