Exercise and glucose metabolism in persons with diabetes mellitus: perspectives on the role for continuous glucose monitoring

Carbohydrate Ingestion Increases Interstitial Glucose and Mitigates Neuromuscular Fatigue during Single-Leg Knee Extensions

INTRODUCTION

We aimed to investigate the neuromuscular contributions to enhanced fatigue resistance with carbohydrate (CHO) ingestion and to identify whether fatigue is associated with changes in interstitial glucose levels assessed using a continuous glucose monitor (CGM).

METHODS

Twelve healthy participants (six males, six females) performed isokinetic single-leg knee extensions (90°·s -1 ) at 20% of the maximal voluntary contraction (MVC) torque until MVC torque reached 60% of its initial value (i.e., task failure). Central and peripheral fatigue were evaluated every 15 min during the fatigue task using the interpolated twitch technique and electrically evoked torque. Using a single-blinded crossover design, participants ingested CHO (85 g sucrose per hour), or a placebo (PLA), at regular intervals during the fatigue task. Minute-by-minute interstitial glucose levels measured via CGM and whole blood glucose readings were obtained intermittently during the fatiguing task.

RESULTS

CHO ingestion increased time to task failure over PLA (113 ± 69 vs 81 ± 49 min, mean ± SD; P < 0.001) and was associated with higher glycemia as measured by CGM (106 ± 18 vs 88 ± 10 mg·dL -1 , P < 0.001) and whole blood glucose sampling (104 ± 17 vs 89 ± 10 mg·dL -1 , P < 0.001). When assessing the values in the CHO condition at a similar time point to those at task failure in the PLA condition (i.e., ~81 min), MVC torque, percentage voluntary activation, and 10 Hz torque were all better preserved in the CHO versus PLA condition ( P < 0.05).

CONCLUSIONS

Exogenous CHO intake mitigates neuromuscular fatigue at both the central and peripheral levels by raising glucose concentrations rather than by preventing hypoglycemia.

Practical considerations for continuous glucose monitoring in elite athletes with type 1 diabetes mellitus: A narrative review

Type 1 diabetes mellitus (T1DM) refers to a metabolic condition where a lack of insulin impairs the usual homeostatic mechanisms to control blood glucose levels. Historically, participation in competitive sport has posed a challenge for those with T1DM, where the dynamic changes in blood glucose during exercise can result in dangerously high (hyperglycaemia) or low blood glucoses (hypoglycaemia) levels. Over the last decade, research and technological development has enhanced the methods of monitoring and managing blood glucose levels, thus reducing the chances of experiencing hyper- or hypoglycaemia during exercise. The introduction of continuous glucose monitoring (CGM) systems means that glucose can be monitored conveniently, without the need for frequent fingerpick glucose checks. CGM devices include a fine sensor inserted under the skin, measuring levels of glucose in the interstitial fluid. Readings can be synchronized to a reader or mobile phone app as often as every 1-5 min. Use of CGM devices is associated with lower HbA1c and a reduction in hypoglycaemic events, promoting overall health and athletic performance. However, there are limitations to CGM, which must be considered when being used by an athlete with T1DM. These limitations can be addressed by individualized education plans, using protective equipment to prevent sensor dislodgement, as well as further research aiming to: (i) account for disparities between CGM and true blood glucose levels during vigorous exercise; (ii) investigate the effects of temperature and altitude on CGM accuracy, and (iii) explore of the sociological impact of CGM use amongst sportspeople without diabetes on those with T1DM.

Is rating of perceived exertion a valid method for monitoring exergaming intensity in type-1 diabetics? A cross-sectional randomized trial

AIMS

The rating of perceived exertion (RPE) provides correlations with physiological measurements of exercise intensity, including metabolic equivalent (MET), oxygen consumption (V˙O2), and heart rate (HR), in real (RS) and virtual (VS) sessions. To use RPE in patients with pathology, we aimed to examine the concurrent validity of RPE in type-1 diabetes mellitus (T1DM) patients while exergaming.

METHODS

Ten T1DM patients performed two 30-min crossover sessions of moderate-intensity exercise (washout 72-196 h). The RS group performed running, and the VS group played the Kinect Adventures! video game. METs were measured by a direct gas analyzer during the sessions, and RPE was measured on the 6 - 20 point Borg scale after the sessions.

RESULTS

RS and VS showed similar RPE (13.2 ± 2.7 vs. 14.2 ± 2.4) and MET (4.6 ± 1.1 vs. 4.0 ± 0.8) values (p > 0.05). RPE vs. MET correlation-coefficients were large in RS (r = 0.64; R2 = 41; p = 0.04) and were moderate in VS (r = 0.42; R2 = 18; p = 0.22). Additionally, RS secondary values (V˙O2 and HR vs. RPE) showed high coefficients (V˙O2-r = 0.62; average HRr = 0.62; maximal HRr = 0.50, p < 0.05). VS secondary values, on the other hand, showed low-moderate coefficients (V˙O2-r = 0.42; average HRr = 0.23; maximal HRr = 0.21, p > 0.05).

CONCLUSION

The current validation showed that RPE may not be a valid and strong method for T1DM patients while exergaming. Healthcare professionals should cautiously use the 6 - 20 point RPE scale in pathological patients, specifically in T1DM while exergaming.

The role of continuous glucose monitoring in physical activity and nutrition management: perspectives on present and possible uses

PURPOSE

Continuous glucose monitoring (CGM) is on the rise as the prevalence of obesity and diabetes increases. This review aimed to explore the use of CGM and its potential novel applications in physical activity and nutrition management.

METHODS

We searched PubMed, Web of Science, and Wiley Online Library databases using the keywords 'continuous glucose monitor,' 'nutrition,' 'physical activity,' and 'numerical modeling.'

RESULTS

Continuous blood glucose measurement is useful for individuals with obesity and diabetes. Long-term blood glucose data allow for personalized planning of nutritional composition, meal timing, and physical activity type and intensity, as well as help prevent hypoglycemia and hyperglycemia. Thus, understanding the limitations of CGM is important for its effective use.

CONCLUSION

CGM systems are being increasingly used to monitor and identify appropriate blood glucose controlling interventions. Blood glucose level is influenced by various factors such as nutrient composition, meal timing, physical activity, circadian rhythm, and cortisol levels. Numerical modeling can be used to analyze the complex relationship between stress, sleep, nutrition, and physical activity, which affect blood glucose levels. In future, blood glucose, sleep, and stress data will be integrated to predict appropriate lifestyle levels for blood glucose management. This integrated approach improves glucose control and overall wellbeing, potentially reducing societal costs.

Plasma Proteomic Kinetics in Response to Acute Exercise

Regular exercise has many favorable effects on human health, which may be mediated in part by the release of circulating bioactive factors during each bout of exercise. Limited data exist regarding the kinetic responses of plasma proteins during and after acute exercise. Proteomic profiling of 4163 proteins was performed using a large-scale, affinity-based platform in 75 middle-aged adults who were referred for treadmill exercise stress testing. Plasma proteins were quantified at baseline, peak exercise, and 1-h postexercise, and those with significant changes at both exercise timepoints were further examined for their associations with cardiometabolic traits and change with aerobic exercise training in the Health, Risk Factors, Exercise Training and Genetics Family Study, a 20-week exercise intervention study. A total of 765 proteins changed (false discovery rate < 0.05) at peak exercise compared to baseline, and 128 proteins changed (false discovery rate < 0.05) at 1-h postexercise. The 56 proteins that changed at both timepoints included midkine, brain-derived neurotrophic factor, metalloproteinase inhibitor 4, and coiled-coil domain-containing protein 126 and were enriched for secreted proteins. The majority had concordant direction of change at both timepoints. Across all proteins assayed, gene set enrichment analysis showed increased abundance of coagulation-related proteins at 1-h postexercise. Forty-five proteins were associated with at least one measure of adiposity, lipids, glucose homeostasis, or cardiorespiratory fitness in Health, Risk Factors, Exercise Training and Genetics Family Study, and 20 proteins changed with aerobic exercise training. We identified hundreds of novel proteins that change during acute exercise, most of which resolved by 1 h into recovery. Proteins with sustained changes during exercise and recovery may be of particular interest as circulating biomarkers and pathways for further investigation in cardiometabolic diseases. These data will contribute to a biochemical roadmap of acute exercise that will be publicly available for the entire scientific community.

