Peripheral Oxygen Extraction and Exercise Limitation in Asymptomatic Patients with Diabetes Mellitus.

Kobayashi Y; Christle JW; Contrepois K; Nishi T; Moneghetti K; Cauwenberghs N; Myers J; Kuznetsova T; Palaniappan L; Haddad F;

The American journal of cardiology [Am J Cardiol] 2021 Mar 20. Date of Electronic Publication: 2021 Mar 20.

Patients with diabetes mellitus (DM) frequently present reduced exercise capacity. We aimed to explore the extent to which peripheral extraction relates to exercise capacity in asymptomatic patients with DM. We prospectively enrolled 98 asymptomatic patients with type-2 DM (mean age of 59±11 years and 56% male sex), and compared with 31 age, sex and body mass index (BMI)-matched normoglycemic controls. Cardiopulmonary exercise testing (CPX) with resting echocardiography was performed. Exercise response was assessed using peak oxygen uptake (peak VO 2 ) and ventilatory efficiency was measured using the slope of the relationship between minute ventilation and carbon dioxide production (VE/VCO 2 ). Peripheral extraction was calculated as the ratio of VO 2 to cardiac output. Cardiac function was evaluated using left ventricular longitudinal strain (LVLS), E/e’, and relative wall thickness (RWT). Among patients with DM, 26 patients (27%) presented reduced percent-predicted-peak VO 2 (<80%) and 18 (18%) presented abnormal VE/VCO 2 slope (>34). There was no significant difference in peak cardiac output; peripheral extraction was lower in patients with DM compared to controls. Higher peak E/e’ (beta=-0.24, p=0.004) was associated with lower peak VO 2 along with age, sex and BMI (R 2 =0.53). A network correlation map revealed the connectivity of peak VO 2 as a central feature and cluster analysis found LVLS, E/e’, RWT and peak VO 2 in different clusters.
In conclusion, impaired peripheral extraction may contribute to reduced peak VO 2 in asymptomatic patients with DM. Furthermore, cluster analysis suggests that CPX and echocardiography may be complementary for defining subclinical heart failure in patients with DM.