Incidence of cancer for patients after bariatric surgery: evidence from 33 cohort studies

BACKGROUND

With the rising prevalence of severe obesity, bariatric surgery has emerged as a crucial treatment option. As the number of surgeries performed worldwide increases, there has been growing interest in the impact of bariatric surgery on cancer incidence. While several studies have examined this relationship, the topic remains controversial.

OBJECTIVES

We conducted this systematic review of cohort studies with meta-analysis to evaluate the effect of bariatric surgery versus nonsurgical treatment on overall cancer incidence. However, the effects may vary when focusing on specific cancer types, surgical procedures, or gender, so we conducted additional subgroup analyses.

SETTING

A meta-analysis. University hospital.

METHODS

The Cochrane, Embase, PubMed, and Web of Science databases were searched for studies from 1 January 2000 to 1 December 2022. Meta-analysis was conducted to evaluate the pooled effect and further implemented subgroup analysis stratified by cancer type, operation type, and sex.

RESULTS

All cohort studies were included in this meta-analysis from 18,216 studies. The overall cancer incidence demonstrated a significant decrease in the group with bariatric surgery (odds ratios [OR] = .56, P = .000, 95% CI .46 to .68). In subgroup analysis, similar decrease effect was found in 9 cancers. Furthermore, the incidence of cancer decreased significantly in male (OR = .66, P = .001, 95% CI .51 to .85) and female patients (OR = .63, P = .000, 95% CI .57 to .69) and patients undergoing gastric bypass (OR = .46, P = .000, 95% CI .33 to .63) or sleeve gastrectomy (OR = .44, P = .001, 95% CI .27 to .70).

CONCLUSIONS

In the overall analysis, bariatric surgery could reduce the incidence of cancer significantly. Further large-scale well-matched studies are needed to verify the protective effect of bariatric surgery on cancer incidence.

Development and validation of a nomogram for Siewert II esophagogastric junction adenocarcinoma: a retrospective analysis

Background

Due to the complex histological type and anatomical structures, there has been considerable debate on the classification of adenocarcinoma of the esophagogastric junction (AEG), especially Siewert II AEG. Furthermore, neither the American Joint Committee on Cancer (AJCC) 7th tumor-node-metastasis (TNM) [esophageal adenocarcinoma (E) or gastric cancer (G)] nor the AJCC 8th TNM (E or G) accurately predicted the prognosis of patients with Siewert II AEG.

Objective

This study aimed to investigate the factors influencing the survival and prognosis of patients with Siewert II AEG and establish a new and better prognostic predictive model.

Design

A retrospective study.

Methods

Patients with Siewert II AEG, retrieved from the Surveillance, Epidemiology, and End Results (SEER) databases, were assigned to the training set. Patients retrieved from a single tertiary medical center were assigned to the external validation set. Significant variables were selected using univariate and multivariate Cox regression analyses to construct the nomogram. Nomogram models were assessed using the concordance index (C-index), a calibration plot, decision curve analysis (DCA), and external validation.

Results

Age, tumor grade, and size, as well as the T, N, and M stages, were included in the nomograms. For the SEER training set, the C-index of the nomogram was 0.683 (0.665-0.701). The C-index of the nomogram for the external validation set was 0.690 (0.653-0.727). The calibration curve showed good agreement between the nomogram estimations and actual observations in both the training and external validation sets. The DCA showed that the nomogram was clinically useful.

Conclusion

The new predictive model showed significant accuracy in predicting the prognosis of Siewert II AEG.

Association between circulating tumor cells in the peripheral blood and the prognosis of gastric cancer patients: a meta-analysis

Background

Research on the correlation between circulating tumor cells (CTCs) and gastric cancer (GC) has increased rapidly in recent years. However, whether CTCs are associated with GC patient prognosis is highly controversial.

Objective

This study aims to evaluate the value of CTCs to predict the prognosis of GC patients.

Design

A meta-analysis.

Data Sources and Methods

We searched the PubMed, Embase, and Cochrane Library databases for studies that reported the prognostic value of CTCs in GC patients before October 2022. The association between CTCs and overall survival (OS) and disease-free survival (DFS)/recurrence-free survival (RFS) and progression-free survival (PFS) of GC patients was assessed. Subgroup analyses were stratified by sampling times (pre-treatment and post-treatment), detection targets, detection method, treatment method, tumor stage, region, and HR (Hazard Ratio) extraction methods. Sensitivity analysis was performed by removing individual studies to assess the stability of the results. Publication bias was evaluated using funnel plots, Egger's test, and Begg's test.

