Haptoglobin genotypes and refractory hypertension in type 2 diabetes mellitus patients.
BACKGROUND
It has been suggested that haptoglobin polymorphism may influence the pathogenesis of microvascular and macrovascular complications in diabetic patients.


OBJECTIVE
This cross sectional study was carried out to investigate the existence or not of an association between haptoglobin genotypes and prevalence of ischemic cardiovascular events (stable angina, unstable angina and acute myocardial infarction), systemic arterial hypertension, refractory hypertension, obesity and dyslipidemia in 120 type-2 diabetes mellitus patients followed up at Hospital de Clínicas da UNICAMP in Campinas, São Paulo state, southeastern Brazil.


METHODS
Haptoglobin genotyping was performed by allele-specific polymerase chain reactions. The frequencies of the haptoglobin genotypes were compared with the presence/absence of cardiovascular disease, systemic arterial hypertension, refractory hypertension, obesity and dyslipidemia; systolic and diastolic blood pressure measurements; plasma levels of glucose, cholesterol (total, high density lipoprotein-HDL and low density lipoprotein-LDL) and triglycerides; and serum creatinine levels.


RESULTS
Although no association between haptoglobin genotype and the presence of cardiovascular disease could be identified, we found a significant excess of patients with Hp2-1 genotype among those with refractory hypertension, who also had higher systolic and diastolic blood pressure, and total and LDL cholesterol levels.


CONCLUSIONS
Our results suggest that type-2 diabetes mellitus patients with the Hp2-1 genotype may have higher chances of developing refractory hypertension. Further studies in other diabetic populations are required to confirm these findings.
Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Unicamp, Campinas, SP, Brasil.
Vânia Pereira Albuquerque
VP
Wobeto
Paula da Cunha
Pda C
Pinho
José Roberto M
JR
Souza
Tânia Regina
TR
Zaccariotto
Maria de Fátima
Mde F
Zonati
D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D001938:Brazil / Q000453:epidemiology; D002784:Cholesterol / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000235:genetics* / Q000503:physiopathology; D003971:Diastole / Q000502:physiology; D004812:Epidemiologic Methods; D005260:Female; D006242:Haptoglobins / Q000235:genetics*; D006801:Humans; D006973:Hypertension / Q000453:epidemiology / Q000235:genetics*; D008297:Male; D008875:Middle Aged
D008078:Cholesterol, LDL; D006242:Haptoglobins; D002784:Cholesterol