Magnesium supplementation, metabolic and inflammatory markers, and global genomic and proteomic profiling: a randomized, double-blind, controlled, crossover trial in overweight individuals.
Study Goal
The researchers aimed to examine the effects of oral magnesium supplementation on metabolic biomarkers and global genomic and proteomic profiling in overweight individuals.
Results Summary
Magnesium supplementation significantly decreased fasting C-peptide concentrations and appeared to reduce fasting insulin levels. Gene expression and proteomic profiling showed distinct changes, suggesting favorable effects on metabolic pathways.
Population
14 healthy, overweight volunteers (BMI ≥25).
Effective Dosage
500 mg elemental Mg/day (as magnesium citrate).
Duration
4 weeks.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
oral magnesium supplementation | decrease | fasting C-peptide concentrations | overweight individuals | change: -0.4 ng/mL after magnesium treatment compared with +0.05 ng/mL after placebo treatment | significantly decreased | #1 |
oral magnesium supplementation | decrease | fasting insulin concentrations | overweight individuals | change: -2.2 μU/mL after magnesium treatment compared with 0.0 μU/mL after placebo treatment | appeared to decrease | #2 |
oral magnesium supplementation | no change | inflammatory biomarkers | overweight individuals | - | No consistent patterns were observed | #3 |
oral magnesium supplementation | increase | 24 genes | overweight individuals | - | revealed up-regulation | #4 |
oral magnesium supplementation | decrease | 36 genes | overweight individuals | - | revealed down-regulation | #5 |
oral magnesium supplementation | neutral | several peptides and proteins | overweight individuals | - | showed significant differences in the expression amounts | #6 |
Magnesium supplementation for 4 wk | neutral | gene expression and proteomic profiling | overweight individuals | - | led to distinct changes | #7 |
BACKGROUND: Dietary magnesium intake has been favorably associated with reduced risk of metabolic outcomes in observational studies; however, few randomized trials have introduced a systems-biology approach to explore molecular mechanisms of pleiotropic metabolic actions of magnesium supplementation. OBJECTIVE: We examined the effects of oral magnesium supplementation on metabolic biomarkers and global genomic and proteomic profiling in overweight individuals. DESIGN: We undertook this randomized, crossover, pilot trial in 14 healthy, overweight volunteers [body mass index (in kg/m(2)) ≥25] who were randomly assigned to receive magnesium citrate (500 mg elemental Mg/d) or a placebo for 4 wk with a 1-mo washout period. Fasting blood and urine specimens were collected according to standardized protocols. Biochemical assays were conducted on blood specimens. RNA was extracted and subsequently hybridized with the Human Gene ST 1.0 array (Affymetrix, Santa Clara, CA). Urine proteomic profiling was analyzed with the CM10 ProteinChip array (Bio-Rad Laboratories, Hercules, CA). RESULTS: We observed that magnesium treatment significantly decreased fasting C-peptide concentrations (change: -0.4 ng/mL after magnesium treatment compared with +0.05 ng/mL after placebo treatment; P = 0.004) and appeared to decrease fasting insulin concentrations (change: -2.2 μU/mL after magnesium treatment compared with 0.0 μU/mL after placebo treatment; P = 0.25). No consistent patterns were observed across inflammatory biomarkers. Gene expression profiling revealed up-regulation of 24 genes and down-regulation of 36 genes including genes related to metabolic and inflammatory pathways such as C1q and tumor necrosis factor-related protein 9 (C1QTNF9) and pro-platelet basic protein (PPBP). Urine proteomic profiling showed significant differences in the expression amounts of several peptides and proteins after treatment. CONCLUSION: Magnesium supplementation for 4 wk in overweight individuals led to distinct changes in gene expression and proteomic profiling consistent with favorable effects on several metabolic pathways. This trial was registered at clinicaltrials.gov as NCT00737815.