Synergistic and Non-synergistic Associations for Cigarette Smoking and Non-tobacco Risk Factors for Cardiovascular Disease Incidence in the Atherosclerosis Risk In Communities (ARIC) Study

Cigarette smoking, various metabolic and lipid-related factors and hypertension are well-recognized cardiovascular disease (CVD) risk factors. Since smoking affects many of these factors, use of a single imprecise smoking metric, e.g., ever or never smoked, may allow residual confounding and explain inconsistencies in current assessments of interactions. Using a comprehensive model in pack-years and cigarettes/day for the complex smoking-related relative risk (RR) of CVD to reduce residual confounding, we evaluated interactions with non-tobacco risk factors, including additive (non-synergistic) and multiplicative (synergistic) forms. Data were from the prospective Atherosclerosis Risk in Communities (ARIC) Study from four areas of the U.S. recruited in 1987-89 with follow-up through 2008. Analyses included 14,127 participants, 207,693 person-years and 2,857 CVD events. Analyses revealed distinct interactions with smoking: including statistical consistency with additive (body mass index, waist to hip ratio, diabetes mellitus, glucose, insulin, high density lipoproteins [HDL] and HDL(2)); and multiplicative (hypertension, total cholesterol, low density lipoproteins, apolipoprotein B, total cholesterol to HDL ratio and HDL(3)) associations, as well as indeterminate (apolipoprotein A-I and triglycerides) associations. The forms of the interactions were revealing but require confirmation. Improved understanding of joint associations may help clarify the public health burden of smoking for CVD, links between etiologic factors and biological mechanisms, and the consequences of joint exposures, whereby synergistic associations highlight joint effects and non-synergistic associations suggest distinct contributions. Joint associations for cigarette smoking and non-tobacco risk factors were distinct, revealing synergistic/multiplicative (hypertension, TC, LDL, apoB, TC/HDL, HDL(3)), non-synergistic/additive (BMI, WHR, DM, glucose, insulin, HDL, HDL(2)) and indeterminate (apoA-I and TRIG) associations. If confirmed, these results may help better define the public health burden of smoking on CVD risk and identify links between etiologic factors and biologic mechanisms, where synergistic associations highlight joint impacts and non-synergistic associations suggest distinct contributions from each factor

HIV prevalence and factors associated with HIV infection among male injection drug users under 30: a cross-sectional study in Long An, Vietnam

BACKGROUND: Sufficient targeted HIV prevention activities aiming at reducing HIV transmission within and from an extremely marginalized population of injection drug users (IDUs) must urgently and efficiently be implemented in Vietnam. This study was conducted to facilitate the development of such activities by describing transmission risks of young IDUs and evaluating factors in association with HIV infection. METHODS: Thirty clusters were selected from 29 hotspot communes in Long An province by probability proportional to size (PPS) sampling method. The snowball technique was used for enrolling participants in each cluster. The cross-sectional association of factors obtained during direct structured interviews to 248 male IDUs aged 14 to 29 years old and with their HIV test results were examined. RESULTS: The HIV prevalence among the studied IDUs was 32%. Age range of 18–20 years old, low educational level, sharing injection equipment or injection drug use in the other cities were independently associated with HIV serostatus in the multivariate analysis. Sexual behaviors did not differ between HIV-positive and -negative IDUs. Among HIV seropositive IDUs who had sexual contact with primary (n = 37), casual (n = 6), and commercial (n = 15) partners, only 5.4% (n = 2), 33.3% (n = 2), and 46.7% (n = 7), respectively, responded that they had used condoms every time. CONCLUSION: About one-third of young IDUs aged less than 30 identified in the hotspot communes in Long An, Vietnam was found to be infected with HIV, and socio-demographic and injection-related factors might account for the infection risk. Prevailing risky sexual behavior of this extremely marginalized population highlights the need to reduce their high transmission risks as a public health priority

Alcohol consumption and mortality from aortic disease among Japanese men: The Japan Collaborative Cohort study

Background and aimsOnly a few population-based prospective studies have examined the association between alcohol consumption and abdominal aortic aneurysm, and the results are inconsistent. Moreover, no evidence exists for aortic dissection. We examined the effect of alcohol consumption on risk of mortality from aortic diseases.MethodsA total of 34,720 men from the Japan Collaborative Cohort study, aged 40–79 years, without history of cardiovascular disease and cancer at baseline 1988 and 1990 were followed up until the end of 2009 for their mortality and its underlying cause. Hazard ratios of mortality from aortic diseases were estimated according to alcohol consumption categories of never-drinkers, ex-drinkers, regular drinkers of ≤30 g, and >30 g ethanol per day.ResultsDuring the median 17.9-year follow-up period, 45 men died of aortic dissection and 41 men died of abdominal aortic aneurysm. Light to moderate drinkers of ≤30 g ethanol per day had lower risk of mortality from total aortic disease and aortic dissection compared to never-drinkers. The respective multivariable hazard ratios (95% confidence intervals) were 0.46 (0.28–0.76) for total aortic disease and 0.16 (0.05–0.50) for aortic dissection. Heavy drinkers of >30 g ethanol per day did not have reduced risk of mortality from total aortic disease, albeit had risk variation between aortic dissection and abdominal aortic aneurysm.ConclusionsLight to moderate alcohol consumption was associated with reduced mortality from aortic disease among Japanese men.Available online 21 September 2017, In Pres

