The electronic cigarette: the new cigarette of the 21st century?

The electronic nicotine delivery system, also known as the electronic cigarette, isgenerating considerable controversy, not only in the general population but alsoamong health professionals. Smokers the world over have been increasingly usingelectronic cigarettes as an aid to smoking cessation and as a substitute forconventional cigarettes. There are few available data regarding the safety ofelectronic cigarettes. There is as yet no evidence that electronic cigarettes areeffective in treating nicotine addiction. Some smokers have reported using electroniccigarettes for over a year, often combined with conventional cigarettes, thusprolonging nicotine addiction. In addition, the increasing use of electroniccigarettes by adolescents is a cause for concern. The objective of this study was todescribe electronic cigarettes and their components, as well as to review theliterature regarding their safety; their impact on smoking initiation and smokingcessation; and regulatory issues related to their use.     

Does herbal medicine reduce the risk of hepatocellular carcinoma?

Many herbal medicines are effective anti-inflammatory agents and may therefore suppress the development of hepatocellular carcinoma(HCC). Recently, treatment with a single-tablet regimen containing ledipasvir and sofosbuvir resulted in high rates of sustained virologic response among patients with hepatitis C virus genotype1 infection who did not respond to prior interferon-based treatment. Patients with chronic hepatitis C are expected to receive this treatment worldwide. However, many patients have hepatitis-like fatty liver and nonalcoholic steatohepatitis. A strategy to prevent the development of HCC in this subgroup of patients is urgently required.Whether herbal medicines can suppress the development of HCC remains to be established. However, herbal medicines are effective anti-inflammatory agents and may inhibit the development of HCC. Clinical trials exploring the effectiveness of herbal medicines in the prevention and treatment of HCC are therefore warranted. The current lack of knowledge and of educational programs is a barrier to increasing the use of potentially effective herbal medicines and performing prospective clinical trials.     

Can metformin use reduce the risk of stroke in diabetic patients? A systematic review and meta-analysis

Background and aimStroke and cardiovascular diseases are major causes of death and disability, especially among diabetic patients. Some studies have shown that metformin has been effective in preventing cardiovascular diseases. In this study, we aim to evaluate the effect of metformin on stroke in type 2 diabetic patients.MethodsA comprehensive search was conducted in Medline, Embase, Scopus, and Web of Science databases from their inception till 1st July 2022. Randomized clinical trials (RCT) and cohort studies were included. Two independent researchers screened the records, extracted the data, and assessed the risk of bias and certainty of evidence. Findings were reported as risk ratio (RR) and 95% confidence interval (CI). All statistical analyses were performed using the STATA 17.0 software package.ResultsAnalysis of 21 included studies with 1,392,809 patients demonstrated that metformin monotherapy was effective in reducing stroke risk in both RCTs (RR = 0.66, 95% CI: 0.50, 0.87 p = 0.004) and cohort studies (RR = 0.67, 95% CI: 0.55, 0.81, p < 0.0001). However, combined administration of metformin with other antihyperglycemic agents had no significant effect on stroke risk reduction in either the RCTs (RR = 0.92, 95% CI: 0.69, 1.22 p = 0.558) or the cohort studies (RR = 0.79, 95% CI: 0.59, 1.06, p = 0.122).ConclusionLow to moderate level of evidence in RCTs showed that metformin monotherapy could reduce stroke risk in type 2 diabetic patients. However, the preventive effect of metformin in stroke was not observed in patients who received a combination of metformin plus other hypoglycemic agents.     

Stage B: What is the Evidence for Treatment of Asymptomatic Left Ventricular Dysfunction?

Although patients with American College of Cardiology / American Heart Association (ACC/AHA) Stage B heart failure, or asymptomatic left ventricular dysfunction (ALVD) are at high risk for developing symptomatic heart failure, few manage-ment strategies have been shown to slow disease state progression or improve long-term morbidity and mortality. Of the pharmacologic therapies utilized in patients with symptomatic disease, only angiotensin converting enzyme (ACE) inhibitors (and to a lesser extent, angiotensin receptor blockers, or ARBs) have been shown to improve clinical outcomes among pa-tients with ALVD. Although evidence to support the use of beta blockers in this setting has been primarily derived from ret-rospective studies or subgroup analyses, they are generally recommended in most patients with ALVD, especially those with ischemic etiology. Statins are associated with improvements in both major adverse cardiovascular events and heart failure events among patients with a history of acute myocardial infarction. Finally, in eligible patients, placement of an automatic implantable cardioverter defibrillator (ICD) has been associated with reduced mortality rates among those with ALVD due to ischemic cardiomyopathy, and some subgroups may derive benefit from cardiac resynchronization therapy or biventricular pacing.     

Can the single-breath helium dilution method predict lung volumes as measured by whole-body plethysmography?

