Abstract:
Objective To investigate the relationship between DNA methylation level of glucose transporter 4(GLUT4)gene and obstructive sleep apnea syndrome(OSAS)in hypertensive patients. Methods All the subjects were consecutively recruited from Hypertension Department,Xinjiang Autonomous Region People’s Hospital between January and March in 2010. Fourteen Han Chinese male hypertensives complicated with severe OSAS,aged30-50 years old,with normal liver and kidney function were served as the OSAS group. While 16age-,body mass index(BMI)-matched Han Chinese male hypertensives without OSAS were selected as the control group.DNA methylation of GLUT4 gene was quantitatively detected. Sample sizes were increased to 66 cases in OSAS group and 39 cases in control group after the detection of aberrant methylation sites. The massARRAY analyses of CpG island at those sites were performed to further analyze DNA methylation levels of GLUT4 gene in OSAS patients. Results DNA methylation level of GLUT4 gene showed no significant differences between OSAS and control group,whereas DNA methylation level of the locus 2.10 and locus 2.14 were significantly higher in OSAS subjects without diabetes than in the control grouploc2.10:3.0(2.0-6.5)vs 0.5(0-3.0),P=0.014;loc2.14:6.0(2.0-9.5)vs 1.5(0-4.0),P=0.004. Spearman correlation analysis showed that the lowest saturation of oxygen was negatively related to the DNA methylation level of the loci 2.10 and 2.14(r
s=-0.480,P=0.008 and r
s=-0.520,P=0.004,respectively). Further analysis in a larger sample population showed that DNA methylation levels of the loci 2.10 and 2.14 were significantly higher in OSAS group than control group loc 2.10:9.0(4.5-55.0)vs 4.5(2.0-23.0),loc 2.14:13.5(6.0-40.3)vs 6.0(2.0-24.0);both P<0.05,and so were DNA methylation levels of the loc 2.3,loc 2.6,loc 2.7,loc 2.9,loc 2.13 and loc 2.17. Conclusion In the nondiabetic population with hypertension and OSAS,high DNA methylation of GLUT4 gene is found in male adult patients,which is related to hypoxia index induced by OSAS.