1,398 research outputs found
Cadmium-Related Mortality and Long-Term Secular Trends in the Cadmium Body Burden of an Environmentally Exposed Population
BACKGROUND: Few population studies have reported on the long-term changes in the internal cadmium dose and simultaneously occurring mortality.
OBJECTIVE: We monitored blood cadmium (BCd), 24-hr urinary cadmium (UCd), and mortality in an environmentally exposed population.
METHODS: Starting from 1985, we followed BCd (until 2003), UCd (until 1996), and mortality (until 2007) among 476 and 480 subjects, randomly recruited from low- exposure areas (LEA) and high-exposure areas (HEA). The last cadmium-producing plant in the HEA closed in 2002.
RESULTS: From 1985-1989 to 1991-1996, BCd decreased by 40.3% and 18.9% in the LEA and HEA, respectively (p < 0.0001 for between-area difference). From 1991-1996 until 2001-2003, BCd remained unchanged in the HEA (+ 1.8%) and increased by 19.7% in the LEA (p < 0.0001). Over the entire follow-up period, the annual decrease in BCd averaged 2.7% in the LEA (n = 258) and 1.8% in the HEA (n = 203). From 1985-1989 to 1991-1996, UCd fell by 12.9% in the LEA and by 16.6% in the HEA (p = 0.22), with mean annual decreases of 2.7% (n = 366) and 3.4% (n = 364). Over 20.3 years (median), 206 deaths (21.5%) occurred. At baseline, BCd (14.6 vs. 10.2 nmol/L) and UCd (14.1 vs. 8.6 nmol/24-hr) were higher in deaths than in survivors. The risks (p <= 0.04) associated with a doubling of baseline UCd were 20% and 44% for total and noncardiovascular mortality, and 25% and 33% for a doubling of BCd.
CONCLUSIONS: Even if zinc-cadmium smelters close, historical environmental contamination remains a persistent source of exposure. Environmental exposure to cadmium increases total and noncardiovascular mortality in a continuous fashion without threshold
Bone Resorption and Environmental Exposure to Cadmium in Women: A Population Study
BACKGROUND: Environmental exposure to cadmium decreases bone density indirectly through hypercalciuria resulting from renal tubular dysfunction.
OBJECTIVE: We sought evidence for a direct osteotoxic effect of cadmium in women.
METHODS: We randomly recruited 294 women (mean age, 49.2 years) from a Flemish population with environmental cadmium exposure. We measured 24-hr urinary cadmium and blood cadmium as indexes of lifetime and recent exposure, respectively. We assessed the multivariate-adjusted association of exposure with specific markers of bone resorption, urinary hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP), as well as with calcium excretion, various calciotropic hormones, and forearm bone density.
RESULTS: In all women, the effect sizes associated with a doubling of lifetime exposure were 8.4% (p = 0.009) for HP, 6.9% (p = 0.10) for LP, 0.77 mmol/day (p = 0.003) for urinary calcium, -0.009 g/cm(2) (p = 0.055) for proximal forearm bone density, and -16.8% (p = 0.065) for serum parathyroid hormone. In 144 postmenopausal women, the corresponding effect sizes were -0.01223 g/cm(2) (p = 0.008) for distal forearm bone density, 4.7% (p = 0.064) for serum calcitonin, and 10.2% for bone-specific alkaline phosphatase. In all women, the effect sizes associated with a doubling of recent exposure were 7.2% (p = 0.001) for urinary HP, 7.2% (p = 0.021) for urinary LP, -9.0% (p = 0.097) for serum parathyroid hormone, and 5.5% (p = 0.008) for serum calcitonin. Only one woman had renal tubular dysfunction (urinary retinol-binding protein > 338 mu g/day).
