A PUBLIC HEALTH PERSPECTIVE ON THE IMPORTANCE OF PLASMA PHENYLALANINE AND TYROSINE DETERMINATION IN RELATION TO NEWBORN SCREENING AND MONITORING OF TREATMENT IN PHENYLKETONURIA.

Newborn screening of phenylketonuria (PKU) is performed in many countries, including Romania, in addition to screening for congenital hypothyroidism. Patients affected by PKU require frequent measurements of phenylalanine (Phe) level in blood plasma. Such a determination is important not only in early diagnostic, but also in monitoring the treatment of PKU to maintain phenylalaninemia within limits that will not affect the brain. A simple, highly sensitive, accurate and rather inexpensive procedure for the simultaneous determination of Phe and Tyr plasma concentrations was previously described in this journal. The new procedure may be applied in many clinical laboratories, including those with no previous experience in diagnosis of inherited amino acid metabolic disorders. In this way the major public health problems linked to PKU not being detected in the first weeks of life (including the burden of institutionalized children with preventable mental retardation) may be avoided.

Obesity is a strong determinant of hypertensive target organ damage in young-to-middle-age patients.

OBJECTIVE: To examine the impact of overweight and obesity on development of target organ damage in the early stage of hypertension. SUBJECTS: Participants were 727 young-to-middle-age subjects screened for stage 1 hypertension and followed for 8 years. MEASUREMENTS: Ambulatory blood pressure (BP), albumin excretion rate and echocardiographic data were obtained at entry, every 5 years and/or before starting antihypertensive treatment. RESULTS: During the follow-up, hypertension needing treatment was developed by 54.7% of the subjects with normal weight, 66.6% of those with overweight and 73.0% of those with obesity (P<0.001). Kaplan-Meier curves showed that patients with obesity or overweight progressed to sustained hypertension earlier than those with normal weight (P<0.001). At study end, rate of organ damage was 10.7% in the normal weight, 16.4% in the overweight and 30.1% in the obese subjects (P<0.001). In a multivariable logistic regression analysis, overweight (P=0.008) and obesity (P<0.001) were significant predictors of final organ damage. Inclusion of changes in 24-h BP and body mass index, and of baseline organ damage did not virtually modify these associations (P=0.002 and <0.001, respectively). Obesity was a significant predictor of both left ventricular hypertrophy (P<0.001) and microalbuminuria (P=0.015) with an odds ratio (95% confidence interval) of 8.5 (2.7-26.8) and 3.5 (1.3-9.6), respectively. CONCLUSION: These data indicate that in hypertensive subjects obesity has deleterious effects on the cardiovascular system already at an early age. Preventive strategies addressed to achieve weight reduction should be implemented at a very early stage in young people with excess adiposity and high BP.

Phosducin rs12402521 polymorphism predicts development of hypertension in young subjects with overweight or obesity.

BACKGROUND AND AIMS: The G-protein regulator phosducin has been shown to be associated with stress-dependent blood pressure, but whether obesity is a modulator of the relationship between phosducin and risk of hypertension is unknown. We studied the effect of two phosducin polymorphisms on risk of hypertension in 273 overweight or obese (Ov-Ob) young-to-middle-age participants from the HARVEST and 287 normal weight (NW) participants. METHODS AND RESULTS: Genotyping of phosducin SNPs rs12402521 and rs6672836 was performed by real time PCR. For rs12402521, 64.6% of the participants were homozygous for the G allele, 27.9% heterozygous, and 7.5% homozygous for the A allele. During 7.7 years of follow-up, 339 subjects developed hypertension. In a Cox multivariable model, carriers of the A allele had a 1.28 (95% CI,1.00-1.63, p = 0.046) increased risk of hypertension. However, increased incidence of hypertension associated with A allele (AA + AG, 79% and GG, 59%, p = 0.001) was observed only among Ov-Ob individuals with a hazard ratio of 1.60 (95% CI, 1.13-2.21, p = 0.007) whereas in NW subjects the incidence of hypertension did not differ by genotype (56% in both groups). In the whole cohort, there was a significant interaction of phosducin genotype with body mass index on the risk of hypertension (p = 0.012). For SNP rs6672836 no association was found with incident hypertension. No haplotype effect was detected on the risk of hypertension. CONCLUSION: These data suggest that phosducin rs12402521 polymorphism is an important genetic predictor of obesity-related hypertension. In Ov-Ob carriers of the A allele aggressive nonpharmacological measures should be implemented.

