Differences in physiological responses to cardio-pulmonary exercise testing in adults with type 1 diabetes and controls without type 1 diabetes – a pooled analysis
To investigate physiological responses to cardio-pulmonary exercise (CPX) testing in adults with type 1 diabetes compared to age-, sex- and body mass index- (BMI) matched controls without type 1 diabetes.
RESEARCH DESIGN AND METHODS
We compared results from CPX tests on a cycle ergometer in individuals with type 1 diabetes and controls without type 1 diabetes. Parameters were peak and threshold variables of oxygen uptake, heart rate and power output. Differences between groups were investigated via restricted maximum likelihood modelling and post-hoc tests. Differences between groups were explained by stepwise linear regressions (p<0.05).
RESULTS
Among 303 individuals with type 1 diabetes (age 33 [22; 43] years, 93 females, BMI 23.6 [22; 26] kg/m2, HbA1c 6.9 [6.2; 7.7]%; 52 [44; 61] mmol/mol), peak oxygen uptake (32.55 [26.49; 38.72] vs. 42.67 ± 10.44) (mL/kg/min), peak heart rate (179 [170; 187] vs. 184 [175; 191]) (bpm) and peak power (216 [171; 253] vs. 245 [200; 300]) (Watt) were lower in comparison to 308 controls without type 1 diabetes (all p<0.001). Individuals with type 1 diabetes displayed an impaired degree and direction of the heart rate to performance curve compared against controls without type 1 diabetes (0.07 [-0.75; 1.09] vs. 0.66 [-0.28; 1.45] (p<0.001)). None of the exercise physiological responses were associated with HbA1c in individuals with type 1 diabetes.
CONCLUSIONS
Individuals with type 1 diabetes show altered responses to CPX testing, which cannot be explained by HbA1c. Intriguingly, the participants in our cohort consisted of people with recent-onset type 1 diabetes, heart rate dynamics were altered during CPX testing.