The Complete Health Improvement Program and Physical Activity

Background: The Complete Health Improvement Program (CHIP) has demonstrated effectiveness in improving multiple cardiovascular disease risk factors. CHIP promotes physical activity, as well as a plant-based whole-food diet. The study objective is to evaluate the effectiveness of CHIP on improving levels of physical activity. Methods: CHIP participants had biomarkers measured at baseline and after the 11th session, consisting of level of physical activity, blood pressure (BP), body mass index (BMI), fasting blood sugar (FBS), and lipid panel. Pre and post data were analyzed using paired t-tests. Results. CHIP demonstrated significant increase in level of physical activity ( P < .001) and decreased BMI, FBS, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides (all P < .001). Increased levels of physical activity correlated with decreased BMI ( P < .001), but not with other biomarkers. Conclusion: CHIP is effective in producing increased level of physical activity and improvement in multiple biomarkers. The increase in physical activity is correlated with decreased BMI.

The Development of an Exercise Advisor App for Type 1 Diabetes: Digitization Facilitates More Individualized Guidance

Maintaining blood glucose levels in the target range during exercise can be onerous for people with type 1 diabetes (T1D). Using evidence-based research and consensus guidelines, we developed an exercise advisor app to reduce some of the burden associated with diabetes management during exercise. The app will guide the user on carbohydrate feeding strategies and insulin management strategies before, during, and after exercise and provide targeted and individualized recommendations. As a basis for the recommendations, the decision trees for the app use various factors including the type of insulin regimen, time of activity, previous insulin boluses, and current glucose level. The app is designed to meet the various needs of people with T1D for different activities to promote safe exercise practices.

Glucose and unstructured physical activity coupling during sleep and wake in young adults with type 1 diabetes

Glucose variations have a bidirectional relationship with the sleep/wake and circadian systems in type 1 diabetes (T1D); however, the mechanisms remain unclear. The aim of this study was to describe the coupling between glucose and unstructured physical activity over 168 h in young adults with T1D. We hypothesized that there would be differences in sleep and wake characteristics and circadian variations. Glucose was measured with a continuous glucose monitoring device every 5 min and activity with a non-dominant wrist-worn actigraph in 30-s epochs over 6–14 days. There was substantial glucose and unstructured physical activity coupling during sleep and wake, along with circadian variation based on the wavelet coherence analysis. The extent to which glucose fluctuations result in disrupted sleep over longer than one week should be examined considering the harmful effects on achieving glycemic targets. Further studies are needed to delineate the respective roles of glucose production and utilization and the potential for improved meal and insulin timing to optimize glucose and sleep in this population reliant on exogenous insulin.

Protective effects of physical activity against health risks associated with type 1 diabetes: "Health benefits outweigh the risks"

The magnitude of diabetes mellitus (DM) has increased in recent decades, where the number of cases and the proportion of the disease have been gradually increasing over the past few decades. The chronic complications of DM affect many organ systems and account for the majority of morbidity and mortality associated with the disease. The prevalence of type 1 DM (T1DM) is increasing globally, and it has a very significant burden on countries and at an individual level. T1DM is a chronic illness that requires ongoing medical care and patient self-management to prevent complications. This study aims to discuss the health benefits of physical activity (PA) in T1DM patients. The present review article was performed following a comprehensive literature search. The search was conducted using the following electronic databases: "Cochrane Library", Web of Science, PubMed, HINARI, EMBASE, Google for grey literature, Scopus, African journals Online, and Google Scholar for articles published up to June 21, 2021. The present review focused on the effects of PA on many outcomes such as blood glucose (BG) control, physical fitness, endothelial function, insulin sensitivity, well-being, the body defense system, blood lipid profile, insulin resistance, cardiovascular diseases (CVDs), insulin requirements, blood pressure (BP), and mortality. It was found that many studies recommended the use of PA for the effective management of T1DM. PA is a component of comprehensive lifestyle modifications, which is a significant approach for the management of T1DM. It provides several health benefits, such as improving BG control, physical fitness, endothelial function, insulin sensitivity, well-being, and the body defense system. Besides this, it reduces the blood lipid profile, insulin resistance, CVDs, insulin requirements, BP, and mortality. Overall, PA has significant and essential protective effects against the health risks associated with T1DM. Even though PA has several health benefits for patients with T1DM, these patients are not well engaged in PA due to barriers such as a fear of exercise-induced hypoglycemia in particular. However, several effective strategies have been identified to control exercise-induced hypoglycemia in these patients. Finally, the present review concludes that PA should be recommended for the management of patients with T1DM due to its significant health benefits and protective effects against associated health risks. It also provides suggestions for the future direction of research in this field.

Joint associations of fresh fruit intake and physical activity with glycaemic control among adult patients with diabetes: a cross-sectional study

OBJECTIVE

To investigate the joint associations of fresh fruit intake and physical activity with glycaemic control in adult patients with diabetes mellitus (DM).

DESIGN

It was an observational study involving adult patients with DM through a face-to-face questionnaire survey, physical measurements and laboratory examinations. Data were analysed by introducing a generalised linear mixed model, and a significant difference was set at p<0.05.

SETTING

Nanjing, Jiangsu, China.

PARTICIPANTS

A total of 5663 adult patients with DM from the 2017 Nanjing Chronic Disease and Risk Factor Surveillance were recruited.

RESULTS

Based on the food frequency questionnaire, fresh fruit intake was classified as 'not eat', '1~99 g/day' and '≥100 g/day'. Physical activity level was calculated based on the data of Global Physical Activity Questionnaire and classified into insufficient physical activity (<600 MET-min/week) and sufficient physical activity (≥600 MET-min/week). The likelihood of glycaemic control in adult patients with DM with fresh fruit intake ≥100 g/day was 37.8% (OR: 1.378; 95% CI: 1.209 to 1.571) higher than those with fresh fruit intake <100 g/day, which was 26% (OR: 1.260; 95% CI: 1.124 to 1.412) higher in adult patients with DM with sufficient physical activity than those with insufficient physical activity. Adult patients with DM with fresh fruit intake ≥100 g/day and sufficient physical activity presented the greatest likelihood of glycaemic control (OR: 1.758; 95% CI: 1.471 to 2.102) compared with those with both fresh fruit intake <100 g/day and insufficient physical activity.

CONCLUSIONS

Fresh fruit intake ≥100 g/day combined with sufficient physical activity is associated with a significantly higher likelihood of glycaemic control in adult patients with DM.

