scholarly journals Reproducibility of Glucose Fluctuations Induced by Moderate Intensity Cycling Exercise in Persons with Type 1 Diabetes

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Gabriel Tafdrup Notkin ◽  
Peter Lommer Kristensen ◽  
Ulrik Pedersen-Bjergaard ◽  
Andreas Kryger Jensen ◽  
Stig Molsted

Aims. The purpose was to assess the reproducibility of glucose changes during three sessions of standardized moderate intensity continuous training of cycling on an individual level in people with type 1 diabetes. Methods. Twelve adults (six females) with type 1 diabetes performed three test sessions on an ergometer bicycle (30 min, 67% of predicted heart rate) on three different days. The participants were 36.5 (26.6-45.5) (median, IQR) years old, and their HbA1c was 65 ± 15   mmol/mol ( mean ± SD ). Two hours before the tests, the participants had a standard meal. Interstitial glucose (IG) and capillary glucose (CG) were measured using an iPro2 Medtronic continuous glucose monitor and the Bayer Contour XT-device, respectively. Prior to the test sessions, resting heart rate was measured using a digital blood pressure monitor to estimate the desired intensity of the exercise. Results. The average within-participant relationship between the average slope in glucose during sessions 2 and 1 was in IG -0.29 (95% CI -1.11; 0.58) and in CG -0.04 (-0.68; 0.77). Between sessions 3 and 2, IG is 0.18 (-0.27; 0.64) and in CG 0.13 (-0.25; 0.55). Between sessions 3 and 1, IG was 0.06 (-0.57; 0.71) and in CG 0.06 (-0.39; 0.52). The results indicate low reproducibility at participant levels and remained unchanged after adjustment for baseline glucose values. Conclusion. On an individual level, the glucose declines during three standardized sessions of PA were not associated with identical responses of the measured IG and CG levels. An overall anticipated decline of glucose concentrations was found in the moderate intensity cycling sessions. This highlights the importance of regular CG measurements during and after physical activity and awareness towards potential exercise-induced hypoglycemia in persons with type 1 diabetes.

2020 ◽  
Author(s):  
Elodie Lespagnol ◽  
Olivia Bocock ◽  
Joris Heyman ◽  
François-Xavier Gamelin ◽  
Serge Berthoin ◽  
...  

<b>Objective</b> <p>In type 1 diabetes, autonomic dysfunction may occur early as a decrease in heart rate variability (HRV). In nondiabetic populations, the positive effects of exercise training on HRV are well documented. However, exercise in individuals with type 1 diabetes, particularly if strenuous and prolonged, can lead to sharp glycemic variations, which can negatively impact HRV. This study explores the impact of a 9-day cycling tour on HRV in this population, with a focus on exercise-induced glycemic excursions<i>.</i></p> <p><b>Research Design and Methods</b></p> <p>Twenty amateur athletes with uncomplicated type 1 diabetes cycled 1500km. HRV and glycemic variability were measured by heart rate and continuous glucose monitoring. Linear mixed models were used to test the effects of exercise on HRV, considering concomitant glycemic excursions and subject characteristics as covariates.</p> <p><b>Results</b></p> <p>Nighttime HRV tended to decrease with the daily distance traveled. The more time the subjects spent in hyperglycemia, the lower the parasympathetic tone was. This result is striking given that hyperglycemic excursions progressively increased throughout the 9 days of the tour, and to a greater degree on the days a longer distance was traveled, while time spent in hypoglycemia surprisingly decreased. This phenomenon occurred despite no changes in insulin administration and a decrease in carbohydrate intake from snacks. </p> <p><b>Conclusions</b></p> <p><a>In sports enthusiasts with type 1 diabetes</a>, multiday prolonged exercise at moderate-to-vigorous intensity worsened hyperglycemia with the latter being negatively associated with parasympathetic cardiac tone. Considering the putative deleterious consequences on cardiac risks, future work should focus on understanding and managing exercise-induced hyperglycemia.</p>


2020 ◽  
Author(s):  
Elodie Lespagnol ◽  
Olivia Bocock ◽  
Joris Heyman ◽  
François-Xavier Gamelin ◽  
Serge Berthoin ◽  
...  