Results

We initially screened 2000 studies, of which 28 were available for further analysis, involving 2383 GC patients. The pooled analysis concluded that the detection of CTCs was associated with poor OS (HR = 1.933, 95% CI 1.657-2.256, p < 0.001), DFS/RFS (HR = 3.228, 95% CI 2.475-4.211, p < 0.001), and PFS (HR = 3.272, 95% CI 1.970-5.435, p < 0.001). Furthermore, the subgroup analysis stratified by tumor stage (p < 0.01), HR extraction methods (p < 0.001), detection targets (p < 0.001), detection method (p < 0.001), sampling times (p < 0.001), and treatment method (p < 0.001) all showed that CTC detection was associated with poor OS and DFS/RFS for GC patients. Furthermore, the study showed that CTCs were associated with the poor DFS/RFS of GC when CTCs were detected for patients from Asian or No-Asian regions (p < 0.05). In addition, higher CTCs predicted poorer OS for GC patients who are from Asian regions (p < 0.001), but without statistical difference for GC patients from No-Asian regions (p = 0.490).

Conclusion

CTC detection in peripheral blood was associated with poor OS, DFS/RFS, and PFS in patients with GC.

A Gastrectomy for early-stage gastric cancer patients with or without preserving celiac branches of vagus nerves: A meta-analysis

BACKGROUND

Vagus nerve-preserving gastrectomy is increasingly popular in treating gastric cancer in the early stage, however the long and short-term outcomes after gastrectomy while preserving the celiac branch of the vagus nerve are not well defined. We aimed to summarize and compare perioperative and longer-term outcomes after celiac branch vagus nerve-preserving gastrectomy (CBP, preserving both the celiac and hepatic branches of the vagus nerve), compared to those without CBP (non-CBP, only the hepatic branch of the vagus nerve is preserved).

METHODS

We searched the Embase, PubMed, Cochrane Library and Web of Science databases for papers published before October 2021. The primary results were evaluated by short-term and long-term postoperative complications, whereas the secondary outcomes included surgery-related parameters, recovery-related parameters and overall survival. Random-effects or fixed-effects model were used to estimate odds ratio, and weighted mean difference for the outcomes. The underlying publication bias was identified via funnel charts, Begg's test and Egger's test. Sensitivity analysis was conducted by removing the research one by one.

RESULTS

A total of 9 studies consisting of 8 retrospective studies and one randomized control trial were included. The analysis included 1,109 patients, with 568 (51.2%) of patients receiving CBP and 541 (48.8%) patients who received non-CBP. The CBP group had a shorter time in terms of first flatus (weighted mean difference = -0.436, 95% confidence interval: -0.603 to -0.269; P < 0.001) and hospital stay (weighted mean difference = -0.456, 95% confidence interval: -0.874 to -0.037, P = 0.033) than the non-CBP group, but the time to the start of oral intake was comparable between the groups. Regarding short-term complications and surgery-related parameters, between CBP and non-CBP, no evident differences were observed in pancreatic complications, anastomotic leakage, postoperative bleeding, operation time, blood loss or lymph nodes examined. In terms of long-term complications, the incidence of gallstones in CBP was lower than that in non-CBP (odds ratio = 0.582, 95% confidence interval: 0.356-0.953, P = 0.031), and the incidence of bile reflux in CBP was lower than that in non-CBP (odds ratio = 0.473, 95% confidence interval: 0.280-0.800, P = 0.005). However, the prevalence rates of diarrhea, early dumping syndrome, esophageal reflux, and delayed gastric emptying were comparable between CBP and non-CBP.

CONCLUSION

The present research showed that gastric cancer patients in the early stage under CBP were superior to those without CBP in terms of incidence of gallstones, bile reflux, time of first flatus and hospital stay. Furthermore, it is imperative to conduct randomized control studies with larger sample sizes to determine the oncological survival outcomes when preserving the celiac branch.

Mitochondrial micropeptide STMP1 enhances mitochondrial fission to promote tumor metastasis