Do estimated metabolic equivalent and energy expenditure verify the physical effort of type-1 diabetics in resting and exercise situations? A randomized crossover trial

ABSTRACT To compare measured and estimated metabolic equivalent (MET) and energy expenditure (EE) in different situations with Type-1 diabetes (T1DM) patients. Ten T1DM patients performed three 30-minute sessions (resting, running-RS, and exergame-VS) at moderate intensity. MET and EE were measured by direct gas analyzer and estimated using the formula applying heart rate and V̇02peak. MET values (measured vs. estimated) were statistically different during RS (4.58±1.11 vs.7.59±1.36) and VS (3.98± 0.84 vs. 5.77±0.84) (p<0.001). EE values were similar: RS (147±43 vs. 246±157) and VS (129±33 vs. 184±20) (p<0.001). The error between the methods: 0.41, 1.51, and 1.07 METs and 20.1, 51.5, and 32.5 Kcals for resting, RS, and VS. Estimation could be used in resting and with caution for RS and VS.

Predicting Progression Patterns of Type 2 Diabetes using Multi-sensor Measurements

Type 2 diabetes - a prevalent chronic disease worldwide - increases risk for serious health consequences including heart and kidney disease. Forecasting diabetes progression can inform disease management strategies, thereby potentially reducing the likelihood or severity of its consequences. We use continuous glucose monitoring and actigraphy data from 54 individuals with Type 2 diabetes to predict their future hemoglobin A1c, HDL cholesterol, LDL cholesterol, and triglyceride levels one year later. We use a combination of convolutional and recurrent neural networks to develop a deep neural network architecture that can learn the dynamic patterns in different sensors' data and combine those patterns with additional demographic and lab data. To further demonstrate the generalizability of our models, we also evaluate their performance using an independent public dataset of individuals with Type 1 diabetes. In addition to diabetes, our approach could be useful for other serious and chronic physical illness, where dynamic (e.g., from multiple sensors) and static (e.g., demographic) data are used for creating predictive models.

Adherence to physical activity recommendations and barriers to physical activity participation among adults with type 1 diabetes

Background

Physical activity (PA) is important for those with type 1 diabetes (T1DM); however, accurate information on PA in people with T1DM is limited.

Aims

This study assessed adherence to PA guidelines using both objective and subjective PA measures and evaluated the relationship between accelerometer-measured PA and cardiovascular disease (CVD) risk factors. Barriers to PA were also assessed.

Methods

Using an observational cross-sectional design, PA was measured objectively over 7 days in 72 participants (34 males) using an accelerometer (ActiGraph) and subjectively using the International Physical Activity Questionnaire (IPAQ). Perceived barriers to PA were assessed using the Barriers to Physical Activity in Diabetes (type 1) scale. Multiple linear regression models assessed the influence of PA on HbA1c and CVD risk factors.

Results

Mean age ± SD was 40.9 ± 12.9 years, diabetes duration was 18 ± 11.6 years, and HbA1c was 65 ± 14 mmol/mol /8.0 ± 1.3%. Twenty-three (32%) participants exercised according to PA recommendations as measured by an accelerometer. Sixty-nine (97%) participants reported meeting the recommendations as per the IPAQ. Those meeting recommendations (accelerometry) had a lower HbA1c (p = 0.001), BMI (p = 0.032), waist circumference (p = 0.006), and fat mass (p = 0.032) and a greater number of hypoglycaemic events (p = 0.004). Fear of hypoglycaemia was the strongest barrier to PA (mean 3.4 ± 2.0).

Conclusion

The majority of participants failed to meet PA recommendations. Meeting the recommendations was associated with healthier CVD risk factor profiles. Individuals with T1DM possibly overestimate their PA using self-reported measures and require support and education to safely improve activity levels.

Metabolomic profiles of being physically active and less sedentary: a critical review

BACKGROUND

Being physically active has multiple salutary effects on human health, likely mediated by changes in energy metabolism. Recent reviews have summarized metabolomic responses to acute exercise. However, metabolomic profiles of individuals who exercise regularly are heterogeneous.

AIM OF REVIEW

We conducted a systematic review to identify metabolites associated with physical activity (PA), fitness, and sedentary time in community-dwelling adults and discussed involved pathways. Twenty-two studies were eligible because they (1) focused on community-dwelling adults from observational studies; (2) assessed PA, fitness, and/or sedentary time, (3) assessed metabolomics in biofluid, and (4) reported on relationships of metabolomics with PA, fitness, and/or sedentary time.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Several metabolic pathways were associated with higher PA and fitness and less sedentary time, including tricarboxylic acid cycle, glycolysis, aminoacyl-tRNA biosynthesis, urea cycle, arginine biosynthesis, branch-chain amino acids, and estrogen metabolism. Lipids were strongly associated with PA. Cholesterol low-density lipoproteins and triglycerides were lower with higher PA, while cholesterol high-density lipoproteins were higher. Metabolomic profiles of being physically active and less sedentary indicate active skeletal muscle biosynthesis supported by enhanced oxidative phosphorylation and glycolysis and associated with profound changes in lipid and estrogen metabolism. Future longitudinal studies are needed to understand whether these metabolomic changes account for health benefits associated with PA.

Diabetes education in pediatrics: How to survive diabetes

Diabetes mellitus is the most common abnormal carbohydrate metabolism disorder affecting millions of people worldwide. It is characterized by hyperglycemia as a result of ß-cell destruction or dysfunction by both genetic and environmental factors. Over time chronic hyperglycemia leads to microvascular (i.e., retinopathy, nephropathy and neuropathy) and macrovascular (i.e., ischemic heart disease, peripheral vascular disease, and cerebrovascular disease) complications of diabetes. Diabetes complication trials showed the importance of achieving near-normal glycemic control to prevent and/or reduce diabetes-related morbidity and mortality. There is a staggering rate of increased incidence of diabetes in youth, raising concerns for future generations' health, quality of life and its enormous economic burden. Despite advancements in the technology, diabetes management remains cumbersome. Training individuals with diabetes to gain life-long survival skills requires a comprehensive and ongoing diabetes education by a multidisciplinary team. Diabetes education and training start at the time of diagnosis of diabetes and should be continuous throughout the course of disease. The goal is to empower the individuals and families to gain diabetes self-management skills. Diabetes education must be individualized depending on the individual's age, education, family dynamics, and support. In this article, we review the history of diabetes, etiopathogenesis and clinical presentation of both type 1 and type 2 diabetes in children as well as adolescents. We then focus on diabetes management with education methods and materials.

Aerobic Training Modulates the Increase in Plasma Concentrations of Cytokines in response to a Session of Exercise

Acute physical exercise can modulate immune function. For example, acute exercise is known to increase the circulating concentration of cytokines. Exercise is also known to modulate immune function chronically. It is not known whether exercise training can result in training of the immune system. Here, we investigated the effects of six weeks of aerobic training on cytokine responses induced by acute exercise until fatigue. Twelve healthy men performed a fatiguing exercise at the anaerobic threshold (AT) intensity. After the training period, the participants performed another bout of acute exercise at the same duration and intensity of the pretraining situation. The analysis was made at the beginning, end, and at 10, 30, and 60 minutes during the recovery period. Training at AT induced a gain of 11.2% of exercise capacity. Before training, a single bout of acute exercise induced a significant increase in plasma levels of cytokines, including IL-6, TNF-α, sTNFR1, IL-10, CXCL10, BDNF, leptin, resistin, and adiponectin. After six weeks of aerobic training, levels of IL-6, sTNFR1, BDNF, and leptin increased to a lesser extent after an acute bout exercise at the same absolute intensity as the pretraining period. Responses to the same relative exercise intensity were similar to those observed before exercise. These results show that aerobic training is associated with training of acute immune responses to acute exercise until fatigue.

