Tag: T2D

Intermittent Fasting in Patients with Type 2 Diabetes

Currently experiencing a surge in popularity, intermittent fasting has become an increasingly adopted dietary regimen due to its many purported health benefits. The concept of intermittent fasting refers to a spectrum of nutritional behaviors that aim to intentionally disrupt energy consumption for extended periods of time, for example, for between 16 and 24 hours on a regular intermittent schedule. In some intermittent regimens, individuals restrict food consumption to a 6- to 8-hour period, while in others they fast for a full 24 hours during several days of the week.

Some individuals may be inclined to adopt these dietary patterns as a means of weight loss or for their promised health benefits supported by anecdotal evidence, including the treatment of type 2 diabetes which remains unproven and untested entirely. While caloric restriction and weight loss are known to beneficially influence health outcomes in patients with type 2 diabetes – leading to improved glucose control, hypertension, and abnormal lipid levels – achieving them with intermittent fasting presents concerns.

Published on July 2, 2020 in JAMA, a new viewpoint underscores the limited body of evidence of the health benefits of intermittent fasting among type 2 diabetes patients and reveals the potential adverse complications that may result from this approach if patients are not carefully monitored.

Intermittent Fasting and T2D

To date, intermittent fasting in patients with T2D has only been studied in a few small, short-term trials yielding limited evidence of its benefit. Recently, a team of researchers examined the evidence for the health benefits and safety of intermittent fasting in this group of patients specifically. For the purposes of the study, intermittent fasting was defined as time-restricted feeding, or fasting on alternate days or during 1-4 days of the week, with only water, juice, or bone broth and no more than 700 calories consumed on fasting days.

In total, the study’s authors found seven published studies of fasting in T2D patients – only one trial had over 63 patients. Most studies were short in duration, occurring over 4 months or less, and evaluated five different fasting frequencies. All reported a connection between intermittent fasting and weight loss, while the majority also noted decreased A1c and improved glucose levels, quality of life, and blood pressure. Due to the lack of homogeneity in design, measures, and regimen styles, clinically meaningful conclusions could not be drawn.

In addition, only one study addressed the safety of two intermittent fasting regimens, finding that both increased the incidence of hypoglycemic events despite the use of a medication dose-change protocol.

Improved Glucose, Heightened Risks

The primary implication of the latest findings is that intermittent fasting may be less safe than caloric restriction, although it could be equivalently effective. Patients with existing diabetes who experienced weight loss saw a benefit of improved glucose, blood pressure, and lipid levels, according to the researchers.

While weight loss associated with intermittent fasting appears to be similar to that attained with caloric restriction, in the case of type 2 diabetes patients it can pose a risk of glycemic variability. Hypoglycemia can occur during fasting and hyperglycemia during feeding times, researchers note, and presents potentially dangerous clinical implications.

“Studies have raised concern that glycemic variability leads to both microvascular (eg, retinopathy) and macrovascular (eg, coronary disease) complications in patients with type 2 diabetes,” the authors cautioned. As such, the report highlights the need for continuous glucose monitoring aimed at detecting glycemic variability in susceptible patients as well as throughout studies of clinical interventions involving intermittent fasting in T2D patients.


Although further evidence is needed, the study’s lead author, Benjamin D. Horne, PhD, MStat, MPH, concluded that he would recommend intermittent fasting for patients with type 2 diabetes with caveats due to safety issues. These can include factors such as low blood pressure, weakness, headaches, dizziness – all of which are important considerations alongside the risk for hypoglycemia. Thus, caloric restriction may be a safer choice for certain patients.

Horne recommends giving patients intervention options to choose from as some may be better positioned to handle intermittent fasting. Until intermittent fasting is proven more effective at controlling diabetes, the currently available study data implicate that such regimens for patients with type 2 diabetes should be approached with caution, the risk of hypoglycemia closely monitored, and medications carefully adjusted to ensure both safety and efficacy of nutritional interventions.


Prevention of Cardiovascular Disease in Type 2 Diabetes Patients

With a dramatic increase in the prevalence of type 2 diabetes mellitus (T2DM), the unrelenting obesity epidemic, and rising cardiovascular disease-related mortality rates, the management of cardiometabolic risk factors and prevention of the progression to disease are essential steps toward improving population health. The underlying connection between T2DM and cardiovascular disease underscores the significance of several key lifestyle factors, such as nutrition and physical activity, and their impact on patient outcomes. Currently, the repercussions of poorly managed T2DM are severe; individuals with T2DM face a doubled mortality risk as well as 10-fold increased rate of hospitalization for coronary heart disease.


More than one-third of American adults are at risk of developing type 2 diabetes, while over 35 million currently have diabetes – of which 90-95% are cases of T2D – and experiences a substantially higher risk of CVD. There is an urgent need to develop more comprehensive prevention strategies for these at-risk patients, involving not only on endocrinology and primary care, but also cardiology to successfully reduce the risk of cardiovascular events and effectively manage T2DM.


