Association of high viral load and abnormal liver function with high aflatoxin B1–albumin adduct levels in HIV-positive Ghanaians: preliminary observations

We examined the association between certain clinical factors and aflatoxin B₁–albumin adduct (AF-ALB) levels in HIV-positive people. Plasma samples collected from 314 (155 HIV-positive and 159 HIV-negative) people were tested for AF-ALB levels, viral load, CD4+ T-cell count, liver function profile, malaria parasitaemia, and hepatitis B and C virus infections. HIV-positive participants were divided into high and low groups based on their median AF-ALB of 0.93?pmol?mg^?1 albumin and multivariable logistic and linear regression methods used to assess relationships between clinical conditions and AF-ALB levels. Multivariable logistic regression showed statistically significant increased odds of having higher HIV viral loads (OR?=?2.84; 95% CI?=?1.17–7.78) and higher direct bilirubin levels (OR?=?5.47; 95% CI?=?1.03–22.85) among HIV-positive participants in the high AF-ALB group. There were also higher levels of total bilirubin and lower levels of albumin in association with high AF-ALB. Thus, aflatoxin exposure may contribute to high viral loads and abnormal liver function in HIV-positive people and so promote disease progression.     

北方地区成人脂肪肝危险因素的病例对照研究

目的：探索北方地区成人脂肪肝的危险因素。方法：采用病例对照研究对294名病例和655名对照的相关资料进行非条件Logistic回归分析。结果：超重（OR=6．3,95％CI=4．4,8．9）、肥胖（OR=16．9,95％CI=9．9,28．9）、腹型肥胖（OR：2．9,95％CI=1．9,4．5）、血脂异常（OR=2．1,95％CI：1．5,3．0）及ST．T改变（OR=1．6,95％CI=1．0,2．3）与脂肪肝的患病明显相关（P〈0．05）。摄入肉类较多、高盐饮食及自觉压力较大均为脂肪肝的危险因素,其OR值分别为1．5（95％CI,1．0,2．1）、1．5（95％CI,1．1,2．1）及1．4（95％CI,1．0,2．2）。在家就餐超过5d为脂肪肝的保护因素,OR为0．6（95％CI,0．4,0．9）。结论：脂肪肝的发生与代谢性疾病及生活方式密切相关。     

Perceived risk of harm from cigarettes or smokeless tobacco among U.S. high school seniors.

This study examined perceived risk of harm from smoking or ST use in a U.S. nationally representative sample of high school seniors and examined its association with current smoking status. Data were derived from the Monitoring the Future project for 1999 through 2003 (n = 11,093). We used multiple logistic regression analysis to examine the association between comparative perceived risk of harm of smoking and ST use with current smoking status, while adjusting for sex, race, and perceived risk of harm from smoking. In 1999-2003, 74.0% of high school seniors perceived great risk of harm from smoking and 44.9% perceived great risk from using ST. Perceived risk varied by smoking intensity: 80.3% of non-smokers perceived great risk of harm from smoking, compared to 49.7% of students who smoked about one-half pack per day and 36.1% of pack-a-day smokers. Overall, 52.7% perceived equal risk of harm from using either product, 41.3% perceived greater risk from cigarettes, and 6.1% perceived a greater risk from using ST. Adjusting for sex and race, high school seniors who perceived that smoking conveyed a greater risk for harm than did using smokeless tobacco were significantly more likely to be smokers than were those who perceived equal risk from the products (odds ratio [OR] = 1.43; 95% confidence interval [CI] 1.29-1.60). Those who perceived that using smokeless tobacco was riskier than smoking were even more likely to be current smokers (OR = 2.43; 95% CI 1.96-3.01). Effective methods for communicating accurate health risks to young people are needed.     

