Hello. I was hoping a chemist or someone familiar with the chemistry of propylene glycol could respond to this. Could vapors be ingesting enough pg to significantly increase D-lactate concentrations leading to ailments similar to what the cats in the study experienced: depression, ataxia, encephalopathy, etc.? We must be ingesting exorbitant amounts of pg daily and I wonder if this could lead to depression, etc? I've been vaping on and off since 2011 and love it but I'm concerned with the potential risks associated with inhaling pg. Here is a copy of the study:
Christopher MM, Eckfeldt JH, Eaton JW.
Department of Veterinary Pathobiology, University of Minnesota, St. Paul.
Propylene glycol (1,2-propanediol) is a solvent in numerous pharmaceuticals and a major preservative and source of carbohydrates in processed foods. In mammals, propylene glycol is metabolized similar to ethanol, proceeding via hepatic alcohol and aldehyde dehydrogenases to lactate, which can then enter gluconeogenesis. We observed that cats ingesting 1.6 gm of propylene glycol/kg body weight/day developed increased anion gap. To investigate this further, we measured D- and L-lactate concentrations in these cats; we also measured D-lactate in cats ingesting high doses of propylene glycol (8.0 gm/kg). While L-lactate actually decreased throughout the 35-day course of propylene glycol feeding, D-lactate levels were significantly increased on a dose-dependent basis and correlated positively with anion gap. In cats ingesting the high dose of propylene glycol, D-lactate concentrations were as high as 7 mmol/liter, levels associated with encephalopathy in humans. Indeed, this group of cats developed depression and ataxia, consistent with intoxication by D-lactate. These findings are significant not only for animals ingesting diets which contain propylene glycol, but for humans who receive propylene glycol-containing medications.
PMID: 2296157 [PubMed - indexed for MEDLINE]
Related Articles
* Unusual D-lactic acid acidosis from propylene glycol metabolism in overdose. [J Toxicol Clin Toxicol. 2004]
* Contribution of propylene glycol-induced Heinz body formation to anemia in cats. [J Am Vet Med Assoc. 1989]
* Propylene glycol-induced Heinz body formation and D-lactic acidosis in cats. [Prog Clin Biol Res. 1989]
* ReviewRecognition, treatment, and prevention of propylene glycol toxicity. [Semin Dial. 2007]
* ReviewD-lactic acidosis. A review of clinical presentation, biochemical features, and pathophysiologic mechanisms. [Medicine (Baltimore). 1998]
Christopher MM, Eckfeldt JH, Eaton JW.
Department of Veterinary Pathobiology, University of Minnesota, St. Paul.
Propylene glycol (1,2-propanediol) is a solvent in numerous pharmaceuticals and a major preservative and source of carbohydrates in processed foods. In mammals, propylene glycol is metabolized similar to ethanol, proceeding via hepatic alcohol and aldehyde dehydrogenases to lactate, which can then enter gluconeogenesis. We observed that cats ingesting 1.6 gm of propylene glycol/kg body weight/day developed increased anion gap. To investigate this further, we measured D- and L-lactate concentrations in these cats; we also measured D-lactate in cats ingesting high doses of propylene glycol (8.0 gm/kg). While L-lactate actually decreased throughout the 35-day course of propylene glycol feeding, D-lactate levels were significantly increased on a dose-dependent basis and correlated positively with anion gap. In cats ingesting the high dose of propylene glycol, D-lactate concentrations were as high as 7 mmol/liter, levels associated with encephalopathy in humans. Indeed, this group of cats developed depression and ataxia, consistent with intoxication by D-lactate. These findings are significant not only for animals ingesting diets which contain propylene glycol, but for humans who receive propylene glycol-containing medications.
PMID: 2296157 [PubMed - indexed for MEDLINE]
Related Articles
* Unusual D-lactic acid acidosis from propylene glycol metabolism in overdose. [J Toxicol Clin Toxicol. 2004]
* Contribution of propylene glycol-induced Heinz body formation to anemia in cats. [J Am Vet Med Assoc. 1989]
* Propylene glycol-induced Heinz body formation and D-lactic acidosis in cats. [Prog Clin Biol Res. 1989]
* ReviewRecognition, treatment, and prevention of propylene glycol toxicity. [Semin Dial. 2007]
* ReviewD-lactic acidosis. A review of clinical presentation, biochemical features, and pathophysiologic mechanisms. [Medicine (Baltimore). 1998]