Rev Bras Fisiol Exerc 2021;19(1):16-23

doi: 10.33233/rbfe.v19i1.3905

ORIGINAL ARTICLE

Analysis of glycemic safety of a moderate-intensity resistance exercise session in patients with diabetes type 1

 

Leandro Paim da Cruz Carvalho¹, Samira Socorro Nunes de Souza², Djenane Cristovam Souza², Flávio de Souza Araujo3, Ferdinando Oliveira Carvalho4, José Fernando Vila Nova de Moraes4, Jorge Luiz de Brito Gomes4

 

1Especialista, Universidade Federal do Vale do São Francisco, 2Discente, Universidade Federal do Vale do São Francisco, 3Mestre, Universidade Federal do Vale do São Francisco, 4D.Sc, Universidade Federal Do Vale do São Francisco

 

Received 2020 Jan 10; accepted 2020 Feb 10

Corresponding author: Leandro Paim da Cruz Carvalho

 

Leandro Paim da Cruz Carvalho: leandroopaim@hotmail.com

Samira Socorro Nunes de Souza: samira.nunes@hotmail.com

Djenane Cristovam Souza: janacristovam@yahoo.com.br

Flávio de Souza Araujo: araujo.Fsouza@gmail.com

Ferdinando Oliveira Carvalho: ferdinando.carvalho@univasf.edu.br

José Fernando Vila Nova de Moraes: josefernando.moraes@univasf.edu.br

Jorge Luiz de Brito Gomes: jorge.brito@univasf.edu.br

 

Abstract

Introduction: Type 1 diabetes is an autoimmune disease that results in the destruction of pancreatic beta cells, implying the use of insulin therapy to maintain adequate blood glucose levels. When stimulated by physical exercise, glycemic homeostasis becomes impaired, providing complications in the daily lives of this population, constituting a barrier to physical exercise practice. Objective: To evaluate the glycemic safety of a Resistance exercise session of moderate intensity in people with type 1 diabetes. Methods: 12 people with type 1 diabetes (7 male), performed a resistance exercise session of moderate intensity at 60% of 1 RM consisting of 7 exercises. Capillary blood glucose was assessed at the pre-session (GP), immediately after (G IA) and 20 minutes after (G 20). ANOVA for repeated measures was performed (p < 0.05). Results: In the absolute values of glycemia, no significant differences were found (P = 0.061). However, when checking the delta blood glucose variation, a difference was found between G IA and G20 vs GP (P < 0.05). Clinically important reductions above 20 mg/dl (PI: ~ 37 mg/dl; 20P: ~ 45 mg/dl) without providing hypoglycemia. Conclusion: A moderate-intensity resistance exercise session proved to be safe from a glycemic point of view in people with type 1 diabetes.

Keywords: diabetes mellitus type 1; resistance training; exercise.

 

Resumo

Análise da segurança glicêmica de uma sessão de exercício resistido de intensidade moderada em pessoas com diabetes tipo 1

Introdução: A diabetes tipo 1 é uma doença autoimune que resulta na destruição das células beta pancreáticas, implicando no uso de insulinoterapia para manter níveis adequados de glicemia. Diante do estímulo do exercício físico, a homeostase glicêmica torna-se prejudicada, podendo incidir em complicações como hipoglicemia. Tais repercussões proporcionam empecilhos no dia a dia dessa população, constituindo uma barreira para prática de exercícios físicos. Objetivo: Avaliar a segurança glicêmica de uma sessão de exercício resistido de intensidade moderada em pessoas com diabetes tipo 1. Métodos: 12 pessoas com diabetes tipo 1 (7 homens) realizaram uma sessão de exercício resistido de intensidade moderada a 60% de 1 RM composta por 7 exercícios. A glicemia capilar foi avaliada no momento pré-sessão (GP), imediatamente após (G IP) e 20 minutos após (G 20). ANOVA para medidas repetidas foi realizada (p < 0.05). Resultados: Nos valores absolutos de glicemia não foram encontradas diferenças significativas (P = 0,061). Contudo, ao verificar o delta variação da glicemia foi encontrada diferença entre G IP e G20 vs. GP (P < 0,05). Reduções clinicamente importantes acima de 20 mg/dl (IP: ~37 mg/dl; 20P: ~45 mg/dl) sem proporcionar hipoglicemias. Conclusão: Uma sessão de exercício resistido de intensidade moderada se mostrou segura do ponto de vista glicêmico em pessoas com diabetes tipo 1.

Palavras-chave: diabetes mellitus tipo 1; treinamento de resistência; exercício.