Passive smoking as well as active smoking increases the risk of acute stroke

OBJECTIVE: To estimate the relative risk of stroke associated with exposure to environmental tobacco smoke (ETS, passive smoking) and to estimate the risk of stroke associated with current smoking (active smoking) using the traditional baseline group (never-smokers) and a baseline group that includes lifelong non-smokers and long-term (> 10 years) ex-smokers who have not been exposed to ETS. DESIGN AND SETTING: Population-based case-control study in residents of Auckland, New Zealand. SUBJECTS: Cases were obtained from the Auckland stroke study, a population-based register of acute stroke. Controls were obtained from a cross-sectional survery of major cardiovascular risk factors measured in the same population. A standard questionnaire was administered to patients and controls by trained nurse interviewers. RESULTS: Information was available for 521 patients with first-ever acute stroke and 1851 community controls aged 35-74 years. After adjusting for potential confounders (age, sex, history of hypertension, heart disease, and diabetes) using logistic regression, exposure to ETS among non-smokers and long-term ex-smokers was associated with a significantly increased risk of stroke (odds ratio (OR) = 1.82; 95% confidence interval (95% CI) = 1.34 to 2.49). The risk was significant in men (OR = 2.10; 95% CI = 1.33 to 3.32) and women (OR = 1.66; 95% CI = 1.07 to 2.57). Active smokers had a fourfold risk of stroke compared with people who reported they had never smoked cigarettes (OR = 4.14; 95% CI = 3.04 to 5.63); the risk increased when active smokers were compared with people who had never smoked or had quit smoking more than 10 years earlier and who were not exposed to ETS (OR = 6.33; 95% CI = 4.50 to 8.91). CONCLUSIONS: This study is one of the few to investigate the association between passive smoking and the risk of acute stroke. We found a significantly increased risk of stroke in men and in women. This study also confirms the higher risk of stroke in men and women who smoke cigarettes compared with non-smokers. The stroke risk increases further when those who have been exposed to ETS are excluded from the non-smoking reference group. These findings also suggest that studies investigating the adverse effects of smoking will underestimate the risk if exposure to ETS is not taken into account.     

Smoking cessation by socioeconomic status and marital status: the contribution of smoking behavior and family background.

We studied socioeconomic status and marital status as predictors of smoking cessation, adjusting for previous smoking behavior and family background by using a large Finnish prospective twin dataset unselected for smoking behavior. The data were collected by postal surveys in 1981 and 1990, and the sample comprised 3,069 current smokers, of whom 20% had quit smoking by 1990. Logistic regression analyses of all twin individuals and conditional logistic regression analysis of discordant pairs were used to predict smoking cessation. High education predicted smoking cessation among both men (OR=2.32, 95% CI=1.31-4.10) and women (OR=3.98, 95% CI=1.85-8.51) as did high social class among women. Additionally, starting at a late age, smoking a small number of cigarettes per day, and a low level of nicotine per cigarette predicted cessation. Socioeconomic differences in cessation diminished only slightly when we adjusted for smoking behavior factors. Among the twin pairs who were discordant in terms of smoking cessation, the twin who continued smoking also smoked more on average at baseline (men: OR=.94, 95% CI=.89-.99; women: OR=.82, 95% CI=.71-.94). The male twins who continued smoking had a smaller probability of getting married during the follow-up than had the cotwin who had quit smoking (OR=3.91, 95% CI=1.02-15.02). Indicators of socioeconomic status were important predictors of smoking cessation even when we adjusted for previous smoking behavior. For men, marriage was associated with an increased probability of cessation     

Cigarette smoking and quitting behaviors among unemployed adults in the United States.

Little is known about factors associated with smoking among the unemployed. This study estimated the prevalence of smoking and examined sociodemographic factors associated with current, former, and successful quitting among unemployed adults aged 18-64. Cross-sectional data on 13,480 participants in the 1998-1999 and 2001-2002 Tobacco Use Supplements to the Current Population Surveys were analyzed. Multivariate logistic regression analyses were used to examine factors associated with study outcomes (current vs. never, former vs. current, successful quitter vs. other former smoker). Among the unemployed, 35% were current smokers and 13% were former smokers. Of the former smokers, 81% quit successfully for at least 12 months. Participants with family incomes of less than US$25,000 were more likely than those with incomes of $50,000 or more to currently smoke (OR=2.13, 95% CI=1.85-2.46). Service workers and blue-collar workers were less likely than white-collar workers to report former smoking. Participants unemployed for 6 months or more were twice as likely as those unemployed for less than 6 months to quit successfully (OR=2.05, 95% CI=1.07-3.95). Unemployed blue-collar workers had a greater odds ratio of successfully quitting than white-collar workers (OR=1.83, 95% CI=1.17-2.87). Smoking rates were high among the unemployed, and quitting behaviors varied by sociodemographic factors and length of unemployment. Studies are needed to examine the feasibility of cessation interventions for the unemployed.     

Relationship between smokeless tobacco use and body weight in young adult military recruits.

