Evaluation of selected trace metals in some hypertensive subjects in a tertiary health institution in Southwest Nigeria

Published reports on the possible roles of trace metals in the aetiology of primary hypertension have not been consistent. This study investigated the possible aetiological role of zinc (Zn), manganese (Mn), copper (Cu) and selenium (Se) in primary hypertension. Atomic absorption spectrophotometry (AAS) was used to determine the serum levels of Zn, Cu, Mn and Se in 45 patients with primary hypertension (stage I and stage II) and 47 apparently healthy control subjects (normotensives and pre-hypertensives). Both patients and control subjects were classified based on the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7). The weight, height and blood pressure of all subjects were measured and their body mass indices (BMI) computed. The mean serum zinc concentration was significantly higher in the patients with hypertension than in the control subjects (135.78 ± 9.10 vs 130.80 ± 12.50 μg/ml, p = 0.032). However, serum levels of copper (68.16 ± 3.72 vs 68.53 ± 5.33 μg/dl, p = 0.697), manganese (63.11 ± 4.40 vs 62.87 ± 4.59 μg/dl, p = 0.800) and selenium (75.91 ± 5.66 vs 78.13 ± 5.92 μg/L, p = 0.070) were not statistically different between the patients and the control subjects. This study did not show any gender-, age- or obesity-related differences in serum level of zinc, copper, manganese and selenium. Elevated level of serum zinc may play an aetiological role in subjects with primary hypertension. However, further studies will be necessary to define the roles of trace elements in the aetiology of primary hypertension in these individuals.