A) Non hypotonic hyponatremia
With increased Posm: Hyperglycemia - induced (dilutional)
With normal Posm: Pseudohyponatremia (marked hypertriglyceridemia and hyperproteinemia)
B) Hypotonic hyponatremia
• Hypovolemia-induced
• Drug –induced hyponatremia (mainly with thiazides and first generation sulphonylureas)
• Diabetes mellitus - associated hyponatremia
• Syndrome of inappropriate antidiuresis associated with coexisting disorders or administered drugs
• Chronic renal failure (diabetic nephropathy) or associated with the syndrome of hyporeninemichypoaldosteronism
Table 1: Causes of hyponatremia in diabetic patients.