Look AHEAD (Action for Health in Diabetes) was a large, impressive and ambitious study of over 5000 overweight or obese individuals with type 2 diabetes over 10 years. It aimed to look at the difference in cardiovascular events in response to standard diabetes support and education (DSE) compared to intensive lifestyle intervention (ILI), in addition to whatever medications were already being taken. Any treatment offered outside the realms of the study intervention – hospitalisation, medication changes, and unrelated appointments – was carried out by the participants’ own healthcare practitioner.
Look AHEAD went on to prove the point that the DPP (Diabetes Prevention Program) study had already shown in “pre-diabetic” people: that diet and physical activity are a crucial and effective part of managing diabetes. In 2013, the Look AHEAD Research Group showed ILI produced sustained weight loss of 7.9% and 2.5% at 1 and 10 years respectively, alongside improvements in physical fitness and many measures of health, including diabetes control, blood pressure, plasma lipid profile, sleep quality, physical function and depression. The degree of weight loss is particularly impressive as it is known that individuals with diabetes lose approximately half the amount of weight on any given intervention than people without diabetes.
However, despite these highly impressive accomplishments, the sponsors of the study pulled the plug early for reasons of “statistical futility” as the intervention did not achieve the primary outcome to significantly reduce overall risk of major cardiovascular events, the reason being so few people actually suffered an event.
Critics could point to the fact that the dietary element of the study was based on calorie restriction and a reduced fat intake, hence the failure to meet the primary outcome. It is possible that the same degree of weight loss by carbohydrate reduction might have had more impressive cardiovascular results.
Undaunted by this cruel twist of fate, the Look AHEAD study group are continuing to crunch the data, hence the interest in this latest instalment. Although the obvious improvements in health induced by the intervention could not be shown to reduce cardiovascular events, this recent paper (summarised alongside) demonstrates a significant reduction in global medical costs compared to DSE in drug costs, episodes of hospitalisation and length of stay. Of particular note is a 17% reduction in the per-participant average annual cost of glucose-lowering agents among those on the ILI. Although the actual figures given for money saved – over $5000 per patient – must be disregarded because of the US setting for the study, much of the health economic data, such as drug costs, remain highly relevant to the UK as far as commissioners are concerned.
A final suggestion emerging from this latest instalment of Look AHEAD is a possible legacy effect, whereby effective weight loss not only improves metabolic syndrome and cardiovascular risk, but also the associated benefits still confer reduced risk for years after the end of the intervention. The moral of the story is that, in this age of impressive, fancy new drugs for diabetes, lifestyle interventions are effective and important and should not be forgotten.
To view the summaries of each paper, please download the PDF of this article.
Attempts to achieve remission, or at least a substantial improvement in glycaemic control, should be the initial focus at type 2 diabetes diagnosis.
9 May 2024