Meeting Summary of the 2021 & 2022 EASD Symposium

This article will highlight some of the topics presented in the 57th and 58th European Association for the Study of Diabetes Annual Meeting (EASD).

The 57th EASD 2021 symposium presented postprandial glycemic excursions (PPH) as a key component in controlling diabetes. The session emphasized combining drug and nutrition for optimal glycemic control.

Based on EASD 2021 symposium highlights about “Postprandial Glycaemic Excursions: Implications for Health and Effects of Non-Pharmacological Interventions”

1. Postprandial Hyperglycemia (PPH)

Louis Monnier

Monnier introduced the concept of ‘The Ominous Quartet’—four glycemic disorders causing cardiovascular complications:

1. Chronic/ambient hyperglycemia
2. Glycaemic variability (GV)
3. Postprandial glucose (PPH) excursions
4. Hypoglycaemic episodes.

Ambient hyperglycemia and hypoglycemia have a well-established negative impact on cardiovascular outcomes.^1-4 For instance, a 1% reduction in HbA1c can lower cardiovascular disease risk by 20%. Hypoglycemia also enhances platelet aggregation and has pro-arrhythmic effects. HbA1c should be maintained below 7%, with time in range above 70%. The threshold for hypoglycemia is 70 mg/dL and significant hypoglycemia below 54 mg/dL.

However, thresholds for GV and PPH remain unclear. Moreover, the role of PPH and GV in adverse outcomes remains uncertain. Monnier stressed the importance of setting thresholds and targets for these glycemic disorders (PPH and GV) for better monitoring and control of patients.^5-6

So, what is PPH? After meals, carbohydrates are absorbed, leading to an increase in blood glucose. This postprandial state lasts 4–5 hours, followed by a post-absorptive period (6–8 hours) and then the fasting state (10 hours post-meal).⁷ At the same time, if we follow insulin secretion, we find out that it differs among those with normoglycemia, impaired glucose tolerance (IGT), and Type 2 diabetes (T2D). In normoglycemia, insulin secretion is 80–100%, compared to 50–80% in IGT and <50% in T2D. Reduced insulin sensitivity leads to hepatic glucose overproduction, contributing to fasting and postprandial hyperglycemia. Peak glucose concentration occurs 30 minutes post-meal in normoglycemia but is delayed to 60–120 minutes in T2D.⁸ Studies show peak PPH levels are highest after breakfast, as hepatic glucose production follows a circadian rhythm. Therefore, the optimal time to check postprandial glycaemia in diabetes is 1–2 hours post-breakfast.^9,10

2. Importance of Addressing PPH

Louis Monnier

Setting a threshold for PPH excursions is crucial. A strong correlation exists between HbA1c and peak post-breakfast glucose, with an HbA1c of 7% corresponding to a peak glucose value of ~160 mg/dL. The International Diabetes Federation (IDF) recommends keeping peak post-breakfast glucose below 160 mg/dL to maintain HbA1c <7%, whereas the American Diabetes Association sets the threshold at <180 mg/dL, which corresponds to an HbA1c <7.5%.9 Monnier suggested that the IDF recommendation may be preferable to ensure better glycemic control. Additionally, in well-controlled T2D (HbA1c ≥6.8%), PPH contributes more to overall hyperglycemia, while in poorly controlled diabetes, fasting hyperglycemia plays a larger role.¹¹

Now let’s take a closer look at GV. A strong positive correlation exists between changes in PPH excursions and GV, with approximately 50% of GV attributed to PPH excursions.¹¹  The %GV (standard deviation of glucose/mean glucose) is the best metric for assessing GV, with a threshold of 36% distinguishing stable from unstable glycaemia.¹² However, Monnier noted that “we have no strong evidence that GV is responsible for adverse outcomes.”

