Oral magnesium supplementation does not affect insulin sensitivity in people with insulin-treated type 2 diabetes and a low serum magnesium: a randomised controlled trial

Models based on dietary nutrients predicting all-cause and cardiovascular mortality in people with diabetes

Dietary intervention plays a vital role in improving the prognosis of people with diabetes mellitus (DM). Currently, there is a lack of systematic analysis of the relation between dietary nutrients and long-term mortality risk in people with DM. The study aims to establish models predicting long-term mortality and explore dietary nutrients associated with reduced long-term events to guide daily dietary decisions in people with DM. The retrospective cohort study collected 5060 participants with DM from the National Health and Nutrition Examination Survey (NHANES) 1999-2018. The least absolute shrinkage and selection operator (LASSO) regression and random forest (RF) algorithm were applied to identify key mortality-related dietary factors, which were subsequently incorporated into risk prediction nomogram models. The receiver operating characteristic (ROC) curve, calibration plot and decision curve analysis (DCA) were utilized to evaluate the performance of the models. The association of key dietary nutrients with all-cause and cardiovascular mortality were visualized by restricted cubic spline (RCS) models both in the whole and subgroups by sex, age, drinking and smoking status. The overall median age of the cohort was 62.0 years (interquartile range (IQR) 52.0-70.0), 2564 (50.67%) being male. During a median follow-up period of 56.0 months, 997 (19.70%) all-cause deaths were recorded, with 219 (21.97%) of which being ascribed to cardiovascular disease. The nomogram models based on key dietary nutrients identified by LASSO and RF demonstrated a significant predicative value for all-cause and cardiovascular mortality. Dietary fiber and magnesium were the common predictive nutrients in the two nomogram models. The RCS curve revealed that dietary fiber and magnesium were negatively associated with long-term mortality in the whole and subgroups of people with DM after adjustment of potential confounders. The diet of people with DM is closely associated with mortality. The nomogram models based on dietary nutrients can predict long-term mortality of people with DM, and the higher intake of dietary fiber and magnesium was associated with reduced risks of both long-term all-cause and cardiovascular mortality.

Effects of deep ocean-derived magnesium-enhanced water on metabolic diseases with microbiome changes

AIMS

To investigate the effects of magnesium (Mg) from deep ocean sources, we conducted a randomized clinical trial involving adults with hypertension, diabetes, or hyperlipidemia.

METHODS

Subjects consumed either Mg-enriched water (MEW) or a placebo (80 or 6 mg of Mg per 2 L/day, respectively) for 4 weeks. We examined the detoxifying effects of MEW on environmental toxicants, including polycyclic aromatic hydrocarbons (PAHs) and oxidative stress, and its impact on gut microbiome composition (N = 30; 49.26 ± 9.55 yrs).

RESULTS

Most subjects consumed less Mg than the RDA, enabling their participation in the trial. Despite limitations in serum Mg measurement to assess Mg intake, MEW intake led to improvements in body mass index (BMI), insulin levels, triglycerides, glucose-BMI, and fatigue. Regardless of Mg content, water consumption reduced urinary levels of 1-hydroxypyrene, a major PAH metabolite, and malondialdehyde, an oxidative stress biomarker. Moreover, the MEW group exhibited greater diversity in gut microbiome composition than the placebo group. Notably, MEW kept the abundance of Clostridium, Dorea, or Desulfovibrio, indicating a balanced Mg intake.

CONCLUSION

MEW (80 mg of Mg/day) appears safe for RDA and effective for preventing CVD or T2DM, as evidenced by gut microbiome and biomarker outcomes.

Hypomagnesemia in adults with type 2 diabetes mellitus in Riyadh, Saudi Arabia: A cross-sectional study

This study investigates the prevalence of hypomagnesemia in adults with type 2 diabetes mellitus (T2DM) in Riyadh, Saudi Arabia, and examines its association with various metabolic parameters. Conducted as a cross-sectional study at King Saud University, Riyadh, it included 294 Saudi adults aged 25 to 65 years, comprising 119 T2DM patients, 80 prediabetics, and 95 nondiabetic controls. Participants underwent physical examinations, and fasting blood samples were analyzed for glucose, glycated hemoglobin (HbA1c), lipid profile, and serum magnesium levels. Statistical analysis revealed that lower magnesium levels were significantly more prevalent in T2DM patients (1.65 ± 4.9 mg/L) compared to prediabetes (2.48 ± 5.2 mg/L) and controls (2.9 ± 5.4 mg/L; P < .001). T2DM patients with magnesium deficiency exhibited higher levels of fasting glucose (11.2 ± 3.9 mmol/L), HbA1c (8.6 ± 2.1 mmol/L), and triglycerides (2.1 ± 0.9 mmol/L), along with increased insulin resistance (Homeostatic Model Assessment of Insulin Resistance = 6.6) and decreased insulin sensitivity (Quantitative Insulin Sensitivity Check Index = 0.29). Magnesium levels correlated negatively with glucose (R = -0.58) and HbA1c (R = -0.61). The area under the curve for serum magnesium in predicting HbA1c > 5.7 was 0.88, and for HbA1c ≥ 6.5, it was 0.91, indicating high diagnostic accuracy. These findings suggest that magnesium deficiency significantly impacts the metabolic profile of T2DM patients in Riyadh. Therefore, routine monitoring of magnesium levels is crucial in diabetes management, and further research is needed to explore the benefits of magnesium supplementation in T2DM care.