OBJECTIVE:

To compare TLC and RV values obtained by the single-breath helium dilution (SBHD) method with those obtained by whole-body plethysmography (WBP) in patients with normal lung function, patients with obstructive lung disease (OLD), and patients with restrictive lung disease (RLD), varying in severity, and to devise equations to estimate the SBHD results.

METHODS:

This was a retrospective cross-sectional study involving 169 individuals, of whom 93 and 49 presented with OLD and RLD, respectively, the remaining 27 having normal lung function. All patients underwent spirometry and lung volume measurement by both methods.

RESULTS:

TLC and RV were higher by WBP than by SBHD. The discrepancy between the methods was more pronounced in the OLD group, correlating with the severity of airflow obstruction. In the OLD group, the correlation coefficient of the comparison between the two methods was 0.57 and 0.56 for TLC and RV, respectively (p < 0.001 for both). We used regression equations, adjusted for the groups studied, in order to predict the WBP values of TLC and RV, using the corresponding SBHD values. It was possible to create regression equations to predict differences in TLC and RV between the two methods only for the OLD group. The TLC and RV equations were, respectively, ∆TLC_WBP-SBHD in L = 5.264 − 0.060 × FEV₁/FVC (r² = 0.33; adjusted r² = 0.32) and ∆RV_WBP-SBHD in L = 4.862 − 0.055 × FEV₁/FVC (r² = 0.31; adjusted r² = 0.30).

CONCLUSIONS:

The correction of TLC and RV results obtained by SBHD can improve the accuracy of this method for assessing lung volumes in patients with OLD. However, additional studies are needed in order to validate these equations.     

Can the changes in dietary fat intake reduce the risk of onset and development of atherosclerosis and of ischemic cardiopathy in particular?

In this review we have collected data from epidemiologic studies and clinical trials published from 1968 to 1989 on the relationship between dietary fat and risk of coronary heart disease. Although the reported observational studies of diet and coronary heart disease provide general support for the classic diet-heart hypothesis, evidence of specific dietary lipids is weak. A positive association with saturated fat intake was seen in two prospective studies. A positive association with cholesterol intake was found in only two cohort studies, and an inverse relationship with polyunsaturated fat intake in only one. Clear evidence from dietary trials in the prevention of coronary heart disease has not been found. The analysis of trends in coronary heart disease and stroke mortality of developed countries has shown a discrepancy between fat intakes, cholesterol levels and mortality. The reduction in intake of certain foods "at high risk" such as meat, eggs, milk and cheese, as a preventive intervention, is based on weak scientific evidence. A strategy program has to emphasize the maintenance of ideal body weight by caloric control, an adequate level of physical activity, and the control of other risk factors such as hypertension, hypercholesterolemia, and diabetes.     

Can bronchodilators improve exercise tolerance in COPD patients without dynamic hyperinflation?

OBJECTIVE:

To investigate the modulatory effects that dynamic hyperinflation (DH), defined as a reduction in inspiratory capacity (IC), has on exercise tolerance after bronchodilator in patients with COPD.

METHODS:

An experimental, randomized study involving 30 COPD patients without severe hypoxemia. At baseline, the patients underwent clinical assessment, spirometry, and incremental cardiopulmonary exercise testing (CPET). On two subsequent visits, the patients were randomized to receive a combination of inhaled fenoterol/ipratropium or placebo. All patients then underwent spirometry and submaximal CPET at constant speed up to the limit of tolerance (Tlim). The patients who showed ΔIC(peak-rest) < 0 were considered to present with DH (DH+).

RESULTS:

In this sample, 21 patients (70%) had DH. The DH+ patients had higher airflow obstruction and lower Tlim than did the patients without DH (DH-). Despite equivalent improvement in FEV₁ after bronchodilator, the DH- group showed higher ΔIC(bronchodilator-placebo) at rest in relation to the DH+ group (p < 0.05). However, this was not found in relation to ΔIC at peak exercise between DH+ and DH- groups (0.19 ± 0.17 L vs. 0.17 ± 0.15 L, p > 0.05). In addition, both groups showed similar improvements in Tlim after bronchodilator (median [interquartile range]: 22% [3-60%] vs. 10% [3-53%]; p > 0.05).

CONCLUSIONS:

Improvement in TLim was associated with an increase in IC at rest after bronchodilator in HD- patients with COPD. However, even without that improvement, COPD patients can present with greater exercise tolerance after bronchodilator provided that they develop DH during exercise.     

Does Pseudohypoaldosteronism Mask the Diagnosis of Congenital Adrenal Hyperplasia?

