Hyponatremia in Diabetes Mellitus: Clues to Diagnosis and Treatment

Abstract

Hyponatremia is the most common electrolyte abnormality in clinical practice and is associated with increased morbidity and mortality [1,2]. Even small decreases of serum sodium are associated with increased probability for adverse outcomes (cognitive impairment, falls, osteoporosis and fractures) [3].Decreased serum sodium levels are occasionally observed in patients with diabetes mellitus and can be attributed to numerous underlying pathogenetic mechanisms (Table 1) [4,5].The direct measurement of serum osmolality (Posm) can differentiate between hypotonic hyponatremia (with decreased Posm) and hyponatremia associated with normal or even increased tonicity. In the latter case hyponatremia is usually due to the coexistent hyperglycemia [6]. In fact, glucose is an osmotic active substance. Thus, in cases of marked hyperglycemia Posm is increased leading to movement of water out of cells and subsequently to a reduction of serum sodium levels (dilutional hyponatremia). In such cases the corrected, for the degree of hyperglycemia, serum sodium value should be calculated. Thus, to obtain the "true" sodium level in cases of extreme hyperglycemia, the addition of 2.4 mEq/L to the measured concentration for every 100 mg/dl increment in plasma glucose above normal levels is required [7]. This corrected serum sodium level should be used during treatment of severe hyperglycemic states [8]. In patients with dilutional hyponatremia the treatment of hyperglycemia is usually followed by a normalization of serum sodium levels [4].No hypotonic hyponatremia (with a normal measured Posm) can also be due to pseudohyponatremia associated with hyperglycemiainduced severe hypertriglyceridemia and perhaps hypovolemiainduced hyperproteinemia. It is well known that when the proportion of a serum sample occupied by substances other than water and electrolytes (such as lipids and proteins) exceeds the usual value of 7%, serum sodium levels measured by ion-selective electrodes using the indirect method are falsely lower than true values [9][10][11][12][13]. Thus, in patients with lipemic serum and severe hypertriglyceridemia, sodium levels should be measured by direct potentiometry in blood gas panels. This method does not include a predilution step and is not susceptible to the aforementioned errors [13]. Diagnosis of pseudohyponatremia is necessary to avoid dangerous overtreatment. It should be mentioned that pseudohyponatremia does not produce any of the symptoms classically attributed to hyponatremia. Improvement in glycemic control is associated with a rapid decrease in serum triglycerides resulting in the correction of pseudohyponatremia. Thus, no specific treatment is required [4,6].The most common cause of hypotonic hyponatremia in patients with diabetes is osmotic diuresis-induced hypovolemia [4]. It should be mentioned that in patients with diabetic ketoacidosis the excretion of β-hydroxybutyrate and acetoacetate obligate urine sodium losses resulting in aggravation of hypovolemia [14]. Hypovolemia can also be due to diabetes mel...

Low rates of hyponatraemia in patients with diabetes treated with variable rate intravenous insulin infusion (VRIII)

“…This has multiple aetiologies including the physiological response to surgical stress and lack of Glucose after attention to detail in fluid balance. 10,11 It is perhaps not surprising to see a small fall in serum sodium in this group. There are few published data to directly compare with this study.…”

“…Papers have reported the association of the use of dextrose infusion with hyponatraemia as part of larger studies of the causes of hyponatraemia in hospitals, but details of the infusions used are not given. 6,11,12 We have not reported details of other intravenous fluids used before the period of VRIII. While this may be considered a weakness of the study, the clinical question was whether this specific VRIII results in significant hyponatraemia.…”

Hyponatremia in Patients with Heart Failure beyond the Neurohormonal Activation Associated with Reduced Cardiac Output: A Holistic Approach

“…Immune-Mediated HF Autoimmune diseases may be complicated with the development of HF [51]. Hyponatremia in these patients may be the consequence of steroid-induced hyperglycemia [67], while other commonly prescribed drugs, such as NSAIDs and methotrexate, may lead to or deteriorate Cardiology 2022;147:507-520 DOI: 10.1159/000526912 hyponatremia. Specifically, methotrexate in high doses may activate natriuretic peptides or change the distribution of body fluid volumes [32,46].…”

“…Hypovolemia is among the most common causes of hyponatremia in diabetic subjects. Osmotic diuresis in uncontrolled DM or DM-associated diarrhea and vomiting, either from the disease itself or antidiabetic therapy (i.e., metformin, glucagon-like peptide-1 receptor analogs), is the usual culprit of hypovolemia [67].…”

Symptomatic hyponatremia during the diabetic ketoacidosis in 5 years old child with new onset diabetes – own experience

“…Decreased serum sodium levels are occasionally observed in patients with diabetes mellitus, especially in those, who present with diabetic ketoacidosis and can be attributed to numerous underlying pathogenetic mechanisms. [1] Diabetic ketoacidosis (DKA) results from deficiency of circulating insulin and increased levels of the counterregulatory hormones (catecholamines, glucagon, cortisol, growth hormone). It is characterized by severe depletion of water and electrolytes from both the intra-and extracellular fluid compartments.…”