Abstract
During an exhaustive graded bicycle spiroergometer test, several arterial blood samples
were taken from six type I diabetics and seven normal controls for determination of
catechol- amines and paramters of carbohydrate and lipid metabolism. In both groups
during exercise, glucose remained unchanged, and lactate associated metabolic acidosis
was compensated by respiratory gas exchange.
Diabetics showed an impaired exercise-induced response of adrenaline and noradrenaline
(62±8 to 176±24 and 98±6 to 612±175pg·ml-1), respectively, compared to controls (55±6 to 1213±720 and 95±17 to 1710±506 pg·ml-1). Free glycerol increased to an equivalent extent in both groups. Simultaneously
produced free fatty acids decreased at high work loads in diabetics. In addition to
insulin deficiency and impaired catecholamine secretion, diabetics showed high values
of growth hormone, ACTH, and Cortisol. These may be responsible for the high values
of free glycerol and free fatty acids. At maximum the FFA values decreased in both
groups, although levels of lactate and pyruvate were high.
It is suggested that insulin deficiency is the reason for the disturbed hormonal and
metabolic response to exhaustive exercise and reduces physical fitness in diabetics.
Key words
exhaustive exercise - diabetes mellitus - lipolysis - lactic acidosis - adrenaline
- noradrenaline
