Xita N, Milionis H J, Galidi A, Lazaros L, Katsoulis K, Elisaf M S, Georgiou I, Tsatsoulis A
Department of Endocrinology, University of Ioannina, Ioannina, Greece.
Exp Clin Endocrinol Diabetes. 2011 Feb;119(2):126-8. doi: 10.1055/s-0030-1262801. Epub 2010 Aug 5.
Low serum Sex Hormone-Binding Globulin (SHBG) has been proposed as an indicator of the Metabolic Syndrome (MS) and cardiovascular disease in men. On the other hand, the (TAAAA)n repeat polymorphism in the SHBG gene has been shown to affect SHBG levels. The possible role of this polymorphism in the MS was examined in the present study.
The study population consisted of 83 men with MS aged 54.9±14.8 years and 166 healthy men of the same age. The diagnosis of MS was based on the criteria proposed by the National Cholesterol Education Program - Third Adult Treatment Panel (NCEP-ATP III). The waist circumference was recorded and blood samples were obtained after overnight fasting for biochemical and hormonal tests. The SHBG(TAAAA)N polymorphism was genotyped in peripheral blood leucocytes.
Genotype analysis for the (TAAAA)n polymorphism of the SHBG gene in the patients and controls identified 6 alleles having 6-11 TAAAA repeats. Patients with MS had more frequently short-allele genotypes (with 6/6, 6/7, 6/8, 7/7, 7/8 or 8/8 tandem repeats) compared to controls (53% vs. 39.8%, p=0.047). In the entire study population, men homozygous for the 6 TAAAA repeat allele had lower SHBG levels (p=0.01) and higher waist circumference (p=0.006) than men heterozygous or non-carriers of this allele.
Short SHBG(TAAAA)N allele genotypes may play a role in the development of the MS. The mechanism of this contribution remains unclear.
低血清性激素结合球蛋白（SHBG）已被认为是男性代谢综合征（MS）和心血管疾病的一个指标。另一方面，SHBG基因中的（TAAAA）n重复多态性已被证明会影响SHBG水平。本研究探讨了这种多态性在MS中的可能作用。
研究人群包括83名年龄为54.9±14.8岁的MS男性患者和166名同龄健康男性。MS的诊断基于美国国家胆固醇教育计划成人治疗专家组第三次报告（NCEP-ATP III）提出的标准。记录腰围，并在空腹过夜后采集血样进行生化和激素检测。对外周血白细胞中的SHBG（TAAAA）N多态性进行基因分型。
对患者和对照组SHBG基因（TAAAA）n多态性的基因型分析确定了6个等位基因，其TAAAA重复次数为6至11次。与对照组相比，MS患者更频繁地出现短等位基因基因型（6/6、6/7、6/8、7/7、7/8或8/8串联重复）（53%对39.8%，p=0.047）。在整个研究人群中，6次TAAAA重复等位基因纯合的男性比该等位基因杂合或非携带者的男性SHBG水平更低（p=0.01），腰围更高（p=0.006）。
短的SHBG（TAAAA）N等位基因基因型可能在MS的发生中起作用。这种作用的机制尚不清楚。