Continuous Blood Glucose Monitoring Increases Vigorous Physical Activity Levels and Is Associated With Reduced Hypoglycemia Avoidance Behavior In Youth With Type 1 Diabetes

The primary goal of this study was to explore physical activity (PA) levels, hypoglycemia fear scores and hypoglycemia episodes according to insulin administration and blood glucose monitoring methods in youth with type 1 diabetes (T1D). A self-administered questionnaire was completed by 28 children and 33 adolescents with T1D, and their PA was assessed. Hypoglycemia episodes, fear of hypoglycemia scores, insulin therapy (pump vs. injection) and blood glucose monitoring (continuous blood glucose monitors [CGMs] vs. blood glucose meters) methods are reported in the present work. There were no significant differences in the number of hypoglycemic episodes, child hypoglycemia fear survey behavior or total scores, or any components of the PA profile between youth using injections and those using a pump. However, these variables differed significantly when compared according to blood glucose monitoring method (CGMs vs. blood glucose meters): 41.2 vs. 81.8, p<0.01; 1.03 ± 0.05 vs. 2.6 ± 0.63, p<0.01; 1.09 ± 0.43 vs. 2.94 ± 0.22, p<0.01; and 222 ± 18 vs. 49 ± 11, p<0.01 (for total time in vigorous PA in minutes per week), respectively. CGM use correlated significantly with VPA levels (β=0.6; p=0.04). Higher VPA levels were associated with higher child hypoglycemia fear survey behavior scores (β=0.52; p=0.04). The latter correlates negatively with the number of episodes of hypoglycemia in the past 12 months in all category groups. The type of insulin injection was not associated with more activity in youth with T1D. In contrast, CGM use may be associated with increased vigorous PA among T1D youth. Those with higher hypoglycemia fear survey behavior scores engaged in more VPA and had fewer hypoglycemia episodes. Although CGM use ensures continuous monitoring of glycemia during exercise, increasing hypoglycemia avoidance behavior is still a necessary part of exercise management strategies in active youth with T1D.

Association of Metabolic Syndrome with Aerobic Exercise and LPL rs3779788 Polymorphism in Taiwan Biobank Individuals

PURPOSE

The Lipoprotein lipase (LPL) gene is a significant contributor to dyslipidemia. It has shown associations with several conditions including atherosclerosis, obesity, and metabolic syndrome (MetS). We assessed the interactive association between MetS and rs3779788 of the LPL gene based on aerobic exercise.

MATERIALS AND METHODS

Data were available for 7532 Taiwan Biobank (TWB) participants recruited between 2008 and 2016. We used multiple logistic regression to determine the odds ratios (OR) for MetS and their 95% confident intervals (C.I.). Potential variables included LPL rs3779788, aerobic exercise, sex, age, education, marital status, body mass index (BMI), smoking, alcohol consumption, midnight snacking, vegetarian diet, coffee, dietary fat, and tea drinking.

RESULTS

Aerobic exercise was protective against MetS (OR, 0.858; 95% C.I., 0.743-0.991). Compared to CC/CT genotype, the OR for developing MetS was 0.875, (95% C.I., 0.571-1.341) in TT individuals. The test for interaction was significant for the rs3779788 variant and aerobic exercise (p = 0.0484). In our group analyses, the OR for MetS was 0.841 (95% C.I., 0.727-0.974) in CC/CT and 4.076 (95% C.I., 1.158-14.346) in TT individuals who did aerobic exercise compared to those who did not.

CONCLUSION

Our study indicated that aerobic exercise improved metabolic syndrome in Taiwanese adults with rs3779788 CC/CT genotype relative to those with TT genotype.

Acute glycaemic management before, during and after exercise for cardiac rehabilitation participants with diabetes mellitus: a joint statement of the British and Canadian Associations of Cardiovascular Prevention and Rehabilitation, the International Council for Cardiovascular Prevention and Rehabilitation and the British Association of Sport and Exercise Sciences

Type 1 (T1) and type 2 (T2) diabetes mellitus (DM) are significant precursors and comorbidities to cardiovascular disease and prevalence of both types is still rising globally. Currently,~25% of participants (and rising) attending cardiac rehabilitation in Europe, North America and Australia have been reported to have DM (>90% have T2DM). While there is some debate over whether improving glycaemic control in those with heart disease can independently improve future cardiovascular health-related outcomes, for the individual patient whose blood glucose is well controlled, it can aid the exercise programme in being more efficacious. Good glycaemic management not only helps to mitigate the risk of acute glycaemic events during exercising, it also aids in achieving the requisite physiological and psycho-social aims of the exercise component of cardiac rehabilitation (CR). These benefits are strongly associated with effective behaviour change, including increased enjoyment, adherence and self-efficacy. It is known that CR participants with DM have lower uptake and adherence rates compared with those without DM. This expert statement provides CR practitioners with nine recommendations aimed to aid in the participant's improved blood glucose control before, during and after exercise so as to prevent the risk of glycaemic events that could mitigate their beneficial participation.

Effects of acute aerobic, resistance and combined exercises on 24-h glucose variability and skeletal muscle signalling responses in type 1 diabetics

PURPOSE

To compare the effect of high-intensity aerobic (AER), resistance (RES), and combined (COMB: RES + AER) exercise, on interstitial glucose (IG) variability and skeletal muscle signalling pathways in type 1 diabetes (T1D).

METHODS

T1D participants (6 M/6F) wore a flash glucose monitoring system in four randomized sessions: one control (CONT), and one AER, RES and COMB (40 min each). Mean amplitude of glycemic excursions (MAGE), standard deviation (SD) and coefficient variation (CV) of IG were used to compare the 24 h post-exercise IG variability. Blood and muscle samples were collected to compare exercise-induced systemic and muscle signalling responses related to metabolic, growth and inflammatory adaptations.

RESULTS

Both RES and COMB decreased the 24 h MAGE compared to CONT; additionally, COMB decreased the 24 h SD and CV. In the 6-12 h post-exercise, all exercise modalities reduced the IG CV while SD decreased only after COMB. Both AER and COMB stimulated the PGC-1α mRNA expression and promoted the splicing of IGF-1Ea variant, while Akt and p38MAPK phosphorylation increased only after RES and COMB. Additionally, COMB enhanced eEF2 activation and RES increased myogenin and MRF4 mRNA expression. Blood lactate and glycerol levels and muscle IL-6, TNF-α, and MCP-1 mRNAs increased after all exercise sessions, while serum CK and LDH level did not change.

CONCLUSION

COMB is more effective in reducing IG fluctuations compared to single-mode AER or RES exercise. Moreover, COMB simultaneously activates muscle signalling pathways involved in substrate metabolism and anabolic adaptations, which can help to improve glycaemic control and maintain muscle health in T1D.

The effect of endurance training on levels of LINC complex proteins in skeletal muscle fibers of STZ-induced diabetic rats

The changes of the linker of nucleoskeleton and cytoskeleton (LINC) complex have been studied in many muscular abnormality conditions; however, the effects of diabetes and physical activities on it have still remained to be defined. Therefore, the purpose of the this study was to evaluate the impacts of a six-week endurance training on the levels of SUN1 and Nesprin-1 proteins in Soleus and EDL muscles from diabetic wistar rats. A total number of 48 male Wistar rats (10 weeks, 200-250 gr) were randomly divided into healthy control (HC, N = 12), healthy trained (HT, N = 12), diabetic control (DC, N = 12), and diabetic trained (DT, N = 12) groups. Diabetes was also induced by a single intraperitoneally injection of streptozocin (45 mg/kg). The training groups ran a treadmill for five consecutive days within six weeks. The levels of the SUN1 and the Nesprin-1 proteins were further determined via ELISA method. The induction of diabetes had significantly decreased the levels of Nesprin-1 protein in the soleus and EDL muscles but it had no effects on the SUN1 in these muscles. As well, the findings revealed that six weeks of endurance training had significantly increased the levels of Nesprin-1 in DT and HT groups in the soleus as well as the EDL muscles; however, it had no impacts on the SUN1 in these muscles. The muscle fiber cross-sectional area (CSA) and myonuclei also decreased in diabetic control rats in both studied muscles. The training further augmented these parameters in both studied muscles in HT and DT groups. The present study provides new evidence that diabetes changes Nesprin-1 protein levels in skeletal muscle and endurance exercise training can modify it.

