Vasectomy and non-fatal acute myocardial infarction: a hospital-based case-control study in Seoul, Korea

Review of Vasectomy Complications and Safety Concerns

Vasectomy is a simple, safe, effective, and economical method used worldwide for long-term male contraception. As a surgical operation, it has short-term and long-term complications such as hematoma formation, infection, sterilization failure, sperm granulomas, short-term postoperative pain (nodal pain, scrotal pain, and ejaculation pain), and chronic pain syndrome. Whether it increases the risk of autoimmune disease, cardiovascular disease, testicular cancer, or prostate cancer is still controversial. Changes in plasma concentrations of luteinizing hormone, follicle-stimulating hormone, and testosterone after vasectomy have also been studied, as well as the relation between vasectomy and sexual function. Sperm quality decreases very slowly after vasectomy, and vasovasostomy and intracytoplasmic sperm injection could help a couple achieve a pregnancy if they change their minds at any point. We include a follow-up strategy and suggestions for follow-up care at the end of this review.

Vasectomy and cardiovascular disease risk: A systematic review and meta-analysis

BACKGROUND

Even though several studies comparing vasectomy and cardiovascular disease (CVD) risk have been reported, most are small series with conflicting results. However, the extent of the risk is still uncertain. We therefore explored whether an association exists between vasectomy and CVD incidence and mortality.

METHODS

We searched PubMed, Embase, Web of Science, and Cochrane Library databases for relevant studies published before January 2017. Multivariate adjusted odds ratio (OR) and associated 95% confidence intervals (CIs) and those by subgroups were extracted and pooled using random-effects models.

RESULTS

Overall, 12 observational studies (2 cross-sectional studies, 4 case-control studies, and 6 retrospective cohort studies) comprising 299,436 participants were identified. There was no statistically significant relationship between vasectomy and CVD risk (OR: 0.90, 95% CI: 0.81-1.00). Moreover, vasectomy was not associated with CVD mortality (OR: 0.90, 95% CI: 0.81-1.00), coronary heart disease (CHD) incidence (OR: 0.94, 95% CI: 0.88-1.01), stroke incidence (OR: 0.90, 95% CI: 0.72-1.13), and myocardial infarction (MI) incidence (OR: 0.95, 95% CI: 0.88-1.02), with no significant publication bias. In subgroup analyses, the findings on the association between vasectomy and CVD risk were consistent.

CONCLUSION

Our findings suggest that vasectomy is not associated with the excess risk of CVD incidence and mortality. Nevertheless, large-volume, well-designed observational studies, with different ethnic populations, low risk of bias, and adjusted confounding factors, are awaited to confirm and update the findings of this analysis.

Vasectomy: AUA guideline

PURPOSE

The purpose of this guideline is to provide guidance to clinicians who offer vasectomy services.

MATERIALS AND METHODS

A systematic review of the literature using the search dates January 1949-August 2011 was conducted to identify peer-reviewed publications relevant to vasectomy. The search identified almost 2,000 titles and abstracts. Application of inclusion/exclusion criteria yielded an evidence base of 275 articles. Evidence-based practices for vasectomy were defined when evidence was available. When evidence was insufficient or absent, expert opinion-based practices were defined by Panel consensus. The Panel sought to define the minimum and necessary concepts for pre-vasectomy counseling; optimum methods for anesthesia, vas isolation, vas occlusion and post-vasectomy follow up; and rates of complications of vasectomy. This guideline was peer reviewed by 55 independent experts during the guideline development process.

RESULTS

Vas isolation should be performed using a minimally-invasive vasectomy technique such as the no-scalpel vasectomy technique. Vas occlusion should be performed by any one of four techniques that are associated with occlusive failure rates consistently below 1%. These are mucosal cautery of both ends of the divided vas without ligation or clips (1) with or (2) without fascial interposition; (3) open testicular end of the divided vas with MC of abdominal end with FI and without ligation or clips; and (4) non-divisional extended electrocautery. Patients may stop using other methods of contraception when one uncentrifuged fresh semen specimen shows azoospermia or ≤ 100,000 non-motile sperm/mL.

