Hypoglycemia during moderate intensity exercise reduces counterregulatory responses to subsequent hypoglycemia

Postprandial glucose-management strategies in type 1 diabetes: Current approaches and prospects with precision medicine and artificial intelligence

Postprandial glucose control can be challenging for individuals with type 1 diabetes, and this can be attributed to many factors, including suboptimal therapy parameters (carbohydrate ratios, correction factors, basal doses) because of physiological changes, meal macronutrients and engagement in postprandial physical activity. This narrative review aims to examine the current postprandial glucose-management strategies tested in clinical trials, including adjusting therapy settings, bolusing for meal macronutrients, adjusting pre-exercise and postexercise meal boluses for postprandial physical activity, and other therapeutic options, for individuals on open-loop and closed-loop therapies. Then we discuss their challenges and future avenues. Despite advancements in insulin delivery devices such as closed-loop systems and decision-support systems, many individuals with type 1 diabetes still struggle to manage their glucose levels. The main challenge is the lack of personalized recommendations, causing suboptimal postprandial glucose control. We suggest that postprandial glucose control can be improved by (i) providing personalized recommendations for meal macronutrients and postprandial activity; (ii) including behavioural recommendations; (iii) using other personalized therapeutic approaches (e.g. glucagon-like peptide-1 receptor agonists, sodium-glucose co-transporter inhibitors, amylin analogues, inhaled insulin) in addition to insulin therapy; and (iv) integrating an interpretability report to explain to individuals about changes in treatment therapy and behavioural recommendations. In addition, we suggest a future avenue to implement precision recommendations for individuals with type 1 diabetes utilizing the potential of deep reinforcement learning and foundation models (such as GPT and BERT), employing different modalities of data including diabetes-related and external background factors (i.e. behavioural, environmental, biological and abnormal events).

Factors Affecting Reproducibility of Change in Glucose During Exercise: Results From the Type 1 Diabetes and EXercise Initiative

AIMS

To evaluate factors affecting within-participant reproducibility in glycemic response to different forms of exercise.

METHODS

Structured exercise sessions ~30 minutes in length from the Type 1 Diabetes Exercise Initiative (T1DEXI) study were used to assess within-participant glycemic variability during and after exercise. The effect of several pre-exercise factors on the within-participant glycemic variability was evaluated.

RESULTS

Data from 476 adults with type 1 diabetes were analyzed. A participant's change in glucose during exercise was reproducible within 15 mg/dL of the participant's other exercise sessions only 32% of the time. Participants who exercised with lower and more consistent glucose level, insulin on board (IOB), and carbohydrate intake at exercise start had less variability in glycemic change during exercise. Participants with lower mean glucose (P < .001), lower glucose coefficient of variation (CV) (P < .001), and lower % time <70 mg/dL (P = .005) on sedentary days had less variable 24-hour post-exercise mean glucose.

CONCLUSIONS

Reproducibility of change in glucose during exercise was low in this cohort of adults with T1D, but more consistency in pre-exercise glucose levels, IOB, and carbohydrates may increase this reproducibility. Mean glucose variability in the 24 hours after exercise is influenced more by the participant's overall glycemic control than other modifiable factors.

Exercise in adults with type 1 diabetes mellitus

Regular physical activity improves cardiometabolic and musculoskeletal health, helps with weight management, improves cognitive and psychosocial functioning, and is associated with reduced mortality related to cancer and diabetes mellitus. However, turnover rates of glucose in the blood increase dramatically during exercise, which often results in either hypoglycaemia or hyperglycaemia as well as increased glycaemic variability in individuals with type 1 diabetes mellitus (T1DM). A complex neuroendocrine response to an acute exercise session helps to maintain circulating levels of glucose in a fairly tight range in healthy individuals, while several abnormal physiological processes and limitations of insulin therapy limit the capacity of people with T1DM to exercise in a normoglycaemic state. Knowledge of the acute and chronic effects of exercise and regular physical activity is critical for the formulation of clinical strategies for the management of insulin and nutrition for active patients with T1DM. Emerging diabetes-related technologies, such as continuous glucose monitors, automated insulin delivery systems and the administration of solubilized glucagon, are demonstrating efficacy for preserving glucose homeostasis during and after exercise in this population of patients. This Review highlights the beneficial effects of regular exercise and details the complex endocrine and metabolic responses to different types of exercise for adults with T1DM. An overview of basic clinical strategies for the preservation of glucose homeostasis using emerging technologies is also provided.

