The magnesium and glucose (MAG) study: The prevalence and effect of hypomagnesaemia on diabetes control in a regional hospital in KwaZulu-Natal

Abstract

Background: Diabetes mellitus (DM) poses a great burden of disease worldwide. The adverse effects of hypomagnesaemia (hypoMg2+) in patients with DM have been well described, with a higher prevalence of hypoMg2+ in patients with DM than in the general population (up to 35% vs. up to 15%). No data exist for South Africa (SA). Objectives: The study aimed to determine the prevalence of hypoMg2+ in a cohort of patients visiting a specialised DM clinic and to ascertain whether there is a relationship between hypoMg2+ and glycaemic control and hypoMg2+ and renal dysfunction. Methods: Data recorded on standardised clinical sheets from patients who attended a specialised DM clinic at Edendale Hospital, Pietermaritzburg, SA, over a period of one year (July 1, 2015 to June 30, 2016) were collected. Patient demographics, diabetes type, glycaemic control, serum magnesium (Mg2+) and renal function are presented for statistical analysis. Results: A total of 744 patients were enrolled. Most patients were female (527; 70.8%) and were diagnosed with Type 2 diabetes (DM2) (633; 85.1%) with a mean age of 52.3 (SD 15.6 years). The prevalence of hypoMg2+ was found to be 8.44%. HypoMg2+ was associated with poor glycaemic control (r = -0.16, p < 0.0001). A significant relationship was observed between glycaemic control and hypoMg2+ in males (r = -0.21, p = 0.0038), but not females (r = -0.011, p = 0.81). No significant relationship was evident between hypoMg2+ and renal dysfunction (r = -0.064, p = 0.11). Conclusion: HypoMg2+ in patients with DM was associated with poorer glycaemic control in the male population, potentially increasing the risk of adverse health outcomes. However, the prevalence of hypoMg2+ was not higher than in published data, but population-specific controls are required. No association could be found between hypoMg2+and renal dysfunction. The need for routine Mg2+ testing and supplementation in our population requires further assessment.