Interaction between Dietary Magnesium Intake and Genetic Risk Score on the Risk of Gestational Diabetes

SCOPE

We aim to assess the interaction between genetic risk and magnesium (Mg) intake during pregnancy on the development of gestational diabetes mellitus (GDM).

METHODS AND RESULTS

Three thousand ninety-six pregnant women from Tongji Maternal and Child Health Cohort are involved in our study. One hundred twelve susceptibility genetic variants of diabetes are selected and genotyped through Asian Screening Array bead chip. Mg intake were assessed by a validated food frequency questionnaire conducted at gestational weeks 25.1 ± 2.7 before GDM diagnosis. The study identifies 22 variants associated with GDM. Weighted genetic risk score (GRS) based on these 22 SNPs is associated with higher occurrence of GDM. There is an interaction between GRS and Mg intake on GDM risk (p-interaction = 0.019). Pregnant women with high GRS (≥23.48) and insufficient Mg intake (<370.0 mg d-1) have a 1.74 (95% confidence interval [CI]: 1.02, 2.98) fold risk of GDM after adjusting for potential confounders. No such relationship exists among pregnant women with low GRS (<23.48) (adjusted relative risk [RR] = 1.18; 95% CI: 0.73, 1.92).

CONCLUSION

Genetic predisposition to GDM is modified by Mg intake. This suggests that clinical nutrition guidance may benefit from being tailored by screening women with high diabetic genetic risk.

Magnesium biology

Magnesium (Mg2+) is essential for energy metabolism, muscle contraction and neurotransmission. As part of the Mg-ATP complex, it is involved in over 600 enzymatic reactions. Serum Mg2+ levels are tightly regulated between 0.7 and 1.1 mmol/L by interplay of intestinal absorption and renal excretion. In the small intestine, Mg2+ is absorbed paracellularly via claudin-2 and -12. In the colon, transcellular absorption of Mg2+ is facilitated by TRPM6/7 and CNNM4. In the kidney, the proximal tubule reabsorbs only 20% of the filtered Mg2+. The majority of the filtered Mg2+ is reabsorbed in the thick ascending limb, where the lumen-positive transepithelial voltage drives paracellular transport via claudin-16/-19. Fine-tuning of Mg2+ reabsorption is achieved in the distal convoluted tubule (DCT). Here, TRPM6/7 tetramers facilitate apical Mg2+ uptake, which is hormonally regulated by insulin and epidermal growth factor. Basolateral Mg2+ extrusion is Na+ dependent and achieved by CNNM2 and/or SLC41A3. Hypomagnesemia (serum Mg2+ <0.7 mmol/L) develops when intestinal and/or renal Mg2+ (re)absorption is disturbed. Common causes include alcoholism, type 2 diabetes mellitus and the use of pharmacological drugs, such as proton-pump inhibitors, calcineurin inhibitors and thiazide diuretics. Over the last decade, research on rare genetic and acquired Mg2+ disorders have identified Mg2+ channel and transporter activity, DCT length, mitochondrial function and autoimmunity as mechanisms explaining hypomagnesemia. Classically, treatment of hypomagnesemia depended on oral or intravenous Mg2+ supplementation. Recently, prebiotic dietary fibers and sodium-glucose cotransporter 2 inhibitors have been proposed as promising new therapeutic pathways to treat hypomagnesemia.

Magnesium Supplementation Modulates T-cell Function in People with Type 2 Diabetes and Low Serum Magnesium Levels

CONTEXT

Low magnesium levels, which are common in people with type 2 diabetes, are associated with increased levels of proinflammatory molecules. It is unknown whether magnesium supplementation decreases this low-grade inflammation in people with type 2 diabetes.

OBJECTIVE

We performed multidimensional immunophenotyping to better understand the effect of magnesium supplementation on the immune system of people with type 2 diabetes and low magnesium levels.

METHODS

Using a randomized, double-blind, placebo-controlled, 2-period, crossover study, we compared the effect of magnesium supplementation (15 mmol/day) with placebo on the immunophenotype, including whole blood immune cell counts, T-cell and CD14+ monocyte function after ex vivo stimulation, and the circulating inflammatory proteome.

RESULTS

We included 12 adults with insulin-treated type 2 diabetes (7 males, mean ± SD age 67 ± 7 years, body mass index 31 ± 5 kg/m2, HbA1c 7.5 ± 0.9%) and low magnesium levels (0.73 ± 0.05 mmol/L). Magnesium treatment significantly increased serum magnesium and urinary magnesium excretion compared with placebo. Interferon-γ production from phorbol myristate acetate/ionomycin stimulated CD8+ T-cells and T-helper 1 cells, as well as interleukin (IL) 4/IL5/IL13 production from T-helper 2 cells was lower after treatment with magnesium compared with placebo. Magnesium supplementation did not affect immune cell numbers, ex vivo monocyte function, and circulating inflammatory proteins, although we found a tendency for lower high sensitivity C-reactive protein levels after magnesium supplementation compared with placebo.