<b>Objective</b> <p>In type 1 diabetes, autonomic dysfunction may occur early as a decrease in heart rate variability (HRV). In nondiabetic populations, the positive effects of exercise training on HRV are well documented. However, exercise in individuals with type 1 diabetes, particularly if strenuous and prolonged, can lead to sharp glycemic variations, which can negatively impact HRV. This study explores the impact of a 9-day cycling tour on HRV in this population, with a focus on exercise-induced glycemic excursions<i>.</i></p> <p><b>Research Design and Methods</b></p> <p>Twenty amateur athletes with uncomplicated type 1 diabetes cycled 1500km. HRV and glycemic variability were measured by heart rate and continuous glucose monitoring. Linear mixed models were used to test the effects of exercise on HRV, considering concomitant glycemic excursions and subject characteristics as covariates.</p> <p><b>Results</b></p> <p>Nighttime HRV tended to decrease with the daily distance traveled. The more time the subjects spent in hyperglycemia, the lower the parasympathetic tone was. This result is striking given that hyperglycemic excursions progressively increased throughout the 9 days of the tour, and to a greater degree on the days a longer distance was traveled, while time spent in hypoglycemia surprisingly decreased. This phenomenon occurred despite no changes in insulin administration and a decrease in carbohydrate intake from snacks. </p> <p><b>Conclusions</b></p> <p><a>In sports enthusiasts with type 1 diabetes</a>, multiday prolonged exercise at moderate-to-vigorous intensity worsened hyperglycemia with the latter being negatively associated with parasympathetic cardiac tone. Considering the putative deleterious consequences on cardiac risks, future work should focus on understanding and managing exercise-induced hyperglycemia.</p>


2006 ◽  
Vol 290 (6) ◽  
pp. E1331-E1338 ◽  
Author(s):  
Darleen A. Sandoval ◽  
Deanna L. Aftab Guy ◽  
M. Antoinette Richardson ◽  
Andrew C. Ertl ◽  
Stephen N. Davis

Exercise-induced hypoglycemia can occur within hours after exercise in type 1 diabetes mellitus (T1DM) patients. This study tested the hypothesis that an acute exercise bout causes (within hours) blunted autonomic and metabolic responses to subsequent hypoglycemia in patients with T1DM. Twelve T1DM patients (3 W/9 M) were studied during a single-step, 2-h hyperinsulinemic (572 ± 4 pmol/l) hypoglycemic (2.8 ± 0.1 mmol/l) clamp 2 h after either a hyperinsulinemic euglycemic (AM EUG) or hypoglycemic clamp (AM HYPO) or after sitting in a chair with basal insulin infusion (AM CON) or 90 min of moderate-intensity exercise (50% V̇o2 max, AM EX). Both AM HYPO and AM EX significantly blunted epinephrine responses and muscle sympathetic nerve activity responses to subsequent hypoglycemia compared with both control groups. Endogenous glucose production was significantly lower and the exogenous glucose infusion rate needed to maintain the hypoglycemic level was significantly greater during subsequent hypoglycemia in AM EX vs. CON. Rate of glucose disposal (Rd) was significantly reduced following AM HYPO. In summary, within 2.5 h, both moderate-intensity AM EX and AM HYPO blunted key autonomic counterregulatory responses. Despite this, glucose Rdwas reduced during afternoon hypoglycemia following morning hypoglycemia, indicating posthypoglycemic insulin resistance. After morning exercise, endogenous glucose production was blunted, but glucose Rdwas maintained during afternoon hypoglycemia, thereby indicating reduced metabolic defenses against hypoglycemia. These data suggest that exercise-induced counterregulatory failure can occur very rapidly, increasing the risk for hypoglycemia in T1DM within hours.


2018 ◽  
Vol 4 (1) ◽  
pp. e000432 ◽  
Author(s):  
Alif Abdulrahman ◽  
Janisha Manhas ◽  
Hannah Linane ◽  
Mark Gurney ◽  
Catriona Fitzgerald ◽  
...  

