Short-term moderate sodium restriction induces relative hyperfiltration in normotensive normoalbuminuric Type I diabetes mellitus

Aims/hypothesis. Type I (insulin-dependent) diabetes mellitus is associated with an increased extracellular volume. Sodium restriction might seem a logical form of treatment but data on its renal effects is conflicting. We therefore studied the effects of sodium restriction on renal haemodynamics in uncomplicated Type I diabetes mellitus. Methods. Uncomplicated Type I diabetic patients (n = 24) and matched control subjects (n = 24) were studied twice in random order: after a week of 50 mmol or after 200 mmol sodium intake, respectively. The diabetic patients were studied under normoglycaemic clamp conditions. Glomerular filtration rate and effective renal plasma flow were measured as the clearances of iothalamate and hippuran, respectively. Results. During liberal sodium intake, glomerular filtration, effective renal plasma flow and filtration fraction were similar between the diabetic patients and the control subjects. Sodium restriction decreased the effective renal plasma flow in both groups, whereas glomerular filtration rate only decreased in the control subjects. Consequently, in the diabetic patients, the filtration fraction was increased on low sodium (4.1 ± 8.4 %, p < 0.05 vs liberal sodium). As a consequence, filtration fraction (24.0 ± 2.6 vs 22.1 ± 2.0 %, p < 0.05) and glomerular filtration (119 ± 14 vs 110 ± 13 ml/min, p < 0.05) were higher in the diabetic patients than in the control subjects during sodium restriction. Conclusion/interpretation. Short-term moderate sodium restriction induces relative hyperfiltration in uncomplicated Type I diabetes. This could indicate an increased intraglomerular pressure. Sodium restriction could be an unfavourable preventive approach in diabetes mellitus but its long-term effects are not known. [Diabetologia (2002) 45: ▪–▪] Received: 17 September 2001 and in revised form: 7 November 2001     

Acute and late outcomes of Transcatheter Aortic Valve Implantation (TAVI) for the treatment of severe symptomatic aortic stenosis in patients at high- and low-surgical risk

Background: This prospective study examines the impact of EuroSCORE and transfemoral (TF) or transapical (TA) delivery approach on mortality at 30 days and 1 year in patients with severe aortic stenosis implanted with either the Edwards SAPIEN Transcatheter Heart Valve (THV) or Medtronic CoreValve. Methods and Results: TAVI was successfully performed in 293 (97.7%) of 300 patients (TF: 174, TA: 126, mean EuroSCORE 24.0). The mortality at 30 days and after 1 year was 6.0% and 17.3%. Mortality depends significantly on the logistic EuroSCORE with a 30‐day odds ratio (OR) of 1.92 (95% CI 1.41 to 2.62, P < 0.001) and after 1 year of 1.67 (95% CI 1.34 to 2.08, P < 0.001). Mortality in patients with a logistic EuroSCORE <15 (n = 113) or ≥15 (n = 187) at 30 days was 0.9% versus 9.1% and after 1 year 7.1% versus 23.5% demonstrating significantly less mortality (P < 0.001) in patients with lower logistic EuroSCOREs. In this specific setup of our center there was no significant difference (P = 0.553) in mortality regarding the technical approach for TA (4.0% and 15.9%) and for TF (7.5% and 18.4%). Severe cardiac complications occurred in 20 patients (6.7%) with a 30‐day mortality of 45.0%. Conclusion: The mortality in patients undergoing TAVI correlates significantly with the logistic EuroSCORE. Patients with a logistic EuroSCORE <15 can be implanted, with a low 30‐day mortality and good long‐term outcome over 1 year. (J Interven Cardiol 2012;25:364–374)     

Blood pressure during the interdialytic period in haemodialysis patients: estimation of representative blood pressure values.