SHAred DEcision making in Pelvic Organ Prolapse (SHADE-POP); Implementation is not as easy as it seems.

OBJECTIVE: Despite the positive effects of decision aids (DAs), implementation remains a significant challenge. The aim of the current study was to determine what barriers clinicians experience using a DA for pelvic organ prolapse (POP). METHODS: This study was conducted with a qualitative descriptive design including in-depth semi-structured interviews according to COREQ-criteria. Participants included clinicians and patients. Grounded theory analysis was used to describe the main themes. RESULTS: A total of 9 clinicians and 4 patients participated. Four major themes (1) opinions about shared decision making (SDM), (2) current practice, (3) experience with the DA, (4) suggestions for improvement and one minor theme (5) experience with the study, emerged. Clinicians were predominantly positive about the DA. CONCLUSION: Despite the positive attitudes of the clinicians in this study, the implementation of a DA is still challenging. The DA is forgotten regularly as improvement of logistics is needed, clinicians assume they already provide good care which might result in a reluctance to change and more engagement of physicians is needed. PRACTICE IMPLICATIONS: Regular contact with clinicians to remind, help and increase engagement and a decrease of the logistic burden is needed to ensure all patients can fully benefit of the DA.

Contaminant-associated disruption of vitamin A and its receptor (retinoic acid receptor alpha) in free-ranging harbour seals (Phoca vitulina).

Polychlorinated biphenyls (PCBs) have been associated with a number of toxic effects in marine mammals such as endocrine disruption and immunotoxicity that, in turn, are widely thought to have contributed to population level impacts including reproductive failure and outbreaks of disease. In this study, the dietary hormone vitamin A and expression levels of one of its receptors, retinoic acid receptor alpha (RARalpha), were used as biomarkers of PCB-associated health effects in harbour seals. Harbour seal pups (n=24) were live-captured in coastal British Columbia, Canada, and Washington State, USA, and sampled for whole blood (to obtain peripheral blood mononuclear cells, PBMCs) and blood plasma, as well as biopsies of blubber and skin. Concentrations of circulatory vitamin A (retinol) in plasma and stored vitamin A in blubber were negatively associated with blubber PCB concentrations (R=-0.518, p=0.013 and R=-0.645, p=0.009, respectively). However, vitamin A concentrations in skin, an important target tissue, remained constant, which likely reflects a compensatory transfer from blubber to maintain physiological functions. In addition, we characterized the harbour seal RARalpha, and investigated its expression levels as a potential biomarker in seals. RARalpha expression in blubber, but not on PBMCs, was elevated in more contaminated animals (R=0.580, p=0.009). This may represent a direct contaminant-related effect, or, a compensation for the contaminant-related disruption of (circulatory and/or blubber) hormone levels. Since vitamin A is critical to developmental, reproductive and immunological health, our observations of a contaminant-related disruption of its physiology in free-ranging seals may portend population level consequences. Vitamin A concentrations and RARalpha expression levels can therefore represent relevant and sensitive biomarkers of PCB-associated toxic effects in toxicological studies of marine mammals.

Sodium-lithium countertransport has low affinity for sodium in hyperinsulinemic hypertensive subjects.