CONCLUSION

In conclusion, magnesium supplementation modulates the function of CD4+ and CD8+ T-cells in people with type 2 diabetes and low serum magnesium levels.

Magnesium from Deep Seawater as a Potentially Effective Natural Product against Insulin Resistance: A Randomized Trial

Background and Objectives: Deep seawater has been shown to restore pancreatic function in obese diabetic mice and considerably improve the homeostatic model assessment for insulin resistance, total cholesterol, and low-density lipoprotein cholesterol concentrations in patients with impaired fasting glucose or glucose tolerance. In this study, the effect of 12-week daily consumption of magnesium (Mg2+)-containing deep seawater mineral extracts on blood glucose concentration and insulin metabolism-associated indicators was investigated in patients with impaired glucose tolerance. Materials and methods: In this 12-week randomized, double-blind trial, patients (n = 37) with impaired glucose tolerance consumed deep seawater mineral extracts. Changes in blood glucose concentration and related indicators were compared between the treatment group and placebo group (n = 38). Results: The fasting insulin, C-peptide, homeostatic model assessment for insulin resistance, quantitative insulin sensitivity check index, homeostatic model assessment of beta-cell function, and Stumvoll insulin sensitivity index values in the deep seawater mineral extract group showed improvements compared with the placebo group. However, no significant differences between groups were observed in fasting blood glucose, postprandial blood glucose, glycated hemoglobin, or incremental area under the curve values. Conclusions: Oral supplementation with deep seawater mineral extracts enriched in Mg2+ markedly improves insulin sensitivity in patients with pre-diabetes. This study illustrates the potential clinical application of natural Mg2+ from deep seawater to alleviate insulin resistance in patients with pre-diabetes. Trial registration: This trial was retrospectively registered with Clinical Research information Service (CRIS), No. KCT0008695, on 8 August 2023.

Inquiry of the Metabolic Traits in Relationship with Daily Magnesium Intake: Focus on Type 2 Diabetic Population

Magnesium (Mg), an essential nutrient with a wide area of physiological roles, stands as a cofactor in over 600 enzymatic reactions involved in the synthesis of proteins and nucleic acids, DNA repair, neuromuscular functions, neuronal transmission, cardiac rhythm regulation, and the modulation of metabolic pathways, as well as acting as a natural blocker for the calcium channels. Our objective was to highlight the most recent clinical data with respect to daily Mg intake (DMI) and metabolic traits, particularly type 2 diabetes mellitus (DM). This was a PubMed-based review of the English-language medical papers across different key terms of search; the time frame was from January 2019 until April 2024. We included (clinically relevant) original studies and excluded cases reports, series, reviews, editorials, opinion, experimental studies, and non-human data as well as studies that did not specifically assessed DMI and only provided assays of serum Mg, studies on patients diagnosed with type 1 or secondary DM. A total of 30 studies were included and we organized the key findings into several sections as follows. Studies investigating DMI in relationship with the adherence to local recommendations in diabetic subjects (n = 2, one transversal and another retrospective cohort; N = 2823) found that most of them had lower DMI. Deficient DMI was correlated with the risk of developing/having DM across five studies (n = 5, one prospective and four of cross-sectional design; N = 47,166). An inverse correlation between DMI and DM prevalence was identified, but these data are presented amid a rather heterogeneous spectrum. Four novel studies (N = 7279) analysed the relationship between DMI and DM control according to various methods (HbA1c, fasting and postprandial glycaemia, and insulin); the association may be linear in diabetic subjects only at certain levels of DMI; additionally, the multifactorial influence on HBA1c should take into consideration this dietary determinant, as well, but there are no homogenous results. Three studies concerning DMI and diabetic complications (one cross-sectional, one prospective, and another case-control study) in terms of retinopathy (n = 1, N = 3794) and nephropathy (n = 2, N = 4805) suggested a lower DMI was associated with a higher risk of such complications. Additionally, two other studies (one prospective and one retrospective cohort) focused on mortality (N = 6744), which, taking only certain mortality indicators into consideration, might be decreased in the subgroups with a higher DMI. Seven studies (N = 30,610) analysed the perspective of DMI in the general population with the endpoint of different features amid glucose profile, particularly, insulin resistance. Concerning HOMA-IR, there were three confirmatory studies and one non-confirmatory, while fasting plasma glucose was highlighted as inversely correlated with a DMI (n = 1). The highest level of evidence regarding Mg supplementation effects on glucose metabolism stands on seven randomised controlled trials (N = 350). However, the sample size was reduced (from 14 to 86 individuals per study, either diabetic or pre-diabetic) and outcomes were rather discordant. These clinical aspects are essential from a multidisciplinary perspective and further trials are mandatory to address the current areas of discordant results.