Associations of Daily Walking Time With Pneumonia Mortality Among Elderly Individuals With or Without a Medical History of Myocardial Infarction or Stroke: Findings From the Japan Collaborative Cohort Study

Background: The association between daily walking and pneumonia mortality, stratified by the presence of disease conditions, such as myocardial infarction (MI) or stroke, was investigated.Methods: The study participants were 22,280 Japanese individuals (9,067 men and 13,213 women) aged 65–79 years. Inverse propensity weighted competing risk model was used to calculate the hazard ratio (HR) and 95% confidence interval (CI) for pneumonia mortality.Results: After a median of 11.9 years of follow-up, 1,203 participants died of pneumonia. Participants who did not have a history of MI or stroke and who walked for 1 hour/day or more were less likely to die from pneumonia (HR 0.90; 95% CI, 0.82–0.98) than those walked for 0.5 hours/day. A similar inverse association of pneumonia and walking (0.5 hours/day) was observed among participants with a history of MI (HR 0.66; 95% CI, 0.48–0.90). Among the participants with a history of stroke, those who walked for 0.6–0.9 hours/day were less likely to die because of pneumonia (HR 0.65; 95% CI, 0.43–0.98).Conclusions: Regular walking for ≥1 hour/day may reduce the risk of pneumonia mortality in elderly individuals with or without cardiovascular disease history

Comparison of Urinary Levels of 8-Hydroxy-2’-deoxyguanosine between Young Females with and without Depressive Symptoms during Different Menstrual Phases

This study aimed to clarify the association between depressive symptoms and a marker of oxidative stress-induced DNA damage in young females. Since the menstrual cycle may confound or modify this association, depressive symptoms and urinary levels of 8-hydroxy-2ʼ deoxyguanosine (8-OHdG) were evaluated during each menstrual phase. A total of 57 female fourth-year students (aged 21.6±0.8) from a Japanese health science university were studied. The menstrual cycle was divided into 3 phases:menstrual (days 1 to 3 after the onset of menses);proliferative (days 13 to 15);and secretory (days 24 to 26). Depressive symptoms were assessed by the self-rating depression scale (SDS). Positive depressive symptoms were defined as a score of 53 or more during 2 different menstrual phases. The association between the presence of depressive symptoms and 8-OHdG levels adjusting for the menstrual cycle was examined by two-way analysis of variance with the menstrual cycle (menstrual, proliferative, and secretory phases) as the within-individual factor. The menstrual cycle did not show a significant correlation with urinary 8-OHdG levels. On the other hand, the menstrual cycle-adjusted 8-OHdG level was significantly higher in those with depressive symptoms (7.01ng/mL) than in those without them (3.98ng/mL). The ROC curve analysis showed that urinary 8-OHdG levels had reasonably high discriminative performance throughout all the menstrual cycles (0.73-0.81;all p＜0.05). These results indicated the presence of oxidative stress in subjects with depressive symptoms independent of the menstrual cycle

Factors Predicting Bone Mineral Density (BMD) Changes in Young Women over A One-year Study:Changes in Body Weight and Bone Metabolic Markers during the Menstrual Cycle and Their Effects on BMD

Currently, 26% of Japanese women in their twenties are under weight, and therefore at risk of developing various metabolic abnormalities due to an inadequate nutrient intake, which in turn affects the acquisition of a peak bone mineral density (BMD). In this study, we aimed to clarify the effects of menstrual cycle-related changes in body weight and bone metabolic marker levels on the BMD changes. The subjects were 42 women (19.6±0.8 years). The levels of osteocalcin (OC), BAP, s-NTx, u-DPD, and E2 in the menstrual and ovulatory phases were measured. The associations between dependent variables (BMD changes/year in the lumbar spine, femur, femoral neck) and explanatory variables (body weight changes/year, the levels of OC, BAP, s-NTx, u-DPD) were evaluated using multiple regression analysis. Analysis of the correlations between the changes in bone metabolic markers and changes in BMD showed a correlation between the OC level in the menstrual phase and changes in the BMD of the entire femur, suggesting that a high OC level protects against BMD reduction, probably by promoting osteoblast activity, and that bone formation activity suppresses the decrease in BMD. These results suggest that, to predict BMD changes from bone metabolic markers in young women, it is necessary to measure OC levels in the menstrual phase

Body Mass Index and Risks of Incident Ischemic Stroke Subtypes: The Japan Public Health Center-Based Prospective (JPHC) Study

