1 Department of Social Medicine, CAPHRI, Maastricht University, 6200 MD Maastricht, The Netherlands.
Eur J Public Health. 2013 Dec;23(6):986-91. doi: 10.1093/eurpub/cks167. Epub 2012 Dec 7.
Lower educated people have a higher prevalence of metabolic risk factors (MRF), that is, high waist circumference (WC), high systolic blood pressure, low high-density lipoprotein cholesterol level, high triglycerides and high fasting glucose levels. Behavioural and psychosocial factors cannot fully explain this educational gradient. We aim to examine the possible role of genetic factors by estimating the extent to which education and MRF share a genetic basis and the extent to which the heritability of MRF varies across educational levels.
We examined 388 twin pairs, aged 18-34 years, from the Belgian East Flanders Prospective Twin Survey. Using structural equation modelling, a Cholesky bivariate model was applied to assess the shared genetic basis between education and MRF. The heritability of MRF across education levels was estimated using a non-linear multivariate Gaussian regression.
Fifteen percent (P < 0.01) of the negative relation between education and WC was because of genes shared between these two traits. Furthermore, the heritability of WC was lower in the lowest educated group (65%) compared with the highest educated group (78%, P = 0.04). The lower heritabilities among the lower educated twins for the other MRF were not significant. The heritability of glucose was higher in the lowest education (80%) group compared with the high education group (67%, P = 0.01).
Our findings suggest that genetic factors partly explain educational differences in WC. Furthermore, the lower heritability estimates in WC in the lower educated young adults suggest opportunities for environmental interventions to prevent the development of full-blown metabolic syndrome in middle and older age.
受教育程度较低的人群代谢风险因素（MRF）的患病率更高，即腰围（WC）高、收缩压高、高密度脂蛋白胆固醇水平低、甘油三酯高和空腹血糖水平高。行为和心理社会因素并不能完全解释这种教育程度的梯度。我们旨在通过估计教育和 MRF 共享遗传基础的程度以及 MRF 的遗传力在不同教育水平下的变化程度，来检验遗传因素的可能作用。
我们对来自比利时东佛兰德前瞻性双胞胎调查的 388 对年龄在 18-34 岁的双胞胎进行了研究。使用结构方程模型，应用 Cholesky 双变量模型评估教育和 MRF 之间的遗传基础。使用非线性多元高斯回归估计 MRF 在教育水平上的遗传力。
15%（P < 0.01）的教育与 WC 之间的负相关是由于这两个特征之间共享的基因造成的。此外，WC 的遗传力在受教育程度最低的组（65%）中低于受教育程度最高的组（78%，P = 0.04）。在受教育程度较低的双胞胎中，其他 MRF 的遗传力较低并不显著。葡萄糖的遗传力在受教育程度最低的组（80%）中高于受教育程度最高的组（67%，P = 0.01）。
我们的研究结果表明，遗传因素部分解释了 WC 方面的教育差异。此外，受教育程度较低的年轻成年人 WC 的遗传力估计值较低，这表明有机会通过环境干预来预防中年和老年时期完全代谢综合征的发展。