 

Introduction

 

Type 1 diabetes is a pathology caused by the progressive destruction of pancreatic beta cells. As consequence, the person with diabetes starts to depend on insulin therapy to control hyperglycemia [1]. Complications of the disease can present in acute form, such as hypoglycemia and diabetic ketoacidosis [2,3] or in a chronic form, such as cardiomyopathy associated with diabetes, nephropathy, retinopathy and peripheral neuropathy [4,5].

In healthy individuals, glycemic homeostasis in maintained by fast-acting hormones (Insulin, glucagon, adrenaline and noradrenaline) and slow and/or permissive hormones (Cortisol, GH and thyroid hormones T3 and T4) [6]. By stimulating physical exercise, there is a reduction in insulin action and a concomitant increase in the action of glucagon, promoting degradation of hepatic glycogen and release of glucose into the bloodstream for later uptake by active muscles [7]. Due to the type 1 diabetic person’s dependence on the application of exogenous insulin, this control becomes impaired, increasing the risk of hypoglycemia (blood glucose < 70 mg/dl) during or after physical exercise [8,9].

The literature has pointed out the beneficial effects of physical training in people with type 1 diabetes. In addition to the physiological benefits, such as increased sensitivity to insulin action and glucose uptake through signaling induced by muscle contraction [10-12], psychological and social benefits also stand out, providing a lifestyle favorable to healthy habits [13]. However, despite the benefits promoted by regular physical exercise, many of these people avoid getting involved in the practice of physical training fearing possible episodes of hypoglycemia induced by exercise; this fear is one of the biggest barriers to the practice of physical activity in this population [14]. That occurs because during a hypoglycemic crisis, the individual is affected by symptoms of malaise, such as sweating, mental confusion, lethargy, and if left untreated, the condition can progress to coma and even death [15].

Due to the benefits of physical exercise, its prescription becomes a potent aid for glycemic control in type 1 diabetic people, and resistance exercise, as it is a widespread and easily accessible training modality, presents itself as an interesting alternative complementary therapy [16]. Thus, the present study aimed to verify the glycemic safety of a moderate intensity resistance exercise session in type 1 diabetic people.

 

Methods

 

An experimental study with 12 type 1 diabetic people (7 male), age 29,8 ± 7,4 years, height 1,69 ± 0,09 m, body mass 70,9 ± 16,8 kg, body mass index 25,2 ± 4,4 kg/m² was performed. All participants were regular in the extension project “Physical exercise as sugar diary” offered by the collegiate of physical education of the Federal University of San Francisco Valley (CEFIS-UNIVASF) – Petrolina/PE. The free and informed consent form was registered at The Research Ethics Committee of UNIVASF under the protocol number: 3.349.261 and this study approved.

The following inclusion criteria were adopted: Female and male type 1 people over 18 years and who do not have medical restrictions for physical exercise or any type of secondary diseases that may be aggravated due to research participation (secondary diseases that have been already diagnosed by the physician responsible for each diabetic; eg, peripheral and/or central vasculopathies, retinopathy and amputations). Participants were excluded from the study if they did not finish the session and or suffered any type of osteomyoarticular injury that prevented the practice of physical exercises or at the request of the physician responsible for everyone outside the scope of the research.

 

Study design

 

Two days before the resistance exercise session, the individuals underwent an assessment of anthropometric measurements (body mass, height and perimeters), body composition (skinfolds) and abdominal resistance test. Then, a 1RM estimation test was performed to measure the training load in each of the six exercises that would later be performed in the session (bench press, horizontal leg press, biceps curl on the low pulley, extension chair, machine development, adductor chair and the abdominal rectus solo - performed from the abdominal resistance test). Based on Brzycki's formula [17], 60% of 1RM of each exercise was determined for the training session.

Subsequently, on the day of the training session, when participants arrived at the weight training laboratory at the Federal University of San Francisco Valley – Petrolina/PE, the individuals were taken to a comfortable chair where they sat at rest for 10 minutes before the measurement of capillary blood glucose and blood pressure and, subsequently, they were released for the weight training session. The individuals underwent the training session with an approximate duration of 30 minutes, and, at the end, immediately seated in the chair and a new measurement of blood glucose and blood pressure was performed. After another 20 minutes of sitting at rest, a last measurement of blood glucose and blood pressure was performed, and the individuals were released.

 

Body composition and anthropometrics variables

 

To verify the individuals' body mass and height, a digital weight balance with stadiometer, Lider brand, model LD-1050, was used. The individuals were positioned on the weight balance, with their backs to the wall, feet together and bare. The anthropometric tape of the Sanny brand, model TR-4010 was used to evaluate body perimeters and the clinical adipometer of the Sanny brand was used for skinfold measurements.