3 .Importance of Addressing PPH (continued)

Bo Ahrén

Ahrén highlighted findings from Monnier et al. about how PPH contributed more than 60% to HbA1c, whereas fasting plasma glucose (FPG) contributed less than 40%.¹³ Furthermore, a prospective study found that while only 64% of patients with FPG <5.5 mmol/L achieved an HbA1c <7%, this figure rose to 94% in patients with PPH <7.8 mmol/L.¹⁴ This underscores the necessity of addressing PPH to lower HbA1c.

4. Managing Blood Sugar Levels through Non-Drug Therapies

Bo Ahrén

Non-pharmacological Management of High PPH

Ahrén stressed that both peak PPH after meals and the duration of elevated PPH must be managed. Strategies to reduce PPH include delaying gastric emptying, lowering hepatic glucagon secretion, and decreasing glucose absorption. Ahrén noted that “pharmacological approaches, however, are not sufficient; non-pharmacological tools are also needed for the management of high PPH.”

Let’s take a closer look at natural ingredients such as cinnamon and blueberries. Although cinnamon has been studied in terms of its effects blood sugar and weight, a Cochrane review concluded there is insufficient evidence to support its use in diabetes.^15,16 Similarly, blueberries have been studied, but no effect on PPH has been demonstrated.¹⁷

Based on the EASD 2022 symposium highlights about “Implications of Elevated Postprandial Glucose and Nutritional Approaches for Postprandial Glucose Management with a Focus on Whey Proteins”

5. Managing Blood Sugar Levels through Non-Drug Therapies (Continued)

Whey Protein

Bo Ahrén

Whey protein (WP) is a scientifically backed nutritional supplement in T2D thanks to its potential to regulate PPH. In a randomized controlled trial, subjects receiving 15 g of WP before breakfast exhibited a two- to threefold increase in plasma Branched Chain Amino Acids (BCAAs) within 20–40 minutes. BCAAs act as potent insulin secretagogues, resulting in lower PPH levels. WP also stimulates insulin secretion through directly stimulating pancreatic β-cells, activating incretin hormones such as GLP-1 and GIP and inhibiting DPP-4.¹⁸

Ahrén presented key clinical trials that demonstrated the benefits of WP in T2D:

1. Ahrén in collaboration with Jakubowicz, conducted a randomized clinical trial in which 15 patients with T2D consumed 50 g WP 30 minutes before a mixed breakfast meal. Results showed a 25% reduction in incremental area under the glucose curve, peak glucose levels lowered from 16 mmol/L to 10–11 mmol/L, and a doubling of insulin and GLP-1 levels.¹⁹
2. Another study in 2017, led by Ahrén and Jakubowicz, examined the effect of WP in 19 subjects who were given 28 g WP as a preload 15 minutes before breakfast over 12 weeks. Results showed sustained reductions in glucose levels, increased insulin and GLP-1 secretion, and improvements in HbA1c and body weight.²⁰

6. Morus Alba Extract (MLE) and Its Role in Glycaemic Control

John L. Sievenpiper

Morus alba L. (MLE) has demonstrated α-glucosidase inhibitor activity.^21,22 Sievenpiper presented studies that demonstrated MLE benefits in T2D patients. The three key studies are:

1. A double-blind RCT involving 38 healthy individuals. Participants were randomized to receive either 250 mg of MLE, containing 12.5 mg of deoxynojirimycin, or a placebo, followed by a 2-hour observation period. MLE significantly reduced PPH and insulin responses.23
2. In another crossover study with 30 T2D patients, MLE combined with 1.75 g fibre, 0.75 μg vitamin D3, and 75 μg chromium, lowered 3-hour PPH and insulin responses to a mixed meal tolerance test containing 55.4 g of carbohydrates.
3. Similarly, in 38 prediabetes patients, a double-blind RCT in 38 adults with prediabetes found that daily intake of 5 g MLE (containing 18 mg deoxynojirimycin) over four weeks reduced PPH and insulin responses to a mixed meal.²⁴