Postexercise responses of muscle sympathetic nerve activity and blood flow to hyperinsulinemia in humans.

Although insulin and exercise cause dramatic changes in physiological parameters, the impact of exercise on neural and hemodynamic responses to insulin administration has not been described. In a study of the effects of a single bout of exercise on blood pressure (BP), muscle sympathetic nerve activity (MSNA), and forearm blood flow (FBF) responses to insulin infusion during the postexercise period, 11 healthy men underwent, in a random order, two hyperinsulinemic euglycemic clamps performed after 45 min of 1) bicycle exercise (50% peak O(2) uptake, Exercise session) and 2) seated rest (Control session). Data were analyzed during baseline and steady-state periods. Although insulin levels and insulin sensitivity were similar, baseline plasma glucose levels were significantly lower in the Exercise than in the Control session. Mean BP was significantly lower (3%) and FBF was higher (27%) in the Exercise session. Exercise increased insulin-induced MSNA enhancement (84%) without changing FBF and BP responses to hyperinsulinemia. In conclusion, a single bout of exercise that does not alter insulin sensitivity exacerbates insulin-induced increase in MSNA without changing FBF and BP responses to hyperinsulinemia.

White coat hypertension in adolescents.

BACKGROUND: Although white coat hypertension (WCH) seems to occur in 20% or more of the adult hypertensive population, this clinical condition has rarely been described in adolescents. DESIGN: Routine use of ambulatory blood pressure monitoring (ABPM) procedure as part of the investigation of arterial hypertension in adolescents. METHODS: Office blood pressure was checked after 5 minutes of rest in the seated position by the auscultation method and ABPM was performed with oscillometrical equipment (SpaceLabs 90207, Redmond, Washington, USA). RESULTS: In the present study 6 adolescents (5 females, 3 white), suspected to suffer from arterial hypertension as judged by office blood pressure measurements, mean age 15.1 years (12.2 - 17.7), mean height 164.5 cm, mean weight 77.2 kg, mean body mass index 28.8 kg/m2 (25 - 35.2), were diagnosed with WCH using ambulatory blood pressure monitoring (ABPM). CONCLUSION: White coat hypertension should also be considered in the evaluation of arterial hypertension in adolescents.

Ambulatory blood pressure monitoring of chronically dialyzed pediatric patients.

BACKGROUND: Background Ambulatory blood pressure monitoring (ABPM) has been shown to be more representative of blood pressure levels in adult patients than are casual measurements of blood pressure. OBJECTIVE: To evaluate, by means of ABPM, the behavior of blood pressure in children with chronic renal failure submitted to continuous ambulatory peritoneal dialysis and compare the results with casual blood pressure monitoring measurements. DESIGN: Evaluation of blood pressures in chronically dialyzed pediatric patients by ABPM. METHODS: Ten pediatric patients, treated by continuous ambulatory peritoneal dialysis were evaluated by ABPM using the oscillometric SpaceLabs 90207 monitor, every 10 min during the day and every 15 min during the night, for 24h. RESULTS: Six of 10 patients were found normotensive by office measurement of blood pressure; four of 10 patients were found hypertensive by casual measurements of blood pressure. With ABPM we obtained a mean success rate of 92.5%, confirmed hypertension in all the patients classified hypertensive in terms of office readings and reclassified six of six patients from normotensive to hypertensive. The mean systolic and diastolic physiologic falls in blood pressure at night were respectively by 10 and 15%. At the time of the ABPM study end-organ damage was present in two patients judged to be normotensive in terms of office blood pressures. CONCLUSION: Casual recordings of blood pressure are not representative of average blood pressure in dialyzed pediatric patients. ABPM seems to be a useful diagnostic aid for assessing treatment of hypertension in children with end-stage renal disease.

Comparison between casual blood pressure and ambulatory blood pressure monitoring parameters in healthy and hypertensive adolescents.

Casual blood pressure measurements were compared with mean ambulatory blood pressure values during wakefulness and sleep in 45 normotensive and 30 hypertensive adolescents of both sexes aged 10-18 years. Two sets of auscultatory casual blood pressure were obtained, one in a pediatric office setting (office blood pressure), performed by the physician, and one in the ambulatory blood pressure monitoring (ABPM) unit, performed by a trained nurse, prior to the initiation of ABPM (pre-ABPM blood pressure). In normotensive and hypertensive subjects of both sexes, the mean office systolic blood pressure (SBP) was lower than the mean pre-ABPM SBP, and the mean office diastolic blood pressure (DBP) was lower than the mean pre-ABPM DBP. In normotensive participants, the mean pre-ABPM SBP/DBP was lower than the mean ABPM SBP/DBP while awake, the mean ABPM SBP/DBP during sleep being lower than the mean ABPM SBP/DBP values while awake and the mean pre-ABPM SBP/DBP. No statistical difference was demonstrated between the mean office SBP and the mean ABPM SBP during sleep, the mean ABPM DBP during sleep being lower than the mean office DBP. The hypertensive adolescents presented a blood pressure profile similar to that of the normotensive group, albeit shifted upwards, with no significant difference between the mean pre-ABPM SBP and the mean ABPM SBP while awake but a higher mean pre-ABPM DBP than mean ABPM DBP while awake. This study suggests that, by evaluating the casual blood pressure in different environment/observer situations, the power of casual blood pressure to predict inadequate blood pressure control, manifested as abnormal ABPM parameters, can be enhanced. Our data indicate ABPM to be the method of choice for the early diagnosis and adequate follow-up of adolescent hypertension.

[Ambulatory blood pressure monitoring in normal adolescents]. / Monitorização ambulatorial da pressão arterial em adolescentes normais.

PURPOSE: To evaluate technical aspects of ambulatory blood pressure monitoring (ABPM) in normal adolescents. METHODS: Forty five normal adolescents (27 female), 10-18 years old. RESULTS: ABPM recordings showed a mean of 90% successful readings; 30% of the patients complained of sleep disruption related to the functioning of the ABPM monitor; the mean systolic, diastolic and heart rate fall during sleep was 13%, 23% and 24% respectively; the mean systolic and diastolic blood pressure load, while awake, was in male adolescents 25.4 +/- 27.7% and 11.8 +/- 14.6%, and in female adolescents, 17.5 +/- 18.7% and 11.8 +/- 11.4%, respectively; the mean systolic and diastolic blood pressure load, while asleep, was in male adolescents 15.4 +/- 22.9% and 2.8 +/- 4.9% and, in female adolescents, 10.5 +/- 18.2% and 1.8 +/- 2.7%, respectively; the mean diastolic values of the first two hours of recording were higher than the ones obtained during the rest of the hours of recording while awake; different mean systolic, diastolic and heart rate values were found during the afternoon and nocturnal sleep periods. CONCLUSION: ABPM was well accepted by the adolescent population, with good technical results.