Long-time cigarette smokers tend to weigh less than nonsmokers, and those who quit smoking typically gain weight. Little is known, however, about the relationship between smokeless tobacco and body weight. The present study investigated the association between smokeless tobacco use and body weight among 22,974 Air Force recruits (27.4% female, mean age=20.2 years, body mass index=22.7) undergoing basic military training. Current, former, and experimental smokeless tobacco users weighed significantly more than recruits who had never tried smokeless tobacco (p values <.05). Logistic regression analysis also indicated that the likelihood of being classified as overweight was significantly greater for daily (OR=1.29, 95% CI=1.07-1.54), occasional (OR=1.50, 95% CI=1.17-1.93), former (OR=1.33, 95% CI=1.05-1.67), and experimental (OR=1.13, 95% CI=1.02-1.24) smokeless tobacco users relative to never-users (p values <.05). These results suggest that smokeless tobacco use does not have significant weight-attenuating effects, at least in the short term. Furthermore, using chewing tobacco or snuff may be associated with a greater body weight among young adults.     

The effects of household and workplace smoking restrictions on quitting behaviours

OBJECTIVE: To assess the association of household and workplace smoking restrictions with quit attempts, six month cessation, and light smoking. DESIGN: Logistic regressions identified the association of household and workplace smoking restrictions with attempts to quit, six month cessation, and light smoking. SETTING: Large population surveys, United States. SUBJECTS: Respondents (n = 48,584) smoked during the year before interview in 1992-1993, lived with at least one other person, and were either current daily smokers or were former smokers when interviewed. MAIN OUTCOME MEASURES: The outcome measures were an attempt to quit during the last 12 months, cessation for at least six months among those who made an attempt to quit, and light smoking (< 15 cigarettes a day). RESULTS: Smokers who lived (odds ratio (OR) = 3.86; 95% confidence interval (CI) = 3.57 to 4.18) or worked (OR = 1.14; 95% CI = 1.05 to 1.24) under a total smoking ban were more likely to report a quit attempt in the previous year. Among those who made an attempt, those who lived (OR = 1.65, 95% CI = 1.43 to 1.91) or worked (OR = 1.21, 95% CI = 1.003 to 1.45) under a total smoking ban were more likely to be in cessation for at least six months. Current daily smokers who lived (OR = 2.73, 95% CI = 2.46 to 3.04) or worked (OR = 1.53, 95% CI = 1.38 to 1.70) under a total smoking ban were more likely to be light smokers. CONCLUSIONS: Both workplace and household smoking restrictions were associated with higher rates of cessation attempts, lower rates of relapse in smokers who attempt to quit, and higher rates of light smoking among current daily smokers.     

Are there sex differences in transdermal nicotine replacement therapy patch efficacy? A meta-analysis.

Smoking-related death and disability rates for women have risen sharply recently. Despite lower smoking cessation success rates for women using behavioral therapies, data are limited on whether specific pharmacological therapies are equally efficacious in men and women. Using meta-analytic techniques, we examined whether significant differences in therapeutic efficacy of nicotine replacement therapy (NRT) for smoking cessation exist by sex. Out of the 31 randomized clinical trials of NRT that met inclusion criteria, 11 contributed to the analysis. The odds ratios for NRT vs. placebo were derived from each trial separately by sex for males and females, and these ratios were combined to give a pooled estimate of the effect of sex in response to NRT. NRT was effective at all time points in men (< 6 months: OR = 2.05, 95% CI= 1.61-2.60; 6 months: OR = 1.98, 95% CI = 1.51-2.60; 12 months: OR = 1.86, 95% CI = 1.39-2.50) and women (< 6 months: OR = 2.09, 95% CI = 1.65-2.65; 6 months, OR = 1.52, 95% CI = 1.17-1.98; 12 months: OR = 1.63, 95% CI = 1.22-2.18). At all time points, no significant difference was observed between sexes (< 6 months: OR = .97, 95% CI = .69-1.36; 6 months: OR = 1.33, 95% CI = .91-1.95; 12 months: OR = 1.21, 95% CI = .79-1.84). The results of this meta-analysis do not support the hypothesis that NRT has higher therapeutic efficacy for men than women.     