CONCLUSIONS

Vasectomy should be considered for permanent contraception much more frequently than is the current practice in the U.S. and many other nations. The full text of this guideline is available to the public at http://www.auanet.org/content/media/vasectomy.pdf.

What limits the effectiveness of school-based anti-smoking programmes?

BACKGROUND

It is generally accepted that living in families where there are smokers, children are stressed not only by the harmful physical exposure to second-hand and third-hand tobacco smoke, but also by the negative models of the adult relatives' behaviour, as relatives who smoke can inspire children to imitate this behaviour, influencing attitudes towards, and early experiments with smoking. In this paper, some of the most important results about influence of family smoking on the effects of the anti-smoking educational programme "Non-smoking Is Normal" are described.

METHODS

The school-based programme was created by medical and educational specialists and targets children at the first level of primary schools (aged from 6 to 11 years). The data about interesting outcomes of the programme (knowledge, attitudes, behaviour) were collected by anonymous questionnaire, administered twice in each school year: one month before the complex of 5 lectures (pre-tests) and 4-5 months after the last lecture (post-tests). The sample of participants (860-910) was divided into four groups, according to the intervention and family backrounds: (1) programme children from smoking families "P-S"; (2) control children from smoking families "C-S"; (3) programme children from non-smoking families "P-NS"; (4) control children from non-smoking families "C-NS". The differences in the frequency of children's answers were analysed using the tests in statistic Epi Info software, version 6.04a (chi-square, Mantel Haenszel, Yates, Fisher).

RESULTS

In the programme group, the number of children with smoking relatives was significantly higher than in the control group (80.1% vs. 73.0%, p < 0.01) as well as of those who reported frequent/daily exposure to secondhand smoke at homes and/or in cars (49.5% vs. 40.0%, p < 0.01). Smoking families significantly influenced the children's seeking of smoking friends (40% vs. 17%, p < 0.01). The programme has significantly increased the amount of knowledge about health risks of smoking. Both in the programme and control groups of children from non-smoking families, the frequency of critics of adults smoking was significantly higher all the time of the study (p < 0.05 and 0.01 resp.); however, the programme influenced children's opinions about smoking (criticism) only partially. Children's actual intentions about their smoking in the future was fully influenced by their smoking household environment: the number of "future no-smokers" has decreased in time and was significantly less frequent among children from smoking families (p < 0.01). The frequency of those willing to smoke significantly increased within the period between 3rd and 5th grades, both in the programme and the control groups (p < 0.01). An almost linear increase of active experimentations with cigarette smoking in follow-up monitoring was seen, trends of smoking children were steeper in groups from smoking families. The number of experiments with smoking was significantly lower in programme children of non-smoking parents only at the end of the study (p < 0.05).

CONCLUSIONS

Despite of the effort to initiate parental participation on the primary prevention of smoking, we have confirmed that smoking in families decreased the efficacy of anti-smoking intervention targeted on young children at school age.

Ocimum gratissimum Aqueous Extract Induces Apoptotic Signalling in Lung Adenocarcinoma Cell A549

Ocimum gratissimum (OG) is widely used as a traditional herb for its antibacterial activity in Taiwan. Recently, antitumor effect of OG on breast cancer cell is also reported; however, the effects of OG on human pulmonary adenocarcinoma cell A549 remain unclear. Therefore, we aimed to investigate whether aqueous OG extract (OGE) affects viability of A549 cells and the signals induced by OGE in A549 cells. Cell viability assays revealed that OGE significantly and dose-dependently decreased the viability of A549 cell but not that of BEAS-2B cell. Morphological examination and DAPI staining indicated that OGE induced cell shrinkage and DNA condensation for A549 cells. Further investigation showed that OGE enhanced activation of caspase-3, caspase-9 and caspase-8 and increased protein level of Apaf-1 and Bak, but diminished the level of Bcl-2. Additionally, OGE inhibited the phosphorylation of extracellular signal-regulated kinase (ERK) yet enhanced the phosphorylation of c-Jun N-terminal kinase (JNK) and p38 MAP kinase (p38). In conclusion, our findings indicate that OGE suppressed the cell viability of A549 cells, which may result from the activation of apoptotic signaling and the inhibition of anti-apoptotic signaling, suggesting that OGE might be beneficial to lung carcinoma treatment.