CONCLUSIONS: In the absence of renal tubular dysfunction, environmental exposure to cadmium increases bone resorption in women, suggesting a direct osteotoxic effect with increased calciuria and reactive changes in calciotropic hormones
Blood pressure changes after renal denervation at 10 European expert centers
We did a subject-level meta-analysis of the changes (Δ) in blood pressure (BP) observed 3 and 6 months after renal denervation (RDN) at 10 European centers. Recruited patients (n=109; 46.8% women; mean age 58.2 years) had essential hypertension confirmed by ambulatory BP. From baseline to 6 months, treatment score declined slightly from 4.7 to 4.4 drugs per day. Systolic/diastolic BP fell by 17.6/7.1 mm Hg for office BP, and by 5.9/3.5, 6.2/3.4, and 4.4/2.5 mm Hg for 24-h, daytime and nighttime BP (P0.03 for all). In 47 patients with 3- and 6-month ambulatory measurements, systolic BP did not change between these two time points (P0.08). Normalization was a systolic BP of <140 mm Hg on office measurement or <130 mm Hg on 24-h monitoring and improvement was a fall of 10 mm Hg, irrespective of measurement technique. For office BP, at 6 months, normalization, improvement or no decrease occurred in 22.9, 59.6 and 22.9% of patients, respectively; for 24-h BP, these proportions were 14.7, 31.2 and 34.9%, respectively. Higher baseline BP predicted greater BP fall at follow-up; higher baseline serum creatinine was associated with lower probability of improvement of 24-h BP (odds ratio for 20-μmol l(-1) increase, 0.60; P=0.05) and higher probability of experiencing no BP decrease (OR, 1.66; P=0.01). In conclusion, BP responses to RDN include regression-to-the-mean and remain to be consolidated in randomized trials based on ambulatory BP monitoring. For now, RDN should remain the last resort in patients in whom all other ways to control BP failed, and it must be cautiously used in patients with renal impairment
Fracture risk and the use of a diuretic (indapamide sr) ± perindopril: a substudy of the Hypertension in the Very Elderly Trial (HYVET)
BACKGROUND: The Hypertension in the Very Elderly Trial (HYVET) is a placebo controlled double blind trial of treating hypertension with indapamide Slow Release (SR) ± perindopril in subjects over the age of 80 years. The primary endpoints are stroke (fatal and non fatal). In view of the fact that thiazide diuretics and indapamide reduce urinary calcium and may increase bone mineral density, a fracture sub study was designed to investigate whether or not the trial anti-hypertensive treatment will reduce the fracture rate in very elderly hypertensive subjects. METHODS: In the trial considerable care is taken to ascertain any fractures and to identify risk factors for fracture, such as falls, co-morbidity, drug treatment, smoking and drinking habits, levels of activity, biochemical abnormalities, cardiac irregularities, impaired cognitive function and symptoms of orthostatic hypotension. POTENTIAL RESULTS: The trial is expected to provide 10,500 patient years of follow-up. Given a fracture rate of 40/1000 patient years and a 20% difference in fracture rate, the power of the sub study is 58% to detect this difference at the 5% level of significance. The corresponding power for a reduction of 25% is 78%. CONCLUSION: The trial is well under way, expected to complete in 2009, and on target to detect, if present, the above differences in fracture rate
Immediate and late benefits of treating very elderly people with hypertension: results from active treatment extension to Hypertension in the Very Elderly randomised controlled trial
Objective To assess if very elderly people with hypertension obtain early benefit from antihypertensive treatment. Design One year open label active treatment extension of randomised controlled trial (Hypertension in the Very Elderly Trial (HYVET)). Setting Hospital and general practice based centres mainly in eastern and western Europe, China, and Tunisia. Participants People on double blind treatment at the end of HYVET were eligible to enter the extension. Interventions Participants on active blood pressure lowering treatment continued taking active drug; those on placebo were given active blood pressure lowering treatment. The treatment regimen was as used in the main trial-indapamide SR 1.5 mg (plus perindopril 2-4 mg if required)-with the same target blood pressure of less than 150/80 mm Hg. Main outcome measures The primary outcome was all stroke; other outcomes included total mortality, cardiovascular mortality, and cardiovascular events. Results Of 1882 people eligible for entry to the extension, 1712 (91%) agreed to participate. During the extension period, 1682 patient years were accrued. By six months, the difference in blood pressure between the two groups was 1.2/0.7 mm Hg. Comparing people previously treated with active drug and those previously on placebo, no significant differences were seen for stroke (n=13; hazard ratio 1.92, 95% confidence interval 0.59 to 6.22) or cardiovascular events (n=25; 0.78, 0.36 to 1.72). Differences were seen for total mortality (47 deaths; hazard ratio 0.48, 0.26 to 0.87; P=0.02) and cardiovascular mortality (11 deaths; 0.19, 0.04 to 0.87; P=0.03). Conclusion Very elderly patients with hypertension may gain immediate benefit from treatment. Sustained differences in reductions of total mortality and cardiovascular mortality reinforce the benefits and support the need for early and long term treatment