Micropeptides are a recently discovered class of molecules that play vital roles in various cellular processes, including differentiation, proliferation, and apoptosis. Here, we sought to identify cancer-associated micropeptides and to uncover their mechanistic functions. A micropeptide named short trans-membrane protein 1 (STMP1) that localizes at the inner mitochondrial membrane was identified to be upregulated in various cancer types and associated with metastasis and recurrence of hepatocellular carcinoma. Both gain- and loss-of-function studies revealed that STMP1 increased dynamin-related protein 1 (DRP1) activation to promote mitochondrial fission and enhanced migration of tumor cells. STMP1 silencing inhibited in vivo tumor metastasis in xenograft mouse models. Overexpression of STMP1 led to redistribution of mitochondria to the leading edge of cells and enhanced lamellipodia formation. Treatment with a DRP1 inhibitor abrogated the promotive effect of STMP1 on mitochondrial fission, lamellipodia formation, and tumor cell migration in vitro and metastasis in vivo. Furthermore, STMP1 interacted with myosin heavy chain 9 (MYH9), the subunit of non-muscle myosin II, and silencing MYH9 abrogated STMP1-induced DRP1 activation, mitochondrial fission, and cell migration. Collectively, this study identifies STMP1 as a critical regulator of metastasis and a novel unit of the mitochondrial fission protein machinery, providing a potential therapeutic target for treating metastases.

Effects of Preoperative Oral Nutritional Supplements on Improving Postoperative Early Enteral Feeding Intolerance and Short-Term Prognosis for Gastric Cancer: A Prospective, Single-Center, Single-Blind, Randomized Controlled Trial

BACKGROUND

Early enteral nutrition (EN) after abdominal surgery can improve the prognosis of patients. However, the high feeding intolerance (FI) rate is the primary factor impeding postoperative EN.

METHODS

Sixty-seven patients who underwent radical subtotal or total gastrectomy for gastric cancer (GC) were randomly allocated to the preoperative oral nutritional supplement group (ONS group) or dietary advice alone (DA group). Both groups were fed via nasojejunal tubes (NJs) from the first day after surgery to the fifth day. The primary endpoint is the FI rate.

RESULTS

Of the patients, 66 completed the trial (31 in the ONS group, 35 in the DA group). The FI rate in the ONS group was lower than that in the DA group (25.8% vs. 31.4%, p = 0.249). The postoperative five-day 50% energy compliance rate in the ONS group was higher than that in the DA group (54.8% vs. 48.6%, p = 0.465). The main gastrointestinal intolerance symptoms were distension (ONS vs. DA: 45.2% vs. 62.9, p = 0.150) and abdominal pain (ONS vs. DA: 29.0% vs. 45.7%, p = 0.226). Postoperative nausea/vomiting rate and heartburn/reflux rate were similar between the two groups. We noted no difference in perioperative serum indices, short-term prognosis or postoperative complication rates between the two groups.

CONCLUSIONS

The study shows that short-term preoperative ONS cannot significantly improve FI and the energy compliance rate in the early stage after radical gastrectomy.

Dietary Sodium 'Controversy'-Issues and Potential Solutions

PURPOSE OF REVIEW

High dietary sodium is estimated to be the leading dietary risk for death attributed to 1.8 million deaths in 2019. There are uniform recommendations to reduce sodium consumption based on evidence that increased dietary sodium is responsible for approximately a third of the prevalence of hypertension, and meta-analyses of randomized controlled trials show that sodium reduction lowers blood pressure, cardiovascular disease, and total mortality. Nevertheless, there is a perception that the beneficial effect of reducing dietary sodium is controversial. We provide experiential evidence relating to some sources of the controversy and propose potential solutions.

RECENT FINDINGS

Inappropriate research methodology, lack of rigor in research, conflicts of interest and commercial bias, questions of professional conduct, and lack of policies to protect public interests are likely to contribute to the controversy about reducing dietary sodium. There is a failure to protect policies to reduce dietary sodium from nonscientific threats. Significant efforts need to be made to ensure the integrity of nutritional research and maintain public trust.

Left armpit subcutaneous metastasis of gastric cancer: A case report

BACKGROUND

Gastric cancer is the third most lethal malignant tumor worldwide. Metastasis has always been a major cause of poor prognosis. Epidemiological evidence shows that the most common sites for metastasis of gastric carcinoma are the liver (48%), peritoneum (32%), lung (15%), and bone (12%); however, subcutaneous metastasis is are and occurs in approximately 0.8% of cases. We report a rare case of armpit subcutaneous metastasis of gastric cancer. The best surgical window was missed, as a result of lacking attention of the mass.

CASE SUMMARY

A 69-year-old man who had previously undergone radical gastrectomy and received eight cycles of oral chemotherapy for gastric cancer showed a rapidly growing mass in his the left armpit; within just 3 mo, the mass grew to a size of 6.9 cm × 4.4 cm × 5.7 cm. Color Doppler ultrasonography and Positron emission tomography/computed tomography prompted the possibility of metastasis of the malignancy. Fine needle aspiration biopsy guided by color Doppler ultrasound showed the presence of cancer cells in the mass. Immunohistochemical examination showed CDX-2 (+), PCK (+), CK20 (+), CK7 (-), and TTF (-), which supported the metastasis of gastric cancer. Considering the risk of resection, the patient did not undergo surgical treatment.