Metabolic parameters in transition cows as indicators for early-lactation culling risk

A retrospective cohort study was performed with the objective of determining whether the serum concentrations of nonesterified fatty acids (NEFA), β-hydroxybutyric acid (BHBA), or calcium were associated with the risk of culling within 60 d in milk (DIM) in Holstein cows, and to establish thresholds for each metabolite that were predictive of increased culling risk. Data from 5,979 cows in Ontario (Canada) and several US states were obtained from 4 previously reported studies. For each metabolite and each of 3 sampling weeks (-1, +1, and +2 relative to calving), an optimal threshold was calculated based on having the maximum combined sensitivity (Se) and specificity (Sp) and used to categorize the serum concentrations into high and low risk groups. Logistic regression models were built for each metabolite and each week of sampling, as well as considering together all metabolites in wk -1 and wk +1 relative to calving. Cow was considered the experimental unit and herd as a random effect. Considered separately, precalving NEFA ≥ 0.4 mmol/L [odds ratio (OR)=1.8; 95% confidence interval (CI)=1.4 to 2.2], NEFA ≥ 0.8 mmol/L in wk +1 relative to calving (OR=2.0; 95% CI=1.5 to 2.6) and NEFA ≥ 0.8 mmol/L in wk +2 (OR=4.2; 95% CI=1.9 to 9.4 for cows in lactation 2; OR=2.1; 95% CI=1.4 to 3.3 for cows in lactation ≥ 3) were each associated with an increased risk of culling within the first 60 DIM. Similarly, BHBA ≥ 0.7 mmol/L in wk -1 (OR=1.8; 95% CI=1.3 to 2.5), BHBA ≥ 1.2 mmol/L in wk +1 (OR=1.8; 95% CI=1.4 to 2.2), and BHBA ≥ 1.6 mmol/L in wk +2 (OR=3.2; 95% CI=1.6 to 6.4 for cows in lactation 2; OR=2.3; 95% CI=1.6 to 3.3 for cows in lactation ≥ 3) were each associated with an increased risk of culling within the first 60 DIM. Likewise, calcium ≤ 2.3 mmol/L in wk -1 (OR=1.6; 95% CI=1.2 to 2.2), calcium ≤ 2.2 mmol/L in wk +1 (OR=1.5; 95% CI=1.2 to 1.9), and calcium ≤ 2.3 mmol/L in wk +2 (OR=2.3; 95% CI=1.1 to 3.1) were each associated with an increased risk of culling within the first 60 DIM. When all metabolites were analyzed together, serum NEFA and calcium concentrations in wk -1 and serum NEFA concentration in wk +1 remained in the models. In conclusion, elevated serum NEFA and BHBA concentrations and lower serum calcium concentrations within 1 wk before calving through 2 wk after calving were associated with an increased risk of culling in early lactation. Measuring the concentration of selected metabolites around parturition may help to develop monitoring and intervention strategies to prevent early culling in transition dairy cows.     

Sociodemographic predictors of success in smoking intervention

AIM: To examine the role of sociodemographic factors as predictors of sustained smoking cessation for the population who volunteer to participate in intervention programmes. METHOD: Data for the 3575 smokers who participated in the CEASE (collaborative European anti-smoking evaluation) trial, a European multicentred study that used transdermal nicotine patches as an adjunct to smoking cessation in the chest clinic, were analysed. The effects of age, sex, smoking habit, socioeconomic status (housing conditions, education, and employment), disease, smoking habits of relatives, and baseline markers of tobacco use on sustained smoking cessation (self-reported abstinence and expired carbon monoxide < 10 parts per million) were assessed using logistic regression modelling (odds ratio (OR), 95% confidence interval (CI)). RESULTS: 477/3575 smokers were sustained abstainers one year after the intervention (overall success rate 13.3%). In the univariable logistic regression models an effect of active treatment on smoking cessation was observed (OR 1.50, 95% CI 1.15 to 1.96), and additional effects on outcome were found for age (OR 1.02, 95% CI 1.01 to 1.03), sex (men v women: OR 1.38, 95% CI 1.14 to 1.68), housing conditions (OR 1.43, 95% CI 1.25 to 1.65), current respiratory (OR 0.79, 95% CI 0.67 to 0.92) or cardiac disease (OR 0.46, 95% CI 0.28 to 0.75), and markers of tobacco use (cigarettes per day: OR 0.79, 95% CI 0.69 to 0.90; expired carbon monoxide: OR 0.98, 95% CI 0.97 to 0.99). Education and employment did not have a significant effect on the outcome. The effect of the variables associated with success in smoking cessation persisted after adjustment for covariates. CONCLUSION: Age, sex, and housing conditions have a major effect on smoking cessation in European smokers participating in smoking cessation programmes.     