Muscle Strength and Glycaemic Control among Patients with Type 2 Diabetes

Poor glycaemic control is associated with chronic life-threatening complications. This cross-sectional study examined whether there is an association between handgrip strength and glycaemic control among patients with diabetes. Data on 1058 participants aged 40 and older were collected from the National Health and Nutritional Examination Survey (NHANES). Muscle strength was assessed using a handgrip dynamometer, and glycaemic control was assessed using HbA1c. Handgrip strength was presented as age- and gender-specific quartiles, with participants in quartile 1 having the lowest handgrip strength and participants in quartile 4 having the highest handgrip strength. Logistic regression analyses were used to assess the association between handgrip strength and poor glycaemic control among participants with diabetes. Three models, each adjusted to include different variables, were employed. Odds ratio (OR) values revealed no association between handgrip strength and glycaemic control after adjusting for age, gender, and race in model 1. With further adjustment for sedentary activity, income-to-poverty ratio, education, and smoking, patients in quartile 4 of handgrip strength had 0.51 odds of poor glycaemic control (95% CI: 0.27-0.99). However, the reported association above vanished when further adjusted for insulin use (OR = 0.67; 95% CI: 0.35-1.28). In conclusion, findings may indicate an association between glycaemic control and muscle strength. This association may be altered by insulin use; further investigations are required.

In peripheral artery disease, diabetes is associated with reduced physical activity level and physical function and impaired cardiac autonomic control: A cross-sectional study

BACKGROUND

Diabetes has been considered a major risk factor for peripheral artery disease (PAD). The effect of diabetes on daily physical activity level and cardiovascular function in PAD patients is poorly known.

OBJECTIVE

To analyze the effect of diabetes on physical activity level, physical function and cardiovascular health parameters in patients with PAD and claudication symptoms.

METHODS

Cross-sectional study of 267 PAD patients, 146 without and 121 with diabetes. Physical activity levels were objectively measured by using an accelerometer, and time spent in sedentary (0-100 counts/min), light (101-1040 counts/min) and moderate to vigorous (≥1041 counts/min) physical activity was obtained. Physical function assessment included the 6-min walk test, handgrip strength test and short physical performance battery. Cardiovascular health parameters measured were brachial blood pressure, heart rate variability, and arterial stiffness.

RESULTS

Diabetic PAD patients spent more time in sedentary behavior (P=0.001, effect size [ES] 0.234) and less time in light (P=0.003, ES=0.206) and moderate-to-vigorous physical activity (P<0.001, ES=0.258) than non-diabetic PAD patients. Diabetic PAD patients presented lower 6-min walk distance (P=0.005, ES=0.194) and impaired cardiac autonomic modulation (standard deviation of all NN intervals [SDNN], P<0.001, ES=0.357; square root of the mean of the sum of the squares of differences between adjacent NN intervals [RMSSD], P<0.001, ES=0.280; and NN50 count divided by the total number of all NN intervals [pNN50], P<0.001, ES=0.291) as compared with non-diabetic PAD patients. After adjustment for confounders, diabetes remained associated with sedentary behavior (P=0.011), light (P=0.020) and moderate-to-vigorous physical activity (P=0.008), 6-min walk distance (P=0.030), SDNN (P<0.001), RMSSD (P=0.004), and PNN50 (P=0.004).

CONCLUSION

Diabetic PAD patients presented lower physical activity level, reduced physical function and impaired autonomic modulation as compared with non-diabetic PAD patients.

Efficacy of the Diabeloop closed-loop system to improve glycaemic control in patients with type 1 diabetes exposed to gastronomic dinners or to sustained physical exercise

AIMS

To compare closed-loop (CL) and open-loop (OL) systems for glycaemic control in patients with type 1 diabetes (T1D) exposed to real-life challenging situations (gastronomic dinners or sustained physical exercise).

METHODS

Thirty-eight adult patients with T1D were included in a three-armed randomized pilot trial (Diabeloop WP6.2 trial) comparing glucose control using a CL system with use of an OL device during two crossover 72-hour periods in one of the three following situations: large (gastronomic) dinners; sustained and repeated bouts of physical exercise (with uncontrolled food intake); or control (rest conditions). Outcomes included time in spent in the glucose ranges of 4.4-7.8 mmol/L and 3.9-10.0 mmol/L, and time in hypo- and hyperglycaemia.

RESULTS

Time spent overnight in the tight range of 4.4 to 7.8 mmol/L was longer with CL (mean values: 63.2% vs 40.9% with OL; P ≤ .0001). Time spent during the day in the range of 3.9 to 10.0 mmol/L was also longer with CL (79.4% vs 64.1% with OL; P ≤ .0001). Participants using the CL system spent less time during the day with hyperglycaemic excursions (glucose >10.0 mmol/L) compared to those using an OL system (17.9% vs 31.9%; P ≤ .0001), and the proportions of time spent during the day with hyperglycaemic excursions of those using the CL system in the gastronomic dinner and physical exercise subgroups were of similar magnitude to those in the control subgroup (18.1 ± 6.3%, 17.2 ± 8.1% and 18.4 ± 12.5%, respectively). Finally, times spent in hypoglycaemia were short and not significantly different among the groups.

CONCLUSIONS

The Diabeloop CL system is superior to OL devices in reducing hyperglycaemic excursions in patients with T1D exposed to gastronomic dinners, or exposed to physical exercise followed by uncontrolled food and carbohydrate intake.

Identifying sources of support and barriers to physical activity in pediatric type 1 diabetes

OBJECTIVES

Reports suggest that children with type 1 diabetes (T1D) perform less than the recommended daily activity and are less active than their non-diabetic peers. We aimed to: (a) Identify barriers and sources of support for exercise performance in pediatric T1D. (b) Identify strengths and limitations in the exercise-directed education provided by our diabetes team.

METHODS

Patients with T1D 5 to 20 years of age were recruited while attending a routine clinic visit. Participants completed a set of questionnaires assessing demographics, health data, barriers, and sources of support for exercise performance and diabetes related exercise education. The clinics' medical staff filled-out a questionnaire assessing the exercise-directed education provided in clinic.

RESULTS

Ninety-six subjects were included in this study, mean age 13.7 ± 3.8 years. Median weekly reported exercise time was 3.5 hours. The two most prevalent barriers were fear of hypoglycemia and low fitness, reported by 76% and 51%, respectively. Mean family and social support scores were 4.1 ± 0.7 and 3.3 ± 1.1, respectively (1-5 scale); the latter correlated with the amount of activity performed (cc = 0.360; P < .001). The majority of participants (97%) reported receiving guidance for physical activity, to their satisfaction. Yet, knowledge and implementation were suboptimal. All staff members reported conducting routine exercise-directed teaching, with variations in frequency and content.

CONCLUSIONS

Our findings suggest that in order to increase the amount of safely performed exercise in pediatric patients with T1D, fear of hypoglycemia must be addressed. Further efforts should focus on: (a) encouraging active family and social involvement (b) standardization of education.