We recently reported that incubation of red blood cells with insulin markedly decreases the affinity for external Na+ and increases the maximal transport rate (Vmax) of Na(+)-Li+ countertransport. The association of hypertension with insulin resistance and its compensatory hyperinsulinemia led us to investigate the relationship between insulin levels in vivo and the Na+ activation kinetics of this antiporter. We studied normotensive (n = 28) and hypertensive (n = 25) subjects after they had fasted overnight and determined their plasma glucose and insulin concentrations. Insulin levels were higher in the hypertensive subjects (11.7 +/- 1.5 microU/mL, mean +/- SEM) than in the normotensive subjects (8.2 +/- 1.2 microU/mL), but glucose levels were similar and within normal limits. Antiporter activity was measured as sodium-stimulated Li+ efflux by a new procedure that uses isosmotic conditions to raise external Na+ to 280 mmol/L. In normotensive subjects, Vmax was reached between 50 and 100 mmol/L Na+, whereas in most hypertensive subjects, Na+ concentrations higher than 150 mmol/L were needed. This different kinetic behavior was because the Na+ concentration for half-maximal activation (Km) was twofold higher in hypertensive subjects (58.9 +/- 5.3 mmol/L) than in normotensive subjects (29.8 +/- 2.6 mmol/L, P < .001). Hypertensive subjects with fasting insulin levels greater than 10 microU/mL (n = 12) had a higher Km for Na+ than subjects with insulin levels less than 10 microU/mL (n = 13) (73.4 +/- 8.7 versus 45.6 +/- 3.9 mmol/L, respectively, P < .01) and similar Vmax (0.57 +/- 0.05 versus 0.41 +/- 0.05 mmol.L-1.h-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Target-organ damage in stage I hypertensive subjects with white coat and sustained hypertension: results from the HARVEST study.

Controversy remains on whether white coat hypertension is a benign clinical condition or carries an increased risk of target-organ damage. Nine hundred forty-two stage I hypertensive subjects enrolled in the HARVEST trial underwent 24-hour ambulatory blood pressure monitoring and urine collection for albumin measurement. Reliable echocardiographic data were obtained in 722 subjects. White coat hypertensive subjects were defined on the basis of three different partition values: mean daytime blood pressure <130/90 mm Hg, <135/85 mm Hg, or <140/90 mm Hg. Ninety-five normotensive subjects with similar age and sex distribution were studied as controls. With all threshold levels, left ventricular mass index and wall thicknesses were greater in the sustained hypertensive subjects than in the white coat hypertensive subjects, also when these differences were adjusted for blood pressure readings taken in the office. Relative wall thickness was similar in the two hypertensive groups. All echocardiographic dimensional data were greater in the white coat hypertensive subjects than in the normotensive subjects. Urinary albumin and the prevalence of microalbuminuria were also greater in the sustained hypertensive subjects than in the white coat hypertensive subjects. No significant differences in urinary albumin were found between the white coat hypertensive and the normotensive subjects. These results show that within a population of subjects with stage I hypertension, subjects with white coat hypertension have a smaller degree of hypertensive complications than those with sustained hypertension, irrespective of their blood pressure levels taken in the office. However, in comparison with normotensive subjects, white coat hypertensive subjects seem to be at greater risk. Cardiac involvement seems to precede glomerular damage in the early stage of hypertension.

Ambulatory blood pressure predicts end-organ damage only in subjects with reproducible recordings. HARVEST Study Investigators. Hypertension and Ambulatory Recording Venetia Study.

