Background and objective: Arterial hypertension is one of the most prevalent chronic diseases worldwide and is a major contributor to cardiovascular burden and premature mortality. Growing evidence suggests that low serum magnesium may contribute to increased peripheral vascular resistance. However, original studies that directly measure this relationship in Arab-region populations remain scarce. This study aimed to measure serum magnesium levels in patients with hypertension, compare them with healthy controls, and determine the quantitative relationship between magnesium levels and systolic and diastolic blood pressure values.
Materials and methods: A case-control study was conducted in three teaching hospitals from March to December 2023. The study included 240 participants (120 untreated hypertensive cases and 120 healthy controls), matched for age, sex, and body mass index. Serum magnesium was measured by colorimetric spectrophotometry, and blood pressure was measured using three readings according to the 2018 ESH/ESC protocol. Multiple linear regression and stratified analysis were used to assess the independent association after adjustment for confounding variables.
Results: The mean serum magnesium level in the case group was significantly lower than that in the control group (0.61 +/- 0.09 vs. 0.88 +/- 0.07 mmol/L; p < 0.001; Cohen's d = 1.84). A strong inverse correlation was found between magnesium and systolic blood pressure (r = -0.74, p < 0.001) and diastolic blood pressure (r = -0.68, p < 0.001). The multiple regression model showed that serum magnesium remained an independent predictor of elevated blood pressure (beta = -0.54, p < 0.001) after adjusting for age, body mass index, sodium, and sex. Stratified analysis showed that the prevalence of hypertension increased from 18.7% in the normal-magnesium category to 82.4% in the severe-deficiency category.
Conclusion: Serum magnesium deficiency represents an independent factor associated with arterial hypertension, and this association increases progressively with the severity of deficiency. Routine measurement of magnesium is recommended in patients with hypertension, especially those who do not respond adequately to conventional pharmacological therapy. The effect of systematic magnesium replacement should be explored in future experimental studies.