Guidance on Medication for Diabetes Patients on Low Carb Diet

Peter Russell

July 15, 2019

Some people with type 2 diabetes who have made significant health progress since adopting a low carbohydrate diet should have their medications adjusted, according to guidance.

A protocol for reducing hypoglycaemic medications for patients who have improved glycaemic control from following the Low Carb Program, was published in the British Journal of General Practice .

"A low carbohydrate approach is very popular now in clinical practice", author Dr Campbell Murdoch told Medscape News UK. "One of the reasons for that is it's very easy to implement – you don't need any other resources."

Dr Murdoch, a GP and media officer for Diabetes Digital Media, which provides the Low Carb Program, added: "As far as health improvement, you cannot not improve type 2 diabetes by reducing carbohydrate. Everybody who reduces their carbohydrate intake will, to some degree, improve their type 2 diabetes."

More than 417,000 people have enrolled on the digital platform since 2015. The program is delivered on a paid-for basis but can also be accessed for free in some areas via the NHS.

One-year outcomes of the digitally-delivered program involving 1000 individuals, published in JMIR Diabetes in 2018, found that:

  • Average weight loss was 7.45 kg

  • Average HbA1c reduction was 1.2% / 13mmol/mol

  • 40.4% of people on medication eliminated at least one of them

  • 60% of patients receiving insulin eliminated or reduced the medication

Insulin, Sulphonylureas, and Meglitinides

According to the paper, there are three key clinical considerations when looking at the safety of taking specific type 2 diabetes medications, alongside following a low-carb diet.

  • Is there a risk of the drug causing hypoglycaemia or other adverse event?

  • What is the degree of carbohydrate restriction?

  • Once carbohydrate is reduced does the drug continue to provide health benefit, and if so are the potential drug benefits greater than or less than possible risks and side effects?

The guidance said that practical experience suggested a 50% reduction of daily insulin at initiation of the program would be appropriate in most cases. However, individuals with markedly elevated HbA1c levels might only be able to make an initial 30% reduction.

Some patients could expect to come off insulin completely over days or months as insulin resistance resolved, it said.

"And then the sulphonylureas, and meglitinides," said Dr Murdoch. "They've got to be immediately adjusted – roughly a 50% reduction at onset, and then you continue to wean down."

SGLT2 Inhibitors and Ketoacidosis Risk

The protocol also listed SGLT2 inhibitors ('flozins') that might need adjustment due to an increased risk of diabetic ketoacidosis for people on a low-carbohydrate diet. "So, the general consensus is, we're fixing the problem, so let's not take that risk," said Dr Murdoch.

The guidance also listed treatments that pose no excess risk when combined with a low-carbohydrate diet. These were:

  • Metformin

  • GLP-1 agonists ('-enatides' and '-glutides')

  • Thiazolidinediones ('glitazones')

  • DPP-4 inhibitors ('gliptins')

  • Acarbose

  • Blood glucose testing strips

"Metformin has lots of potential benefits so I certainly wouldn't rush to take anyone off that," Dr Murdoch said.


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