Background: The association of body mass index (BMI) with risks of ischemic stroke subtypes have not been established.Methods: Cumulative average BMI was calculated using self-reported body weight and height obtained from baseline (Cohort I in 1990, and Cohort II from 1993–1994) and 5- and 10-year questionnaire surveys of Japan Public Health Center-based prospective (JPHC) study. A total of 42,343 men and 46,413 women aged 40–69 years were followed-up for the incidence of lacunar, large-artery occlusive, and cardioembolic strokes. A sub-distribution hazard model was used to estimate sub-distribution hazard ratios (SHRs) and the 95% confidence intervals (CIs).Results: During a median of 20.0 years of follow-up, we documented 809 and 481 lacunar, 395 and 218 large-artery occlusive, and 568 and 298 cardioembolic strokes in men and women, respectively. After adjustment for baseline age, updated smoking, alcohol consumption, leisure-time physical activity, and histories of hypertension, dyslipidemia, and diabetes mellitus, cumulative average BMI was positively linearly associated with lacunar (trend P = 0.007), large-artery occlusive (trend P = 0.002), and cardioembolic (trend P < 0.001) strokes in men, and with lacunar (trend P < 0.001) and large-artery occlusive (trend P = 0.003) strokes in women. There were approximately two-fold excess risk of cardioembolic stroke in both sexes and of lacunar and large-artery occlusive strokes in women for cumulative average BMI ≥30 kg/m2 compared to BMI 23–<25 kg/m2.Conclusion: Cumulative average BMI showed a positive linear effect on sub-distribution hazards of lacunar, large-artery occlusive, and cardioembolic strokes in both sexes, except for cardioembolic stroke in women

Postural Changes in Blood Pressure and Incidence of Ischemic Stroke Subtypes: The ARIC Study

The relation of orthostatic blood pressure decrease, or increase, with occurrence of ischemic stroke subtypes has not been examined. We investigated the association of orthostatic blood pressure change (within 2 minutes after supine to standing) obtained at baseline (1987–89) in the Atherosclerosis Risk in Communities Study with incidence of ischemic stroke subtypes through 2007. Among 12,817 black and white individuals without a history of stroke at baseline, 680 ischemic strokes (153 lacunar, 383 nonlacunar thrombotic, and 144 cardioembolic strokes) occurred during a median follow-up of 18.7 years. There was a U-shaped association between orthostatic systolic blood pressure change and lacunar stroke incidence (quadratic p=0.004). In contrast, orthostatic systolic blood pressure decrease of 20 mmHg or more was associated with increased occurrence of nonlacunar thrombotic and cardioembolic strokes independent of sitting systolic blood pressure, antihypertensive medication use, diabetes, and other lifestyle, physiological, biochemical, and medical conditions at baseline (hazard ratio: 2.02, 95% confidence interval: 1.43–2.84 for nonlacunar thrombotic, hazard ratio: 1.85, 95% confidence interval: 1.01–3.39 for cardioembolic). Orthostatic diastolic blood pressure decrease was associated with increased risk of nonlacunar thrombotic and cardioembolic strokes; the hazard ratios (95% confidence interval) associated with 10 mmHg lower orthostatic diastolic blood pressure (continuous) were 1.26 (1.06–1.50) and 1.41 (1.06–1.88), respectively, in fully-adjusted models. In conclusion, the present study found that nonlacunar ischemic stroke incidence was positively associated with an orthostatic decrease of systolic and diastolic blood pressure whereas greater lacunar stroke incidence was associated with both orthostatic increases and decreases in systolic blood pressure

Associations of Obesity Measures with Subtypes of Ischemic Stroke in the ARIC Study

BackgroundAssociations between obesity and lacunar, nonlacunar thrombotic, and cardioembolic stroke are not firmly established.MethodsBody mass index (BMI), waist circumference, and waist-to-hip ratio (WHR) were recorded at baseline between 1987 and 1989 in the Atherosclerosis Risk in Communities (ARIC) Study for 13 549 black and white adults who were aged from 45 to 64 years and had no history of cardiovascular disease or cancer. The incidence of ischemic stroke subtypes was ascertained from surveillance of hospital records over a median follow-up of 16.9 years. Cox proportional hazards regression analyses adjusted for age, sex, race, education, smoking status and cigarette years, usual ethanol intake, and leisure time sports index were used to estimate hazard ratios (HRs).ResultsThe ARIC sample at baseline was 43.8% men and 27.3% blacks; mean age was 53.9 years. Mean BMI, waist circumference, and WHR were 27.7 kg/m2, 96.8 cm, and 0.92, respectively. The associations of lacunar (n = 138), nonlacunar (n = 338), and cardioembolic (n = 122) ischemic stroke incidence with obesity measures were all generally positive and linear. The HRs for the highest versus lowest quintile of the 3 obesity measures ranged from 1.43–2.21 for lacunar stroke, 1.90–2.16 for nonlacunar stroke, and 2.37–2.91 for cardioembolic stroke.ConclusionsAlthough different pathophysiological mechanisms may exist, the incidences of lacunar, nonlacunar, and cardioembolic stroke were all significantly positively associated with the degree of obesity, regardless of the measure used

Association between physical activity and risk of stroke subtypes: The Atherosclerosis Risk in Communities (ARIC) Study

The relationship between stroke subtypes and physical activity is unclear