 

Blood glucose, arterial blood pressure and heart rate

 

The heart rate was monitored during the session using a Polar cardiac monitor, model FT1. Subsequently, blood pressure was measured using a digital arm blood pressure meter of the OMRON brand, model HEM-7113 following the recommendations of the 7th guideline for arterial hypertension of the Brazilian Society of Cardiology [18]. Capillary blood glucose was measured by a qualified nurse at the pre-session moment (after 10 minutes of rest), immediately after and 20 minutes after the session using a Glucometer and lancets (Active Accu Check Roche), following the recommendations of the Society Brazilian Diabetes [8].

 

Training session

 

The weight training session was conducted and supervised by a qualified Physical Education professional. Composed of 3 sets of 10-12 repetitions at 60% of 1RM of the seven exercises previously described, with an interval of 50-60 seconds between each set, and a cadence of 3s (1.5 for eccentric contraction and 1.5 for concentric contraction). Ultra-fast insulin before the last pre-session meal was reduced according to guidelines [8].

 

Statistical analysis

 

The data were analyzed using the Graph Pad (3.0) software. The Shapiro-Wilk normality test and the ANOVA test for repeated measures were performed (p < 0.05). The minimum detectable difference was performed to identify important changes in blood glucose, according to a previous study [19].

 

Results

 

Analyzing the absolute blood glucose values, no statistically significant differences were found between the pre-session moments, immediately after and 20 minutes after the session (P = 0.061). However, when checking the delta glycemia variation between the three moments, a statistically significant difference was found between the moment immediately after and the moment 20 minutes post-session, in relation to rest (P < 0.05). The description of the study participants is shown in table I.

 

Table I - Sample data description

 

BMI = Body mass index; HR = Heart rate; BPM = Beats per minute; 

SBP = Systolic blood pressure; DBP = Diastolic blood pressure; 

SSF = Somatory of skin folds; DT = Diagnosis time

The following are the glycemic changes in the moments pre, immediately after and 20 min after a resistance exercise session of moderate intensity (Figure 1). Frame A shows glycemic safety without providing hypoglycemia. Frame B, in turn, reveals the significant differences in the variation delta in relation to rest (p < 0.05). In addition, the minimum detectable difference was verified after the session and after 20 minutes of the session, presenting clinical importance at these moments.

 

 

*Significant difference in relation to rest and MDD > 19.2 mg/dl with a clinically important reduction in relation to rest

Figure 1 - Absolute and relative variation (Δ) of capillary glycemia at rest (pre), immediately after (G IA) and 20 minutes after (G 20) a weight training session of moderate intensity in type 1 diabetic individuals

 

Discussion

 

The aim of the present study was to assess the glycemic safety of a moderate-intensity resistance exercise session in people with type 1 diabetes. The main findings show that the variation in glycemic reduction (Δ) between the moments of the session was significant for the moment immediately after (G IP) and 20 minutes after the session (G 20), which correspond to a decrease of 17.8% and 21.7% respectively. Still, a clinically important reduction was found for the participants after a resistance exercise session with moderate intensity, without providing hypoglycemia

It is known that physical exercise improves insulin signaling and increases the uptake of glucose by the muscle in ways independent of insulin action. The muscular contraction itself, from the imbalance in the AMP/ATP balance and calcium signaling, promotes the stimulus for the activation and translocation of the GLUT-4 vesicles to the plasma membrane, allowing glucose to enter the intracellular medium [20]. The consumption of glucose, free fatty acids and other substrates increases during physical exercise, which may enhance the action of insulin, and the proportion of use of these substrates will depend on the intensity and duration of physical exercise. Thus, it is necessary that the dose of fast-acting insulin be adjusted before exercise, considering the characteristic and duration of the training session [21].

Intensity is an important factor and can modulate the glycemic response of individuals with diabetes differently. In the study by Cruz et al. [22], the authors demonstrated that light intensity in resistance exercise (40% of 1 RM) decreased glycemic levels in type 2 diabetic women for a period of 24 hours when compared to a high intensity session (80% of 1RM) and a control session. In the study by Yardley et al. [23] with type 1 diabetic people, which evaluated the glycemic response for 24 hours between aerobic exercise (60% VO2max) and resistance exercise (seven exercises with three sets of eight maximum repetitions), it was shown that resistance exercise caused a lower glycemic reduction during the session, however, over the 24 hours, it was associated with more prolonged reductions. Such behavior is like that found by Shetty et al. [7] who, when comparing different intensities of aerobic exercise (35, 50, 65 and 80% VO2 peak), demonstrated that the increase in intensity above 50% of VO2 peak leads to higher glycemic levels.