CONCLUSION

The case indicates that unidentified subcutaneous masses in patients with a history of gastric cancer should be carefully evaluated.

New compound with DNA Topo I inhibitory activity purified from Penicillium oxalicum HSY05

Strain HSY05 was isolated from sea sediment collected from the South China Sea and was later identified as Penicillium oxalicum by 16S rDNA sequence analysis. Various chromatographic processes led to the isolation and purification of two metabolites from the fermentation culture of HSY05, including one new compound, 2,2',4,4'-tetrahyoxy-8'-methyl-6-methoxy-acyl-ethyl-diphenylmethanone (1), and a known compound secalonic acid D (SAD, 2), as characterised by UV, IR, 1D, 2D-NMR and MS data. The inhibitory activities against topoisomerase I of these two compounds were evaluated. The result showed that in addition to the known topo I inhibitor SAD (2), compound 1 also exhibited a moderate inhibitory effect.

Importance of controlling blood pressure

Cardiovascular disease is the leading cause of death and disability world-wide. Blood pressure, throughout the range seen in developed countries, is the most important risk factor for cardiovascular disease. Lowering blood pressure within the whole population by lifestyle interventions, such as reducing dietary salt intake and increasing the consumption of fruit and vegetables, will be of great benefit. Blood pressure-lowering trials also demonstrate immense benefits in preventing strokes, heart failure and coronary heart disease. There are no differences in outcome between the different methods used to lower blood pressure and the benefit is proportional to the degree of blood pressure-lowering. Thiazide diuretics are effective in lowering blood pressure and have been the most widely prescribed blood pressure-lowering drugs. They work by causing both sodium and water loss, but also cause potassium loss and a fall in plasma potassium levels. The latter may mitigate the beneficial effects from blood pressure-lowering. Some diuretics, such as spironolactone, affect the distal tubule and do not cause a fall in plasma potassium levels. However, spironolactone has endocrine side-effects associated with the fact that it is not specific for the mineralocorticoid receptor. The development of a more selective aldosterone antagonist without endocrine side-effects could be a major advance as it would be able to oppose the effects of aldosterone, both on sodium retention and potassium loss and the other vascular effects.

A comprehensive review on salt and health and current experience of worldwide salt reduction programmes

Cardiovascular disease (CVD) is the leading cause of death and disability worldwide. Raised blood pressure (BP), cholesterol and smoking, are the major risk factors. Among these, raised BP is the most important cause, accounting for 62% of strokes and 49% of coronary heart disease. Importantly, the risk is throughout the range of BP, starting at systolic 115 mm Hg. There is strong evidence that our current consumption of salt is the major factor increasing BP and thereby CVD. Furthermore, a high salt diet may have direct harmful effects independent of its effect on BP, for example, increasing the risk of stroke, left ventricular hypertrophy and renal disease. Increasing evidence also suggests that salt intake is related to obesity through soft drink consumption, associated with renal stones and osteoporosis and is probably a major cause of stomach cancer. In most developed countries, a reduction in salt intake can be achieved by a gradual and sustained reduction in the amount of salt added to food by the food industry. In other countries where most of the salt consumed comes from salt added during cooking or from sauces, a public health campaign is needed to encourage consumers to use less salt. Several countries have already reduced salt intake, for example, Japan (1960-1970), Finland (1975 onwards) and now the United Kingdom. The challenge is to spread this out to all other countries. A modest reduction in population salt intake worldwide will result in a major improvement in public health.

Salt and blood pressure in children and adolescents

To study the relationship between salt intake and blood pressure in children and adolescents, we analysed the data of a large cross-sectional study (the National Diet and Nutrition Survey for young people), which was carried out in Great Britain in 1997 in a nationally representative sample of children aged between 4 and 18 years. A total of 1658 participants had both salt intake and blood pressure recorded. Salt intake was assessed by a 7-day dietary record. The average salt intake, which did not include salt added in cooking or at the table, was 4.7+/-0.2 g/day at the age of 4 years. With increasing age, there was an increase in salt intake, and by the age of 18 years, salt intake was 6.8+/-0.2 g/day. There was a significant association of salt intake with systolic blood pressure as well as with pulse pressure after adjusting for age, sex, body mass index and dietary potassium intake. An increase of 1 g/day in salt intake was related to an increase of 0.4 mm Hg in systolic and 0.6 mm Hg in pulse pressure. The magnitude of the association with systolic blood pressure is very similar to that observed in a recent meta-analysis of controlled trials where salt intake was reduced. The consistent finding of our present analysis of a random sample of free-living individuals with that from controlled salt reduction trials provides further support for a reduction in salt intake in children and adolescents.

