Prevalence of metabolic syndrome among Vietnamese adult employees

BACKGROUND AND AIMS

Metabolic syndrome (MtS) is associated with increased risk of many health disorders, especially cardiovascular diseases. In Vietnam, study examining MtS is meager and especially lacking for the workforce. We estimated the prevalence of MtS and its associated factors among Vietnamese employees.

METHODS AND RESULTS

We analyzed secondary data of annual health check of employees of 300 Vietnamese companies from the Vinmec Healthcare System. We used three definitions for MtS: International Diabetes Federation (IDF), National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III), and NCEP ATP III-Asia. Of 57,997 participants evaluated, 48.5 % were males and 66.2 % were younger than 40 years old. The unadjusted MtS prevalence was 8.4 % (IDF), 10.2 % (NCEP ATP III), and 16.0 % (NCEP ATP III-Asia). The age-sex adjusted prevalence of MtS (NCEP ATP III-Asia) was 21.8 % (95 % confidence interval (CI): 21.4 %, 22.2 %). MtS prevalence increased with age, reached 49.6 % for age ≥60. The aging related increase was more remarkable in females than males (prevalence ratio (PR) (95 % CI) for age ≥60 comparing to age <30 years old in males vs. females was 4.0 (3.6, 4.3) vs. 20.1 (17.7, 22.9)). High blood triglyceride (83.4 %) and abdominal obesity (74.5 %) were the predominant contributors to MtS.

CONCLUSION

In this relatively young Vietnamese working population, 16 % had MtS with high triglyceride and abdominal obesity being the predominant contributors. These findings emphasize the need for developing effective high triglyceride and abdominal obesity prevention and control programs to curb the emerging epidemic of metabolic disorders in the workforce.

Gastric cancer: epidemiology, biology, and prevention: a mini review

Gastric cancer is one of the most common causes of cancer-related mortality worldwide. The objective of this article is to review the epidemiology and biology of gastric cancer risk. This literature review explores the biological, clinical, and environmental factors that influence the rates of this disease and discuss the different intervention methods that may not only increase the awareness of gastric cancer but also increase screening in efforts to reduce the risk of gastric cancer. Helicobacter pylori infection is the primary risk factor for gastric cancer. Additional risk factors include geographical location, age, sex, smoking, socioeconomic status, dietary intake, and genetics. Primary and secondary prevention strategies such as dietary modifications and screenings are important measures for reducing the risk of gastric cancer. Interventions, such as H. pylori eradication through chemoprevention trials, have shown some potential as a preventative strategy. Although knowledge about gastric cancer risk has greatly increased, future research is warranted on the differentiation of gastric cancer epidemiology by subsite and exploring the interactions between H. pylori infection, genetics, and environmental factors. Better understanding of these relationships can help researchers determine the most effective intervention strategies for reducing the risk of this disease.

Racial/ethnic, age and sex disparities in leukemia survival among adults in the United States during 1973-2014 period

There has been marked improvement in leukemia survival, particularly among children in recent time. However, the long-term trends in survival among adult leukemia patients and the associated sex and racial survival disparities are not well understood. We, therefore, evaluated the secular trends in survival improvement of leukemia patients from 1973 through 2014, using Surveillance Epidemiology and End-Result Survey Program (SEER) data. ICD-O-3 morphology codes were used to group leukemia into four types: acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), chronic myeloid leukemia (CML). Survival analysis for each leukemia type stratified by race/ethnicity, age, sex was performed to generate relative survival probability estimates for the baseline time period of 1973 through 1979. Hazard ratios (HR) and respective 95% confidence intervals (CIs) for survival within subsequent 10-year time periods by race, age and sex were calculated using Cox proportional hazard models. Of the 83,255 leukemia patients for the current analysis, the 5-year survival of patients with ALL, AML, CLL, and CML during 1973-1979 were 42.0%, 6.5%, 66.5%, and 20.9%, respectively. Compared to the baseline, there were substantial improvements of leukemia-specific survival in 2010-2014 among African-American (81.0%) and Asian (80.0%) patients with CML and among 20-49 year of age with CLL (96.0%). African-American patients, those with AML and those older than 75 years of age had the lowest survival improvements. Asians experienced some of the largest survival improvements during the study period. Others, including African-American and the elderly, have not benefited as much from advances in leukemia treatment.

