Cardiovascular Responses to Sustained Handgrip in Normal Subjects and in Patients with Diabetes Mellitus: A Test of Autonomic Function

1974 ◽  
Vol 46 (3) ◽  
pp. 295-306 ◽  
Author(s):  
D. J. Ewing ◽  
J. B. Irving ◽  
F. Kerr ◽  
J. A. W. Wildsmith ◽  
B. F. Clarke
Keyword(s):  
Diabetes Mellitus ◽  
Blood Pressure ◽  
Blood Pressure Response ◽  
Muscle Tension ◽  
Maximum Voluntary Contraction ◽  
Pressure Rise ◽  
Cardiovascular Responses ◽  
Normal Subjects ◽  
Simple Method ◽  
Patients With Diabetes

1. The blood pressure and heart rate responses to static muscular exercise were measured in sixty normal subjects and 124 patients with diabetes mellitus, aged 25–54 years, during a standardized sustained handgrip test at 30% maximum voluntary contraction (MVC). 2. The normal range of the response was established. Females had a smaller blood pressure rise than males, and their MVC was lower. In the normal subjects there was a significant correlation between the size of the MVC and the height of the blood pressure response. The absolute muscle tension exerted should be taken into account in addition to the percentage MVC, when comparing responses to sustained exercise in different disease states. 3. The diabetic subjects showed a similar sex difference in their response. The mean diastolic blood pressure rises were smaller than in the control groups, both in males and females, but this was related to a smaller mean MVC. 4. Twenty-two of the diabetic subjects had an abnormally low response to sustained handgrip, which was not related to age, duration of diabetes, treatment or control of the disease. These diabetic subjects probably had damage of the autonomic fibres mediating the response. The findings would suggest that sustained handgrip is a useful and simple method of detecting involvement of the autonomic nervous system in diabetes.

Cardiovascular Responses to Graded Reductions of Central Blood Volume in Normal Subjects and in Patients with Diabetes Mellitus

1980 ◽  
Vol 58 (3) ◽  
pp. 193-200 ◽  
Author(s):  
T. Bennett ◽  
D. J. Hosking ◽  
J. R. Hampton
Keyword(s):  
Diabetes Mellitus ◽  
Negative Pressure ◽  
Lower Body Negative Pressure ◽  
Cardiovascular Responses ◽  
Normal Subjects ◽  
Systemic Arterial Pressure ◽  
Normal Function ◽  
Diabetic Patients ◽  
Vasomotor Function ◽  
Patients With Diabetes

1. Cardiovascular responses to graded increments of lower body negative pressure were studied in non-diabetic subjects and in patients with diabetes mellitus. 2. In all subjects, low levels of negative pressure (which did not affect significantly systemic arterial pressure) induced forearm vasoconstriction, suggesting normal function of the ‘low pressure’ cardiopulmonary baroreflex. However, in some diabetic patients the response to higher levels of negative pressure was abnormal, and it seems likely that although afferent mechanisms were intact there was impairment of efferent vasoconstrictor function. 3. Changes in R—R interval were linearly related to changes in systolic blood pressure induced by higher levels of negative pressure. The slope of the relationship was taken as the sensitivity of the ‘high pressure’ arterial baroreflex; diabetic patients showed a reduced sensitivity compared with normal subjects. Furthermore, in diabetic patients, abnormalities of R—R interval control were more common than abnormalities of vasoconstrictor function, suggesting that heart-rate control is impaired earlier than vasomotor function in diabetic autonomic neuropathy.

Desmopressin Stimulates Parallel Norepinephrine and Tissue Plasminogen Activator Release in Normal Subjects and Patients with Diabetes Mellitus

1988 ◽  
Vol 59 (02) ◽  
pp. 269-272 ◽  
Author(s):  
M B Grant ◽  
C Guay ◽  
R Lottenberg
Keyword(s):  
Diabetes Mellitus ◽  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Time Course ◽  
Vascular Endothelial Cells ◽  
Normal Subjects ◽  
Plasma Norepinephrine ◽  
Endogenous Catecholamine ◽  
Tissue Plasminogen ◽  
Patients With Diabetes

SummaryDesmopressin acetate administration markedly stimulates release of tissue plasminogen activator (t-PA) from vascular endothelial cells. The mechanism for this effect is unknown. Because infusion of epinephrine has been shown to increase t-PA levels, we examined the role of endogenous catecholamine mediation of t-PA release by desmopressin. Intravenous desmopressin acetate (0.3 μg/kg) was infused over 30 min in 9 controls and 11 subjects with diabetes mellitus, a condition associated with abnormalities of the fibrinolytic system. Plasma was collected in the supine, overnight fasted state at 15 min intervals (0-60 min) for measurement of t-PA activity, t-PA antigen and fractionated catecholamines. t-PA activity peaked at 30-45 min and subsequently decreased. The norepinephrine levels paralleled the t-PA activity. t-PA activity increased 10-fold from 0.14 ± .12 to 1.49 ± 0.79 IU/ml (Mean ± SD) and plasma norepinephrine increased 2- fold from 426 ± 90 to 780 ± 292 pg/ml. However, epinephrine and dopamine levels did not change significantly. The response to desmopressin of control and diabetic subjects was not shown to differ and their data were combined. We conclude that desmopressin increases plasma norepinephrine in addition to t-PA and that the parallel time course of change suggests a possible role for norepinephrine in mediating endothelial cell t-PA release.

Respiratory and cardiovascular responses to static handgrip exercise in humans

1993 ◽  
Vol 75 (6) ◽  
pp. 2789-2796 ◽  
Author(s):  
G. A. Fontana ◽  
T. Pantaleo ◽  
F. Bongianni ◽  
F. Cresci ◽  
R. Manconi ◽  
...  
Keyword(s):  
Heart Rate ◽  
Time Course ◽  
Minute Ventilation ◽  
Muscle Tension ◽  
Maximum Voluntary Contraction ◽  
Cardiovascular Responses ◽  
Inspiratory Flow ◽  
Electromyographic Activity ◽  
Handgrip Exercise ◽  
Cardiovascular Variables

We studied the time course of respiratory and cardiovascular responses by evaluating changes in the breathing pattern, mean blood pressure (MBP), and heart rate elicited by 3 min of static handgrip at 15, 25, and 30% of the maximum voluntary contraction (MVC) in 15 healthy volunteers. Muscle tension and integrated electromyographic activity remained fairly constant during each trial. During 15% MVC bouts, initially only mean inspiratory flow increased; then, tidal volume and minute ventilation (VI) also rose progressively. No significant changes in MBP and heart rate were observed. During 25 and 30% MVC bouts, not only did mean inspiratory flow, VT, and VI increase but MBP and heart rate increased as well. A slight and delayed rise in respiratory rate was also observed. Unlike 15 and 25% MVC handgrip, 30% MVC handgrip caused a small decrease in end-tidal PCO2. Changes in the pattern of breathing occurred more promptly than those in cardiovascular variables in the majority of subjects. Furthermore, we found a positive correlation between changes in VI and those in cardiovascular variables at the end of 25 and 30% MVC trials. This study indicates that respiratory and cardiovascular responses to static handgrip exercise are controlled independently.

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