Increased consumption of fruit and vegetables is related to a reduced risk of coronary heart disease: meta-analysis of cohort studies

Increased consumption of fruit and vegetables has been shown to be associated with a reduced risk of coronary heart disease (CHD) in many epidemiological studies, however, the extent of the association is uncertain. We quantitatively assessed the relation between fruit and vegetable intake and incidence of CHD by carrying out a meta-analysis of cohort studies. Studies were included if they reported relative risks (RRs) and corresponding 95% confidence interval (CI) of CHD with respect to frequency of fruit and vegetable intake. Twelve studies, consisting of 13 independent cohorts, met the inclusion criteria. There were 278,459 individuals (9143 CHD events) with a median follow-up of 11 years. Compared with individuals who had less than 3 servings/day of fruit and vegetables, the pooled RR of CHD was 0.93 (95% CI: 0.86-1.00, P=0.06) for those with 3-5 servings/day and 0.83 (0.77-0.89, P<0.0001) for those with more than 5 servings/day. Subgroup analyses showed that both fruits and vegetables had a significant protective effect on CHD. Our meta-analysis of prospective cohort studies demonstrates that increased consumption of fruit and vegetables from less than 3 to more than 5 servings/day is related to a 17% reduction in CHD risk, whereas increased intake to 3-5 servings/day is associated with a smaller and borderline significant reduction in CHD risk. These results provide strong support for the recommendations to consume more than 5 servings/day of fruit and vegetables.

[Pathology and immunohistochemistry of thyroid in severe acute respiratory syndrome]

OBJECTIVE

To study the pathological characteristics of thyroid gland and the changes on hormone content of thyroid cells in severe acute respiratory syndrome (SARS) patients.

METHOD

Hematoxylin and eosin staining and light microscopy were used to examine the histology of the thyroid tissues from 4 dead SARS patients and 5 healthy thyroid samples used as negative controls. Immunohistochemistry was used, with monoclonal antibodies, to detect the thyroglobulin (TG), calcitonin and parathyroid hormone (PTH) in the thyroid glands.

RESULTS

Deformation, enlargement, and dystrophy of follicular cells in thyroid glands were found in the SARS patients. The normal follicular epithelial cells were strongly TG positive, however, the number and intensity of TG positive follicular epithelial cells were significantly lower in the SARS patients. Calcitonin positive cells were found in the normal thyroid glands and not in the thyroid glands of the SARS patients. PTH positive cells were seen in the normal thyroid glands and those of the SARS patients with a slightly weaker intensity of reaction, however, with significant difference in IOD (P < 0.01) and without significant difference in mean slight absorption MOD (P > 0.05).

CONCLUSION

The thyroid tissue structure and morphology in SARS patients were significantly changed, involving both follicular epithelial cells and parafollicular cells; which may imply that the hormonal production of follicular epithelial cells and the parafollicular cells were affected.

Effect of longer-term modest salt reduction on blood pressure

BACKGROUND

Many randomised trials assessing the effect of salt reduction on blood pressure show reduction in blood pressure in individuals with high blood pressure. However, there is controversy about the magnitude and the clinical significance of the fall in blood pressure in individuals with normal blood pressure. Several meta-analyses of randomised salt reduction trials have been published in the last few years. However, most of these included trials of very short duration (e.g. 5 days) and included trials with salt loading followed by salt deprivation (e.g. from 20 to 1 g/day) over only a few days. These short-term experiments are not appropriate to inform public health policy which is for a modest reduction in salt intake over a prolonged period of time. A meta-analysis by Hooper et al is an important attempt to look at whether advice to achieve a long-term salt reduction (i.e. more than 6 months) in randomised trials causes a fall in blood pressure. However, most trials included in this meta-analysis achieved a small reduction in salt intake; on average, salt intake was reduced by 2 g/day. It is, therefore, not surprising that this analysis showed a small fall in blood pressure, and that a dose-response to salt reduction was not demonstrable.

OBJECTIVES

To assess the effect of the currently recommended modest reduction in salt intake (WHO 2003; SACN 2003; Whelton 2002), on blood pressure in individuals with normal and elevated blood pressure. To assess whether the magnitude of the reduction in blood pressure is dependent on the magnitude of the reduction in salt intake.

SEARCH STRATEGY

We searched MEDLINE, EMBASE, Cochrane library, CINAHL, and reference list of original and review articles.

