Isolated dietary protein increases postprandial hyperglycemia in type 1 diabetes patients, study reports

People with type 1 diabetes who consumed 75 or more grams of liquid protein experienced higher blood glucose levels than those who drank water, according to a new study.
Researchers at the Hunter Medical Research Institute and the School of Medicine and Public Health at the University of Newcastle, Australia sought to assess how protein alone affected postprandial (after meal) hyperglycemia in type 1 diabetes patients.
Data was analysed from 27 children and adults aged 7-40 years who either received insulin pump therapy or multiple daily injections. All participants had an HbA1c of less than 8.5 per cent (69.4 mmol/mol) and a healthy BMI.
Participants received beverages in a randomised order over eight days and four hours after eating an evening meal, which was standardised for amount and type of carbohydrate, fat and protein.
They consumed five whey isolate protein drinks and water (12.5g, 25g, 50g, 75g and 100g doses) plus one control glass of water, and two 150ml glucose drinks (10g and 20g) without insulin. Participants fasted for five hours afterwards and used continuous glucose monitoring to assess postprandial blood sugar levels.
The participants experienced blood glucose rises between three to five hours after consuming the 75g or 100g protein drinks, but no significant rise from the doses below 75g. Levels were higher in the 180-300 minute interval than the 60-120 minute interval.
The researchers concluded: “The glycemic profiles resulting from high protein loads differ significantly from the excursion from glucose in terms of time to peak glucose and duration of the glycemic excursion.
“To our knowledge, this is the first study to document the postprandial glycemic response to protein alone. This helps inform our understanding of the glycemic impact of protein; providing further supporting evidence of additional insulin requirements to offset late glucose rises following high-protein meals.”
The findings were published in Diabetic Medicine.