Resources to Guide Exercise Specialists Managing Adults with Diabetes

Exercise is an important element to optimize health and well-being, though navigating exercise safely can be challenging for exercise specialists working with people with diabetes. Measuring glucose levels before an exercise session assists in the determination of whether exercise is safe for a person with diabetes. A number of organizations have recently developed guidelines to provide exercise and diabetes recommendations based on glucose levels and other relevant factors. However, there are limited easy-to-use resources to assist exercise specialists to determine whether exercise should be started and continued by people with diabetes. The type of diabetes, pre-exercise glucose level, medications and their timing, recent food intake and general sense of wellness all warrant consideration when determining the approach to each exercise session. An expert group was convened to review the published literature and develop resources to guide exercise specialists in assessing the safety of an adult with diabetes starting exercise, and indications to cease exercise, based upon glucose levels and other factors. Contraindications to people with diabetes starting or continuing exercise are (1) glucose < 4.0 mmol/L; (2) glucose > 15.0 mmol/L with symptoms of weakness/tiredness, or with ketosis; (3) hypoglycaemic event within the previous 24 h that required assistance from another person to treat and (4) feeling unwell. To optimize diabetes and exercise safety, recommendations (stratified by pre-exercise glucose level) are provided regarding carbohydrate ingestion, glucose monitoring and medication adjustment.

Avoiding hypoglycemia: the use of insulin pump combined with continuous glucose monitor in type 1 diabetes crossing a Rocky Gorge

BACKGROUND

Continuous subcutaneous insulin infusion (CSII) and continuous glucose monitoring systems (CGMS) have been proven very effective in diabetes management.

AIM

This study evaluated the usefulness of these devices during prolonged, intense physical activity in an uncontrolled natural environment away from the clinical research center.

DESIGN

Non-randomized, prospective and observational study.

METHODS

During the summer, 38 participants with type 1 diabetes crossed the Samaria gorge, the second largest gorge in Europe (17 km). Twenty subjects on CSII combined with real-time CGMS and 18 on multiple daily injections (MDI) combined with professional (retrospective) CGMS participated in the program. All participants were unsupervised during the event.

RESULTS

All 38 participants managed to reach the destination point safely. There were no episodes of severe hypoglycemia. The duration of the exercise (mean ±SD) was 6.4 ± 1.3 h. The CSII group exhibited significantly lower hypoglycemic episodes during exercise (0.1 ± 0.3 vs. 0.4 ± 0.6; P = 0.047) as well as lower AUC below 70 mg/dl compared with the MDI, during the 24 h (0.61 ± 0.78 vs. 1.84 ± 1.55; P = 0.007). Individuals on CSII were significantly less likely to develop a hypoglycemic episode during exercise (P = 0.038). Exercise induced nocturnal hypoglycemia was not prevented effectively in neither group.

CONCLUSIONS

CSII combined with CGMS is effective in controlling blood glucose levels in type 1 diabetics who perform prolonged strenuous exercise. The use of insulin pump technology in regions with hot Mediterranean climates is safe and can provide protection against exercise-induced hypoglycemia. Development of precise instructions for T1DM who occasionally get involved in exercise activities, requires further studies.

Glucose impairments and insulin resistance in prostate cancer: the role of obesity, nutrition and exercise

BACKGROUND

Hyperinsulinemia, obesity and related metabolic diseases are associated with prostate cancer development. Prostate cancer patients undergoing androgen deprivation therapy (ADT) are at increased risk for metabolic syndrome, cardiovascular disease and diabetes, while pre-existing metabolic conditions may be exacerbated.

PURPOSE

An integrative approach is used to describe the interactions between insulin, glucose metabolism, obesity and prostate cancer. The potential role of nutrition and exercise will also be examined.

FINDINGS

Hyperinsulinemia is associated with prostate cancer development, progression and aggressiveness. Prostate cancer patients who undergo ADT are at risk of diabetes in survivorship. It is unclear whether this is a direct result of treatment or related to pre-existing metabolic features (e.g. hyperinsulinemia and obesity). Obesity and metabolic syndrome are also associated with prostate cancer development and poorer outcomes for cancer survivors, which may be driven by hyperinsulinemia, pro-inflammation, hyperleptinemia and/or hypoadiponectinemia.

CONCLUSIONS

Independently evaluating changes in glucose metabolism near the time of prostate cancer diagnosis and during long-term ADT treatment is important to distinguish their unique contributions to the development of metabolic disturbances. Integrative approaches, including metabolic, clinical and body composition measures, are needed to understand the role of adiposity and insulin resistance in prostate cancer and to develop effective nutrition and exercise interventions to improve secondary diseases in survivorship.

High-intensity interval exercise and glycemic control in adolescents with type one diabetes mellitus: a case study

Current physical activity guidelines for youth with type 1 diabetes (T1D) are poorly supported by empirical evidence and the optimal dose of physical activity to improve glycemic control is unknown. This case report documents the effect of acute high‐intensity interval exercise (HIIE) and moderate‐intensity exercise (MIE) on 24‐h glycemic control in three adolescents with T1D using continuous glucose monitoring. Results highlight varied individual response to exercise across the participants. In two participants both MIE and HIIE resulted in a drop in blood glucose during exercise (−38 to −42% for MIE and −21–46% in HIIE) and in one participant both MIE and HIIE resulted in increased blood glucose (+19% and + 36%, respectively). Over the 24‐h period average blood glucose was lower for all participants in the HIIE condition, and for two for the MIE condition, compared to no exercise. All three participants reported HIIE to be more enjoyable than MIE. These data show both HIIE and MIE have the potential to improve short‐term glycemic control in youth with T1D but HIIE was more enjoyable. Future work with a larger sample size is required to explore the potential for HIIE to improve health markers in youth with T1D.

We Can Work (It) Out Together: Type 1 Diabetes Boot Camp for Adult Patients and Providers Improves Exercise Self-Efficacy

OBJECTIVES

This project aimed to use education sessions and exercise classes to improve exercise self-efficacy in individuals with type 1 diabetes and in diabetes care providers (DCPs).

METHODS

We recruited 12 adults with type 1 diabetes and 12 DCPs who participated in 4 weekly group sessions to learn about exercise physiology and to experience various exercise types. We provided participants who had type 1 diabetes with real-time continuous glucose monitors and heart rate monitors to enhance experiential learning. Both groups completed questionnaires before and after the study to assess confidence concerning exercise. Following the study, focus groups assessed the impact of the study on knowledge and self-efficacy.

RESULTS

There was an improvement in DCPs' attitudes toward exercise (p=0.004). DCPs' confidence in providing clients with advice regarding the time, type and intensity of exercise (p=0.005) and strategies for overcoming barriers to exercise (p=0.016) improved significantly. We found no significant changes in results in the questionnaires of participants with type 1 diabetes. Focus group analysis suggested that the study improved awareness of the importance of exercise as well as knowledge about the effects of exercise in type 1 diabetes by both DCPs and participants. Continuous glucose monitor use alleviated fear of hypoglycemia by participants with type 1 diabetes.

CONCLUSIONS

These findings suggest that a 4-week education- and exercise-focused program improves DCPs' self-efficacy in providing exercise advice to patients. People with type 1 diabetes did not experience an improvement in exercise self-efficacy; however, the study supports the use of continuous glucose monitoring and the grouping of DCPs and individuals with type 1 diabetes to facilitate experiential learning.

Diabetes mellitus in a patient with glycogen storage disease type Ia: a case report

BACKGROUND

Glycogen storage disease type Ia is a genetic disorder that is associated with persistent fasting hypoglycemia and the inability to produce endogenous glucose. The development of diabetes with glycogen storage disease is exceedingly rare. The underlying pathogenesis for developing diabetes in these patients is unclear, and there are no guidelines for treatment.