OBJECTIVE: To determine whether the prediction of target-organ damage varies according to the reproducibility of 24 h blood pressure. SETTING: Seventeen hypertension clinics in northeast Italy. MAIN OUTCOME MEASURES: Correlations of left ventricular mass index and albumin excretion rate with 24 h and office blood pressures in relation to tertiles of ambulatory blood pressure reproducibility. PATIENTS AND METHODS: In 716 consecutive, stage I, hypertensives enrolled in the Hypertension and Ambulatory Recording Venetia Study (HARVEST), ambulatory blood pressure monitoring was performed twice, 3 months apart In all subjects, the albumin excretion rate was measured by radioimmunoassay, and in 567, the left ventricular mass index was assessed by echocardiography. RESULTS: The subjects were divided into tertiles of ambulatory blood pressure consistency (between-monitoring differences, regardless of the sign). In the tertile of subjects with good reproducibility, correlation coefficients of systolic and diastolic ambulatory blood pressure with left ventricular mass and urinary albumin excretion were significant and higher than those of office blood pressure. In contrast, in the two tertiles with poorer reproducibility, the coefficients were barely or not significant for both pressures. The advantage of ambulatory blood pressure over office blood pressure in predicting target-organ damage was no longer present for systolic blood pressure differences greater than 3.8 mmHg and diastolic blood pressure differences greater than 3.1 mmHg. CONCLUSIONS: These data indicate that ambulatory blood pressure is a better predictor of left ventricular mass and urinary albumin excretion than office blood pressure, but only in subjects with good pressure reproducibility. Therefore, the assessment of hypertensive patients should be based on duplicate blood pressure monitorings. Recordings with 24 h systolic and diastolic blood pressure differences greater than 4 and 3 mmHg, respectively, should be considered with caution.

An independent relationship between plasma leptin and heart rate in untreated patients with essential hypertension.

OBJECTIVE: To test the hypothesis that hemodynamic measurements in patients with essential hypertension are related independently to plasma leptin levels. PATIENTS AND METHODS: We measured plasma leptin, insulin, office and ambulatory blood pressure and heart rate in 60 men with untreated mild hypertension. RESULTS: Plasma leptin correlated significantly with body mass index (r = 0.43, P = 0.001), 24 h heart rate (r = 0.35, P = 0.006) and 24 h diastolic blood pressure (r = 0.27, P = 0.04) but not with age (r = 0.03; P = 0.85) or 24 h systolic blood pressure (r = -0.08, P = 0.56). Plasma leptin levels adjusted for body mass index correlated significantly with 24 h heart rate (r = 0.36, P = 0.005) but not with 24 h diastolic blood pressure (r = 0.19, P = 0.15). We divided the patient population into tertiles of body mass index-adjusted plasma leptin levels. Age, plasma insulin, blood pressure, smoking status and physical activity habits were similar across the adjusted leptin tertiles. Patients from the third tertile of adjusted plasma leptin distribution (those with leptin levels higher than would be expected on the basis of body mass index) had significantly faster ambulatory heart rates than subjects from both the first and the second tertiles. The difference in heart rate across the three tertiles was most pronounced for the night-time values. CONCLUSIONS: In patients with essential hypertension, heart rate is faster in those patients with higher plasma leptin levels. This relationship is independent of age, body mass index, insulin levels, blood pressure level, smoking status and physical activity.

Relationship between albumin excretion rate, ambulatory blood pressure and left ventricular hypertrophy in mild hypertension.

OBJECTIVE: To study the relationship of urinary albumin excretion to ambulatory blood pressure and other cardiovascular risk factors in borderline to mild hypertension. PATIENTS AND METHODS: We studied 779 patients with borderline to mild hypertension (mean +/- SEM age 33 +/- 0.3 years; mean +/- SEM office blood pressure 146 +/- 0.4/94 +/- 0.2 mmHg) at 17 hypertension clinics in northeast Italy. Office and 24-h blood pressures were recorded with simultaneous urine collection for albumin measurement. In 510 subjects, left ventricular mass was measured by echocardiography. RESULTS: Subjects with overt (> or = 30 mg/24 h) and borderline (16-29 mg/24 h) microalbuminuria had similar 24-h blood pressure levels, higher than those in the subjects without microalbuminuria. In the univariate and multiple regression analyses the albumin excretion rate was closely correlated with 24-h systolic blood pressure and not related to age, body mass index, metabolic parameters, lifestyle factor and degree of left ventricular hypertrophy. CONCLUSIONS: Borderline values of urinary albumin excretion (16-29 mg/24 h) may be clinically relevant in subjects with borderline to mild hypertension. Renal and cardiac damage do not develop in parallel in the initial phases of hypertension.

24-hour blood pressure control by once-daily administration of irbesartan assessed by ambulatory blood pressure monitoring. Irbesartan Multicenter Investigators' Group.

