TY - JOUR

T1 - Metabolic and physiological responses to graded exercise testing in individuals with type 1 diabetes using insulin pump therapy

AU - McCarthy, Olivia M.

AU - Kristensen, Kasper Birch

AU - Christensen, Merete Bechmann

AU - Schmidt, Signe

AU - Ranjan, Ajenthen G.

AU - Nicholas, Chloe

AU - Bain, Stephen C.

AU - Nørgaard, Kirsten

AU - Bracken, Richard

N1 - Publisher Copyright: © 2022 The Authors. Diabetes, Obesity and Metabolism published by John Wiley & Sons Ltd.

PY - 2023

Y1 - 2023

N2 - Aims: To profile acute glycaemic dynamics during graded exercise testing (GXT) and explore the influence of glycaemic indicators on the physiological responses to GXT in adults with type 1 diabetes using insulin pump therapy. Methods: This was a retrospective analysis of pooled data from four clinical trials with identical GXT protocols. Data were obtained from 45 adults with type 1 diabetes using insulin pumps [(30 females); haemoglobin A1c 59.5 ± 0.5 mmol/mol (7.6 ± 1.0%); age 49.7 ± 13.0 years; diabetes duration 31.2 ± 13.5 years; V̇O2peak 29.5 ± 8.0 ml/min/kg]. Integrated cardiopulmonary variables were collected continuously via spiroergometry. Plasma glucose was obtained every 3 min during GXT as well as the point of volitional exhaustion. Data were assessed via general linear modelling techniques with age and gender adjustment. Significance was accepted at p ≤.05. Results: Despite increasing duration and intensity, plasma glucose concentrations remained similar to rest values (8.8 ± 2.3 mmol/L) throughout exercise (p =.419) with an overall change of +0.3 ± 1.1 mmol/L. Starting glycaemia bore no influence on subsequent GXT responses. Per 1% increment in haemoglobin A1c there was an associated decrease in V̇O2peak of 3.8 ml/min/kg (p <.001) and powerpeak of 0.33 W/kg (p <.001) concomitant with attenuations in indices of peripheral oxygen extraction [(O2 pulse) −1.2 ml/beat, p =.023]. Conclusion: In adults with long-standing type 1 diabetes using insulin pump therapy, circulating glucose remains stable during a graded incremental cycle test to volitional exhaustion. Glycaemic indicators are inversely associated with aerobic rate, oxygen economy and mechanical output across the exercise intensity spectrum. An appreciation of these nexuses may help guide appropriate decision making for optimal exercise management strategies.

AB - Aims: To profile acute glycaemic dynamics during graded exercise testing (GXT) and explore the influence of glycaemic indicators on the physiological responses to GXT in adults with type 1 diabetes using insulin pump therapy. Methods: This was a retrospective analysis of pooled data from four clinical trials with identical GXT protocols. Data were obtained from 45 adults with type 1 diabetes using insulin pumps [(30 females); haemoglobin A1c 59.5 ± 0.5 mmol/mol (7.6 ± 1.0%); age 49.7 ± 13.0 years; diabetes duration 31.2 ± 13.5 years; V̇O2peak 29.5 ± 8.0 ml/min/kg]. Integrated cardiopulmonary variables were collected continuously via spiroergometry. Plasma glucose was obtained every 3 min during GXT as well as the point of volitional exhaustion. Data were assessed via general linear modelling techniques with age and gender adjustment. Significance was accepted at p ≤.05. Results: Despite increasing duration and intensity, plasma glucose concentrations remained similar to rest values (8.8 ± 2.3 mmol/L) throughout exercise (p =.419) with an overall change of +0.3 ± 1.1 mmol/L. Starting glycaemia bore no influence on subsequent GXT responses. Per 1% increment in haemoglobin A1c there was an associated decrease in V̇O2peak of 3.8 ml/min/kg (p <.001) and powerpeak of 0.33 W/kg (p <.001) concomitant with attenuations in indices of peripheral oxygen extraction [(O2 pulse) −1.2 ml/beat, p =.023]. Conclusion: In adults with long-standing type 1 diabetes using insulin pump therapy, circulating glucose remains stable during a graded incremental cycle test to volitional exhaustion. Glycaemic indicators are inversely associated with aerobic rate, oxygen economy and mechanical output across the exercise intensity spectrum. An appreciation of these nexuses may help guide appropriate decision making for optimal exercise management strategies.

KW - cardiopulmonary exercise testing

KW - exercise

KW - graded exercise testing

KW - insulin pump therapy

KW - plasma glucose

KW - type 1 diabetes

U2 - 10.1111/dom.14938

DO - 10.1111/dom.14938

M3 - Journal article

C2 - 36482870

AN - SCOPUS:85145553434

VL - 25

SP - 878

EP - 888

JO - Diabetes, Obesity and Metabolism

JF - Diabetes, Obesity and Metabolism

SN - 1462-8902

IS - 3

ER -