CASE PRESENTATION

We describe a case of a 34-year-old woman of South Asian descent with glycogen storage disease type Ia, who developed uncontrolled diabetes mellitus as a young adult. Hyperglycemia was noted after childbirth, and worsened years later. Treatment for diabetes was difficult due to risks of hypoglycemia from her underlying glycogen storage disease. With minimal hypoglycemic events, the patient's blood glucose improved with exercise in combination with a sodium-glucose co-transporter 2 inhibitor and an alpha glucosidase inhibitor.

CONCLUSION

We report a rare case of diabetes in the setting of glycogen storage disease-Ia. Based on the literature, there appears to be a relationship between glycogen storage disease and metabolic syndrome, which likely plays a role in the pathogenesis. The management of glycemic control remains a clinical challenge, requiring management of both fasting hypoglycemia from glycogen storage disease, as well as post-prandial hyperglycemia from diabetes mellitus.

The Effect of Acute Hyperglycemia on Muscular Strength, Power and Endurance

The purpose of this study was to elucidate the impact of acute hyperglycemia on skeletal muscle strength, power, and endurance. Ten male collegiate athletes (age 21.5 ± 1.5 years, height 186 ± 2.03 cm, body mass 108.8 ± 7.6 kg) participated in 2 testing sessions, separated by 7 days and randomized for either high glucose (HG) or control (C) treatment conditions. HG consumed a high glucose drink (2 g glucose/kg body weight) while controls consumed an isocaloric nutrition bar (40% protein, 30% fat, and 30% carbohydrate). Blood glucose (BC) levels for HG and C were tested at 0 (basal) and 30, 60, 90, and 120 minutes (mins) post consumption. At 30 mins post consumption, HG and C muscular strength was assessed by a 1RM bench press (BP) test followed by lower body power at 60 mins via vertical jump test. Muscular endurance was examined with a 3-set-to-failure BP test at 90 mins. HG exhibited significantly greater BC values (p<0.05) at the 30, 60, 90, and 120 minute time points. HG glucose area under the curve was significantly greater (p<0.05) than C and was positively correlated with %body fat, a finding that trended towards significance, r = 0.587, n= 10, p = 0.074. There were no between group differences in maximal strength, power or muscular endurance. Although performance measures were unaffected by acute hyperglycemia, acute hyperglycemia can be induced and maintained in healthy, active and young subjects. Despite regular physical activity, excess body fat negatively impacts glucose metabolism.

Striving for control: lessons learned from a successful international Type 1 Diabetes Youth Challenge

AIMS

To demonstrate whether young people with T1D using modern insulin treatment and CGM could successfully participate in extreme sport activity while maintaining good glycemic control.

METHODS

The challenge took place in Crete/Greece over 4 days combining a long-distance trek of different levels of severity with final destination the summit of the White Mountains at 2080 m. Eleven participants (5/6 female/male, age 18.2 ± 1.3 years, T1D duration 7.9 ± 3.5 years, HbA1c 7.3 ± .7% (56 ± 16 mmol/mol); mean ± SD) from 11 SWEET centers in Belgium, Brazil, Canada, Germany, Greece, France, India, Italy, Portugal, Slovenia and Sweden participated to the challenge. Five participants were on CSII, six on MDI; all were wearing a continuous glucose monitoring system. The glycemic targets during trekking were defined as 80-180 mg/dl (4.4-10 mmol/l).

RESULTS

All participants completed the challenge. In total, the group walked 54.5 km under varying climate conditions (temperature 14-35 °C). During the challenge, insulin requirements decreased significantly compared to baseline: total daily insulin by 31.1 ± 16.7% (p < .001), basal by 30.8 ± 14.9% (p < .001), and prandial by 32.5 ± 28.0% (p = .023), with no differences between participants with CSII or MDI. No episode of severe hypoglycemia or DKA occurred. Mean glucose levels were 170.7 ± 60.1 mg/dl with 61.5 ± 18.7% of CGM values in the target range, 5.4 ± 5.4% under 80 mg/dl and 32.8 ± 16.6% above 180 mg/dl.

CONCLUSIONS

The results of this SWEET Initiative activity demonstrated that well-educated adolescents and young adults with T1D using modern insulin treatments are able to perform successfully even extraordinary physical challenges while maintaining good glycemic control without diabetes-related acute complications.

Use of Wearable Sensors and Biometric Variables in an Artificial Pancreas System

An artificial pancreas (AP) computes the optimal insulin dose to be infused through an insulin pump in people with Type 1 Diabetes (T1D) based on information received from a continuous glucose monitoring (CGM) sensor. It has been recognized that exercise is a major challenge in the development of an AP system. The use of biometric physiological variables in an AP system may be beneficial for prevention of exercise-induced challenges and better glucose regulation. The goal of the present study is to find a correlation between biometric variables such as heart rate (HR), heat flux (HF), skin temperature (ST), near-body temperature (NBT), galvanic skin response (GSR), and energy expenditure (EE), 2D acceleration-mean of absolute difference (MAD) and changes in glucose concentrations during exercise via partial least squares (PLS) regression and variable importance in projection (VIP) in order to determine which variables would be most useful to include in a future artificial pancreas. PLS and VIP analyses were performed on data sets that included seven different types of exercises. Data were collected from 26 clinical experiments. Clinical results indicate ST to be the most consistently important (important for six out of seven tested exercises) variable over all different exercises tested. EE and HR are also found to be important variables over several types of exercise. We also found that the importance of GSR and NBT observed in our experiments might be related to stress and the effect of changes in environmental temperature on glucose concentrations. The use of the biometric measurements in an AP system may provide better control of glucose concentration.

Update on Management of Type 1 Diabetes and Type 2 Diabetes in Athletes

Optimal blood glucose management still remains the biggest challenge in active individuals with diabetes, particularly in insulin users, but some newer strategies have been introduced to maintain blood glucose control. Recent studies emphasize the importance of exercise intensity on glycemic balance. In individuals with type 1 and type 2 diabetes, both resistance and high-intensity intermittent exercise have been shown to confer beneficial physiological adaptations in training studies, while also showing acute glycemic benefits from single sessions. At the same time, anyone training at higher intensities also should take into consideration potential impairments in thermoregulation in individuals with diabetes, which can increase the risk of heat stress during exercise in hot and/or humid conditions. Recent studies of medication effects on electrolyte balance and hydration give a more complete picture of potential exercise risks for athletes with diabetes. Use of the latest diabetes-related technologies also may benefit the athlete with diabetes.

Multiple Mechanisms Linking Type 2 Diabetes and Alzheimer's Disease: Testosterone as a Modifier

Evidence in support of links between type-2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) has increased considerably in recent years. AD pathological hallmarks include the accumulation of extracellular amyloid-β (Aβ) and intracellular hyperphosphorylated tau in the brain, which are hypothesized to promote inflammation, oxidative stress, and neuronal loss. T2DM exhibits many AD pathological features, including reduced brain insulin uptake, lipid dysregulation, inflammation, oxidative stress, and depression; T2DM has also been shown to increase AD risk, and with increasing age, the prevalence of both conditions increases. In addition, amylin deposition in the pancreas is more common in AD than in normal aging, and although there is no significant increase in cerebral Aβ deposition in T2DM, the extent of Aβ accumulation in AD correlates with T2DM duration. Given these similarities and correlations, there may be common underlying mechanism(s) that predispose to both T2DM and AD. In other studies, an age-related gradual loss of testosterone and an increase in testosterone resistance has been shown in men; low testosterone levels can also occur in women. In this review, we focus on the evidence for low testosterone levels contributing to an increased risk of T2DM and AD, and the potential of testosterone treatment in reducing this risk in both men and women. However, such testosterone treatment may need to be long-term, and would need regular monitoring to maintain testosterone at physiological levels. It is possible that a combination of testosterone therapy together with a healthy lifestyle approach, including improved diet and exercise, may significantly reduce AD risk.