Disparities by race, age, and sex in the improvement of survival for lymphoma: Findings from a population-based study

Objective

To evaluate improvement in survival of lymphoma patients from 1990 to 2014, stratified by age, sex and race using Surveillance Epidemiology and End-Result Survey Program (SEER) data.

Study design and setting

We identified 113,788 incident lymphoma cases from nine SEER cancer registries were followed up for cause-specific mortality from lymphoma. Cox proportional hazard regression was used to estimate hazard ratios (HRs) and their respective 95% confidence interval (CIs) for various time periods within groups stratified by race, age and sex.

Results

Five-year survival for Hodgkin’s lymphoma (HL) was 89% for patients 20–49 years of age. For this age group, compared to 1990–1994, survival significantly improved in 2000–2004 (HR = 0.65; 95% CI: 0.54–0.78), 2005–2009 (HR = 0.46, 95% CI: 0.38–0.57) and 2010–2014 (HR = 0.29, 95% CI: 0.20–0.41). Hodgkin’s lymphoma patients aged 75–85 years had 5-year survival of 37% and in these patients, compared to 1990-1994, survival only improved from 2005 onward (HR = 0.67, 95% CI: 0.50–0.90). In patients with non-Hodgkin’s Lymphoma (NHL), all age groups showed survival improvements between 1990–1994 period and 2010–2014 period. Improvements in HL and NHL survival were seen for all race categories and both genders.

Conclusion

Survival among US lymphoma patients has improved substantially between 1990–1994 period and 2010–2014 period, though disease-specific mortality was still higher in older age groups.

Abstract 1217: The association between birth order and childhood brain tumors: A systematic review and meta-analysis

Background: The incidence of childhood brain tumors (CBT) has increased worldwide, likely resulting from the improvements of early diagnostics. The only known risk factors for CBT are the Li-Fraumeni syndrome and iodization. While both genetic and environmental factors are suggested roles in CBT, birth characteristics, including birth order, maternal age, and mode of delivery, might present the interactions between genetic susceptibility and perinatal environmental causes. Birth order has been hypothesized to play an important role in CBT carcinogenesis due to its possible role as proxy for 1) early infection exposure and 2) hormone levels since first pregnancy differs endocrinologically from later pregnancies. We conducted a systematic review and meta-analysis to clarify the association between birth order and CBT.

Methods: We followed established guidelines to systematically search OvidMedline, PubMed, and the Cochrane Library for English-language studies (both case-control and cohort designs) published prior to November 2017. Meta-analysis provided pooled risk estimates and their 95% confidence intervals (CI) for birth order and CBT. Funnel plots were used to identify sources of heterogeneity and publication bias.

Results: We identified 16 case-control studies with a total sample of 32,439 cases and 166,144 controls. Compared to first birth order, the meta-odds ratio (mOR) for second birth order was 1.04 (95% CI 1.01-1.07), and that for third birth order was 0.98 (95% CI: 0.90-1.06). We also identified 3 cohorts comprising a total of 1,208 cases. The meta-hazard ratio (mHR) for second or higher birth order compared to first birth order was 1.00 (95% CI: 0.96-1.05).

Conclusions: We found no overall association between birth order and CBT in both case-control and cohort study designs; the small association observed for second birth order in case-control studies deserves further consideration. Limited statistical power might have hampered the results of the other analyses.

Citation Format: Mai V. Nguyen, Mo Thi Tran, Chi TDu Tran, Quang H. Tran, Thuy Thi-Van Tuong, Linh C. Le, Paolo Boffetta, Hung N. Luu. The association between birth order and childhood brain tumors: A systematic review and meta-analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1217.

