The aim of the study was to evaluate the effects of hypotensive treatment combined with a higher zinc supply in the diet and supplements on the mineral status and selected biochemical parameters of newly diagnosed hypertensive patients on monotherapy.

The study was designed as a prospective randomized trial and was performed in three stages. In the first stage, primary hypertension was diagnosed and antihypertensive monotherapy was implemented. In the second stage, patients underwent antihypertensive monotherapy lasting three months. The subjects received diuretics; calcium antagonists (Ca-antagonists); angiotensin-converting-enzyme inhibitors (ACE-Is); angiotensin II receptor antagonists (ARBs); or β-blockers. After three months of monotherapy, patients were divided using a randomization list into three equal groups: C (control group), D (diet group) and S (supplementation group). In the third stage, which lasted 30 days, subjects from all groups received the same antihypertensive drug as in the second stage and either an optimal-mineral-content diet (group D), zinc supplementation (group S), or continued drug use with no change in diet and no mineral supplementation (group C). Patients from group D received an optimal-mineral-content properly balanced diet enriched in food with high zinc content prepared individually for each patient by a qualified dietician. Patients from group S received zinc supplementation as one capsule containing 15 mg of Zn taken orally once a day in the morning, two hours after antihypertensive drug administration with no change in diet, through all 30 days of the third stage of the trial.

During the study, patients were asked to not use dietary supplements and not to change their lifestyle or level of physical activity. On the last day of each stage of the study, blood, urine, and hair samples were collected from the subjects, and blood pressure and anthropometric parameters were measured.

Inclusion Criteria:

• informed written consent;
• age 18-65 years;
• primary hypertension;
• beginning monotherapy with an antihypertensive drug;
• stable body weight (less than 3 kg self-reported change during the three months prior to enrollment).

Exclusion Criteria:

• any secondary form of hypertension;
• the use of mineral supplements within the three months prior to enrollment;
• lipid disorders requiring treatment in the three months prior to the trial;
• a history of ischemic heart disease, stroke, congestive heart failure,
• clinically significant arrhythmia or conduction disorders, peripheral artery or vein disease, diabetes mellitus, abnormal renal, liver or thyroid gland function,
• clinically significant chronic or acute inflammatory process within the respiratory, genitourinary, or digestive tract, or in the oral cavity, larynx, pharynx, or in the paranasal sinuses, or connective tissue diseases, arthritis, or malignancy;
• infection in the month prior to enrollment,
• having an pacemaker implanted;
• alcohol, nicotine or drug abuse;
• mental disorders;
• pregnancy, childbirth or lactation at enrollment or in the three months prior to enrollment;
• or any other condition that, in the opinion of investigators, would make participation in the study not in the best interest of the subject, or could prevent, limit, or confound the efficacy of the study.