Algorithms for a Single Hormone Closed-Loop Artificial Pancreas: Challenges Pertinent to Chemical Process Operations and Control

The development of a closed-loop artificial pancreas to regulate the blood glucose concentration of individuals with type 1 diabetes has been a focused area of research for over 50 years, with rapid progress during the past decade. The daily control challenges faced by someone with type 1 diabetes include asymmetric objectives and risks, and one-sided manipulated input action with frequent relatively fast disturbances. The major automation steps toward a closed-loop artificial pancreas include (i) monitoring and overnight alarms for hypoglycemia (low blood glucose); (ii) overnight low glucose suspend (LGS) systems to prevent hypoglycemia; and (iii) fully closed-loop systems that adjust insulin (and perhaps glucagon) to maintain desired blood glucose levels day and night. We focus on the steps that we used to develop and test a probabilistic, risk-based, model predictive control strategy for a fully closed-loop artificial pancreas. We complete the paper by discussing ramifications of lessons learned for chemical process systems applications.

Characteristics of somatic build and physical activity and evaluation of hand grip strength in patients with type 1 diabetes

Introduction: In order to avoid hypoglycaemia, individuals diagnosed with type 1 diabetes usually limit their physical activity, which might lead to changes in somatic build and in the level of muscle strength. The aim of the study was to define somatic build, hand grip strength and physical activity in patients diagnosed with type 1 diabetes.

Materials and methods: The study included 24 patients with type 1 diabetes and 24 healthy individuals. Body build was assessed on the basis of 20 somatic features and indices. Somatic types were assessed using the Sheldon’s method modified by Heath-Carter. Hand grip strength was measured with hand grip dynamometer, while physical activity was evaluated by means of a questionnaire survey.

Results: The results obtained from female subjects showed insignificant intergroup differences concerning the measured features. Endomorphy was a predominant component among female somatotypes. Compared to the healthy controls, males with type 1 diabetes exhibited lower values of arm circumference (tensed), thigh circumference, ankle width and mesomorphy as well as hand grip strength (p<0.05). The diabetic patients preferred cycling while healthy people opted for combat sports.

Conclusions: Differences in somatic build, hand grip strength and physical activity between healthy individuals and patients diagnosed with type 1 diabetes were greater in the case of men than women. Compared to healthy individuals, diabetic men exhibited lower values of somatic features that are typical of mesomorphy and muscle strength. Both women and men diagnosed with type 1 diabetes preferred low-intensity and aerobic physical activity.

Accuracy of Continuous Glucose Monitoring (CGM) during Continuous and High-Intensity Interval Exercise in Patients with Type 1 Diabetes Mellitus

Continuous exercise (CON) and high-intensity interval exercise (HIIE) can be safely performed with type 1 diabetes mellitus (T1DM). Additionally, continuous glucose monitoring (CGM) systems may serve as a tool to reduce the risk of exercise-induced hypoglycemia. It is unclear if CGM is accurate during CON and HIIE at different mean workloads. Seven T1DM patients performed CON and HIIE at 5% below (L) and above (M) the first lactate turn point (LTP₁), and 5% below the second lactate turn point (LTP₂) (H) on a cycle ergometer. Glucose was measured via CGM and in capillary blood (BG). Differences were found in comparison of CGM vs. BG in three out of the six tests (p < 0.05). In CON, bias and levels of agreement for L, M, and H were found at: 0.85 (−3.44, 5.15) mmol·L⁻¹, −0.45 (−3.95, 3.05) mmol·L⁻¹, −0.31 (−8.83, 8.20) mmol·L⁻¹ and at 1.17 (−2.06, 4.40) mmol·L⁻¹, 0.11 (−5.79, 6.01) mmol·L⁻¹, 1.48 (−2.60, 5.57) mmol·L⁻¹ in HIIE for the same intensities. Clinically-acceptable results (except for CON H) were found. CGM estimated BG to be clinically acceptable, except for CON H. Additionally, using CGM may increase avoidance of exercise-induced hypoglycemia, but usual BG control should be performed during intense exercise.

Glycemic control during consecutive days with prolonged walking exercise in individuals with type 1 diabetes mellitus

AIMS

Despite its general benefits for health, exercise complicates the maintenance of stable blood glucose concentrations in individuals with type 1 diabetes. The aim of the current study was to examine changes in food intake, insulin administration, and 24-h glycemic control in response to consecutive days with prolonged walking exercise (∼8h daily) in individuals with type 1 diabetes.

METHODS

Ten individuals with type 1 diabetes participating in the worlds' largest walking event were recruited for this observational study. Simultaneous measurements of 24-h glycemic control (continuous glucose monitoring), insulin administration and food intake were performed during a non-walking day (control) and during three subsequent days with prolonged walking exercise (daily distance 40 or 50km).

RESULTS

Despite an increase in daily energy (31±18%; p<0.01) and carbohydrate (82±71g; p<0.01) intake during walking days, subjects lowered their insulin administration by 26±16% relative to the control day (p<0.01). Average 24-h blood glucose concentrations, the prevalence of hyperglycemia (blood glucose >10 mmol/L) and hypoglycemia (blood glucose <3.9mmol/L) did not differ between the control day and walking days (p>0.05 for all variables). The prolonged walking exercise was associated with a modest increase in glycemic variability compared with the control day (p<0.05).

CONCLUSION

Prolonged walking exercise allows for profound reductions in daily insulin administration in persons with type 1 diabetes, despite large increments in energy and carbohydrate intake. When taking such adjustments into account, prolonged moderate-intensity exercise does not necessarily impair 24-h glycemic control.

Influence of ankle fracture surgery on glycemic control in patients with diabetes

Background

Although ankle fracture surgery can affect glycemic control by either trauma-induced stress or a postoperative decrease in physical activity, there is little evidence on this issue. This study aimed to evaluate the influence of ankle fracture surgery on glycemic control and to assess the risk factors for poor glycemic control after surgery in patients with diabetes.

Methods

We reviewed the medical records of consecutive patients with diabetes who underwent open reduction and internal fixation for the treatment of ankle fracture at our hospital. Patients who underwent blood testing, including fasting blood glucose (FBG), glycated hemoglobin (HbA1c), and cholesterol levels, as part of a routine check-up before surgery and again more than 2 times after surgery were included. Changes in blood test results were adjusted by multiple factors using a linear mixed model with sex, age at time of surgery, body mass index (BMI), and type of ankle fracture as the fixed effects and each subject and timing of blood test as the random effects.

Results

Sixty patients were ultimately included in this study. At 1 month postoperatively, mean FBG and cholesterol levels had increased significantly compared with preoperative levels (p = 0.011 and 0.024, respectively). After surgery, FBG levels showed an estimated monthly decrease of 2.2 mg/dL (p = 0.017). Sex, age at time of surgery, and type of ankle fracture did not significantly affect the monthly change in FBG level. FBG returned to the preoperative level at an estimated period of 8.1 months. BMI significantly affected preoperative FBG level (p = 0.015) but not the postoperative change in FBG level (p = 0.500).

Conclusion

Ankle fracture surgery increased the FBG level at 1 month postoperatively. FBG levels decreased gradually after surgery at an estimated monthly rate of 2.2 mg/dL. Physicians should be aware of the difficulty in postoperative blood glucose control in patients with diabetes, even several months after surgery.