Intensive dietary advice significantly improves HbA(1c) in people with type 2 diabetes who remain hyperglycaemic despite optimised drug treatment
- Department of Agricultural, Food and Nutritional Sciences, University of Alberta, Edmonton, Alberta, Canada
- Correspondence to Rhonda C Bell
Department of Agricultural, Food and Nutritional Sciences, Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta T6G 2E1, Canada;
Is nutrition therapy for diabetes still part of the ‘first Step’ of treatment?
Pharmacological treatments, once considered ‘second step’ treatments for type 2 diabetes (T2D) after the ‘first step’ of diet therapy and physical activity, have increasingly become part of the first step of treatments.1 Clinical guidelines for diabetes treatment outline the important role that lifestyle plays even after pharmacological treatments have been initiated. However, patients find adherence to appropriate dietary patterns to be one of the most difficult aspects of treatment to implement consistently, and evidence suggests that the recommended dietary patterns are not well followed. Do we really need dietary/nutrition therapy after drug therapy has been initiated?
Coppell and colleagues add to the literature that begins to answer this question. The Lifestyle Over and Above Drugs in Diabetes study examined the extent to which evidence-based dietary advice improved glycaemic control among people with T2D, persistent hyperglycaemia and an optimised drug treatment plan. Volunteers were recruited through media, local pharmacies, hospital clinics, etc and were required to have a haemoglobin A1c >7%, despite having received standard dietary advice and having had their drug treatment optimised according to current guidelines. One hundred and four patients were randomised to either usual care + dietary intervention (n=52) or usual care alone (n=52). Outcomes were as follows: A1c, changes in hypoglycaemic drugs, anthropometrics, blood pressure, fasting plasma glucose concentrations and lipid profiles. Dietary intake was assessed at the start and finish of the study.
The intervention group received dietary counselling that included specific recommendations with respect to energy intake, personal food preferences (including recipe and meal suggestions), budget and sociocultural factors. Dietary advice was on the basis of accepted international guidelines. Participants had two individual sessions with the study dietitian within the 1st month and then monthly thereafter for 5 months; additional contact was provided as deemed necessary by the dietitian and was usually by telephone. Family involvement was encouraged.
Participants in the control group were given routine information about appropriate dietary intake but had no further contact with the researchers until the assessment at the end of the study. Participants in both groups were given the same information about physical activity and where to seek ongoing clinical care.
Participants in the dietary intervention group achieved a 0.4% reduction in A1c and improved anthropometric measures over the 6 months of the study (p<0.05 in each case). These improvements are clinically relevant, as was the observation that patients in this group also tended to decrease, rather than increase, their drug doses. Those in the intensive dietary intervention group increased protein intake and decreased saturated fat intake; differences in fibre intake did not reach statistical significance.
Efficacy is important but not sufficient
This efficacy trial provides important evidence underlining that positive dietary behaviours help to improve diabetes outcomes in combination with an optimised drug regime. This situation is highly relevant for people with T2D today but has not been examined thoroughly to date. The fact that patients in both groups were likely highly motivated provides evidence that implementing dietary change requires ongoing support and tailored information in addition to motivation.
Establishing efficacy is important, but it is also important to begin to identify techniques, tools and environmental factors that contributed to, or detracted from, the success of implementing the intervention. Nutrient intake, although important, does not capture the complexity of behavioural changes that people made to implement the dietary advice they received. These details are critical so that programmes can be expanded and adapted when warranted. For the field to advance, we need to know what subjects were told to do, and what they did.
This study reinforces that diet remains a relevant and important part of the first step in diabetes treatment. This is important given the current algorithms for initiating and adjusting diabetes therapy. The details of the dietary intervention, such as the frequency of meetings and types of strategies used to individualise dietary advice, need further description and refinement before being implemented broadly. How the advice given in this study compares to other studies using generic advice2 should also be considered.
Implications for changing practice and remaining gaps
Health professionals should lobby for levels of support for lifestyle modification such as that provided in this study. On-going, personalised care is a hallmark of effective diabetes management, and diet therapy is a place that requires this level of commitment. Future studies should explore mixed method approaches to provide guidance about ‘how to’ implement advice in addition to identifying the important role of the healthcare professional as a person who can engage patients and helps them translate recommendations.