Analysis of Electrolytes and Fluid Volumes Disturbances during Hyperglycemia-Induced Hyponatremia in Diabetes Mellitus Type 1

Abstract: The objective of this study is to investigate the effects of hypovolemia on hyperglycemiainduced hyponatremia in diabetes mellitus type 1 (DMT1). Because of the change in osmolarity due to increased serum glucose, the serum sodium concentration may be relative and may not reflect the actual concentration of sodium. Although it has been accepted that serum sodium must be corrected by a factor of 1.6 during hyperglycemia-induced hyponatremia, recent studies suggest that the correction factor is much higher when serum glucose is higher than 400 mg/dL. In this study we designed a state-based model to provide a generalized approach to the correction factor of serum sodium when hypovolemia occurs in high serum glucose in chronic or uncontrolled hyperglycemia in DMT1. In this simulation study, we demonstrated thatthe intravenous (IV) injection of 1000 mOsm glucose bolus cause rapid fluid shift among the body fluid compartments. This fluid shift momentarily causes an expansion of the Extracellular Fluid (ECF) and the Intracellular Fluid (ICF) fluid compartments. However, after rapid glucose metabolism, some of the plasma fluid will be excreted when the kidney absorptive capacity is exceeded. The initial loss of water from the plasma fluid compartment will be redistributed among the body fluid compartments by the effect of osmosis. This fluid redistribution relatively reduces the effective fluid loss from the plasma fluid compartments, which in turn causes the loss of electrolytes proportionally. The overall loss of fluid not only causes contraction of plasma fluid but also contraction of ICF. A correction factor for sodium may be as high as 5.5 at highHemoglobin A1c (HbA1c) levels. Hyperglycemia causes electrolytes and fluids disturbances that can be predicted using state-based modeling and simulation models using a data-based empirical function of insulin resistance/insufficiency at a priori HbA1c level. Keywords: Electrolytes; Diabetes Mellitus Type 1; Hypovolemia; Correction Factor; Hyperglycemia-Induced Hyponatremia