Can cumulative tobacco consumption, FTND score, and carbon monoxide concentration in expired air be predictors of chronic obstructive pulmonary disease?

Between 15% and 20% of smokers develop chronic obstructive pulmonary disease (COPD). The aim of the present study was to determine which characteristics of smoking, particularly the Fagerstr?m Test for Nicotine Dependence (FTND) score, were associated with the risk of developing COPD. Data from the IBERPOC epidemiological study were analyzed. IBERPOC was a multicenter epidemiological study including 4035 individuals aged 40-69 years, 1023 (25%) of whom were active smokers. We analyzed the association between smoking characteristics--such as the cumulative consumption of tobacco, FTND score, and expired-air carbon monoxide levels--and the diagnosis of COPD. Among the smokers, 153 (15%) were diagnosed with COPD. A cumulative tobacco consumption of more than 30 pack-years (OR=4.24, 95% CI=2.83-6.36) and the FTND score (OR=1.11, 95% CI=1.02-1.21, for each point increase) were significantly associated with the diagnosis of COPD in the model obtained by logistic regression analysis with the full sample of smokers. Cumulative consumption of tobacco was associated with the diagnosis of COPD. For each point increase in the FTND score, the probability of a smoker developing COPD increased by 11%.     

Smokeless Tobacco Use and Its Relation to Panic Disorder, Major Depression, and Posttraumatic Stress Disorder in American Indians

INTRODUCTION: Rates of nicotine use are high in American Indians. Anxiety and depression tend to be associated with cigarette use, but the association of anxiety and depression with smokeless tobacco (ST) is less clear. We asked if panic disorder, major depression, and posttraumatic stress disorder (PTSD) are related to lifetime ST use in 2 American Indian tribes. METHODS: Logistic regression analyses examined the association between lifetime panic disorder, major depression, and PTSD and the odds of lifetime ST use status after controlling for sociodemographic characteristics, smoking status, and alcohol use disorders in 1,506 Northern Plains and 1,268 Southwest tribal members. RESULTS: Odds of lifetime ST use was 1.6 times higher in Northern Plains tribal members with a lifetime history of PTSD after controlling for sociodemographic variables and smoking (95% CI: 1.1, 2.3; p = .01). This association remained significant after further adjustment for panic disorder and major depression (odds ratio [OR] = 1.5; 95% CI: 1.0, 2.2; p = .04) but was diminished after accounting for alcohol use (OR = 1.3; 95% CI: 0.9, 1.9; p = .23). In the Southwest, lifetime psychiatric disorders were not associated with lifetime ST use status. Increasing psychiatric comorbidity was significantly linked to increased odds of ST use in both tribes. Conclusions: This study is the first to examine psychiatric conditions and lifetime ST use in a large, geographically diverse American Indian community sample. Although approximately 30% of tribal members were lifetime users of ST, the association with lifetime psychiatric disorders was not as strong as those observed with cigarette smoking. Understanding shared mechanisms between all forms of tobacco use with anxiety and depressive disorders remains an important area for investigation.     

The association of serum metabolites with clinical disease during the transition period

The objective of this observational field study was to validate the relationship of serum concentrations of nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), and calcium with disease in early lactation across different management systems. Fifty-five Holstein freestall dairy herds located across the United States and Canada were selected and visited weekly for blood sample collection from 2,365 cows. Only diseases that were consistently recorded across herds and blood samples collected before the disease occurred were considered. Metabolite concentrations in serum in wk −1 relative to calving were considered as predictors of retained placenta (RP) and metritis, and metabolite concentrations in serum in wk −1 and wk +1 relative to calving were considered as predictors of displaced abomasum (DA). For each disease, each metabolite, and week of sampling in the case of DA, a critical threshold was calculated based on the highest combined sensitivity and specificity and used to categorize the serum concentrations into high and low risk categories. Multivariable logistic regression models were built for each disease of interest and week of sampling, considering cow as the experimental unit and herd as a random effect. Cows with precalving serum NEFA concentrations ≥0.3 mEq/L were more likely to develop RP [odds ratio (OR) = 1.8; 95% confidence interval (CI) = 1.3 to 2.6] and metritis (OR = 1.8; 95% CI = 1.5 to 2.9) after calving than cows with lower NEFA concentrations. Precalving NEFA ≥0.5 mEq/L (OR = 2.4; 95% CI = 1.5 to 3.7), postcalving NEFA ≥1.0 mEq/L (OR = 2.7; 95% CI = 1.7 to 4.4), and postcalving calcium ≤2.2 mmol/L (OR = 3.1; 95% CI = 1.9 to 5.0) were associated with subsequent risk of DA. In conclusion, elevated serum NEFA concentrations within 1 wk before calving were associated with increased risk of RP, metritis, and DA after calving. Serum NEFA and calcium concentrations in the 2 wk around calving in combination were associated with the risk of DA.     

