Open AccessHeart rate dynamics during cardio-pulmonary exercise testing are associated with glycemic control in individuals with type 1 diabetes
Author(s) -
Othmar Moser,
Max L. Eckstein,
Olivia McCarthy,
Rachel Deere,
Stephen C. Bain,
Hanne Haahr,
Eric Zijlstra,
Tim Heise,
Richard M. Bracken
Publication year - 2018
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0194750
Subject(s) - glycemic , diabetes mellitus , receiver operating characteristic , type 2 diabetes , type 1 diabetes , linear regression , medicine , heart rate , cardiology , materials science , statistics , mathematics , endocrinology , blood pressure
This study investigated the degree and direction (k HR ) of the heart rate to performance curve (HRPC) during cardio-pulmonary exercise (CPX) testing and explored the relationship with diabetes markers, anthropometry and exercise physiological markers in type 1 diabetes (T1DM). Material and methods Sixty-four people with T1DM (13 females; age: 34 ± 8 years; HbA 1c : 7.8 ± 1% (62 ± 13 mmol.mol -1 ) performed a CPX test until maximum exhaustion. k HR was calculated by a second-degree polynomial representation between post-warm up and maximum power output. Adjusted stepwise linear regression analysis was performed to investigate k HR and its associations. Receiver operating characteristic (ROC) curve was performed based on k HR for groups k HR < 0.20 vs. > 0.20 in relation to HbA 1c . Results We found significant relationships between k HR and HbA 1c ( β = -0 . 70 , P < 0 . 0001 ), age ( β = -0 . 23 , P = 0 . 03) and duration of diabetes ( β = 0 . 20 , P = 0 . 04) . Stepwise linear regression resulted in an overall adjusted R 2 of 0.57 ( R = 0 . 79 , P < 0 . 0001 ). Our data revealed also significant associations between k HR and percentage of heart rate at heart rate turn point from maximum heart rate ( β = 0 . 43 , P < 0 . 0001) and maximum power output relativized to bodyweight ( β = 0 . 44 , P = 0 . 001) (overall adjusted R 2 of 0.44 ( R = 0 . 53 , P < 0 . 0001 )). ROC curve analysis based on k HR resulted in a HbA 1c threshold of 7.9% (62 mmol.mol -1 ). Conclusion Our data demonstrate atypical HRPC during CPX testing that were mainly related to glycemic control in people with T1DM.