Short-term effects of a low carbohydrate diet on glycaemic variables and cardiovascular risk markers in patients with type 1 diabetes: A randomized open-label crossover trial.
Study Goal
The researchers aimed to compare the effects of a high-carbohydrate diet (HCD) and a low-carbohydrate diet (LCD) on glycaemic variables and cardiovascular risk markers in patients with type 1 diabetes.
Results Summary
The LCD resulted in more time in euglycaemia, less time in hypoglycaemia, and reduced glucose variability compared to the HCD, without affecting mean glucose levels. Cardiovascular markers were unchanged, but fasting glucagon, ketone, and free fatty acid levels were higher after the LCD.
Population
10 insulin pump-treated patients with type 1 diabetes (4 women, median age 48 ± 10 years).
Effective Dosage
≤50 g carbohydrates per day (LCD) vs. ≥250 g carbohydrates per day (HCD).
Duration
1 week per diet (randomized order).
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
low carbohydrate diet (LCD) | increase | time with glucose values in the range of 3.9 to 10.0 mmol/L | patients with type 1 diabetes | 83% ± 9% vs 72% ± 11% | resulted in more time with glucose values in the range of 3.9 to 10.0 mmol/L | #1 |
low carbohydrate diet (LCD) | decrease | time with values ≤3.9 mmol/L | patients with type 1 diabetes | 3.3% ± 2.8% vs 8.0% ± 6.3% | resulted in less time with values ≤3.9 mmol/L | #2 |
low carbohydrate diet (LCD) | decrease | glucose variability | patients with type 1 diabetes | s.d. 1.9 ± 0.4 vs 2.6 ± 0.4 mmol/L | resulted in less glucose variability | #3 |
low carbohydrate diet (LCD) | increase | fasting glucagon levels | patients with type 1 diabetes | - | fasting glucagon levels were higher at end of the LCD week than the HCD week | #4 |
low carbohydrate diet (LCD) | increase | ketone levels | patients with type 1 diabetes | - | ketone levels were higher at end of the LCD week than the HCD week | #5 |
low carbohydrate diet (LCD) | increase | free fatty acid levels | patients with type 1 diabetes | - | free fatty acid levels were higher at end of the LCD week than the HCD week | #6 |
low carbohydrate diet (LCD) | increase | time in euglycaemia | patients with type 1 diabetes | - | resulted in more time in euglycaemia | #7 |
low carbohydrate diet (LCD) | decrease | time in hypoglycaemia | patients with type 1 diabetes | - | resulted in less time in hypoglycaemia | #8 |
low carbohydrate diet (LCD) | decrease | glucose variability | patients with type 1 diabetes | - | resulted in less glucose variability | #9 |
low carbohydrate diet (LCD) | no change | mean glucose levels | patients with type 1 diabetes | 7.3 ± 1.1 vs 7.4 ± 0.6 mmol/L | without altering mean glucose levels | #10 |
low carbohydrate diet (LCD) | no change | Cardiovascular markers | patients with type 1 diabetes | - | Cardiovascular markers were unaffected | #11 |
The aim of the present study was to assess the effects of a high carbohydrate diet (HCD) vs a low carbohydrate diet (LCD) on glycaemic variables and cardiovascular risk markers in patients with type 1 diabetes. Ten patients (4 women, insulin pump-treated, median ± standard deviation [s.d.] age 48 ± 10 years, glycated haemoglobin [HbA1c] 53 ± 6 mmol/mol [7.0% ± 0.6%]) followed an isocaloric HCD (≥250 g/d) for 1 week and an isocaloric LCD (≤50 g/d) for 1 week in random order. After each week, we downloaded pump and sensor data and collected fasting blood and urine samples. Diet adherence was high (225 ± 30 vs 47 ± 10 g carbohydrates/d; P < .0001). Mean sensor glucose levels were similar in the two diets (7.3 ± 1.1 vs 7.4 ± 0.6 mmol/L; P = .99). The LCD resulted in more time with glucose values in the range of 3.9 to 10.0 mmol/L (83% ± 9% vs 72% ± 11%; P = .02), less time with values ≤3.9 mmol/L (3.3% ± 2.8% vs 8.0% ± 6.3%; P = .03), and less glucose variability (s.d. 1.9 ± 0.4 vs 2.6 ± 0.4 mmol/L; P = .02) than the HCD. Cardiovascular markers were unaffected, while fasting glucagon, ketone and free fatty acid levels were higher at end of the LCD week than the HCD week. In conclusion, the LCD resulted in more time in euglycaemia, less time in hypoglycaemia and less glucose variability than the HCD, without altering mean glucose levels.