The results of the present study demonstrated a drop in blood glucose throughout the session of moderate resistance exercise. However, in absolute values, there was a large intra-subject variation in glycemic behavior. This was already expected, since factors such as time of diagnosis, food and water intake influence glycemic control [21,24]. In addition, in this population, the genetic factor involved in the pathogenesis of the disease is very heterogeneous, with more than 60 gene polymorphisms providing an increased risk for the onset of the disease. Some authors even claim that each type 1 diabetic patient has their own type of diabetes [25]. Even despite such factors, there were no hypoglycemia.

In addition to the aforementioned factors, physically active type 1 diabetic people have a better metabolic profile than their sedentary peers [26], and the pathology should not be considered as an impediment to the practice of physical exercise. On the contrary, exercise should be encouraged in this population, requiring only precautions for greater safety [9]. As verified in the present study, only one session of resistance physical exercises can help to control the acute glycemic variation with clinical importance for practitioners.

Finally, the present study had some limitations, such as the lack of dietary control in the 24 hours prior to the session, the short post-session evaluation period (only 20 minutes) and the absence of a control group. However, the results have a high practical application, since the performance of a session of moderate resistance exercise with alternating exercises by segments can help regulate glucose without causing hypoglycemia and thus reduce the possible fear of the diabetic person of suffering hypoglycemia during and after physical exercise.

 

Conclusion

 

In conclusion, a session of resistance exercise of moderate intensity proved to be safe from the glycemic point of view in people with type 1 diabetes. In addition, it promoted a reduction in blood glucose values in relation to baseline values that varied between 17.8% and 21.7% with clinically important changes, which may be beneficial in the long term for this population.

 

Acknowledgements

 

The authors of this work would like to thank PROEX UNIVASF, the FACEPE development agency, the Bioanalises laboratory, the city hall of Petrolina/PE and Ariel Custódio de Oliveira II for their collaboration.

 

References

 