Where do our children learn to smoke?

BACKGROUND

Primary prevention of smoking in children is mostly carried out through school education schemes organised by trained teachers. The generally accepted notion is that children's opinions and behaviour are influenced by the school, but mainly by the family and their peers, as well as by the broader society. The primary preventive programme aimed at the first three years of primary schools, called "No Smoking is a Norm" strives to encourage parents to take an active part in the education of their children against smoking, as well as about other aspects of a healthy lifestyle. This paper analyses the data documenting the effectiveness of the programme with respect to children's family smoking history.

METHODS

The information about smokers in families was collected during enquiries prior to the initiation of the 1st and 2nd stage (in the 1st and the 2nd class), and again after their conclusion. In the first stage, smoking of mothers, fathers, and grandparents was followed separately. In the second stage, the category of smokers that can influence children, included parents, grandparents, siblings, aunts, and uncles, with whom the children are in contact (the so-called "broader family"). Questionnaires answered by children who did not know whether their parents or grandparents smoked were excluded from the survey The analysis included 1423 (i.e., 76.6%) from the total number of 1857 children from the programme and control groups. The answers were coded and analysed using the chi2 test in EPI INFO software, version 3.3.2.

RESULTS

Approximately 30% of the children's parents are smokers. Almost 60% of the children were exposed to the influence of smoking parents and grandparents, and more than three quarters of the children experienced smoking from the "broader family". The more smokers there are in the family, the more children have the opportunity to handle cigarettes and smoking accessories from an early age: they get, buy, or even light cigarettes. Smoking of parents and other relatives led to a substantial increase in the number of children who were determined to smoke in the future or were considering it. More than half of the eight-year-olds have tasted an alcoholic drink, and significantly more frequently in the families of smokers. 8% of the eight-year-olds have gone through their first smoking attempts and all of them from families with adult smokers. On the other hand, the smoking or non-smoking family environment of the respondents did not influence the knowledge part of the intervention programme. In the study group, in comparison with the control group, there were significantly more children exposed to the influence of smokers in the "broader" family (80.1% vs. 73.0%). This could explain why evaluation of the medium-term efficiency of the programme without consideration of the family environment was highest in the knowledge area, while differences in change of opinions and behaviour were mostly insignificant.

CONCLUSIONS

Smoking of family members significantly reduces the efficiency of school educational anti-smoking activities aimed at children and young people.

Traffic air pollution and lung cancer in females in Taiwan: petrol station density as an indicator of disease development

To investigate the relationship between traffic air pollution exposure and development of lung cancer in females, studies were conducted using a matched cancer case-control model into deaths that occurred in Taiwan from 1997 through 2006. Data on all eligible lung cancer deaths in females were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. The control group consisted of women who died from causes other than neoplasms or diseases that were associated with respiratory problems. The controls were pair matched to the cancer cases by year of birth and year of death. Each matched control was selected randomly from the set of possible controls for each case. Data on the number of petrol stations in study municipalities were collected from the two major petroleum supply companies, Chinese Petroleum Corporation (CPC) and Formosa Petrochemical Corporation (FPCC). The petrol station density (per square kilometer; PSD) for study municipalities was used as an indicator of a subject's exposure to benzene and other hydrocarbons present in ambient evaporative losses of petrol or to air emissions from motor vehicles. The subjects were divided into tertiles according to PSD in their residential municipality. The results showed that there was a significant exposure-response relationship between PSD and risk of lung cancer in females after controlling for possible confounders. The findings of this study warrant further investigation of the role of traffic air pollution exposure in the etiology of lung cancer.