BackgroundThe benefits of exercise for patients with type 1 diabetes (T1D) are difficult to balance with associated glycaemic excursions. The aim of this cohort study was to show that continuous glucose monitoring (CGM) could reduce glycaemic excursions in patients with T1D already using insulin pumps, exercising at moderate to high intensity.MethodsQuestionnaires were used to identify patients with T1D using insulin pumps and naive to CGM use, who reported regular exercise. Six were enrolled and trained on Enlite sensor use with Medtronic Minimed Paradigm Veo system and given activity trackers and written advice on adjustment of insulin or carbohydrate intake for exercise. Resting heart rate (HR) and age were used to determine HR surrogates of moderate and high-intensity exercise. They were to exercise as usual for 3 weeks (run-in week, week 1 and week 2) using the activity trackers and heart rate monitors. Problem areas in Diabetes, Hypoglycaemia fear survey II, Diabetes Technology Questionnaire and Gold scores were completed prior to run-in and at the end. The downloaded sensor glucose data were used to compare the change in time in range (glucose 3.9–10.0 mmol/L) from week 1 to week 2.ResultsFor the duration of exercise, this time in glucose range increased from 72±20 to 88%±16 %, p=0.05. The time in hypoglycaemia range (glucose < 3.9 mmol/L) went from 3.9±7.9 to 2.4%±4.8 %, p=0.39. The time in hyperglycaemia range (> 10 mmol/L) reduced from 24±19 to 10%±17%, p=0.04.ConclusionThese results demonstrate the benefit of CGM use for patients with T1DM doing moderate-intensity to high-intensity exercise.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
O.L.G.A Gumeniuk ◽  
N Bolotova ◽  
A Averianov ◽  
I.U Chernenkov

Abstract   Diabetic cardiovascular autonomic neuropathy (CAN) encompasses damage to the autonomic nerve fibers innervating the heart and blood vessels, resulting in abnormalities in heart rate control and vascular dynamics. Clinical symptoms associated with CAN include resting tachycardia, postural hypotension, dizziness, syncope, exercise intolerance, silent myocardial infarction. The earliest finding of CAN, even at the subclinical stage, is a decrease in heart rate variability (HRV) Purpose To study CAN prevalence and understand the diagnostic capabilities of HRV - tests of diabetic cardiovascular autonomic neuropathy in children with type 1 diabetes. Methods 100 children with type 1 diabetes were assessed for CAN (age 15.2 yrs [9.0–17.8], duration 6.5 yrs [4.0–10.6], HbA1c 8.1% 6.3–9.7]). The degree of compensation of diabetes was estimated according to criteria ISPAD Consensus Guidelines, 2018. Optimal level (HbA1c &lt;7.0%) of compensation was revealed in 62% of children (group I) and nonoptimal in 38% of children (group II). For evaluation of the CAN we used HRV - tests: RR 30:15 ratio, ΔRR quiet breath, ΔRR deep breath, BP response to standing. Results Diabetic cardiovascular autonomic neuropathy was diagnosed in 41 children: in group I – in 6 (29%) and in group II – 35 (71%) children (p=0.00001). The prevalence of DCN correlated with HbA1c level in children and adolescents (groups I and II): ΔRR quiet breath r=−0.47 & r=−0.9; ΔRR deep breath r=−0.65 & r=−0.85; RR30:15 r=−0.77 & r=−0.88 respectively. Prevalence of CAN increased parallel to type 1 diabetes duration (p&lt;0.01). Conclusions Diabetic cardiovascular autonomic neuropathy in children with type 1 diabetes was diagnosed in 41%. Prevalence of diabetic cardiovascular autonomic neuropathy increases parallel to type 1 diabetes duration (p&lt;0.01). In this study we found an association between HRV indexes and HbA1c level. This provides support for HRV - testing to assess diabetic cardiovascular autonomic neuropathy in children. Funding Acknowledgement Type of funding source: None


2006 ◽  
Vol 7 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Firat Kardelen ◽  
Gayaz Akcurin ◽  
Halil Ertug ◽  
Sema Akcurin ◽  
Iffet Bircan

Author(s):  
Abdullah Alansare ◽  
Ken Alford ◽  
Sukho Lee ◽  
Tommie Church ◽  
Hyun Jung

Physically inactive adults are prevalent worldwide. This study compared the effects of short-term high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) on heart rate variability (HRV) in physically inactive adults as a preliminary study. Thirteen physically inactive male adults (27.5 ± 3.80 years) were randomly assigned to HIIT (N = 7) or MICT (N = 6). The HIIT program consisted of 20 min of interval training with cycling to rest ratio of 10/50 s at ≥90% HRpeak, while the MICT program consisted of 40 min of continuous cycling at 60–75% HRpeak. Both groups completed eight sessions of training within two weeks. Time and frequency domains of HRV were measured for 20 min with Actiwave-Cardio monitor (CamNtech, UK). The number of R-R interval and inter-beat interval (IBI) were significantly improved (p < 0.05) in both HIIT and MICT programs following eight sessions of training. A significant interaction effect for group by time was found in the lnLF/HF ratio (p < 0.05) where it was only improved in the HIIT group from pre- to post-test. The HIIT program is superior to MICT in improving HRV in physically inactive adults. The HIIT program can be applied as a time-efficient program for improving cardiac-autoregulation.


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