Hemodynamic mechanisms of the attenuated blood pressure response to mental stress after a single bout of maximal dynamic exercise in healthy subjects

To determine the hemodynamic mechanisms responsible for the attenuated blood pressure response to mental stress after exercise, 26 healthy sedentary individuals (age 29 ± 8 years) underwent the Stroop color-word test before and 60 min after a bout of maximal dynamic exercise on a treadmill. A subgroup (N = 11) underwent a time-control experiment without exercise. Blood pressure was continuously and noninvasively recorded by infrared finger photoplethysmography. Stroke volume was derived from pressure signals, and cardiac output and peripheral vascular resistance were calculated. Perceived mental stress scores were comparable between mental stress tests both in the exercise (P = 0.96) and control (P = 0.24) experiments. After exercise, the blood pressure response to mental stress was attenuated (pre: 10 ± 13 vs post: 6 ± 7 mmHg; P < 0.01) along with lower values of systolic blood pressure (pre: 129 ± 3 vs post: 125 ± 3 mmHg; P < 0.05), stroke volume (pre: 89.4 ± 3.5 vs post: 76.8 ± 3.8 mL; P < 0.05), and cardiac output (pre: 7.00 ± 0.30 vs post: 6.51 ± 0.36 L/min; P < 0.05). Except for heart rate, the hemodynamic responses and the mean values during the two mental stress tests in the control experiment were similar (P > 0.05). In conclusion, a single bout of maximal dynamic exercise attenuates the blood pressure response to mental stress in healthy subjects, along with lower stroke volume and cardiac output, denoting an acute modulatory action of exercise on the central hemodynamic response to mental stress.

Hemodynamic mechanisms of the attenuated blood pressure response to mental stress after a single bout of maximal dynamic exercise in healthy subjects.

To determine the hemodynamic mechanisms responsible for the attenuated blood pressure response to mental stress after exercise, 26 healthy sedentary individuals (age 29 ± 8 years) underwent the Stroop color-word test before and 60 min after a bout of maximal dynamic exercise on a treadmill. A subgroup (N = 11) underwent a time-control experiment without exercise. Blood pressure was continuously and noninvasively recorded by infrared finger photoplethysmography. Stroke volume was derived from pressure signals, and cardiac output and peripheral vascular resistance were calculated. Perceived mental stress scores were comparable between mental stress tests both in the exercise (P = 0.96) and control (P = 0.24) experiments. After exercise, the blood pressure response to mental stress was attenuated (pre: 10 ± 13 vs post: 6 ± 7 mmHg; P < 0.01) along with lower values of systolic blood pressure (pre: 129 ± 3 vs post: 125 ± 3 mmHg; P < 0.05), stroke volume (pre: 89.4 ± 3.5 vs post: 76.8 ± 3.8 mL; P < 0.05), and cardiac output (pre: 7.00 ± 0.30 vs post: 6.51 ± 0.36 L/min; P < 0.05). Except for heart rate, the hemodynamic responses and the mean values during the two mental stress tests in the control experiment were similar (P > 0.05). In conclusion, a single bout of maximal dynamic exercise attenuates the blood pressure response to mental stress in healthy subjects, along with lower stroke volume and cardiac output, denoting an acute modulatory action of exercise on the central hemodynamic response to mental stress.

Preserved heart rate variability in first-degree relatives of subjects with Type 2 diabetes mellitus without metabolic disorders.

AIMS: To investigate the influence of a family history of Type 2 diabetes mellitus (T2DM) on resting heart rate variability in the absence of concomitant metabolic disorders. METHODS: We studied 55 first-degree relatives (FDRs) of subjects with T2DM and 36 control subjects without any known family history of diabetes. FDRs were recruited from a University Hospital out-patient diabetes clinic. The protocol included: oral glucose tolerance test (30, 60, 90 and 120 min after ingestion of 75 g glucose) blood glucose, plasma insulin, cholesterol and subfractions, triglycerides, leptin and C-reactive protein. Heart rate variability (HRV) at rest was determined by spectral analysis of interbeat intervals recorded during 10 min in the supine position. RESULTS: HRV was lower in FDRs compared with control subjects (P < 0.05). Multiple regression analysis identified cholesterol (P = 0.014) and triglycerides (P = 0.014) as significant independent predictors (model r = 0.40; P < 0.001) of HRV. Since FDRs had higher values for anthropometric and metabolic variables known to alter HRV, we performed an ancova adjusted for cholesterol and triglycerides and also another analysis in which the groups were comparable for anthropometric and metabolic characteristics. Comparison of FDRs and comparable control subjects revealed no significant difference in HRV (P > 0.05). CONCLUSIONS: A family history of T2DM, in the absence of concomitant metabolic disorders, does not impair heart rate variability.