Li Hao Richie Xu1, Naim M Maalouf1,2,3. 1. Charles & Jane Pak Center for Mineral Metabolism & Clinical Research, Dallas, TX, USA. 2. Department of Internal Medicine, Division of Mineral Metabolism, University of Texas Southwestern Medical Center, Dallas, TX, USA. 3. Endocrine Section, Medical Service, Veterans Affairs North Texas Health Care System, Dallas, TX, USA.
Abstract
BACKGROUND: Insulin may influence magnesium homeostasis through multiple mechanisms. Acutely, it stimulates the shift of magnesium from plasma into red blood cells and platelets, and in vitro, it stimulates the activity of the TRPM6 channel, a key regulator of renal magnesium reabsorption. We investigated the impact of hyperinsulinemia on magnesium handling in participants with a wide range of insulin sensitivity. METHOD: Forty-seven participants were recruited, including 34 nondiabetic controls and 13 with type 2 diabetes mellitus. After stabilization under fixed metabolic diet, participants underwent hyperinsulinemic-euglycemic clamp. Serum and urine samples were collected before and during hyperinsulinemia. Change in serum magnesium, urinary magnesium to creatinine (Mg2+ :Cr) ratio, fractional excretion of urinary magnesium (FEMg2+ ), and estimated transcellular shift of magnesium were compared before and during hyperinsulinemia. RESULTS: Hyperinsulinemia led to a small but statistically significant decrease in serum magnesium, and to a shift of magnesium into the intracellular compartment. Hyperinsulinemia did not significantly alter urinary magnesium to creatinine ratio or fractional excretion of urinary magnesium in the overall population, although a small but statistically significant decline in these parameters occurred in participants with diabetes. There was no significant correlation between change in fractional excretion of urinary magnesium and body mass index or insulin sensitivity measured as glucose disposal rate. CONCLUSIONS: In human participants, acute hyperinsulinemia stimulates the shift of magnesium into cells with minimal alteration in renal magnesium reabsorption, except in diabetic patients who experienced a small decline in fractional excretion of urinary magnesium. The magnitude of magnesium shift into the intracellular compartment in response to insulin does not correlate with that of insulin-stimulated glucose entry into cells.
BACKGROUND:Insulin may influence magnesium homeostasis through multiple mechanisms. Acutely, it stimulates the shift of magnesium from plasma into red blood cells and platelets, and in vitro, it stimulates the activity of the TRPM6 channel, a key regulator of renal magnesium reabsorption. We investigated the impact of hyperinsulinemia on magnesium handling in participants with a wide range of insulin sensitivity. METHOD: Forty-seven participants were recruited, including 34 nondiabetic controls and 13 with type 2 diabetes mellitus. After stabilization under fixed metabolic diet, participants underwent hyperinsulinemic-euglycemic clamp. Serum and urine samples were collected before and during hyperinsulinemia. Change in serum magnesium, urinary magnesium to creatinine (Mg2+ :Cr) ratio, fractional excretion of urinary magnesium (FEMg2+ ), and estimated transcellular shift of magnesium were compared before and during hyperinsulinemia. RESULTS:Hyperinsulinemia led to a small but statistically significant decrease in serum magnesium, and to a shift of magnesium into the intracellular compartment. Hyperinsulinemia did not significantly alter urinary magnesium to creatinine ratio or fractional excretion of urinary magnesium in the overall population, although a small but statistically significant decline in these parameters occurred in participants with diabetes. There was no significant correlation between change in fractional excretion of urinary magnesium and body mass index or insulin sensitivity measured as glucose disposal rate. CONCLUSIONS: In humanparticipants, acute hyperinsulinemia stimulates the shift of magnesium into cells with minimal alteration in renal magnesium reabsorption, except in diabeticpatients who experienced a small decline in fractional excretion of urinary magnesium. The magnitude of magnesium shift into the intracellular compartment in response to insulin does not correlate with that of insulin-stimulated glucose entry into cells.
Authors: Giuseppe Cianciolo; Antonio De Pascalis; Irene Capelli; Lorenzo Gasperoni; Luca Di Lullo; Antonio Bellasi; Gaetano La Manna Journal: JBMR Plus Date: 2019-11-04
Authors: Katherine M Wang; JingWei Li; Vivek Bhalla; Meg J Jardine; Bruce Neal; Dick de Zeeuw; Greg Fulcher; Vlado Perkovic; Kenneth W Mahaffey; Tara I Chang Journal: Endocrinol Diabetes Metab Date: 2021-03-13