Abstract 1216: Cancer epidemiology research in Vietnam: Current status, challenges and opportunities

Background: Rapid economic growth, industrialization, and widespread adoption of a Western lifestyle in Vietnam have been accompanied by an emerging epidemic of noncommunicable diseases (NCDs), including cancer. We investigated current status, identified challenges and evaluated opportunities for the development of a comprehensive program in cancer epidemiology research in Vietnam.

Methods: We systematically searched OvidMedline, PubMed, and the Cochrane Library for studies published in English on cancer epidemiology in Vietnam prior to November 2017. Data from Vietnam cancer registries were used for descriptive analyses. Technical reports in Vietnamese were also included in our review.

Results: Cancer registry data show that by end of 2013, the total number of new cancer cases was 146,457. The most common cancers, in descending order, among men were lung, gastric, colorectal, liver and esophageal cancers while breast, lung, colorectal, gastric and thyroid cancers were the most common cancers among women. Data from six (6) cancer registries during 2004-2013 show that the incidence of several cancers has increased during the past decade, including colorectal cancer (both genders), lung cancer (men), and breast and thyroid cancers (women). Mortality data are limited due to the unavailability of death registries and/or modes of death ascertainment (i.e., causes of death). There is a scarcity of high-quality research on the risk factors (e.g., lifestyle such as smoking, alcohol consumption, physical activity, and BMI, environmental or genetic factors) for cancer in Vietnam. The majority of prior research consists of hospital-based studies (either case-control or cross-sectional designs) with small sample sizes. Since there is no population-based epidemiologic study on cancer in Vietnam, it is difficult to assess temporal trends and risk factors for cancers. Additional challenges include a lack of studies on infectious agents related to cancers and a paucity of molecular or genetic data in cancer, except for a few publications on HBV, HCV, H. Pylori, or EBV or susceptibility genes, such as BRCA1, BRCA2 for breast cancer or GSTA1, GSTP1, GSTT1 and GSTM1 for gastric cancer.

Conclusions: Currently, there is no population-based epidemiologic research program for cancer in Vietnam due to the lack of a population-based cancer registry, a dearth of well-trained investigators, and the absence of proper research support infrastructure. This, along with the lack of comprehensive etiologic research in Vietnam, prevents the evaluation of the temporal trends of cancer and risk factors for cancer. The cancer registry has provided important data on cancer incidence; however, there are no data on cancer mortality. Data on molecular and genetic epidemiology of cancer are also limited. These challenges shows the need to develop a comprehensive program in cancer control in Vietnam.

Citation Format: Thuan V. Tran, Chi T. Du Tran, Huong T. Tran, Mai V. Nguyen, Mo T. Tran, Quang H. Tran, Thuy Thi-Van Tuong, Martha J. Shrubsole, Qiuyin Cai, Wei Zheng, Xiao-Ou Shu, Linh C. Le, Paolo Boffetta, Hung N. Luu. Cancer epidemiology research in Vietnam: Current status, challenges and opportunities [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1216.

Differential resistance of GaN-based laser diodes with and without polarization effect

In this paper, we used numerical calculation and simulation to investigate the differential resistance of GaN-based laser diodes (LDs) with and without polarization effect. We confirmed the existence of a kink at the vicinity of threshold current in the differential resistance curve of GaN-based LDs and found that the kink polarity can be reversed dependent on the polarization effect. The serial parasitic diodes should be included in the theoretical analysis of the equivalent circuit of the LD devices. We determined that the superposition effects of the n-side, active, and p-side regions of the LDs caused the kink and its polarity. We also found that the differential resistance before and after the threshold was dominated by the p-side region and its gradual reduction is related to an electron overflow into p-side. Finally, we studied the effects of cavity facet reflectivity on the kink.

