HAPTOGLOBIN POLYMORPHISM AND COMPLICATIONS IN ESTABLISHED ESSENTIAL ARTERIAL-HYPERTENSION

Objective: Salt sensitivity and the magnitude of systolic blood pressu re have been linked to haptoglobin (Hp) polymorphism in normotensives. The aim of the present study was to investigate the indices of hypert ension, the severity of complications and the occurrence of coronary a nd peripheral artery disease for the various haptoglobin phenotypes an d their relation to the therapeutic needs (number and class of drugs) of established arterial hypertensives. Design: Haptoglobin polymorphis m was studied in 302 Caucasians with established essential arterial hy pertension who had been treated for at least 1 year. Methods: Haptoglo bin polymorphism was studied using starch-gel electrophoresis of haemo globin-supplemented serum. Results: The relative allele frequencies of Hp 1 and Hp 2 (0.360 and 0.640, respectively) in established hyperten sives were comparable with those of the control population. Logistic r egression analysis confirmed that Hp 2-2 contributes to the therapeuti c needs in hypertension. The most important factors determining therap eutic needs were coronary artery disease, Hp 2-2 phenotype, body mass index (BMI) and left ventricular hypertrophy. Although no contributive effect of serum haptoglobin concentration could be derived from the l ogistic regression approach, analysis of serum haptoglobin concentrati on demonstrated a concentration-related effect on therapeutic needs fo r the Hp 2-2 phenotype only. Conclusions: The present study suggests t hat hypertensives with an Hp 2-2 phenotype need more complex combinati ons of antihypertensive drugs to reduce blood pressure to the same lev el. The hypertensive patient carrying Hp 2-2 is more likely to accumul ate atherosclerotic lesions of the coronary or peripheral arteries, de spite comparable lipid levels, smoking habits and BMI. Hp 1-1 patients are characterized by a younger age at diagnosis and a lower complicat ion rate. In view of the greater therapeutic needs and the higher comp lication rate, Hp 2-2 hypertensives need more careful follow-up.