"There is an extreme range of normal NEFA availability in
humans. Physiologic hyperinsulinemia can reduce plasma NEFA
concentrations from their normal concentration of <500 to
10–20 mmol/L (2). Under conditions of fasting or adrenergic
stimulation, plasma NEFAs may increase to concentrations
³3000 mmol/L (3). Although there is also a wide range of NEFA
flux, it is not as extreme as the 300-fold variation in plasma
NEFA concentrations. Under hyperinsulinemic conditions,
plasma NEFA flux may decrease to 0.5 mmol · kg21 · min21 (2),
whereas with insulin deficiency (such as during fasting), plasma
NEFA flux may increase to 12.5 mmol · kg21 · min21 (2, 3). During
exercise, plasma NEFA flux may increase to as much as 25
mmol · kg21 · min21."