SELECTION CRITERIA

We included randomised trials with a modest reduction in salt intake and a duration of 4 or more weeks.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two persons. Mean effect sizes were calculated using both fixed and random effect models using Review Manager 4.2.1 software. Weighted linear regression was used to examine the relationship between the change in urinary sodium and the change in blood pressure. We used funnel plots to detect publication and other biases in the meta-analysis.

MAIN RESULTS

Seventeen trials in individuals with elevated blood pressure (n=734) and 11 trials in individuals with normal blood pressure (n=2220) were included. In individuals with elevated blood pressure the median reduction in 24-h urinary sodium excretion was 78 mmol (4.6 g/day of salt), the mean reduction in systolic blood pressure was -4.97 mmHg (95%CI:-5.76 to -4.18), and the mean reduction in diastolic blood pressure was -2.74 mmHg (95% CI:-3.22 to -2.26). In individuals with normal blood pressure the median reduction in 24-h urinary sodium excretion was 74 mmol (4.4 g/day of salt), the mean reduction in systolic blood pressure was -2.03 mmHg (95% CI: -2.56 to -1.50) mmHg, and the mean reduction in diastolic blood pressure was -0.99 mmHg (-1.40 to -0.57). Weighted linear regression analyses showed a correlation between the reduction in urinary sodium and the reduction in blood pressure.

REVIEWERS' CONCLUSIONS

Our meta-analysis demonstrates that a modest reduction in salt intake for a duration of 4 or more weeks has a significant and, from a population viewpoint, important effect on blood pressure in both individuals with normal and elevated blood pressure. These results support other evidence suggesting that a modest and long-term reduction in population salt intake could reduce strokes, heart attacks, and heart failure. Furthermore, our meta-analysis demonstrates a correlation between the magnitude of salt reduction and the magnitude of blood pressure reduction. Within the daily intake range of 3 to 12 g/day, the lower the salt intake achieved, the lower the blood pressure.

Potassium: more beneficial effects

Over 70 years ago, potassium was found to have a natriuretic effect and was used in patients with heart failure. However, it took many years for its role in the control of blood pressure to be recognized. Recently, epidemiological and clinical studies in man and experimental studies in animals have shown that increasing potassium intake towers blood pressure and that communities with a high potassium intake tend to have lower population blood pressures. Several studies have shown an interaction between salt intake and potassium intake. However, the recent DASH-Sodium (Dietary Approaches to Stop Hypertension) study demonstrates an additive effect of a low salt and high potassium diet on blood pressure. Increasing potassium intake may have other beneficial effects, for example, reducing the risk of stroke and preventing the development of renal disease independent of its effect on blood pressure. A high potassium intake reduces calcium excretion and could play an important role in the management of hypercalciuria and kidney stone formation, as well as bone demineralization. Potassium intake may also play an important role in carbohydrate intolerance. A reduced serum potassium increases the risk of lethal ventricular arrhythmias in those at risk, i.e. patients with ischemic heart disease, heart failure or left ventricular hypertrophy, and increasing potassium intake may prevent this. In this article, we address the evidence for the important role of potassium intake in regulating blood pressure and other beneficial effects of potassium which may be independent of and additional to its effect on blood pressure.

Cost of poor blood pressure control in the UK: 62,000 unnecessary deaths per year

High blood pressure is the most important risk factor for cardiovascular disease. With the information on systolic blood pressure from the recently published meta-analysis of prospective studies, we calculated the reductions in stroke and ischaemic heart disease with control of all hypertensives to a systolic blood pressure of 140 mmHg. For adults there would be a reduction of 28-44% in stroke and 20-35% in ischaemic heart disease depending on age. In the UK, this would prevent approximately 21,400 stroke deaths and 41,400 ischaemic heart disease deaths each year. Around half of those who suffer a stroke or ischaemic heart disease survive, there would be a proportionate decrease in these people as well. These amount to approximately 42,800 strokes and 82,800 ischaemic heart diseases saved, making a total of 125,600 events saved a year in the UK. This would result in a reduction in disability and major cost savings both to individuals, their families and the Health Service. The blood pressure levels and control of blood pressure in many countries are similar to those in the UK, so the reductions in stroke and ischaemic heart disease worldwide, if the same control of high blood pressure could be obtained, would be immense.

