Physical exercise in type 1 diabetes: recommendations and care

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

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.

Accumulating Physical Activity in Short or Brief Bouts for Glycemic Control in Adults With Prediabetes and Diabetes

Clinical practice guidelines on physical activity and diabetes currently stipulate physical activity can be accumulated in bouts of ≥10 minutes to meet recommendations for health benefits. Individuals are also encouraged to interrupt prolonged sitting with brief activity breaks of ∼1 to 5 minutes in duration. Growing research highlights accumulating activity in shorter bouts across the day as a potential strategy to improve glycemic control and to help those who are largely sedentary meet physical activity guidelines. Research has shown favourable glycemic benefits for postprandial glucose and glycated hemoglobin with either 3 short (10 to 15 minutes) or frequent brief (1 to 5 minutes) bouts of activity spread around meals or throughout the day. To date, most studies examining accumulated activity were done with people with type 2 diabetes compared with sedentary conditions, were short term and measured various indices of glycemic control using continuous glucose monitoring. The 7 trials comparing accumulating 3 short bouts to a single bout showed comparable benefits for glycemic control (i.e. fasting glucose, 24 h mean glucose and postprandial hyperglycemia). Furthermore, timing short bouts around meals may improve postprandial glucose and hyperglycemia more than a single bout. It is unknown whether a threshold for the duration of accumulated bouts exists---that is, "how much is enough?" In this narrative review, we focus on the glycemic effects of physical activity accumulated in short or brief bouts for people with prediabetes and diabetes as compared with a single continuous bout. Given that poor adherence to physical activity recommendations and that fewer opportunities exist in modern societies for incidental (nonexercise) physical activity, accumulating activity may be a choice strategy for improving glycemic control in those with and at risk of diabetes.

Effect of swimming program on glycemic control in male adolescents with type 1 diabetes mellitus

BACKGROUND

Regular physical activity and exercise is the third management for the child with diabetes mellitus after diet regime and insulin therapy. The aim of the study is to evaluate the effect of swimming on glycemic control for a male adolescent with type 1 diabetes mellitus. The study evaluates the effect of swimming on glycemic control for a male adolescent with type 1 diabetes mellitus.

METHODS

The quasi-experimental design was conducted on 40 male adolescents with typ1 diabetes, then divided into two groups; study and control groups. 20 adolescents participated in the swimming program (study group) and other 20 did not expose to exercise program (control group) for 10 weeks. a venous blood sample was received to evaluate glycemic control (HbA1c %), in pre and post 10 weeks to compare HbA1c % for both groups.

RESULTS

Mean age 13.45±1.46 years (study group), while for control group age 13.55±1.5 years, and mean and standard deviation for Hba1c % was 9.61±1.15%, 9.65±2.23% in the study and control group respectively. The study showed that there was a high significant difference between pre and post-test HbA1c in the study group (P value<0.00) also the same result was observed in the control group but negatively (P value<0.00) it means the Hb1c % was raised.

CONCLUSIONS

The study concluded that regular physical activity (swimming) had a positive effect on lowering Glycosylated hemoglobin (HbA1c).

MAXIMAL FAT OXIDATION DURING AEROBIC EXERCISE IN ADOLESCENTS WITH TYPE 1 DIABETES

ABSTRACT Objective: To compare maximal fat oxidation rates (FATMAX) and analyze their association with cardiorespiratory fitness in adolescents with type 1 diabetes mellitus (T1DM). Methods: Twenty-two male and female adolescents aged between 11 to 17 years, following clinical and anthropometric evaluations, were assigned to the diabetic group (DG; n = 10) or control group (CG; n = 12). Cardiorespiratory fitness was determined by maximal oxygen uptake (VO2max) during a maximal aerobic test on a cycle ergometer using the Balke protocol. Maximal fat oxidation (FATMAX) was determined by the respiratory exchange ratio proposed in the Lusk table. Results: Adolescents in the DG had lower mean FATMAX (p<0.01) and %VO2FATMAX (p=0.001) values when compared with those in the CG. FATMAX values were inversely correlated with serum glycosylated hemoglobin (HbA1c) levels (r= −0.77) and directly correlated with BMI z-scores (r=0.76), while %VO2FATMAX results were correlated with age (r=0.81), BMI z-scores (r=0.65), and VO2max values (r=0.81). On multiple linear regression, HbA1c values explained 54% (adjusted r²=0.54, p=0.009) and BMI z-scores explained 3.1% (adjusted r²=-0.031, p=0.009) of the variation in FATMAX in the DG. Adolescents with T1DM had similar cardiorespiratory fitness and lower FATMAX rates (35±11 VO2max) when compared with controls (60±12 VO2max). Conclusion: These results suggest lower fat oxidation rates and greater use of glucose as an energy substrate during exercise and worse control in T1DM. Therefore, results may contribute to appropriate exercise prescription in T1DM, after verifying exercise intensity to reduce hypoglycemia risk. Level of evidence III; Case-control study.