The estimation of representative blood pressure (BP) levels is difficult in haemodialysis (HD) patients as it is not known whether pre- or postdialytic blood pressure are predictive for the average interdialytic BP. Furthermore, the day-night BP rhythm can be disturbed in HD patients. Therefore, in this study, BP was measured during the interdialytic period using non-invasive ambulatory BP measurements in four hypotensive, six normotensive, and 12 hypertensive HD patients. It was assessed whether pre- or postdialytic BP was representative for the average interdialytic BP. Furthermore, the nocturnal BP reduction was compared between HD patients, seven normotensive controls and eight treated subjects with essential hypertension. Postdialytic BP was superior to predialytic BP in predicting the average BP during the interdialytic period. BP did not differ significantly between day 1 and day 2 of the interdialytic period but increased rapidly in the hours before dialysis. Weight gain (corrected for actual body-weight) did not correlate significantly with the increment in systolic BP (r = 0.21; P = 0.2) or diastolic BP (r = -0.02; P = 0.5) during the interdialytic period. The nocturnal decline in systolic BP was significantly attenuated (P less than 0.001) in hypertensive HD patients compared with normotensive controls. The nocturnal reduction in diastolic BP was significantly less in hypotensive (P less than 0.001) and normotensive (P less than 0.001) HD patients compared with normotensive controls and in hypertensive HD patients compared with normotensive (P less than 0.001) and hypertensive (P less than 0.001) controls.(ABSTRACT TRUNCATED AT 250 WORDS)     

Human whole blood assay for rapid and routine testing of non-steroidal anti-inflammatory drugs (NSAIDs) on cyclo-oxygenase-2 activity

Aim of this study was to present a simple, fast and reliable method to examine the capacity of NSAIDs to inhibiting COX-2 activity that uses rapid (stimulation takes only 5 h compared to other existing protocols) and routine testing. The assay includes elimination of COX-1-activity using ASS (a selective COX-1 inhibitor) and the thromboxane synthetase inhibitor (TXBSI), COX-2 induction via LPS and measurement of PGE(2). Using TXBSI reduces the amount of LPS and results in higher prostaglandin production.Cremophor EL((R))-EtOH was used as vehicle instead of DMSO because within a defined concentration range, Cremophor EL((R))-EtOH allows even very hydrophobic drugs to be solubilized and applied in vitro without cell damage. Cremophor EL((R))-EtOH at 0.2% was optimal as at this relatively low concentration excellent drug dissolution was obtained whereas many hydrophobic substances precipitate in 0.2% DMSO.Our results demonstrate that the IC(50) values for the tested NSAIDs are in the range of published data.     

Ruptures of the device landing zone in patients undergoing transcatheter aortic valve implantation: an analysis of TAVI Karlsruhe (TAVIK) patients

Background

Aortic rupture of the device landing zone is a rare complication of transcatheter aortic valve implantation (TAVI) and it is associated with significant mortality.

Methods

This study reports on the experience of a single-center in a case series of more than 1,000 implants. We explored patient and procedural characteristics aiming at identifying variables that increase the risk for aortic root rupture.

Results

Among a total of 1,000 TAVI procedures, six patients (0.6 %) had a rupture of the device landing zone. Five of these patients received the balloon-expandable Edwards SAPIEN valve (5/813; 0.62 %) of which four had a supraannular and one a subannular rupture. One patient received the self-expanding Medtronic CoreValve (1/199; 0.5 %; p = n.s. vs. SAPIEN) and had an annular rupture. Factors that were associated with aortic rupture were: (1) the relative size of the valve compared with the aortic annulus and its geometric form; (2) the need for post-dilation of the new valve because of paravalvular leakage; and (3) the location and severity of calcification. We determined, to avoid aortic rupture, caution may be necessary in the presence of the following conditions: (1) flat sinuses of Valsalva and severe calcifications of either the body or the free edge of the aortic cusps (supraannular rupture); (2) an ellipsoid annulus and bulky calcifications on either the base of the cusps or the rim of the annulus (annular rupture); and (3) a narrow left-ventricular outflow tract (LVOT) and bulky calcification of the LVOT (subannular rupture). After considering these precautions, we observed no case of aortic root rupture in the following 600 cases.

Conclusion

The data indicate that to reduce the frequency of aortic rupture, a careful pre-procedural planning appears essential to avoid this serious and potentially deleterious complication.     

