Very-low-carb diet may help improve symptoms in T1D
Following a very-low-carbohydrate diet (VLCD) can lead to improved glycaemic control without high rates of acute complications such as ketoacidosis and hypoglycaemia in patients with type 1 diabetes (T1D), according to a study based survey data.
The online survey involved 316 participants (57 percent female) in an online community involving people with T1D (42 percent were parents of children with T1D) who were committed to a VLCD. Outcome measures such as HbA1c, total daily insulin dose, adverse events, and patient demographic were self-reported. Among the participants, 148 (47 percent) had confirmatory medical information available, including diabetes diagnosis, glycaemic control, metabolic health measures, and other health outcomes. [Pediatrics 2018;doi:10.1542/peds.2017-3349]
Based on patient-reported data, the mean duration of following a VLCD was 2.2 years and the average daily carbohydrate intake was 36 g (~5 percent of total calories, compared with 45 percent calories from carbohydrate as recommended by the American Diabetes Association).
The participants reported a significant improvement in glycaemic control with VLCD, as indicated by a 1.45-percent reduction in HbA1c from pre- to post-VLCD (p<0.001). The mean HbA1c reported after following a VLCD was 5.67 percent — a level near the normal range, compared with the prevailing overall HbA1c levels of 8.2 percent among individuals with T1D in a previous study. [Diabetes Care 2015;38:971-978]
The daily insulin doses required were also reportedly lower than average at 0.40 U/kg/day.
Rates of adverse events reported were low among the 300 respondents with data available, with diabetes-related hospitalizations reported in 2 percent of them during the past 12 months, including 1 percent each for hypoglycaemia and ketoacidosis.
According to the researchers, severe carbohydrate restriction was believed to prolong the lives of children with T1D in the olden days, before insulin treatment became available, but it fell out of practice after insulin was introduced. [Arch Intern Med (Chic) 1921;27:699-705] Currently, VLCD in T1D has generally been discouraged due to concerns about the risk of hypoglycaemia and ketoacidosis. [Pediatr Diabetes 2018;19:129-137; Free Radic Biol Med 2016;95:268-277]
“We suggest that a VLCD may allow for exceptional control of T1D without increased risk of adverse events,” said the researchers. “These findings are without precedent among people with T1D, revealing a novel approach to the prevention of long-term diabetes complications.”
“The results, if confirmed in clinical trials, indicate that the chronic complications of T1D might be prevented by diet,” they added.
As the study was based on patient-reported data (of which only half was validated with available medical records), the researchers suggested more future studies to confirm the findings. They also noted that the generalizability of the results and long-term safety of the approach were unknown.
“In light of [the] study limitations, these findings by themselves should not be interpreted as sufficient to justify a change in diabetes management,” cautioned the researchers.
“Additional research is needed to determine the degree of carbohydrate restriction (and other dietary aspects) necessary to achieve these benefits, optimal insulin regimen to accompany a VLCD (specifically, with regard to avoiding severe hypoglycaemia), safety and efficacy (in randomized controlled trials),” they wrote.