Dietary salt loading impairs arterial vascular reactivity 1-3

BACKGROUND: Studies of sodium have shown improvements in vascular function and blood pressure (BP). The effect of chronic sodium loading from a low-sodium diet to a Western diet on vascular function and BP has been less well studied.

OBJECTIVE: The objective was to examine the effects of dietary salt intake on vascular function and BP.

DESIGN: Thirty-five hypertensive volunteers met the inclusion criteria. After a 2-wk run-in with a low-sodium diet (60 mmol/d), the participants maintained their diets and were randomly assigned to receive sequentially 1 of 3 interventions for 4 wk, with a 2-wk washout between interventions: sodium-free tomato juice (A), tomato juice containing 90 mmol Na (B), and tomato juice containing 140 mmol Na (C). The outcomes were changes in pulse wave velocity (PWV), systolic BP (SBP), and diastolic BP (DBP).

RESULTS: The difference in PWV between interventions B and A was 0.39 m/s (95% CI: 0.18, 0.60 m/s; P = 0.001) and between C and A was 0.35 m/s (95% CI: 0.13, 0.57 m/s; P = 0.01). Differences in SBP and DBP between interventions B and A were 4.4 mm Hg (95% CI: 1.2, 7.8 mm Hg; P = 0.01) and 2.4 mm Hg (95% CI: 0.8, 4.1 mm Hg; P = 0.001), respectively, and between interventions C and A were 5.6 mm Hg (95% CI: 2.7, 8.4 mm Hg; P = 0.01) and 3.3 mm Hg (95% CI: 1.5, 5.0 mm Hg; P = 0.001), respectively. Changes in PWV correlated with changes in SBP (r = 0.52) and DBP (r = 0.58).

CONCLUSIONS: Dietary salt loading produced significant increases in PWV and BP in hypertensive volunteers. Correlations between BP and PWV suggest that salt loading may have a BP-independent effect on vascular wall function. This further supports the importance of dietary sodium restriction in the management of hypertension. This trial was registered with the Australian and New Zealand Clinical Trials Registry as ACTRN12609000161224.

Structured type 1 diabetes education delivered in routine care in Australia reduces diabetes-related emergencies and severe diabetes-related distress: the OzDAFNE program

AIMS: To evaluate structured type 1 diabetes education delivered in routine practice throughout Australia.

METHODS: Participants attended a five-day training program in insulin dose adjustment and carbohydrate counting between April 2007 and February 2012. Using an uncontrolled before-and-after study design, we investigated: HbA1c (% and mmol/mol); severe hypoglycaemia; diabetes ketoacidosis (DKA) requiring hospitalisation, and diabetes-related distress (Problem Areas in Diabetes scale; PAID), weight (kg); body mass index. Data were collected pre-training and 6-18 months post-training. Change in outcome scores were examined overall as well as between groups stratified by baseline HbA1c quartiles. Data are mean±SD or % (n).

RESULTS: 506 participants had data eligible for analysis. From baseline to follow-up, significant reductions were observed in the proportion of participants reporting at least one severe hypoglycaemic event (24.7% (n=123) vs 12.1% (n=59), p<0.001); and severe diabetes-related distress (29.3% (n=145) vs 12.6% (n=60), p<0.001). DKA requiring hospitalisation in the past year reduced from 4.1% (n=20) to 1.2% (n=6). For those with above target baseline HbA1c there was a small, statistically significant improvement (n=418, 8.4±1.1% (69±12mmol/mol) to 8.2±1.1% (66±12mmol/mol). HbA1c improvement was clinically significant among those in the highest baseline quartile (n=122, 9.7±1.1% (82±11mmol/mol) to 9.0±1.2% (75±13mmol/mol), p<0.001).

CONCLUSIONS: The proportion of participants reporting severe hypoglycaemia, DKA and severe diabetes-related distress was at least halved, and HbA1c reduced by 0.7% (7mmol/mol) among those with highest baseline levels. Structured type 1 diabetes education delivered in routine practice offers clinically important benefits for those with greatest clinical need.

Effect of processing parameters on the magnetic properties and macrotexture of a Nd13.5Fe73.8Co6.7B5.6Ga0.4 alloy processed by equal channel angular pressing with back pressure

Equal channel angular pressing (ECAP) is a well-established thermo-mechanical processing technique, which could induce the c-axis texture of Nd2Fe14B in a melt-spun Nd13.5Fe73.8Co6.7B5.6Ga0.4 alloy. However, the effects of ECAP processing parameters, such as temperature, back pressure (BP), and multiple-pass ECAP routes, remain unknown for this alloy. In this paper, we have investigated the effects of these processing parameters on the c-axis texture formation. It is found by X-ray diffraction macrotexture analysis that the maximum intensity of (001) pole figures for the tetragonal-Nd2Fe14B phase (Imax) shows an increase from 2.7 to 4.1 m.r.d. (multiples of random distribution) by increasing the ECAP temperature from 723 to 823 K, while the difference in remanent magnetization between easy and hard directions (Δ Mr) rises from 24.0 to 41.5 Am2/kg. When the BP was increased from 0.25 to 0.5 GPa at 823 K, Imax showed an increase from 2.8 to 4.1 m.r.d. However, Imax saturated for BPs above 0.5 GPa, suggesting that BP has limited effect on the texture formation, although it is necessary for the compaction of the alloy powders. Two multiple-pass ECAP routes conventionally known as routes A and C were employed for two-pass ECAP at 823 K. It is found that route A processing is effective in enhancing the texture formation, while the texture is lost by a subsequent pressing when adopting route C. Therefore, the compaction of Nd13.5Fe73.8Co6.7B5.6Ga0.4 alloy powder using route A ECAP passes with 0.5 GPa BP at 823 K results in pronounced texture, which is beneficial for anisotropic hard magnetic properties.