Associations of subclinical hypocalcemia with fertility in a herd of grazing dairy cows

The main objective was to assess the associations of subclinical hypocalcemia (SCH), diagnosed at parturition (SCH-0) and 7 d in milk (SCH-7), with fertility in a herd of grazing dairy cows. Additional objectives were to characterize Ca concentration on 0 and 7 d in milk (DIM), assessing the risk factors for SCH-0 and SCH-7 and also the relationship with health status (metritis, endometritis, subclinical ketosis, and culling). A prospective observational study was carried out in a dairy farm in Argentina. Holstein cows (n = 126) were body condition scored (BCS, 1–5) on ?21 ± 3, 0, 7 ± 3, and 28 ± 7 DIM and blood was collected on 0 and 7 ± 3 DIM to determine Ca and β-hydroxybutyrate concentrations. Calcium concentrations <2.0 and <2.14 mmol/L were used to define SCH-0 and SCH-7, respectively. The associations of SCH with (1) the odds for pregnancy to first service (P1AI) and pregnancy by 100 DIM (P100) were evaluated by logistic models, (2) the services per pregnancy was evaluated by a Poisson regression model, and (3) the hazards of insemination and pregnancy were evaluated with proportional hazards regression models whereas median days from calving to first insemination and to pregnancy were estimated by Kaplan-Meier method. Additionally, Ca concentration was assessed by linear regression models, and the associations of SCH-0 and SCH-7 with the odds for metritis, endometritis, subclinical ketosis, and culling were evaluated by logistic models. Calcium concentrations were similar at 0 and 7 DIM (2.40 vs. 2.41 mmol/L, respectively); they were higher in cows calving in fall than in summer (2.58 vs. 2.24 mmol/L), and they also were higher in primiparous than in multiparous cows (2.53 vs. 2.28 mmol/L, respectively). The proportion of cows having SCH-0 and SCH-7 was 27.3 and 39.3%, respectively. Fall-calving cows had lower odds for SCH-0 [odds ratio (OR) = 0.31, 95% confidence interval (CI) = 0.12–0.86] than summer-calving cows, multiparous cows had higher odds for SCH-0 (OR = 3.96, 95% CI = 1.09–14.39) than primiparous cows, and cows with prepartum BCS ≥3.00 had higher odds for SCH-0 (OR = 4.03, 95% CI = 1.17–13.89) than in cows with BCS <3.00. Conversely, parity and prepartum BCS were not important predictors for SCH-7. Surprisingly, SCH-0 was not a risk factor for SCH-7. Cows with SCH-0 had lower odds for P1AI (OR = 0.26, 95% CI = 0.07–0.99) than normocalcemic cows, given that P1AI was 14 versus 38%, respectively. The hazard of first service was not associated with SCH-0 (hazard ratio = 1.03, 95% CI = 0.63–1.70) but cows with SCH-0 had lower hazard of pregnancy (hazard ratio = 0.39, 95% CI = 0.16–0.98) and took 32 d longer to get pregnant (105 vs. 73) than normocalcemic cows. Conversely, SCH-7 was not associated with fertility. Finally, SCH-0 and SCH-7 were associated with the odds for subclinical ketosis and metritis, respectively. In conclusion, SCH-0 but not SCH-7 is associated with reduced fertility in a herd of grazing dairy cows, but both were associated with health status.     

