When 150 children with diabetes were admitted to hospital in Paris for overnight hourly blood glucose monitoring nearly a half had nocturnal hypoglycaemia and half of those were asymptomatic (Journal of Pediatrics 1997;131:27–33). Risk factors for nocturnal hypoglycaemia were more than one previous episode of severe hypoglycaemia, daily insulin dose over 0.85 IU/kg, more than 5% of recent home blood glucose values of 3.3 mmol/l or less, young age, and low blood glucose values before the evening meal (5.2 mmol/l or less at 7.30 pm) or in the early morning (6.7 mmol/l or less at 7.00 am).

Treatment with terbutaline (which stimulates adrenaline release) could prevent night time hypoglycaemia in people with insulin dependent diabetes. Researchers in Missouri, USA (Diabetes Care 1997; 20 :1231–6) studied 15 patients and showed that terbutaline was better than alanine plus glucose, or a bedtime snack, at preventing hypoglycaemia during the second half of the night. Nocturnal hypoglycaemia occurred 10 times after a bedtime snack and once after terbutaline.

In Wisconsin, USA, over 650 000 newborn babies were screened for cystic fibrosis using serum immunoreactive trypsinogen and, later, DNA analysis (New England Journal of Medicine 1997;335:963–9) but only half were assigned to early diagnosis by following up positive screening tests with sweat tests. The mean age …