Reducing the burden of cardiovascular disease in the United States requires a multifactorial approach, combining physicians across specialties to ensure comprehensive patient care. To improve prevention strategies, the American College of Cardiology (ACC) and the American Heart Association (AHA) updated its latest guidelines to include specific recommendations for the management of patients with T2D. Targeting four key areas – nutrition, statin therapy, physical activity, and antihyperglycemic agents – the new guidelines aim to inform clinicians about the benefits of effectively lowering blood pressure, and thus CVD risk, using a combination of these methods.


4 Key Recommendations for Primary Prevention




In order to improve glycemic control, assist in weight management, and ameliorate other risk factors, the AHA and ACC recommend all adults with T2D to implement a heart-healthy diet. Increased consumption of vegetables, fruits, nuts, whole grains, and healthy fats combined with a reduced intake of refined carbohydrates, processed meats, and sugar-sweetened beverages has a range of positive health effects and has proven especially efficacious at improving glycemic control in patients.


Previous research has found that the Mediterranean, Dietary Approaches to Stop Hypertension (DASH), and vegetarian diets can significantly improve CVD risk factors <>. A large-scale clinical trial evaluating the impact of the Mediterranean diet on cardiac death, myocardial infarction, and stroke found a 30% decrease in primary outcome in individuals consuming the diet. Further analysis revealed that the risk reductions were applicable to participants with and without T2DM.


Nutritional counseling should be performed with the help of a diabetes specialist or dietitian, while established weight and dietary goals should be closely monitored.


Physical Activity


Alongside a heart-healthy diet, an active lifestyle is another key component of successful CVD prevention. Advocating for further lifestyle modifications, the AHA and ACC highlight the importance of physical activity, providing a target goal of at least 150 minutes of moderate physical activity or 75 minutes of vigorous activity per week.


Clinical trial results reveal variation in the magnitude of blood glucose and weight reduction dependent on patient specific factors, however, overall improvement was observed for both measures. In a 2001 meta-analysis of 14 exercise studies, researchers found a reduction in hemoglobin A1c of 0.5% as a result of physical activity interventions. A combination of aerobic and resistance exercise was found to be the most effective, lowering HbA1c levels by nearly 1%. Although it is difficult to measure the impact of lifestyle interventions on CVD outcomes in long-term, large-scale trials, several studies have revealed improvement in rates of CVD events in T2DM patients associated with regular physical activity.




According to the AHA and ACC guidelines, the use of metformin as a first-line therapy at the time of T2DM diagnosis is recommended alongside lifestyle interventions focused on glycemic control and the reduction of CVD risk. In younger patients, however, lifestyle changes alone may be considered prior to beginning metformin therapy.


A well-established treatment for TD2M for patients unable to maintain glycemic control through lifestyle modifications, metformin can reduce HbA1c levels without the weight gain or hypoglycemia associated with other oral therapies. Metformin use has been consistently linked to lower cardiovascular mortality rates and when added to insulin can reduce the required dose to reach optimal targets. Although insulin is effective for targeting glucose levels, it may lead to increased resistance and weight gain in patients with type 2 diabetes while increasing CVD events and all-cause mortality. Lower insulin doses related to metformin use have been associated with improved health outcomes.



SGLT-2 Inhibitors and GLP-1 Receptor Agonists


The final recommendation from the updated guidelines encourages adults with T2DM who are unable to obtain glycemic control, despite both lifestyle modifications and metformin therapy, to consider the introduction of either of the two new medication classes. Both sodium-glucose cotransporter-2 (SGLT-2) inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1RAs) have been found to effectively lower blood pressure, reducing the number of CVD events in T2DM patients without leading to weight gain.


SGLT-2 inhibitors cause a decrease in serum glucose, diuresis, and weight loss which has led to an 11% reduction in CV death, myocardial infarction, and stroke in clinical trials. However, this association was only observed in patients with a history of cardiovascular disease although, the medication lowered heart failure hospitalization rates by 31% regardless of CVD history. The body of research concerning SGLT-2 inhibitors is still growing yet some studies suggest their use may be tied to increased risks of lower limb amputations.


Yielding a similar reduction in HbA1c levels, GLP-1RAs lower glucose levels by stimulating insulin production and suppressing glucagon in hyperglycemic states. In clinical trials, GLP-1RAs had a better safety profile than SGLT-2 inhibitors and proved just as effective at improving CVD outcomes – however, no reduction in heart failure rates occurred.



Reducing the burden of CVD in the American population requires a comprehensive approach to T2DM patient care, combining the strengths of cardiologists, endocrinologists, and primary care physicians to achieve optimal health outcomes. The AHA and ACC guidelines targeted at the T2DM population facing a high risk for CVD illustrate the necessity of cardiologist involvement to effectively manage the condition and prevent cardiovascular disease progression. As data from forthcoming trials becomes available, new strategies for primary prevention therapies may emerge, however, the universally important lifestyle factors of healthy nutritional patterns and regular physical activity constitute the first-line of therapy.