Older men with well-controlled type 2 diabetes who are treated with metformin could have improved blood glucose levels after meals when vildagliptin and a protein preload are combined as add-on therapy, a new study finds.
Vildagliptin is a dipeptidyl peptidase-4 (DPP-4) inhibitor that can help lower blood glucose levels. It is an oral medication that is usually prescribed once-daily and can be combined with other anti-diabetic drugs, such as metformin and sulphonylureas.
In this new study, published in Diabetes Care, researchers at the University of Adelaide, Australia investigated whether a protein preload could improve the efficacy of vildagliptin in type 2 patients.
The authors explained: “Nutrient ‘preloads’ given before meals can attenuate postprandial glycemic excursions, at least partly by slowing gastric emptying and stimulating secretion of the incretins (i.e., glucagon-like peptide-1 [GLP-1] and glucose-dependent insulinotropic polypeptide [GIP]).”
They analysed data from 22 men with type 2 diabetes who were treated with metformin. Their average age was 64 years, mean HbA1c was 48.6 mmol/mol (6.6 per cent) and mean duration of diabetes was 5.6 years.
The participants were studied on four separate occasions, separated by seven days. They randomly received either 50mg of vildagliptin or placebo on both the evening before and the morning of each study day.
The morning dose was followed 60 minutes later by a drink containing 25g whey protein or control flavouring. The participants then ate a mashed potato meal 30 minutes afterwards. Participants ate a standardized beef lasagne meal with the evening dose.
Levels of gastric emptying, hormones and plasma glucose were then measured, and the researchers observed that the participants assigned vildagliptin and the protein drink had lower postprandial blood sugar levels compared to the placebo/protein and vildagliptin/control drink groups.
The authors wrote: “In metformin-treated type 2 diabetes, a protein preload has the capacity to enhance the efficacy of vildagliptin to slow gastric emptying, increase plasma intact incretins, and reduce postprandial glycemia.
“Remarkably, the addition of the whey preload to treatment with vildagliptin approximately doubled the reduction in peak postprandial blood glucose. The dose of whey […] proved sufficient to stimulate GLP-1 and GIP secretion and slow gastric emptying.”