OBJECTIVES: To compare 24 h ambulatory blood pressure and trough office blood pressure lowerings after 8 weeks of therapy with 75 mg irbesartan once a day, 150 mg irbesartan once a day , and 75 mg irbesartan twice a day versus placebo; and to assess safety and tolerability of irbesartan therapy. DESIGN: Multicenter, double-blind, randomized, placebo-controlled trial. SETTING: Sixteen centers in Italy. PATIENTS: Caucasian patients (n = 215) aged > or = 18 years with seated diastolic blood pressure 95-110 mmHg and ambulatory diastolic blood pressure (ADBP) > or = 85 mmHg. PRIMARY OUTCOME: Mean 24 h ADBP after 8 weeks of irbesartan therapy. RESULTS: Mean changes (value before treatment minus value after treatment) in ADBP for placebo, 75 mg irbesartan once a day, 150 mg irbesartan once a day, and 75 mg irbesartan twice a day were -0.2, -5.4, -7.2, and -7.2 mmHg, respectively; respective changes in ambulatory systolic blood pressure were +1.6, -8.3, -10.5, and -9.7 mmHg. All irbesartan regimens reduced trough office seated diastolic blood pressure and seated systolic blood pressure after 2 and 8 weeks of treatment (all P < 0.01, versus placebo except for seated systolic blood pressure in patients in the 75 mg irbesartan once a day group). Trough: peak ratios were > or = 55% with 150 mg irbesartan once a day. Percentages of patients whose blood pressures were normalized with 150 mg irbesartan once a day (45%) and 75 mg irbesartan twice a day (47%) were greater than those with placebo (14%, P < 0.01) and with 75 mg irbesartan once a day (19%, NS, versus placebo). Adverse events with irbesartan were similar to those with placebo. CONCLUSIONS: All irbesartan regimens significantly reduced mean 24 h ADBP and ambulatory systolic blood pressure, and were well tolerated. Administration of 150 mg irbesartan once a day provided significant reduction of blood pressure for 24 h, equivalent to that obtained with the same daily dose divided into two separate administrations.

Beats modulate blood pressure during running.

Blood pressure (BP) changes during running were studied in 25 subjects with intraarterial monitoring. Periodic pulse pressure variations ranging from 20 to 200 mm Hg were recorded throughout the exercise. To prove that these pressure oscillations were due to a "beat" phenomenon 10 athletes ran with a Teruflex container filled with saline: pressure changes up to +/- 62 mm Hg were recorded in the container. These pressure waves were added by computer to the sphygmic waves recorded intraarterially in the same subject during bicycle ergometry: the resultant tracing showed a beat-shaped pattern similar to that recorded during running.

Structural abnormalities and not diastolic dysfunction are the earliest left ventricular changes in hypertension. HARVEST Study Group.

It has been claimed that diastolic dysfunction is the earliest cardiac abnormality in hypertension, preceding the development of left ventricular (LV) structural abnormalities. To detect early signs of hypertensive cardiac involvement 722 subjects (533 men and 189 women), 18-45 years old, with stage I hypertension, were studied by M-mode and Doppler echocardiography. Blood pressure was measured by 24-h ambulatory monitoring. Ninety-five normotensive individuals of similar age and gender distributions were studied as controls. Significant, though modest, changes of LV mass and geometry were found in the participants in comparison with the normotensive controls. The increment was +10.4 g/m2 for LV mass index, +1.8 mm for LV wall thickness, and +0.032 for relative wall thickness. A slight increase in atrial filling peak velocity was found in the hypertensive subjects at Doppler analysis of transmitral flow, but the ratio of early to atrial velocity of LV diastolic filling did not differ between the two groups. In multiple regression analyses, which included age, body mass index, heart rate, smoking, and physical activity, 24-h mean blood pressure emerged as a significant predictor of LV mass index (men, P = .003; women, P = .04) and wall thickness (men, P = .03; women, P = .004) in the hypertensive subjects, whereas no index of diastolic filling was significantly associated with ambulatory blood pressure in either gender. The present data indicate that changes in LV anatomy are the earliest signs of hypertensive cardiac involvement. Left ventricular filling is affected only marginally in the initial phase of hypertension.

