Thorsby P M, Berg J P, Birkeland K I
Hormone Laboratory and Aker-Ullevål Diabetes Research Centre, Aker University Hospital, Oslo, Norway.
Scand J Clin Lab Invest. 2005;65(2):163-8. doi: 10.1080/00365510510013622.
Obesity and related disorders have become a major health problem. Understanding the interaction between genetic and environmental factors influencing the susceptibility to develop obesity is important when pinpointing people at risk. In a longitudinal study of 256 non-obese adolescents, the influence of the insulin gene (INS) variable number of tandem repeats (VNTR) on anthropometric measures and fat mass was investigated. The adolescents were examined at the age of 12.4 (2.3) (mean, SD) and 16.2 (2.3) years, and at follow-up with dual x-ray absorptiometry (DXA) for measurement of body composition. INS VNTR classes I and III alleles were investigated using the -23T/A single nucleotide polymorphism as a surrogate marker. There was a non-significant trend towards increased body mass index (BMI) and fat mass with the class III allele in girls. Homozygotes for the INS VNTR class III allele had a greater increase in BMI compared with those that were homozygous or heterozygous for the class I allele (3.8 (1.6) versus 2.4 (1.9) kg/m2, p = 0.03), and they had higher fat mass (36.4 (3.9) versus 31.3 (6.8)%, p = 0.02) at follow-up. Our finding that homozygosity of the INS VNTR class III allele seems to predispose to increased weight gain and fat mass raises the possibility that this genotype may be one of the important factors in the gene-environment interaction that eventually results in overweight and insulin resistance.
肥胖及相关疾病已成为一个主要的健康问题。在确定有肥胖风险的人群时，了解影响肥胖易感性的遗传和环境因素之间的相互作用非常重要。在一项对256名非肥胖青少年的纵向研究中，研究了胰岛素基因（INS）可变串联重复序列（VNTR）对人体测量指标和脂肪量的影响。这些青少年在12.4（2.3）岁（均值，标准差）和16.2（2.3）岁时接受检查，并在随访时采用双能X线吸收法（DXA）测量身体成分。使用 -23T/A 单核苷酸多态性作为替代标记来研究 INS VNTR I类和III类等位基因。在女孩中，携带III类等位基因的个体体重指数（BMI）和脂肪量有增加的趋势，但差异不显著。与INS VNTR I类等位基因的纯合子或杂合子相比，INS VNTR III类等位基因的纯合子BMI增加幅度更大（3.8（1.6）对2.4（1.9）kg/m²，p = 0.03），且在随访时脂肪量更高（36.4（3.9）%对31.3（6.8）%，p = 0.02）。我们的研究发现，INS VNTR III类等位基因的纯合性似乎易导致体重增加和脂肪量增加，这增加了一种可能性，即这种基因型可能是基因 - 环境相互作用中最终导致超重和胰岛素抵抗的重要因素之一。