  1. World Health Organization. Classification of Diabetes Mellitus. Vol. 309, The Lancet. Geneva: World Health Organization; 2019. p.1202-3.
  2. Eid S, Sas KM, Abcouwer SF, Feldman EL, Gardner TW, Pennathur S et al. New insights into the mechanisms of diabetic complications: role of lipids and lipid metabolism. Diabetologia 2019;62(9):1539-49. https://doi.org/10.1007/s00125-019-4959-1
  3. Barone B, Rodacki M, Cenci MCP, Zajdenverg L, Milech A, Oliveira JEP. Cetoacidose diabética em adultos: atualização de uma complicação antiga. Arq Bras Endocrinol Metabol 2007;51(9):1434-47. https://doi.org/10.1590/S0004-27302007000900005
  4. Filardi T, Ghinassi B, Di Baldassarre A, Tanzilli G, Morano S, Lenzi A et al. Cardiomyopathy associated with diabetes: the central role of the cardiomyocyte. Int J Mol Sci 2019;20(13):3299. https://doi.org/10.3390/ijms20133299
  5. Colberg SR, Sigal RJ, Yardley JE, Riddell MC, Dunstan DW, Dempsey PC et al. Physical activity/exercise and diabetes: A position statement of the American Diabetes Association. Diabetes Care 2016;39(11):206579. https://doi.org/10.2337/dc16-1728
  6. Poian AT, Carvalho-Alves PC. Hormônios e metabolismo: Integração e correlações clínicas. São Paulo: Atheneu; 2006. 352p.
  7. Shetty VB, Fournier PA, Davey RJ, Retterath AJ, Paramalingam N, Roby HC et al. Effect of exercise intensity on glucose requirementsh to maintain euglycemia during exercise in type 1 diabetes. J Clin Endocrinol Metab 2016;101(3):972-80. https://doi.org/10.1210/jc.2015-4026
  8. SBD. Diretrizes da Sociedade Brasileira de Diabetes 2017-2018. Oliveira JEPO, Montenegro Junior RMSV, eds. São Paulo: Clannad; 2017. 383p. https://www.diabetes.org.br/profissionais/images/2017/diretrizes/diretrizes-sbd-2017-2018.pdf
  9. Nascimento MS, Espindola CF, do Prado C, Amarins MB, Potenza AL, Pacheco L et al. Type 1 diabetes does not impair the physical capacity of non-sedentary adolescents. Diabetol Metab Syndr 2017;16;9(1):100. https://doi.org/10.1186/s13098-017-0300-7
  10. Ferrari F, Bock PM, Motta MT, Helal L. Biochemical and molecular mechanisms of glucose uptake stimulated by physical exercise in insulin resistance state: role of inflammation. Arq Bras Cardiol 2019;113(6):1139-48. https://doi.org/10.5935/abc.20190224
  11. Marçal DFS, Alexandrino EG, Cortez LER, Bennemann RM. Efeitos do exercício físico sobre diabetes mellitus tipo 1: uma revisão sistemática de ensaios clínicos e randomizados. J Phys Educ 2018;29(1):1-14. https://doi.org/10.4025/jphyseduc.v29i1.2917
  12. Rose AJ, Richter EA. Skeletal muscle glucose uptake during exercise: how is it regulated? Physiology 2005;20(4):260-70. https://doi.org/10.1590/1413-81232015214.20242015 
  13. Sales-Peres SH de C, Guedes M de FS, Sá LM, Negrato CA, Lauris JRP. Estilo de vida em pacientes portadores de diabetes mellitus tipo 1: uma revisão sistemática. Cienc Saude Colet 2016;21(4):1197–206. https://doi.org/10.2337/diaspect.28.1.32
  14. Yardley JE, Sigal RJ. Exercise strategies for hypoglycemia prevention in individuals with type 1 diabetes. Diabetes Spectr 2015;28(1):32–8. https:// doi.org/10.2337/diaspect.28.1.32
  15. Nery M. Hipoglicemia como fator complicador no tratamento do diabetes melito tipo 1. Arq Bras Endocrinol Metabol 2008;52(2):288–98. https://doi.org/10.1590/S000427302008000200016
  16. Barros GR, Castellano SM, Silva SF, Paulo TRS. Motivos para a prática de musculação entre adultos jovens de uma academia no município de Parintins/AM. Rev Acta Bras Mov Hum 2015;5(1):66-75.
  17. Brzycki M. Strength testing predicting a one-rep max from reps-to-fatigue. J Phys Educ Recreat Danc 1993;64(1):88-90. https://doi.org/10.1080/07303084.1993.10606684
  18. SBC SBDC. VII Diretrizes Brasileiras de Hipertensão. Arq Bras Cardiol 2016;107(3Supl.3):1-83.
  19. Alves JD, Gomes JLB, Oliveira CVC, Alves JVMH, Nogueira FRS, Brito AF. Tai-chi-chuan and yoga onpostexercise hypotension: comparison to aerobic and resistance exercise. Fisioter Mov 2016;29(3):543-52. https://doi.org/10.1590/1980-5918.029.003.AO12
  20. Ferrari F, Sacramento MDS, Jesus DS, Soldatelli Â, Motta MT, Petto J. Exercício físico no diabetes mellitus tipo 1: quais as evidências para uma melhor prescrição? Rev Bras Fisiol Exerc 2019;18(1):38. https://doi.org/10.33233/rbfe.v18i1.2878
  21. Jesus IC, Mascarenhas LPG, Lima VA, Decimo JP, Nesi-França S, Leite N. Maximal fat oxidation during aerobic exercise in adolecents with type 1 diabetes. Rev Bras Med Esporte 2019;25(4):299-304. https://doi.org/10.1590/1517-869220192504189259
  22. Cruz LC, Teixeira-Araujo AA, Passos Andrade KT, Rocha TCOG, Puga GM, Moreira SR. Low-intensity resistance exercise reduces hyperglycemia and enhances glucose control over a 24-hour period in women with type 2 diabetes. J Strength Cond Res 2019;33(10):2826-35. https://doi.org/10.1519/JSC.0000000000002410
  23. Yardley JE, Kenny GP, Perkins BA, Riddell MC, Balaa N, Malcolm J, et al. Resistance versus aerobic exercise: acute effects on glycemia in type 1 diabetes. Diabetes Care 2013;36(3):537-42. https://doi.org/10.2337/dc12-0963
  24. Slade JM, Towse TF, Gossain V V., Meyer RA. Peripheral microvascular response to muscle contraction is unaltered by early diabetes but decreases with age. J Appl Physiol 2011;111(5):1361-71. https://doi.org/10.1152/japplphysiol.00009.2011
  25. Ilonen J, Lempainen J, Veijola R. The heterogeneous pathogenesis of type 1 diabetes mellitus. Nat Rev Endocrinol 2019;15(11):635-50. https://doi.org/10.1038/s41574-019-0254-y
  26. Adamo M, Codella R, Casiraghi F, Ferrulli A, Macrì C, Bazzigaluppi E, et al. Active subjects with autoimmune type 1 diabetes have better metabolic profiles than sedentary controls. cell transplant 2017;26(1):23-32. https://doi.org/10.3727%2F096368916X693022