No abstract

We constructed an age-adjusted reference curve for PWV. Using the 95th centile of this curve as a threshold (e.g. 10.94, 11.86, and 13.18 m/s for 20, 40, and 60 years old) shows construct validity, as it appears to identify medium and high CVD risk groups reasonably accurately. This reference range needs to be tested using other datasets.

With body mass included as a covariate all differences were moderate to large, and very likely to almost certainly lower in the squads with lower body mass, with the exception of comparisons between Senior and Under 21 squads. Conclusions: The data demonstrate that there appears to be a ceiling to the VIFT attained in rugby union players which does not increase from Under 16s to Senior level. However, the associated increases in body mass with increased playing level suggest that the ability to perform high intensity running is increased with age, although not translated into greater VIFT due to the detrimental effect of body mass on change of direction. . Practitioners should be aware that VIFT is unlikely to improve, however it needs to be monitored during periods where increases in body mass are evident.

The objective of this study was to re-evaluate the effect of arm position on blood pressure (BP) measurement with auscultatory and oscillometric methods including ambulatory blood pressure monitoring (ABPM). The setting was the hospital outpatient department and the subjects chosen were normotensive and hypertensive. The effect of lowering the arm from heart level on indirect systolic BP (SBP) and diastolic BP (DBP) measurement as well as the importance of supporting the horizontal arm were measured. In the sitting position, lowering the supported horizontal arm to the dependent position increased BP measured by a mercury device from 103 7 10/60 7 7 to 111 7 14/ 67 7 10 mmHg in normotensive subjects, a mean increase of 8/7 mmHg (Po0.01). In hypertensive subjects, a similar manoeuvre increased BP from 143 7 21/78 7 17 to 166 7 29/88 7 20 mmHg, an increase of 23/10 mmHg (Po0.01). Combined results from normotensive and hypertensive subjects demonstrate a direct and proportional association between BP (SBP and DBP) and the increase produced by arm dependency. Similar changes and associations were noted with oscillometric devices in the clinic situation. However, supporting the horizontal arm did not alter BP. Of particular interest, analysis of 13 hypertensive subjects who underwent ABPM on two occasions, once with the arm in the 'usual' position and once with the arm held horizontally for BP measurement during waking hours, demonstrated changes comparable to the other devices. The mean 12-hour BP was 154 7 19/82 7 10 mmHg during the former period and significantly decreased to 141 7 18/74 7 9 mmHg during the latter period (Po0.01). Regression analysis of the change in SBP and DBP with arm position change again demonstrated a close correlation (r 2 ¼ 0.8113 and 0.7273; Po0.001) with the artefact being larger with higher systolic and diastolic pressures. In conclusion, arm movements lead to significant artefacts in BP measurement, which are greater, the higher the systolic or diastolic pressure. These systematic errors occur when using both auscultatory and oscillometric (clinic and ABPM) devices and might lead to an erroneous diagnosis of hypertension and unnecessary medication, particularly in individuals with high normal BP levels. Since clinical interpretations of heart level vary, the horizontal arm position should be the unambiguous standard for all sitting and standing BP auscultatory and oscillometric measurements.

Arterial stiffness measured by pulse wave velocity (PWV) is an accepted strong, independent predictor of cardiovascular events and mortality. However, lack of a reliable reference range has limited its use in clinical practice. In this evidence-based review, we applied published data to develop a PWV risk stratification model and demonstrated its impact on the management of common clinical scenarios. After reviewing 97 studies where PWV was measured, 5 end-stage renal disease patients, 5 hypertensives, 2 diabetics, and 2 elderly studies were selected. Pooling the data by the "fixed-effect model" demonstrated that the mortality and cardiovascular event risk ratio for one level increment in PWV was 2.41 (1.81-3.20) or 1.69 (1.35-2.11), respectively.There was a significant difference in PWV between survived and deceased groups, both in the low and high risk populations. Furthermore, risk comparison demonstrated that 1 standard deviation increment in PWV is equivalent to 10 years of aging, or 1.5 to 2 times the risk of a 10 mmHg increase in systolic blood pressure. Evidence shows that PWV can be beneficially used in clinical practice for cardiovascular risk stratification. Furthermore, the above risk estimates could be incorporated into currently used cardiac risk scores to improve their predictive power and facilitate the clinical application of PWV.

Recollection of micropuncture experiments were performed on acutely thyroparathyroidectomized rats rendered magnesium deficient by dietary deprivation. Urinary magnesium excretion fell from a control of 15 to 3% of the filtered load after magnesium restriction. The loop of Henle, presumably the thick ascending limb, was the major modulator for renal magnesium homeostasis. The transport capacity for magnesium, however, was less in deficient rats than control animals. Absolute magnesium reabsorption increased with acute infusions of magnesium chloride but was always less in magnesium-deficient rats than control rats for any given filtered load, which suggests either a defect of a resetting of the reabsorption mechanism. Recollection micropuncture demonstrated that this was a characteristic of the loop of Henle. Proximal magnesium reabsorption remained unchanged at 15% of the filtered load and was unaffected by magnesium deficiency or acute magnesium repletion. Distal tubular magnesium reabsorption was limited during depletion and increased to a similar extent in control and deficient rats with enhanced magnesium delivery. Calcium reabsorption was not altered in magnesium deficiency; however, elevations of extracellular magnesium resulted in a specific inhibition of calcium reabsorption within the loop of Henle. These data suggest that overall control of renal magnesium reabsorption occurs within the loop of Henle and that the proximal tubule reabsorbs a constant fraction of the filtered load despite variations in body magnesium status.

Blood pressure self-measurement is increasing in most communities and yet its role in the management of hypertension is poorly understood. This study was devised to evaluate the behaviour of doctors in general practice when treating patients with poorly controlled essential hypertension who use self-measurement. Patients, most of whom were already taking antihypertensive medications were commenced on perindopril or indapamide at their doctor's discretion and were randomly allocated to self-measurement (SM) using an OMRON HEM706 oscillometric device or a continuation of their usual care (UC) over an 8-week period. This was an observational study without any specific or set treatment goals for the doctor to follow. Sixty of 62 subjects completed the study and the two groups were equally matched for age, body mass index, gender, and blood pressure (BP). While additional perindopril or indapamide produced a significant fall in BP in both groups over the study period, the systolic pressure remained significantly higher in the SM group (sitting 148 ± 3 compared with 142 ± 3; 145 ± 3 compared with 138 ± 3

This study supports the use of wrist-cuff monitors for self/home use and underlines the need for a more precise definition for arm position when using all BP devices -- mercury and oscillometric.