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eNOS [Glu298Asp] polymorphism, erectile function and ocular pressure in type 2 diabetes
Michel P Hermans1, Sylvie A Ahn, Michel F Rousseau
1Service d'Endocrinologie et Nutrition, Université catholique de Louvain, avenue Hippocrate UCL 54, Brussels, Belgium. michel.hermans@diab.ucl.ac.be
European Journal of Clinical Investigation
|January 10, 2012
Summary
The eNOS G894T gene polymorphism in type 2 diabetes shows that the TT genotype is linked to worse erectile function but better ocular hypertension outcomes. This specific gene variant does not impact glucose control or major vascular complications.
Area of Science:
- Genetics and cardiovascular research
- Endocrinology and metabolic disorders
- Vascular biology
Background:
- Nitric oxide (NO) imbalance is linked to endothelial dysfunction, cardiovascular diseases (CVD), and diabetic complications.
- Endothelial NO synthase (eNOS) gene polymorphisms can influence NO bioavailability and promote adverse cardiovascular conditions.
Purpose of the Study:
- To investigate the association of the eNOS G894T gene polymorphism with glucose homeostasis, cardiometabolic phenotype, and vascular complications in type 2 diabetes (T2DM).
Main Methods:
- Studied 210 T2DM outpatients (mean age 70 years, 19 years diabetes duration).
- Assessed insulin sensitivity and beta-cell function using HOMA, alongside laboratory and endothelin measurements.
- Analyzed micro- and macrovascular complications and specific outcomes like erectile dysfunction and ocular hypertension in relation to eNOS G894T genotypes (GG, GT, TT).
Main Results:
- Prevalence of GG, GT, and TT genotypes was 48%, 39%, and 13% respectively.
- 74% had microangiopathy and 45% had macroangiopathy; the TT genotype did not correlate with increased rates of these complications.
- Erectile dysfunction was significantly more prevalent in TT genotype males (93% vs. 57%, p=0.0088).
- Ocular hypertension/glaucoma showed a markedly different prevalence: 0% in TT genotype vs. 21% in GG & GT genotypes (p=0.0057).
Conclusions:
- The eNOS G894T polymorphism in homozygous TT carriers has opposing effects: detrimental on erectile function and protective against ocular hypertension/glaucoma in T2DM patients.
- This polymorphism does not appear to influence glucose homeostasis or the overall presence of micro- and macrovascular complications in this cohort.
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