Exercise Strategies to Prevent Hypoglycemia in Patients with Diabetes

The importance of adopting healthy exercise routines has been repeatedly emphasized to individuals with diabetes mellitus (DM). However, knowledge about the risk of exercise-induced hypoglycemia is limited. Regular exercise reduces and delays the onset of DM-related complications particularly in individuals who already have DM. However, an excessive exercise can lead to hypoglycemia. Excessive exercise in the evening can cause hypoglycemia while sleeping. Furthermore, if individuals with DM want to have a greater amount of exercise, the exercise duration rather than intensity must be increased. In weight resistance exercises, it is beneficial to first increase the number of repetitions, followed by the number of sets and gradually the weight of resistance. When performing intermittent high-intensity training within a short time period, hypoglycemia may develop for an extended period after exercise. In addition to adjusting exercise regimens, the medication doses must be modified accordingly. Delaying exercise, adjusting the number of snacks consumed prior to exercise, reducing insulin dose before exercise, and injecting insulin into the abdomen rather than the limbs prevent exercise-induced hypoglycemia prior to a spontaneous exercise. Ultimately, with personal knowledge on how to prevent hypoglycemia, the effects of exercise can be maximized in individuals with DM, and a healthy lifestyle can prevent future complications.

Occurrence of severe hypoglycaemic events among US youth and young adults with type 1 or type 2 diabetes

OBJECTIVE

Although severe hypoglycaemia (SH) can lead to adverse health outcomes, little is known about its occurrence and re-occurrence among youth with type 1 or type 2 diabetes.

METHODS

This study included 2740 participants aged <20 years at diabetes diagnosis and 5-14 years diabetes duration from the SEARCH for Diabetes in Youth Cohort Study. Participants reported SH events in the past 6 months. Differences in SH events by demographic and clinical factors were tested using logistic regression models.

RESULTS

Severe hypoglycaemia in the past 6 months was more common among youth with type 1 (7.0%, 168 of 2399) than with type 2 diabetes (2.6%, nine of 341) (P < 0.002). The median number of SH events per youth who had at least one SH event in the past 6 months was 1 for both type 1 type 2 diabetes. For youth with type 1 diabetes, those who reported SH events were older, were more likely to have obesity or to be physically active, and had lower HbA1c. After adjustments, one unit increase in HbA1c was associated with 16% lower likelihood (OR 0.84, 95% CI 0.75, 0.94) and being physically active was associated with an 87% higher likelihood (OR 1.87, 95% CI 1.23, 2.86) of reporting a SH event. There were too few SH events among youth with type 2 diabetes to analyse further.

CONCLUSIONS

In youth with diabetes, SH was common even within a short 6-month window. Better understanding the causes of SH may help prevent them from occurring.

Hypoglycemia during moderate intensity exercise reduces counterregulatory responses to subsequent hypoglycemia

Hypoglycemia, which occurs commonly during and following exercise in people with diabetes, is thought to be due to attenuated counterregulation in the setting of therapeutic insulin excess. To better understand the pathophysiology of counterregulation, we aimed to determine if dextrose administration to maintain euglycemia during moderate intensity exercise alters the attenuation of counterregulatory responses to subsequent hypoglycemia in healthy adults. Counterregulatory responses to hypoglycemia were assessed in 18 healthy adults after bed rest and following exercise with (n = 9) and without (n = 9) dextrose infusion. Responses were measured during a stepped euglycemic‐hypoglycemic clamp 24 h after either bed rest or two 90‐min bouts of exercise at 70% peak oxygen uptake. Hypoglycemia occurred during the second bout of exercise without dextrose infusion. Plasma glucagon and epinephrine responses to stepped hypoglycemia after antecedent exercise without dextrose infusion were significantly lower at the 45 mg/dL glycemic level compared to after bed rest. However, no attenuation of the counterregulatory responses to hypoglycemia was evident after antecedent exercise when dextrose was infused. This study suggests that the attenuation of the counterregulatory responses during hypoglycemia after exercise is likely due to the hypoglycemia that occurs during moderate prolonged exercise and not solely due to exercise or its intensity.