Association between ACE and AGT polymorphism and cardiovascular risk in acromegalic patients

Whether the renin-angiotensin-aldosterone system plays a role or not in the development of cardiovascular morbidity in acromegaly patients is unknown. The aim of the study was to investigate the association between ACE (I/D) and AGT (M235T) gene polymorphisms and cardiovascular and metabolic disorders in the acromegaly.

The study included one hundred and seventeen acromegalic patients (62 F/55 M, age: 50.2 ± 12.3 years) and 106 healthy controls (92 F/14 M, age: 41.4 ± 11.3 years). PCR method was used to evaluate the prevalence of ACE and AGT genotype.

The genotypes of ACE polymorphism in acromegalic patients were distributed as follows; 41.0% (n: 48) for DD, 44.4% (n: 52) for ID and 14.5% (n: 17) for II genotype. The control group had significantly different distribution of the ACE polymorphism [48.1% (n: 51) for DD, 25.5% (n: 27) for ID and 26.4% (n: 28) for II genotype]compared to acromegalic group. Regarding AGT polymorphism, AGT-MT genotype was seen in 88.9% of the acromegalic patients while MM and TT genotype (9.4% and 1.7%, respectively) were present in the rest. The controls had similar distribution of the AGT genotype with the acromegaly group (80.2% MT genotype, 15.1% MM genotype and 4.7% TT genotype). Due to the small number of patients with TT allele (n: 2), T carriers for AGT genotype (AGT-MT+TT) were subgrouped and compared to those with AGT-MM group. ACE-DD, ID and II groups had similar anthropometric measures, blood pressure values and baseline GH and IGF-1 levels. Significantly higher baseline GH levels were found in AGT-MM group compared to T allele carriers [40 (16-60) vs. 12 (5-36) µg/L, p < 0.05]. The compared groups in both polymorphisms had similar fasting plasma glucose levels. Patients with ACE-II genotype had significantly higher HDL-C levels compared to those with ACE-DD and ACE-ID polymorphisms (p < 0.05) whereas there was no significant difference in lipid profile between AGT-MM group and AGT-T allele carriers. Moreover, the compared groups in both polymorphisms had similar distribution of hyperlipidemia, hypertension, impaired glucose metabolism (prediabetes or type 2 diabetes mellitus) and coronary artery disease. In terms of echocardiographic parameters, systolic and diastolic function was similar among the groups in ACE and AGT genotypes. Interestingly, AGT-MM group had higher mitral inflow A_peak values than T allele carriers (0.94 ± 0.46 vs. 0.73 ± 0.20; p = 0.051). No significant difference was observed in LV mass index values in acromegalic patients among the groups in both polymorphisms.

Both ACE (I/D) and AGT (M235T) gene polymorphisms do not seem to have a significant effect on the development of clinical properties or cardiovascular comordities of acromegalic patients.