Effect of modest salt reduction on blood pressure: a meta-analysis of randomized trials. Implications for public health

Two recent meta-analyses of randomised salt reduction trials have concluded that there is little purpose in reducing salt intake in the general population. However, the authors, as with other previous meta-analyses, included trials of very short duration (eg 1 week or less) and trials of acute salt loading followed by abrupt reductions to very low salt intake (eg from 20 to less than 1 g of salt/day). These acute salt loading and salt depletion experiments are known to increase sympathetic tone, and with salt depletion cause a rise in renin release and, thereby, plasma angiotensin II. These trials are not appropriate, therefore, for helping to inform public health policy, which is for a more modest reduction in salt intake, ie, from a usual intake of approximately 10 to approximately 5 g of salt per day over a more prolonged period of time. We carried out a meta-analysis to assess the effect of a modest salt reduction on blood pressure. Our data sources were MEDLINE, EMBASE, Cochrane library, CINAHL, and the reference lists of original and review articles. We included randomised trials with a modest reduction in salt intake and a duration of 4 or more weeks. Meta-analysis, meta-regression, and funnel plots were performed. A total of 17 trials in hypertensives (n=734) and 11 trials in normotensives (n=2220) were included in our study. The median reduction in 24-h urinary sodium excretion was 78 mmol (equivalent to 4.6 g of salt/day) in hypertensives and 74 mmol in normotensives. The pooled estimates of blood pressure fall were 4.96/2.73+/-0.40/0.24 mmHg in hypertensives (P<0.001 for both systolic and diastolic) and 2.03/0.97+/-0.27/0.21 mmHg in normotensives (P<0.001 for both systolic and diastolic). Weighted linear regression analyses showed a dose response between the change in urinary sodium and blood pressure. A reduction of 100 mmol/day (6 g of salt) in salt intake predicted a fall in blood pressure of 7.11/3.88 mmHg (P<0.001 for both systolic and diastolic) in hypertensives and 3.57/1.66 mmHg in normotensive individuals (systolic: P<0.001; diastolic: P<0.05). Our results demonstrate that a modest reduction in salt intake for a duration of 4 or more weeks does have a significant and, from a population viewpoint, important effect on blood pressure in both hypertensive and normotensive individuals. This meta-analysis strongly supports other evidence for a modest and long-term reduction in population salt intake, and would be predicted to reduce stroke deaths immediately by approximately 14% and coronary deaths by approximately 9% in hypertensives, and reduce stroke and coronary deaths by approximately 6 and approximately 4%, in normotensives, respectively.

Importance of the renin system for determining blood pressure fall with acute salt restriction in hypertensive and normotensive whites

Hypertensive (n=93) and normotensive (n=39) white individuals were given a high sodium intake of approximately 350 mmol/d for 5 days followed by a low sodium intake of 10 to 20 mmol/d for 5 days. With this acute and large reduction in salt intake, no significant change was seen in blood pressure in the normotensive individuals, but blood pressure decreased in the hypertensive individuals. Compared with normotensive subjects, hypertensive patients had a 7/7-mm Hg greater fall in blood pressure (P<0.05 for systolic and P<0.01 for diastolic, adjusted for age), with similar changes in urinary sodium excretion. From the high-salt to low-salt diet, plasma renin activity rose from 0.90 to 5.99 ng. mL(-1). h(-1) in normotensives, whereas in hypertensives it rose from 0.73 to only 3.14 ng. mL(-1). h(-1) (P<0.05 between hypertensives and normotensives). Plasma aldosterone rose by 1396 pmol/L in normotensive subjects and by 511 pmol/L in hypertensive patients (P<0.05). Significant inverse correlations were obtained for all subjects between the fall in blood pressure from the high-salt to low-salt diet and the rise in plasma renin activity and aldosterone that occurred in addition to the absolute level on the low-salt diet. These results demonstrate that the larger fall in blood pressure with an acute reduction in salt intake in hypertensives compared with normotensives is, at least in part, due to a less-responsive renin-angiotensin-aldosterone system in the hypertensive patients.

Effect of salt intake on renal excretion of water in humans

Two studies were performed to determine the quantitative relationship between salt intake and urinary volume (U(v)) in humans. In study 1, 104 untreated hypertensives were studied on the fifth day of a high- and a low-salt diet. The 24-hour U(v) was 2.2 L (urinary sodium [U(Na)] 277 mmol) on the high-salt diet and decreased to 1.3 L (P<0.001) (U(Na) 20.8 mmol) on the low-salt diet. The reduction in 24-hour U(v) was significantly related to the decrease in 24-hour U(Na) (P<0.001) and predicts that a 100-mmol/d reduction in salt intake would decrease 24-hour U(v) by 367 mL. In study 2, 634 untreated hypertensives were studied on their usual diet. There was a significant relationship between 24-hour U(v) and U(Na) (P<0.001). This predicts that a 100-mmol/d reduction in salt intake would decrease 24-hour U(v) by 454 mL. The International Study of Salt and Blood Pressure (INTERSALT) of 1731 hypertensives and 8343 normotensives on their usual diet showed that 24-hour U(v) was significantly related to U(Na) (P<0.001) and predicted that a 100-mmol/d reduction in salt intake would decrease 24-hour U(v) by 379 and 399 mL in hypertensives and normotensives, respectively. These findings document the important effect that salt intake has on U(v). The recommended reduction in salt intake in the general population is from 10 to 5 g/d. This would reduce fluid intake in the population by approximately 350 mL/d per person. This would have a large impact on the sales of soft drinks, mineral water, and beer.