Female lung cancer and petrochemical air pollution in Taiwan

To investigate the relationship between petrochemical air pollution and female lung cancer, we conducted a matched case-control study among women who had died in Taiwan from 1990 through 1994. Data about all eligible female lung cancer deaths were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. The control group included women who died from nonneoplasms and diseases that were not associated with respiratory problems. We pair-matched the controls to the cases by sex, year of birth, and year of death. Each matched control was selected randomly from the set of possible controls for each case. We used the proportion of a municipality's total population employed in the petrochemical manufacturing industry as an indicator of a resident's exposure to air emissions from the petrochemical manufacturing industry. The subjects were divided into tertiles according to the above indicator. Women who lived in the 2 groups of municipalities characterized by higher levels of petrochemical pollution had a statistically significant higher risk of developing lung cancer than the group that lived in municipalities with the lowest petrochemical air pollution levels (after controlling for possible confounders). The linear trend was also statistically significant (p < .05). The results of this study shed important light on the relationship between the Taiwan petrochemical industry and the resulting risk to human health.

Vasectomy and subsequent cardiovascular disease in US physicians

Due to previous animal research suggesting accelerated atherosclerosis following vasectomy, we examined whether vasectomy increases the risk of subsequent cardiovascular disease (CVD), including myocardial infarction (MI), angina pectoris, coronary revascularization, and stroke, in the US Physicians' Health Study. Of 22,071 US male physicians participating in the study, aged 40 to 84 years at entry and free from cardiovascular disease and cancer, 21,028 reported on the 60-month questionnaire whether they had undergone vasectomy prior to randomization. Of the 4546 physicians with vasectomy, 1159 had undergone the procedure at least 15 years before entry. During 258,892 person-years of follow-up, we documented 773 cases of MI (719 nonfatal and 54 fatal), 1907 cases of angina pectoris or coronary revascularization, and 604 confirmed cases of ischemic or hemorrhagic stroke (566 nonfatal and 38 fatal). When compared to men without prior vasectomy, the multivariate relative risk (RR) of total MI adjusted for age and other coronary risk factors was 0.94 (95% confidence interval [CI], 0.77-1.14) among men with vasectomy. Risk estimates for fatal and nonfatal events did not appreciably differ from each other. For angina or coronary revascularization or both, the multivariate relative risk was 0.99 (0.88-1.12) and for total stroke the RR was 0.95 (0.75-1.21). For men who had undergone vasectomy 15 or more years previously, the multivariate relative risks were 0.98 (0.73-1.32) for total MI, 1.17 (0.87-1.57) for total stroke, and 1.12 (0.94-1.35) for angina/revascularization. These results provide reassuring evidence that vasectomy does not materially increase the risk of subsequent cardiovascular disease, even 15 or more years following the procedure.

Immunomodulatory effect of beta-carotene on T lymphocyte subsets in patients with resected colonic polyps and cancer

Results from a number of studies suggest that beta-carotene-containing foods prevent the initiation or progression of various cancers. One possible mechanism for this effect could be enhancement of the immune response. The aim of this study was to determine whether beta-carotene modulates T lymphocyte subsets in patients affected with colonic polyps or cancerous lesions. Patients with previous adenomatous colonic polyps (n = 18) or colon cancers (n = 19) were randomized to receive placebo or beta-carotene (30 mg/day) for three months. Percentages of T lymphocyte subsets were determined using flow cytometry in blood samples collected before randomization and at three months. T lymphocyte subsets of 14 normal control subjects were also determined for comparison. Initially, there was no difference in total leukocyte counts, percentage of lymphocytes, and various subsets of lymphocytes among the three groups, although in cancer patients there was a lower percentage of CD4 and interleukin-2 (IL-2) receptor-positive (IL-2R+) cells than in patients with polyps and in controls. After supplementation with beta-carotene, a significant increase in IL-2R+ T lymphocytes (from 12.7 +/- 3.0% to 26.0 +/- 1.9%) and CD4+ lymphocytes (from 40.9 +/- 3.1% to 45.6 +/- 3.2%) was seen only in the cancer patients. These percentages remained unchanged in patients with adenomatous polyps receiving placebo or beta-carotene. We concluded that beta-carotene increased the number of IL-2R+ T lymphocytes and CD4+ lymphocytes, which in turn may produce IL-2 only in patients with cancer who may already have some deficiency in their immune system. This increase in activated T lymphocytes may mediate cytotoxic reactions to cancer cells via cytokine production.

