Interaction between angiotensin-converting enzyme genotype and glycaemic control influences lipoprotein levels in type 2 diabetes mellitus.

Aims: To evaluate the influence of the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism on lipid levels in patients with Type 2 diabetes.

Patients And Methods: 109 patients with Type 2 diabetes were included. The patients were not on any lipid-lowering treatment. The groups with different ACE genotypes had similar ages, sex distributions, body mass indices, systolic blood pressures and indices of glycaemic control. ACE gene I/D polymorphism was determined using polymerase chain reaction.

Results: The mean apolipoprotein B (apoB) level was significantly higher in the group of DD homozygotes compared with the subjects with at least one insertion allele (DD: 1.21 +/- 0.25 g/l vs. ID + II: 1.04 +/- 0.27 g/l; P = 0.007). Significant correlations between glycated haemoglobin (HbA1c) and both apoB and cholesterol levels were found (r = 0.27; P < 0.01). For the apoB, this correlation was highly significant in the DD-genotype subgroup (r = 0.54; P < 0.01), and was not significant in the subgroup of patients with genotypes ID or II. In the multivariate analysis, HbA1c and the interaction of genotype DD with HbA1c were significant independent predictors of apoB (r2 = 0.17) and cholesterol levels.

Conclusion: The present study showed that the interaction between the DD genotype of angiotensin-converting enzyme and chronic hyperglycaemia (expressed by HbA1c level) is related to higher plasma levels of atherogenic lipoproteins, such as apoB and cholesterol, in patients with Type 2 diabetes.