Diurnal blood-pressure variations in haemodialysis and CAPD patients

The influence of variations in fluid state on diurnal bloodpressure was studied by measuring day-time and night-time bloodpressure during a 3-day interdialytic period in 10 normotensiveand 10 hypertensive haemodialysis patients using Spacelab 90207Monitors. Ambulatory blood pressure was also measured during24 h in 11 normotensive and nine hypertensive CAPD patients,and in nine normotensive and 11 hypertensive control patientswith a normal renal function. Antihypertensive drugs had beendiscontinued for at least 3 weeks before the study period. Optimaldry weight in the haemodialysis patients was estimated by echographyof the inferior vena cava and in the CAPD patients on clinicalgrounds. Although in the dialysis patients and controls a significantnocturnal blood pressure reduction was found, day-night bloodpressure difference in the dialysis patients was blunted whencompared with the control patients. No significant differencesin diurnal blood pressure variation was found between the normotensiveand the hypertensive patients. Day-night blood pressure differencesin the haemodialysis patients did not change during the 3-dayinterdialytic period. Also the more stable fluid state of theCAPD patients was not associated with significant differentdiurnal blood pressure variation compared to the haemodialysispatients. We conclude that factors other than changes in extracellularfluid volume are responsible for a blunted day-night differencein blood pressure in dialysis patients.     

The influence of increasing dialysis treatment time and reducing dry weight on blood pressure control in hemodialysis patients: a prospective study.

A good blood pressure control can be achieved with long hemodialysis sessions (dialysis center of Tassin, France). However, it is not well known whether a higher dialysis dose or a lower dry weight is responsible for this phenomenon. In a preliminary study, 21 hypertensive dialysis patients, dialyzed three times a week for 3-5 h, were randomized into three groups during a 3-month study period. In 6 patients, the dialysis treatment time was increased by 2 h, and the dry weight was gradually decreased (group 1). In 7 patients the dialysis treatment time was increased by 2 h without a change in dry weight (group 2). In 8 patients the dry weight was gradually lowered without changing the dialysis treatment time (group 3). Before and after the study, cardiac index and left ventricular mass index (echocardiography) and forearm vascular resistance (strain gauge plethysmography) were determined on a middialytic day. The blood pressure was assessed by 48-hour ambulatory monitoring. The antihypertensive medication was reduced when the postdialytic blood pressure became <130/80 mm Hg. The dry weight was reduced by 2.6 +/- 1.4 kg in group 1 and by 2.3 +/- 0.8 kg in group 3 (p < 0.05). The number of classes of antihypertensive medication was reduced from 3.3 to 1.8 in group 1 (NS), from 2.4 to 1.7 in group 2 (NS), and from 3.1 to 1.3 in group 3 (p < 0.05). The dose of the remaining antihypertensive drugs was reduced by 50% in group 1 (p < 0.05), by 32% in group 2 (NS), and by 72.2% in group 3 (p < 0.05). The interdialytic systolic blood pressure decreased significantly after increasing the dialysis time without changing the dry weight (group 2: 7 +/- 5 mm Hg; p < 0.05). The systolic blood pressure was also lower in the other patients groups: group 1: 13 +/- 26 mm Hg, group 3 : 7 +/- 16 mm Hg (NS). The pulse pressure decreased significantly in group 2 (7 +/- 5 mm Hg; p < 0.05) and in group 3 (6 +/- 7 mm Hg; p < 0.05) and tended to decrease in group 1 (11 +/- 12 mm Hg; p = 0.08). The diastolic blood pressure and the day-night blood pressure difference did not change significantly, nor did cardiac index and left ventricular mass index. The forearm vascular resistance tended to decrease in the patients on long dialysis sessions. This preliminary study suggests that the dialysis treatment time might have an independent beneficial effect on blood pressure control.     

Quantified outdoor micro-activity data for children aged 7-12-years old

Estimation of aggregate exposure and risk requires detailed information regarding dermal contact and mouthing activity. We analyzed micro-level activity time series (MLATS) of children aged 7-12 years to quantify these contact behaviors and evaluate differences by age and gender. In all, 18 children, aged 7-12 years, were videotaped while playing outdoors. Video footage was transcribed via Virtual Timing Device (VTD) software. We calculated the hand and mouth contact frequency, hourly duration and median duration of contact with 16 object categories. Median mouthing frequencies were 12.6 events/h and 2.6 events/h for hands and non-dietary objects, respectively. Median hourly mouthing duration was 0.4 min/h and 0.1 min/h with hands and objects. Median mouthing contact duration was 1 s and 1.5 s with hands and objects, respectively. The median object contact frequency for both the hands combined was 537.3 events/h with an hourly contact duration of 81.8 min/h and a median contact duration of 3 s. There were no significant differences in the mouthing activity between genders or age groups. Female children had longer and more frequent hand contacts with several surface types. Age was negatively correlated with hand contacts of floor and wood surfaces. Contact frequencies in this study are higher than current regulatory recommendations for this age group.