Adding Heart Rate Signal to a Control-to-Range Artificial Pancreas System Improves the Protection Against Hypoglycemia During Exercise in Type 1 Diabetes

Abstract

Background: We present a clinical trial establishing the feasibility of a control-to-range (CTR) closed-loop system informed by heart rate (HR) and assess the effect of HR information added to CTR on the risk for hypoglycemia during and after exercise. Subjects and Methods: Twelve subjects with type 1 diabetes (five men, seven women; weight, 68.9 -3.1 kg; age, 38 -3.3 years; glycated hemoglobin, 6.9 -0.2%) participated in a randomized crossover clinical trial comparing CTR versus CTR + HR in two 26-h admissions, each including 30 min of mild exercise. The CTR algorithm was implemented in the DiAs portable artificial pancreas platform based on an Android Ò (Google, Mountainview, CA) smartphone. We assessed blood glucose (BG) decline during exercise, the Low BG Index (LBGI) (a measure of hypoglycemic risk), number of hypoglycemic episodes (BG < 70 mg/dL) and overall glucose control (percentage time within the target range 70 mg/dL £ BG £ 180 mg/dL). Results: Using HR to inform the CTR algorithm reduced significantly the BG decline during exercise (P = 0.022), indicated marginally lower LBGI (P = 0.3) and fewer hypoglycemic events during exercise (none vs. two events; P = 0.16), and resulted in overall higher percentage time within the target range (81% vs. 75%; P = 0.2). LBGI and average BG remained unchanged overall, during recovery, and overnight. Conclusions: HR-informed closed-loop control can be implemented in a portable artificial pancreas. Although closed loop has been shown to reduce hypoglycemia, adding HR signal may further limit the risk for hypoglycemia during and immediately after exercise. The most prominent effect of adding HR information is reduced BG decline during exercise, without deterioration of overall glycemic control.

Closed-loop glucose control in young people with type 1 diabetes during and after unannounced physical activity: a randomised controlled crossover trial

“…heart rate), exercise announcement or adding additional simple carbohydrates can be of benefit in the intermediate stage of development of artificial pancreas [17,29,30]. In a recent randomised crossover trial with an afternoon mixed exercise protocol in one arm, the closed-loop device switched to exercise algorithm when triggered by a portable heart rate monitor (HRM) [17].…”

Physical Activity Capture Technology With Potential for Incorporation Into Closed-Loop Control for Type 1 Diabetes

“…23 HR was incorporated manually by pressing the exercise button on the Diabetes Assistant when HR was 125% above resting thus triggering the CTR + HR algorithm. When HR was below 125% resting, the exercise button was pressed to return to the CTR algorithm.…”

“…Each of these studies (1) involved only 1 center, (2) involved small sample sizes, (3) was short in duration, and (4) focused primarily on aerobic exercises. [23][24][25] These studies were also limited by manual entry of physical activity output into the controller 23,25 and manually entered CGM data into the controller. 25 Two of the 3 studies used laptops to run the control algorithm.…”

Efeitos Do Exercício Físico Sobre Diabetes Mellitus Tipo 1: Uma Revisão Sistemática De Ensaios Clínicos E Randomizados

“…13 . Breton et al 9 fizeram um estudo piloto com objetivo de estabelecer a viabilidade da adição de informação do monitoramento da Frequência Cardíaca (FC) integrada ao CLC sobre o risco de hipoglicemia durante e após o exercício físico, em DM1. O ensaio verificou que a inclusão da informação sobre o monitoramento da FC reduziu significativamente o declínio da glicose sanguínea durante o exercício (p=0,022), além disso, o risco para hipoglicemia foi menor, também, no grupo experimental (p=0,3).…”

“…Esse quadro tem estimulado diversas estatégias para manter as taxas glicêmicas dentro da normalidade, sobretudo em ensaios cujos pacientes utilizam bombas de insulina e os chamados "pâncreas artificiais" [9][10][11][12][13] . Existe também preocupação em relação à diminuição e, até mesmo, suspensão das doses de insulina pré e pós-exercício para evitar danos causados por esses episódios [14][15][16][17][18] e também relacionado ao índice glicêmico dos alimentos 19,20 .…”