The clinical effects of a carbohydrate-reduced high-protein diet on glycaemic variability in metformin-treated patients with type 2 diabetes mellitus: A randomised controlled study.
Study Goal
The researchers aimed to determine whether a carbohydrate-reduced high-protein (CRHP) diet reduces glycaemic variability (GV) in patients with type 2 diabetes (T2D) compared to a conventional diabetes (CD) diet.
Results Summary
The CRHP diet significantly reduced all indices of glycaemic variability (by 36%-45%) and improved the diurnal glucose profile compared to the CD diet in T2D patients. The results were statistically significant (p < 0.001) across all measured GV metrics.
Population
16 metformin-treated T2D patients (median age 64.0 years, HbA1c 47 mmol/mol, T2D duration 5.5 years).
Effective Dosage
Energy-matched CRHP diet (31% carbohydrates, 29% protein, 40% fat) vs. CD diet (54% carbohydrates, 16% protein, 30% fat).
Duration
Two separate 48-hour intervention periods.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
carbohydrate-reduced high-protein (CRHP) diet | decrease | standard deviation (SD) around the sensor glucose level | patients with metformin-treated T2D | 1.0 ± 0.3 (CRHP) vs 1.6 ± 0.5 mmol/L (CD) | significantly reduced | #1 |
carbohydrate-reduced high-protein (CRHP) diet | decrease | coefficient of variation in percent (CV) | patients with metformin-treated T2D | 12.3 ± 3.8 vs 19.3 ± 5.5% | significantly reduced | #2 |
carbohydrate-reduced high-protein (CRHP) diet | decrease | mean amplitude of glucose excursions (MAGE) | patients with metformin-treated T2D | 2.3 ± 0.9 vs 4.2 ± 1.3 mmol/L | significantly reduced | #3 |
carbohydrate-reduced high-protein (CRHP) diet | decrease | continuous overlapping net glycaemic action (CONGA1) | patients with metformin-treated T2D | 0.8 ± 0.3 vs 1.5 ± 0.4 mmol/L | significantly reduced | #4 |
carbohydrate-reduced high-protein (CRHP) diet | decrease | continuous overlapping net glycaemic action (CONGA4) | patients with metformin-treated T2D | 1.4 ± 0.5 vs 2.5 ± 0.8 mmol/L | significantly reduced | #5 |
carbohydrate-reduced high-protein (CRHP) diet | decrease | mean absolute glucose (MAG) change | patients with metformin-treated T2D | 0.9 ± 0.3 vs 1.4 ± 0.4 mmol/L/h | significantly reduced | #6 |
carbohydrate-reduced high-protein (CRHP) diet | decrease | diurnal glucose profile | patients with metformin-treated T2D | 7.7 ± 1.6 vs 8.6 ± 2.0 mmol/L | improved | #7 |
carbohydrate-reduced high-protein (CRHP) diet | decrease | 24-h mean sensor glucose | patients with metformin-treated T2D | 7.7 ± 1.6 vs 8.6 ± 2.0 mmol/L | reduced | #8 |
iso-energetic replacement of dietary carbohydrates by protein and fat | decrease | all indices of glycaemic variability | T2D patients treated with diet and metformin | 36%-45% | reduced | #9 |
BACKGROUND & AIMS: High glycaemic variability (GV) is associated with late complications in type 2 diabetes (T2D). We hypothesised that a carbohydrate-reduced high-protein (CRHP) diet would reduce GV acutely in patients with T2D compared with a conventional diabetes (CD) diet. METHODS: In this controlled, randomised crossover study, 16 patients with metformin-treated T2D (median (IQR) age: 64.0 (58.8-68.0) years; HbA1c: 47 (43-57) mmol/mol; duration of T2D: 5.5 (2.8-10.3) years) were assigned to an energy-matched CRHP diet and CD diet (31E%/54E% carbohydrate, 29E%/16E% protein and 40E%/30E% fat, respectively) for two separate 48-h intervention periods. Interstitial continuous glucose monitoring (CGM) was performed to assess accepted measures of glycaemic variability, i.e. standard deviation (SD) around the sensor glucose level; coefficient of variation in percent (CV); mean amplitude of glucose excursions (MAGE); continuous overlapping net glycaemic action (CONGA1, CONGA4) of observations 1 and 4 h apart; and mean absolute glucose (MAG) change. RESULTS: All indices of glycaemic variability (mean ± SD) were significantly reduced during CRHP diet compared with CD diet; including SD (1.0 ± 0.3 (CRHP) vs 1.6 ± 0.5 mmol/L (CD)), CV (12.3 ± 3.8 vs 19.3 ± 5.5%), MAGE (2.3 ± 0.9 vs 4.2 ± 1.3 mmol/L), CONGA1 (0.8 ± 0.3 vs 1.5 ± 0.4 mmol/L), CONGA4 (1.4 ± 0.5 vs 2.5 ± 0.8 mmol/L), and MAG change (0.9 ± 0.3 vs 1.4 ± 0.4 mmol/L/h) (p < 0.001 for all). Compared with the CD diet, the CRHP diet improved the diurnal glucose profile by reducing 24-h mean sensor glucose (7.7 ± 1.6 vs 8.6 ± 2.0 mmol/L). CONCLUSIONS: In T2D patients treated with diet and metformin, two days of iso-energetic replacement of dietary carbohydrates by protein and fat reduced all indices of glycaemic variability by 36%-45% when compared with a conventional diabetes diet. These data may support reduction of carbohydrates as dietary advice for T2D patients. CLINICALTRIALS. GOV IDENTIFIER: NCT02472951.