Abstract
Respiration during sleep was studied in six obese women who had impaired prolactin response to insulin induced hypoglycaemia (non-responders), six obese women with a normal prolactin response to hypoglycaemia (responders), and six lean women. Sleep apnoea did not occur in any subject. All the obese women showed a decrease in haemoglobin oxygen saturation when asleep, which occurred predominantly during periods of rapid eye movement sleep. That the fall in oxygen saturation was significantly greater (p less than 0.05) in the obese non-responders suggests that central as well as mechanical factors may be important for the genesis of nocturnal hypoxia and is evidence for a disturbance of central nervous function in some obese women.