Antihypertensive treatment decreases arterial stiffness at night but not during the day. Results from the Hypertension in the Very Elderly Trial
The main Hypertension in the Very Elderly Trial (HYVET) demonstrated a very marked reduction in cardiovascular events by treating hypertensive participants 80 years or older with a low dose, sustained release prescription of indapamide (indapamide SR, 1.5 mg) to which was added a low dose of an angiotensin converting enzyme inhibitor in two-thirds of cases (perindopril 2–4 mg). This report from the ambulatory blood pressure sub-study investigates whether changes in arterial stiffness and ambulatory blood pressure (BP) could both explain the benefits observed in the main trial. A total of 139 participants were randomized to placebo [67] and to active treatment [72] and had both day and night observations of BP and arterial stiffness as determined from the Q wave Korotkoff diastolic (QKD) interval. The QKD interval was 5.6 ms longer (p = 0.017) in the actively treated group at night than in the placebo group. This was not true for the more numerous daytime readings so that 24-h results were similar in the two groups. The QKD interval remained longer at night in the actively treated group even when adjusted for systolic pressure, heart rate and height. The reduced arterial stiffness at night may partly explain the marked benefits observed in the main trial
Cadmium accumulation and interactions with zinc, copper, and manganese, analysed by ICP-MS in a long-term Caco-2 TC7 cell model
The influence of long-term exposure to cadmium (Cd) on essential minerals was investigated using a Caco-2
TC7 cells and a multi-analytical tool: microwave digestion and inductively coupled plasma mass spectrometry.
Intracellular levels, effects on cadmium accumulation, distribution, and reference concentration
ranges of the following elements were determined: Na, Mg, Ca, Cr, Fe, Mn, Co, Ni, Cu, Zn, Mo, and Cd.
Results showed that Caco-2 TC7 cells incubated long-term with cadmium concentrations ranging from 0 to
10 lmol Cd/l for 5 weeks exhibited a significant increase in cadmium accumulation. Furthermore, this
accumulation was more marked in cells exposed long-term to cadmium compared with controls, and that
this exposure resulted in a significant accumulation of copper and zinc but not of the other elements
measured. Interactions of Cd with three elements: zinc, copper, and manganese were particularly studied.
Exposed to 30 lmol/l of the element, manganese showed the highest inhibition and copper the lowest on
cadmium intracellular accumulation but Zn, Cu, and Mn behave differently in terms of their mutual
competition with Cd. Indeed, increasing cadmium in the culture medium resulted in a gradual and significant
increase in the accumulation of zinc. There was a significant decrease in manganese from 5 lmol
Cd/l exposure, and no variation was observed with copper.
Abbreviation: AAS – Atomic absorption spectrometry; CRM– Certified reference material; PBS – Phosphate
buffered saline without calcium and magnesium; DMEM – Dubelcco’s modified Eagle’s medium
Does self-monitoring reduce blood pressure? Meta-analysis with meta-regression of randomized controlled trials
Introduction. Self-monitoring of blood pressure (BP) is an increasingly common part of hypertension management. The objectives of this systematic review were to evaluate the systolic and diastolic BP reduction, and achievement of target BP, associated with self-monitoring.
Methods. MEDLINE, Embase, Cochrane database of systematic reviews, database of abstracts of clinical effectiveness, the health technology assessment database, the NHS economic evaluation database, and the TRIP database were searched for studies where the intervention included self-monitoring of BP and the outcome was change in office/ambulatory BP or proportion with controlled BP. Two reviewers independently extracted data. Meta-analysis using a random effects model was combined with meta-regression to investigate heterogeneity in effect sizes.
Results. A total of 25 eligible randomized controlled trials (RCTs) (27 comparisons) were identified. Office systolic BP (20 RCTs, 21 comparisons, 5,898 patients) and diastolic BP (23 RCTs, 25 comparisons, 6,038 patients) were significantly reduced in those who self-monitored compared to usual care (weighted mean difference (WMD) systolic −3.82 mmHg (95% confidence interval −5.61 to −2.03), diastolic −1.45 mmHg (−1.95 to −0.94)). Self-monitoring increased the chance of meeting office BP targets (12 RCTs, 13 comparisons, 2,260 patients, relative risk = 1.09 (1.02 to 1.16)). There was significant heterogeneity between studies for all three comparisons, which could be partially accounted for by the use of additional co-interventions.
Conclusion. Self-monitoring reduces blood pressure by a small but significant amount. Meta-regression could only account for part of the observed heterogeneity
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