Efficacy of candesartan cilexetil alone or in combination with amlodipine and hydrochlorothiazide in moderate-to-severe hypertension. UK and Israel Candesartan Investigators

This multicenter study evaluated the efficacy of candesartan cilexetil, an angiotensin II type 1 receptor antagonist, used alone or in combination with amlodipine or in combination with amlodipine and hydrochlorothiazide in the treatment of patients with moderate-to-severe essential hypertension. After a 2-week, single-blind, placebo run-in period, patients entered a 12-week, open-label, dose-titration period. The candesartan cilexetil dose was increased from 8 to 16 mg once daily; amlodipine (5 mg once daily), hydrochlorothiazide (25 mg once daily), and additional medication were also added sequentially if necessary. Patients then entered a final 4-week, parallel-group, double-blind, randomized, placebo-controlled withdrawal period of candesartan alone. A total of 216 patients were recruited. After a 2-week run-in period on placebo tablets, mean sitting blood pressure (BP) was 175/108 mm Hg. At the end of the 12-week dose-titration/maintenance period, mean sitting BP fell to 141/88 mm Hg. In 67 patients who were randomized to placebo and had their candesartan withdrawn, there was a highly significant increase in mean systolic/diastolic BP (13/6 mm Hg) compared with those patients who continued with candesartan (ANCOVA, P:<0.0001). In conclusion, candesartan cilexetil is an effective BP-lowering drug when used alone or in combination with amlodipine or amlodipine plus hydrochlorothiazide in the treatment of moderate-to-severe essential hypertension. The drug was well tolerated throughout the investigation period.

Importance of the renin system in determining blood pressure fall with salt restriction in black and white hypertensives

Seventy-one white and 33 black patients with essential hypertension were studied while on a high sodium intake of 350 mmol/d for 5 days and low sodium intake of 10 mmol/d for 5 days. The fall in blood pressure on changing from the high sodium to the low sodium diet was 17/6 mm Hg in whites and 22/10 mm Hg in blacks. Compared with whites, black patients had a 7-mm Hg greater fall (P<0.05) in systolic blood pressure and 4-mm Hg greater fall (P=0.068) in diastolic blood pressure (adjusted for age and blood pressure on the normal diet) with similar changes in urinary sodium excretion. With sodium restriction, plasma renin activity rose from 0.65 to 3.03 ng. mL-1. h-1 in whites, whereas in blacks it rose only from 0.3 to 1.28 ng. mL-1. h-1 (P<0.001 between blacks and whites). From the high to the low salt diet, plasma angiotensin II increased by 31 pmol/L in whites and by 12 pmol/L in blacks (P<0.05 compared with whites), and plasma aldosterone rose by 499 pmol/L in whites and by 256 pmol/L in blacks (P<0.01). Significant inverse correlations were obtained for all patients between the fall in systolic blood pressure from the high to low salt diet and the rise in plasma renin activity and angiotensin II, as well as the absolute level on the low salt diet. These results demonstrate that the larger fall in blood pressure with a reduction in salt intake in blacks is due at least in part to a less responsive renin-angiotensin-aldosterone system in blacks.

Plasma shock wave lithotripsy of gallstones in vitro. Animal experiments and clinical application

It is sometimes very difficult to extract a huge impacted stone through the T-tube fistulous tract by conventional techniques with choledochoscope. To simplify the procedure, a lithotriptor PSW-G type using plasma shock wave to disintegrate the stone was designed. The efficacy to fragmentate stone was investigated both in vitro and in vivo. Stones can be shattered into pieces less than 3 mm in diameter in about 30 times of spark with lower energy ranging from 1.7-3.4 kV and 1-3 J. Animal experiments were carried out to prove the safety of the lithotriptor. There was neither interference with the cardiovascular and respiratory systems nor obvious damage to the adjacent tissue where plasma shock wave applied to break stones. Six patients with retained calculi impacted both in extra- and intra-hepatic duct were successfully treated by plasma shock wave lithotripsy. It appears very useful in dealing with a huge impacted stone in the biliary tract.