[Methods to identify the anaerobic threshold for type-2 diabetic and non-diabetic subjects].
BACKGROUND
In spite of Anaerobic Threshold (AT) to be widely used on exercise evaluation for different populations, there are few studies comparing methods to identify AT for individuals with type-2 diabetes.


OBJECTIVE
To compare methods of AT determination on type-2 diabetics (T2D) and non-diabetic (ND) subjects and verify the acid-base balance as related to AT intensity.


METHODS
T2D (n=10; 54.5+/-9.5 yr; 30.1+/-5.0 kg/m(2)) and younger ND (n=10; 36.6+/-12.8 yr; 23.9+/-5.0 kg/m(2)) performed an incremental test (IT) on a cycle ergometer. The over-proportional increase in VE/VO2 and blood lactate ([lac]) identified the ventilatory (VT) and lactate thresholds (LT) respectively. The workload corresponding to the lower blood glucose ([gluc]) during test identified the individual glucose threshold (IGT). The AT was also determined by polynomial adjustment of the VE/Workload and [lac]/Workload responses to identify exercise intensities above which an over-proportional increase in VE and [lac] did occur and were named VT VE/W and LT[lac]/W.


RESULTS
The workload (Watts-W) corresponding to LT, VT, IGT, LT Lac/W and VT VE/W of diabetics (85.0+/-32.1; 88.0+/-31.7; 86.0+/-33.8; 82.0+/-20.9 and 90.2+/-22.2W) and non-diabetics (139.0+/-39.0; 133.0+/-42.7; 140.8+/-36.4; 122.7+/-44.3 and 133.0+/-39.1W) differed between groups (p<0.001), but not within groups. Thus it was evidenced an agreement among the studied methods. The pH and pCO2 were significantly decreased in parallel to the increase in [lac], pO2 and VE at supra AT intensities.


CONCLUSIONS
The AT intensities, as determined by different methods both for diabetics and non-diabetic individuals, were in agreement to each other and identified exercise intensities above which the acid-basic balance is disrupted.
Simões
Herbert G
HG
Universidade Católica de Brasília, Brasília, DF, Brasil. hgsimoes@gmail.com
Moreira
Sérgio R
SR
Moffatt
Robert J
RJ
Campbell
Carmen S G
CS
D000136:Acid-Base Equilibrium / Q000502:physiology*; D000328:Adult; D015308:Anaerobic Threshold / Q000502:physiology*; D001786:Blood Glucose / Q000378:metabolism; D016022:Case-Control Studies; D002985:Clinical Protocols / Q000145:classification*; D003627:Data Interpretation, Statistical; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism / Q000503:physiopathology*; D005080:Exercise Test / Q000379:methods; D006801:Humans; D007773:Lactates / Q000097:blood; D008875:Middle Aged
D001786:Blood Glucose; D007773:Lactates