DIRECT Remission of Type 2 Diabetes in Primary Care?

There is no reasonable argument against the fact that excess weight gain is one of the key drivers of diabetes risk, and it should come as no surprise to anyone, that losing weight (though bariatric surgery or otherwise) dramatically improves glycemic control in people living with type 2 diabetes.

So what exactly can we learn from the DIRECT study published by Michael Lean and colleagues in The Lancet?

For one, this is a large cluster-randomised trial of obesity intervention conducted entirely in a non-specialist primary care setting with significant weight loss (at least 15 Kg) and diabetes remission (defined as glycated haemoglobin (HbA1c) of less than 6·5% after at least 2 months off all antidiabetic medications) as the pre-defined primary outcome at 12 months.

In the intervention centres, a nurse or dietitian (as available locally) was given a total of 8 h structured training by the study research dietitians experienced in the Counterweight-Plus program.

Initial weight loss was induced with a total diet replacement phase using a low energy formula diet (825–853 kcal/day) for 3 months (extendable up to 5 months if wished by participant), followed by structured food reintroduction of 2–8 weeks (about 50% carbohydrate, 35% total fat, and 15% protein), and an ongoing structured programme with monthly visits for long-term weight loss maintenance.

Given the primary care non-specialist setting of this trial, the key findings (as summarized by the authors), were perhaps surprising:

“Just less than a quarter of participants in the intervention group achieved weight loss of 15 kg or more at 12 months, half maintained more than 10 kg loss, and almost half had remission of diabetes, off antidiabetic medication….Remission was closely related to the degree of weight loss maintained at 12 months, with achievement in 86% of participants with at least 15 kg weight loss, and 73% of those with weight loss of 10 kg or more. 28% of all eligible individuals volunteered to participate,17 and 79% completed the intensive total diet replacement phase…”

In general, the intervention was well tolerated with 117 out of 150 participants (78%) in the intervention group completing the intervention.

So here are the key learning from DIRECT:

For one, there should no longer be any doubt that “remission” of Type 2 diabetes is possible in a substantial number of patients, if we can help them achieve and sustain significant weight loss – the odds of experiencing remission are directly proportional to the amount of weight lost.

Secondly, using a strategy of low-calorie diets and behavioural intervention (allowing ample room for individual preferences) appears feasible in a primary care setting, delivered by health professionals with modest training in obesity management.

Obviously, as anyone who has seen weight loss before is well aware, the challenge in obesity management is more in keeping the weight off than in losing it in the first place. Although sustaining significant weight loss over 12 months is notable, one cannot but wonder how well the participants will do in keeping the weight off in the years to come. This is of course recognised by the researchers, who intend to follow the participants over the next 4 years.

Although a very low calorie diet may not be everyone’s cup of tea, given that the only other intervention that comes anywhere close to the results reported in this paper is bariatric surgery, the findings of this study are indeed notable.

Personally, I would assume that combining the dietary intervention presented in this study with additional pharmacological management may well prove sustainable in the long-term with benefits not just for diabetes control.

I say this because the complex biology of obesity dictates that individuals living with obesity will need a lot more than willpower and hope to sustain meaningful weight loss over time.

Edmonton, AB