Hyponatremia and hyperpotassemia occurring in the first few weeks of life primarily indicate aldosterone deficiency due to salt-losing congenital adrenal hyperplasia (SL-CAH), while mineralocorticoid deficiency and insensitivity are the main causes of hyponatremia and hyperpotassemia in older infants. Some patients who present with vomiting and poor sucking, who have hyponatremia and hyperpotassemia and are initially diagnosed as CAH, during follow-up, are found to suffer from pseudohypoaldosteronism (PHA). This situation has been reported several times before. The cases described here represent the opposite situation: they presented with hyponatremia and hyperpotassemia, thus PHA was considered as aldosterone levels were very high, but subsequent investigation and genetic analysis led to the diagnosis of SL-CAH.     

Does short-term cessation of smoking before lung resections reduce the risk of complications?

BackgroundSmoking cessation is a highly important preparation before thoracic surgery. We examined the effects of short-term smoking cessation intervention before pulmonary resection on postoperative pulmonary complications (PPCs).MethodsA retrospective analysis of prospectively collected data was performed for 753 patients who underwent curative surgical resection for thoracic malignancy at 3 institutions. Patients with a smoking history were instructed to quit smoking. After confirming smoking cessation by at least four weeks before surgery, surgical resection was performed. Subjects were classified into three groups based on their smoking status: abstainers (anyone who had stopped smoking for at least 4 weeks but less than 2 months), former smokers (anyone who had abstained from smoking for more than two months prior to surgery), and never smokers (those who had never smoked). We examined the relationship between the preoperative smoking status and PPCs.ResultsSurgery was performed for 660 primary lung cancers and 93 metastatic lung tumors. The smoking statuses were classified as follows: abstainers (n=105, 14%), former smokers (n=361; 48%) and never smokers (n=287, 38%). The incidence of PPCs among abstainers, former smokers and never smokers was 15%, 8% and 6%, respectively (P=0.01). The mean duration of post-operative chest tube drainage among abstainers, former smokers and never smokers was 3.2, 2.2 and 2.2 days, respectively (P=0.04). The mean post-operative hospital stay among abstainers, former smokers and never smokers was 12.1, 10.6 and 10.2 days, respectively (P=0.07). There was no 30-day mortality in the cohort.ConclusionsShort-term smoking cessation intervention did not enough reduce the PPCs as much as in former or never smokers.     

Can the position of a patient influence the result of an ultrasound examination of venous valve insufficiency?

The goal of our work was to test sensitivity of the duplex ultrasound examination in making a sapheno-femoral junction diagnosis in lying patients. For this reason we tried to find out whether in ultrasound examination of lumen diameter of the great saphenous vein (B-mode) the speed of blood flow and reflux detection (CFM, pulse Doppler detection) are influenced by the position of a patient when lying and when standing. We examined 70 lower limbs of 70 different patients (47 women and 23 men) in whom the sapheno-femoral junction was not diagnosed when examined in the lying position. The difference in the lumen diameter of the great saphenous vein measured when lying and when standing was statistically significant in our group of patients (p < 0.01). Decreased blood flow when standing was also statistically significant (p < 0.01). In any of the 50 examined lower limbs with the competent sapheno-femoral junction during the Valsalvov's manoeuvre when lying was not proved reflux nor it was proved when standing ( CFM, pulse Doppler detection). The examination of the venous reflux in the lying position is a physiologic, delicate, and at the same time reliable method. The lying position is comfortable for both the patient and the physician and as we proved, compared to ultrasonography in the vertical position, it does not lack needed sensitivity.     

Can change in high-density lipoprotein cholesterol levels reduce cardiovascular risk?

Background

The cardiovascular risk reduction observed in many trials of lipid-lowering agents is greater than expected on the basis of observed low-density lipoprotein cholesterol (LDL-C) level reductions. Our objective was to explore the degree to which high-density lipoprotein cholesterol (HDL-C) level changes explain cardiovascular risk reduction.

Methods

A systematic review identified trials of lipid-lowering agents reporting changes in HDL-C and LDL-C levels and the incidence of coronary heart disease (CHD). The observed relative risk reduction (RRR) in CHD morbidity and mortality rates was calculated. The expected RRR, given the treatment effect on total cholesterol level, was calculated for each trial with logistic regression coefficients from observational studies. The difference between observed and expected RRR was plotted against the change in HDL-C level, and a least-squares regression line was calculated.

Results

Fifty-one trials were identified. Nineteen statin trials addressed the association of HDL-C with CHD. Limited numbers of trials of other therapies precluded additional analyses. Among statin trials, therapy reduced total cholesterol levels as much as 32% and LDL-C levels as much as 45%. HDL-C level increases were <10%. Treatment effect on HDL-C levels was not a significant linear predictor of the difference in observed and expected CHD mortality rates, although we observed a trend in this direction (P = .08). Similarly, HDL-C effect was not a significant linear predictor of the difference between observed and expected RRRs for CHD morbidity (P = .20).

Conclusions

Although a linear trend toward greater risk reduction was observed with greater effects on HDL-C, differences were not statistically significant. The narrow range of HDL-C level increases in the statin trials likely reduced our ability to detect a beneficial HDL-C effect, if present.