Type 2 diabetes and reduced exercise tolerance: a review of the literature through an integrated physiology approach

Table 1 Variables evaluated during cardiopulmonary examination grouped by their physiological value

Physiological mechanism	Imaging-CPET primary variables	CPET secondary variables
Whole body	VO₂, work	VO₂ %
Cardiovascular system	HR, BP	VO₂/HR
Cardiac electric activity	ECG morphology and rythm	Chronotropic insufficiency, impaired heart rate recovery
Ventilation	VE, V_T	VE/VCO₂, VE/VO₂
Gas exchange	SpO₂, PETCO₂, PETO₂	AT
Skeletal muscle	Borg scale	Δ(a − v)O₂, AT
Metabolism	RER	AT
Systolic function	LVEF, S’, TAPSE	Systolic reserve
Diastolic function	E/A, E/e’, DT	Diastolic reserve

We indicated “primary” those directly evaluated by CPET hardware, while those derived by mathematical modeling are indicated as “secondary”
ECG, electrocardiography; HR, heart rate; BP, blood pressure; RER, respiratory exchange ratio; VO₂, oxygen uptake; VE, minute ventilation; V_T, tidal volume; VO₂ %, percentage of peak oxygen uptake with respect to maximal theoretic VO₂; AT, anaerobic threshold; RER, respiratory exchange ratio, E/A, E/A wave ratio; E/e’, E/e’ wave ratio; DT, deceleration time, TAPSE, tricuspid annular systolic excursion

ISSN: 1475-2840