Blood pressure changes during running in humans: the "beat" phenomenon.

In 20 runners the intra-arterial blood pressure changes determined by a long-distance run and by a maximal bicycle ergometric test were recorded by means of the portable Oxford system. A peculiar pattern of the phasic waves was observed throughout the run: continuous rhythmic pulse pressure oscillations ranging in frequency between 4 and 28/min and unrelated to respiration were detected. The shape of these oscillations prompted us to investigate whether they were due to a "beat" phenomenon, that is, to the combined effect of two waves with a nearly equal frequency. To test this hypothesis, during the run 10 athletes carried a fluid-filled container around the chest. The pressure waves recorded in the container were added by computer to those recorded intra-arterially during bicycle ergometry. The resultant harmonic showed a pattern similar to that recorded in the athlete's radial artery during running. Conversely, by subtracting the pressure waves recorded in the container from those simultaneously recorded at the radial artery during running, nearly flat tracings were obtained. The source of the beat phenomenon has therefore been identified in the wave, which generates inside the aorta and the great vessels at each foot-strike shock.

Effects of physical exercise on clinic and 24-hour ambulatory blood pressure in young subjects with mild hypertension.

BACKGROUND: The aim of the study was to assess the effect of physical activity on 24-hr ambulatory blood pressure (ABPM) and office blood pressure (BP) in 572 male subjects with borderline to mild hypertension from the HARVEST study. METHODS: Subjects were 18 to 45 years old with diastolic BP of 90-99 mmHg and/or systolic BP of 140-159 mmHg. They never took any anti-hypertensive therapy. All subjects underwent physical examination, office BP measurement and two 24-hr ambulatory BP monitorings performed three months apart. Subjects were classified as non exercisers, group 1 (n=331), mild exercisers, group 2 (n=192) and heavy exercisers, group 3 (n=49). During the three months of follow-up subjects maintained the same physical activity habits. There was no difference in smoking and alcohol consumption between the 3 groups. As the groups differed significantly in age and body mass index data were adjusted for these confounders. RESULTS: At baseline office and ambulatory systolic BP were similar in the 3 groups, while diastolic BP was proportional to the level of physical activity although the difference was significant only between the group of non-exercisers and mild exercisers. Heart rate (HR) was always inversely related to the intensity of exercise. After three months follow-up office systolic BP was similar among the three groups and diastolic BP slightly decreased in the exercisers (group 1 vs group 3 p=0.02, group 2 vs group 3 p=0.04). At ABPM the group of heavy exercisers showed a significant decrease in daytime systolic BP (135.4plus minus0.6 vs 134plus minus0.8 vs 132.2plus minus1.6 mmHg; group 1 vs group 3 p<0.05) and the difference between systolic ambulatory BP at the 3rd month and at baseline, showed an additional significant decrease according to exercise intensity (24-hr systolic BP group 1 vs group 3 p=0.001, group 2 vs group 3 p=0.004; daytime systolic BP group 1 vs group 3 p=0.0009, group 2 vs group 3 p=0.004; night-time systolic BP group 1 vs group 3 p=0.02, group 2 vs group 3 p=0.02). No changes in ambulatory diastolic BP were observed. CONCLUSIONS: In conclusion, physical activity has a positive effect in lowering BP attenuating the risk of hypertension in young subjects with borderline hypertension. The anti-hypertensive effect of physical activity persisted after three months and the group of exercisers had an additional reduction in systolic BP detected by ABPM. To obtain accurate information on chronic levels of arterial pressure over time 24-hr ambulatory BP should be preferred to traditional casual readings.

Tolerability and efficacy of fosinopril and hydrochlorothiazide compared with amiloride and hydrochlorothiazide in patients with mild to moderate hypertension.

