The influence of antihypertensive drugs on mineral status in hypertensive patients.
OBJECTIVES
Long-term therapy of hypertension may influence mineral status in patients. However, drug-micronutrient interactions are largely unexplored in practice. This study intended to evaluate the effect of hypotensive monotherapy on iron, zinc, and copper levels, as well as on selected biochemical parameters, in newly diagnosed patients with hypertension, and to assess the influence of diet with optimal mineral levels on the mineral balance in these subjects.


PATIENTS AND METHODS
Forty-five patients, aged 18-65 years with diagnosed essential hypertension, beginning monotherapy treatment with diuretics, calcium antagonists, angiotensin-converting enzyme inhibitors, and β-blockers, were employed. Over three months, the patients underwent monotherapy (stage II). Next, patients were randomly divided into a diet group (of 27 subjects) and a control group (of 18 subjects). In this stage, which lasted one month, patients were given the same drug but also followed an optimal mineral-content diet (for the diet group), or else continued drug use without any change in diet (for control group) (stage III). Lipids, glucose, ceruloplasmin, and ferritin--along with superoxide dismutase and catalase activities--were assayed in serum. Iron, zinc, and copper concentrations in serum, erythrocytes, and urine were determined using flame atomic absorption spectrometry. Blood pressure was measured. Diet intake was monitored at each stage.


RESULTS
It was found that the zinc level in serum significantly decreased following treatment, and that the use of the optimal-mineral diet during antihypertensive treatment markedly increased zinc serum concentration. After treatment, a significant increase in zinc excretion in the urine was observed. Glucose levels in the serum of patients in stage II were significantly higher than in the baseline. In patients in the diet group, glucose levels markedly decreased. Moreover, a negative correlation was found between serum glucose and zinc levels in patients.


CONCLUSIONS
Antihypertensive treatments should include monitoring of mineral status. It seems that the zinc balance of patients on long-term therapy with hypotensive drugs may benefit from an optimal-mineral diet.