What are the typical lab findings in starvation ketosis?

From the Guidelines

Starvation ketosis is characterized by moderate ketone elevations, normal or slightly low blood glucose levels, and a normal or mildly acidotic blood pH, as evidenced by the most recent guidelines 1. The typical lab findings in starvation ketosis include:

• Moderate ketone elevations, with beta-hydroxybutyrate levels ranging from 2-7 mmol/L
• Normal or slightly low blood glucose levels, typically between 55-70 mg/dL
• A normal or mildly acidotic blood pH, with a pH greater than 7.3
• Serum bicarbonate levels usually maintained above 18 mEq/L
• A mildly elevated anion gap, ranging from 12-16 mEq/L
• Elevated blood urea nitrogen (BUN) due to protein catabolism and relative dehydration
• Mild electrolyte abnormalities, including possible hyponatremia, hypokalemia, and hypophosphatemia
• Low insulin levels and elevated glucagon levels, reflecting the body's adaptation to preserve glucose for vital organs. According to the latest guidelines 1, individuals prone to ketosis should measure ketones in urine or blood if they have unexplained hyperglycemia or symptoms of ketosis, and implement sick-day rules and/or seek medical advice if urine or blood ketones are increased. Key points to note:
• The diagnosis of starvation ketosis is based on the presence of moderate ketone elevations and normal or slightly low blood glucose levels
• The treatment of starvation ketosis involves ingesting carbohydrate-containing foods or drinks, such as glucose or sucrose, to raise blood glucose levels and prevent further ketone production 1
• It is essential to distinguish starvation ketosis from diabetic ketoacidosis, which is a more severe condition characterized by high blood glucose levels, acidic blood pH, and elevated ketone levels.

From the Research

Lab Findings in Starvation Ketosis

The typical lab findings in starvation ketosis include:

• Elevated levels of D-beta-hydroxybutyrate (R-3-hydroxybutyrate) and acetoacetate in the blood 2
• Increased production of ketone bodies by the liver, with a higher rate of beta-hydroxybutyrate production than acetoacetate production 3
• Impaired removal of beta-hydroxybutyrate, with a decrease in fractional clearance 3
• Elevated plasma Beta-OH butyric acid (Beta-OHB) levels, ranging from 2.5-4.5 mM in normal weight individuals after five to seven days of starvation, and in obese subjects after ten to fourteen days of fasting 4
• Increased plasma FFA levels, ranging from 1,000-1,400 muEq/L in normal weight individuals after five to seven days of starvation, and in obese subjects after ten to fourteen days of fasting 4

Ketone Body Kinetics

The kinetics of acetoacetate and beta-hydroxybutyrate have been studied in various conditions, including:

• Insulin-dependent diabetes, where ketone body release into blood is threefold higher than normal 3
• Obesity, where ketone body release into blood increases on starvation from 171 +/- 70 to 569 +/- 286 mumol min-1 m-2 3
• Starvation, where the rate coefficient for removal of ketone bodies decreases, and the fractional removal of beta-hydroxybutyrate is impaired more than that of acetoacetate 3

Clinical Significance

The lab findings in starvation ketosis have clinical significance, as they:

• Indicate a state of nutrient deprivation and energy imbalance 5
• May be associated with various physiological and pathological conditions, such as diabetes, obesity, and neurologic disorders 2, 6
• Can be monitored using quantitative tests of 3HB levels, which offer new options for monitoring and treating diabetes and other states characterized by abnormal metabolism of ketone bodies 6