This 6-month multicentre, randomised, double-blind, parallel group clinical trial compared the tolerability and antihypertensive efficacy of a once-daily combination of fosinopril 20mg/hydrochlorothiazide 12.5mg (FOS/HCTZ) with a combination of amiloride 5mg/hydrochlorothiazide 50mg (AMI/HCTZ) in 217 patients with mild to moderate essential hypertension. Adverse events related to hypotension or to specifically targeted clinical laboratory values were observed infrequently with FOS/HCTZ compared with AMI/HCTZ: with FOS/HCTZ, only 4 of 104 patients (3.9%) experienced such events, compared with 16 of 113 (14.1%) in the AMI/HCTZ group (p < 0.001). While statistically significant differences were found between the two treatment groups for changes from baseline in serum potassium, cholesterol, triglyceride and glucose values, the metabolic profile was uniformly unfavourable towards the AMI/HCTZ group; for example, reductions in potassium and elevations in cholesterol, triglyceride and glucose were more pronounced with the AMI/HCTZ group than with the FOS/HCTZ group. Both antihypertensive regimens produced statistically significant reductions from baseline in seated diastolic blood pressure that were equivalent at most points of measurement during double-blind treatment. Therapeutic response rates were high (>/=95%) and were similar for both regimens throughout the study. Because the relative risk for adverse events was markedly less over the long term with FOS/HCTZ than with AMI/HCTZ, the combination of fosinopril and hydrochlorothiazide may offer significant tolerability advantages over amiloride plus hydrochlorothiazide for such patients.

Ambulatory blood pressure versus casual pressure for the evaluation of target organ damage in hypertension: complications of hypertension.

In 122 patients aged between 14 and 58 years with different degrees of hypertension, mean 24-h ambulatory blood pressure (BP) and casual BP were measured to evaluate the relationship with hypertensive target organ damage. The following results were obtained: (1) In agreement with previous reports, this study found a better relationship between target organ damage and mean ambulatory BP than with causal BP, although the correlation coefficients were similar for both. (2) A higher degree of cardiovascular complications occurred in patients with higher variability in BP. These data emphasize the superiority of BP monitoring over causal BP for the study of hypertension and its complications.

Blood pressure changes during heavy-resistance exercise.

To study the mechanisms of the blood pressure changes during weight-lifting, three hypertensive and five normotensive body-builders underwent continuous intra-arterial monitoring. In two subjects (one normotensive and one hypertensive), intrathoracic and intra-abdominal pressures were also measured. Extremely high blood pressure elevations of up to 345/245 mmHg were observed during the lifts. Squatting caused the highest pressure rises and single-arm curls the lowest. Both the intrathoracic and the intra-abdominal pressures increased greatly during each lift and closely paralleled the changes in intra-arterial pressure. A close correlation was found between the blood pressure increase during the exercise and during a hand-grip test (r = 0.95, P less than 0.001). These results suggest that a pronounced increase in intra-thoracic and intra-abdominal pressures is a major determinant of the blood pressure elevations occurring during weight-lifting. The pressor reflex which accompanies static contractions and the individual baseline blood pressure levels also seem to affect the height of the pressure peaks.

Blood pressure changes during physical exercise (the beat phenomenon).

We have previously reported that blood pressure during running shows a peculiar pattern attributable to the beat phenomenon. To elucidate the mechanism behind this phenomenon in 10 amateur athletes, intra-arterial blood pressure was continuously recorded using the Oxford technique. During the run, each athlete carried on his chest a container filled with saline kept under pressure, connected to a second transducer. In the container, pressure waves ranging in amplitude from +/- 10 to +/- 62 mmHg were recorded. Their frequency was equal to that of the athletes' strides. When these waves were added by computer to the blood pressure tracing recorded during a bicycle ergometric test, the resultant harmonic proved to be similar to the tracing observed during running. The present results demonstrate that the running-induced blood pressure pattern is the sum of the accessory wave generated by the rhythmic aortic shocks produced by running locomotion and the normal sphygmic wave.