Suppression of electron leakage by inserting a thin undoped InGaN layer prior to electron blocking layer in InGaN-based blue-violet laser diodes

InGaN-based blue-violet laser diodes (LDs) suffer from electron leakage into the p-type regions, which could be only partially alleviated by employing the electron blocking layer (EBL). Here, a thin undoped InGaN interlayer prior to EBL is proposed to create an additional forbidden energy range above the natural conduction band edge, which further suppresses the electron leakage and thus improve the characteristics of LDs. Numerical device simulations reveal that when the proper composition and thickness of InGaN interlayer are chosen, the electron leakage could be efficiently eliminated without inducing any severe accumulation of electrons at the interlayer, resulting in a maximum output power of the device.

Determinants of condom use at sexual debut among young Vietnamese

BACKGROUND AND AIMS

Condom use at sexual debut is associated with subsequent condom use and with decreased risk of sexually transmitted infections. There is a dearth of data on determinants of condom use at first sexual intercourse. We aimed to determine factors associated with condom use at first sexual intercourse before marriage among Vietnamese adolescents and youths.

METHODS

The study involved the analysis of data from the Survey Assessment of Vietnamese Youth, 2003, the first nationally representative survey of young people in Vietnam. The survey included 7584 adolescents and youths aged 14-25 years. In this study, data of 605 adolescents and youths who had engaged in premarital sex were analyzed for factors associated with condom use using descriptive analyses, and regression techniques, allowing for sampling weights, clustering and stratification.

RESULTS

Of 605 adolescents and youths who had engaged in premarital sex, 28.6% reported condom use at first sexual intercourse. Condom use at sexual debut was less common in females than males [odds ratio (OR)=0.15; 95% confidence interval (95% CI)=0.07-0.30] and less common in those who experienced peer pressure to engage in social higher risk behaviors (OR=0.57; 95% CI=0.32-0.99). Condom use was more common if a friend/acquaintance or a stranger/sex worker was the first sexual partner (OR=2.20; 95% CI=1.16-4.17 and OR=17.90; 95% CI=6.88-46.54) respectively, each compared with fiancé/boyfriend/girlfriend as first sexual partner.

CONCLUSIONS

These data suggest that approximately one in three unmarried Vietnamese youths used a condom at first sexual intercourse. Gender, peer pressure and the nature of the relationship to the first sexual partner were independently associated with condom use. These results can inform programs directed at preventing HIV and other sexually transmitted infections among young Vietnamese.

Determinants of condom use at sexual debut among young Vietnamese

BACKGROUND AND AIMS

Condom use at sexual debut is associated with subsequent condom use and with decreased risk of sexually transmitted infections. There is a dearth of data on determinants of condom use at first sexual intercourse. We aimed to determine factors associated with condom use at first sexual intercourse before marriage among Vietnamese adolescents and youths.

METHODS

The study involved the analysis of data from the Survey Assessment of Vietnamese Youth, 2003, the first nationally representative survey of young people in Vietnam. The survey included 7584 adolescents and youths aged 14-25 years. In this study, data of 605 adolescents and youths who had engaged in premarital sex were analyzed for factors associated with condom use using descriptive analyses, and regression techniques, allowing for sampling weights, clustering and stratification.

RESULTS

Of 605 adolescents and youths who had engaged in premarital sex, 28.6% reported condom use at first sexual intercourse. Condom use at sexual debut was less common in females than males [odds ratio (OR)=0.15; 95% confidence interval (95% CI)=0.07-0.30] and less common in those who experienced peer pressure to engage in social higher risk behaviors (OR=0.57; 95% CI=0.32-0.99). Condom use was more common if a friend/acquaintance or a stranger/sex worker was the first sexual partner (OR=2.20; 95% CI=1.16-4.17 and OR=17.90; 95% CI=6.88-46.54) respectively, each compared with fiancé/boyfriend/girlfriend as first sexual partner.

CONCLUSIONS

These data suggest that approximately one in three unmarried Vietnamese youths used a condom at first sexual intercourse. Gender, peer pressure and the nature of the relationship to the first sexual partner were independently associated with condom use. These results can inform programs directed at preventing HIV and other sexually transmitted infections among young Vietnamese.