Design: Prospective single-centre before-and-after study
Population: 12 insulin-treated adults with chronic intestinal failure on nocturnal cyclic parenteral nutrition
Primary outcome: CGM glucose metrics and nutritional status over 30 days
Effect: Time in range 44% to 59%; time above 250 mg/dL 27% to 17%; HbA1c −0.7%

Twelve insulin-treated adults with chronic intestinal failure on overnight cyclic parenteral nutrition at one French centre wore a continuous glucose monitor for 30 days, had their insulin regimen redesigned by a diabetologist, then wore it for another 30 days.

Time in range rose from 44% to 59%, time above 250 mg/dL fell from 27% to 17%, and there was no increase in hypoglycaemia. HbA1c fell by 0.7%. Weight rose by a median of 5 kg and serum albumin by 8 g/L, and malnutrition resolved in 8 of 11 participants.

This is a tiny before-and-after study with no control group, so the nutritional gains may owe something to time and other care. The useful idea is the pattern itself: overnight feeds create a glucose peak that fingerstick checks miss, and CGM shows it.

Consider CGM for insulin-treated patients on overnight parenteral feeds, where fingersticks miss the nocturnal peak.
Time insulin to the infusion window rather than to meals.
Check for glycosuria, which signals that calories are being lost in the urine.
Agree targets with the nutrition team so feeds are not reduced to control glucose.

Why it matters

Hyperglycaemia during home parenteral nutrition may be wasting the calories the feed is meant to deliver.

The statistics, in plain English

With only 12 people and no comparison group, these P values show the change was unlikely to be chance within this group, not that the intervention caused it. Small single-centre studies tend to overstate effects.