Expression of mRNA for the gap-junctional protein connexin43 in human colonic tissue is variable in response to beta-carotene supplementation

Increased expression of the gap-junctional protein connexin43 (Cx43) is reported to be increased in mouse and human dermal fibroblasts in vitro in response to beta-carotene treatment. In the present study, we determined the level of Cx43 mRNA expression in colonic mucosa from normal subjects and subjects with a prior history of colonic polyps or cancer before and after three months of administration of a placebo or beta-carotene. RNA was reverse transcribed and used in a polymerase chain reaction assay employing primers selected from the human Cx43 gene sequence. Cx43 mRNA expression was normalized on the basis of beta 2-microglobulin mRNA expression. The beta-carotene concentration in colonic mucosa, as well as serum and diet, was also determined to establish a correlation between Cx43 expression and beta-carotene concentration. In an initial analysis of samples collected from 10 subjects before supplementation, the quantity of Cx43 mRNA was variable and did not correlate with beta-carotene intake or the concentration of beta-carotene in tissue or serum. In samples collected at zero and three months from eight subjects who were controls or received a placebo, there was no correlation between Cx43 mRNA level and tissue or serum beta-carotene concentration. In samples collected from subjects before and after three months of beta-carotene supplementation, there was a significant increase in tissue and serum beta-carotene concentration in all subjects and an increase in Cx43 mRNA expression after supplementation relative to baseline in four of six samples. The high variability in Cx43 expression indicates that induction of Cx43 mRNA expression is not solely dependent on the concentration of beta-carotene in diet, serum, or tissue. However, the results from subjects supplemented with beta-carotene suggest that induced expression may occur in colonic tissue of some individuals. some individuals.

Conducting a hospital-based case-control study of the relationship between vasectomy and cardiovascular disease in Korea--an experience in an Asian setting

An increasing number of case-control studies are being performed in the developing world. This paper describes the difficulties and advantages the author has experienced in conducting a hospital-based case-control study in the Republic of Korea testing the hypothesis of whether vasectomy is associated with subsequent cardiovascular disease. This experience should provide a useful reference for researchers planning studies using a similar approach in an Asian setting.

Incidence of disease after vasectomy: a record linkage retrospective cohort study

OBJECTIVE

To determine whether vasectomy is associated with an increased risk of several diseases, and in particular testicular cancer, after operation.

DESIGN

Retrospective cohort study using linked medical record abstracts.

SETTING

Six health districts in Oxford region.

SUBJECTS

13,246 men aged 25-49 years who had undergone vasectomy between 1970 and 1986, and 22,196 comparison subjects who had been admitted during the same period for one of three specified elective operations, appendicitis, or injuries.

MAIN OUTCOME MEASURES

Hospital admission and death after vasectomy or comparison event.

RESULTS

The mean durations of follow up were 6.6 years for men with a vasectomy and 7.5 years for men with a comparison condition. The relative risk of cancer of the testis in the vasectomy cohort (4 cases) compared with that in the other cohorts (17 cases) was 0.46 (95% confidence interval 0.1 to 1.4), that of cancer of the prostate (1 v 5 cases) 0.44 (0.1 to 4.0), and that of myocardial infarction (97 v 226 cases) 1.00 (0.8 to 1.3). There was no evidence of an increase associated with vasectomy in the incidence of a range of other diseases.

CONCLUSIONS

Vasectomy was not associated with an increased risk of testicular cancer or the other diseases studied. With respect to prostatic cancer, while we found no cause for concern, longer periods of observation on large numbers of men are required.