Late embryonic losses in supplemented grazing lactating dairy cows: Risk factors and reproductive performance

The main objective of this study was to evaluate the risk factors for late embryonic loss (LEL) in supplemented grazing dairy cows. Additional objectives were to assess the incidence of LEL and its association with the reproductive performance of cows. A data set containing productive, reproductive, and health records of 13,551 lactations was used. A retrospective case-control study involving 631 cows with LEL (cases) and 2,524 controls (4 controls per case within each study year) was run. A case of LEL was defined when the embryo had no heartbeat or there was evidence of detached membranes or floating structures including embryo remnants by ultrasonography (US) at 28 to 42 d post-artificial insemination (AI), whereas a non-case was defined as a cow diagnosed with positive pregnancy by US 28 to 42 d post-AI and reconfirmed as pregnant 90 ± 7 d post-AI. Four controls per case were randomly selected from the non-cases with a temporal matching criterion (±3 d around the date of the fecundating AI of the case). Multivariable logistic models were offered with the following predictors: year of LEL (2011 through 2015), season of LEL (summer vs. fall vs. winter vs. spring), parity (1 vs. 2 vs. ≥3), uterine disease (UD), non-uterine disease (NUD), body condition score at parturition, body condition score at 28 to 42 d post-AI (BCS-LEL), days in milk (DIM), and daily milk yield (MY). Statistical significance was set at P < 0.05 and a tendency was set at P ≤ 0.10. We found that 4.7, 22, and 23% of cows had LEL, UD, and NUD, respectively. Cases tended to have higher daily MY than controls (32.5 vs. 31.8 kg); also, cases had much longer calving to pregnancy interval (226 vs. 118 d), lower hazard of pregnancy [hazard ratio = 0.39, 95% confidence interval (CI) = 0.35–0.43], and higher odds for non-pregnancy [odds ratio (OR) = 2.89, 95% CI = 2.37–3.54] than controls. We found that the odds for LEL increased with parity number (OR = 2.48, 95% CI = 1.99–3.08 for parity ≥3) and with BCS-LEL <2.50 (OR = 1.81, 95% CI = 1.33–2.47). Conversely, the odds for LEL decreased with BCS-LEL >3.00 (OR = 0.70, 95% CI = 0.53–0.91). The odds for LEL increased with UD (OR = 1.23, 95% CI = 1.01–1.49), NUD (OR = 1.24, 95% CI = 1.01–1.54), DIM (OR = 1.03, 95% CI = 1.00–1.05), and daily MY (OR = 1.14, 95% CI = 1.04–1.25) in univariable models only. Finally, the odds for LEL were not associated with year, season, DIM, and body condition score at parturition. In conclusion, LEL is associated with extended calving to pregnancy interval, and among its risk factors are parity number and BCS-LEL.     

Exposure to cigarette promotions and smoking uptake in adolescents: evidence of a dose-response relation

OBJECTIVE: To assess whether a dose-response relation exists between the number of cigarette promotional items (CPIs) owned by an adolescent, and smoking behaviour. DESIGN AND SETTING: Voluntary, self administered survey of 1265 sixth through to 12th grade students (ages 10-19 years), representing 79-95% of all students attending five rural New Hampshire and Vermont public (state funded) schools in October 1996. The association between the number of CPIs owned by students and smoking behaviour was examined using multivariate regression methods. OUTCOME MEASURES: Adjusted odds of being a smoker (>/= 100 cigarettes lifetime) and, among never and experimental smokers, adjusted cumulative odds of having higher levels on a smoking uptake index given the number of CPIs owned. RESULTS: One third of students owned a CPI (n = 406). Among owners, 211 owned one, 82 owned two, 57 owned three, 24 owned four, 23 owned five, and 7 students owned six CPIs. The number of CPIs owned by students was not associated with grade in school but was significantly higher in males, those with poorer school performance, those who perceived high prevalence of peer smoking, and those with higher exposure to peer and family smoking. The more items a student owned, the greater the chances of being a smoker. For example, smoking prevalence was 11.2% for those not owning a CPI, 41.5% for those owning two, 58.5% for those owning four, and 71.4% for those owning six CPIs. The dose-response relation remained after controlling for confounding; compared with those who did not own a CPI, the likelihood of being a smoker was significantly higher for those who owned one CPI, with an adjusted odds ratio (OR) of 2.7 (95% confidence interval (CI) 1.7 to 4.1); OR was 3.4 (95% CI 1.9 to 5.9) for those owning two CPIs, and 8.4 (95% CI 5.0 to 14.2) for those owning three or more CPIs. After excluding smokers, there was a crude dose-response association between CPI ownership and higher rates of experimentation with cigarettes among sixth to ninth graders (ages 11-15 years) only (n = 543). After controlling for confounding influences, the dose-response relation remained, with the likelihood of being higher on the smoking uptake index rising with the number of CPIs owned: one CPI, adjusted cumulative OR 1.7 (95% CI 1.1 to 2.60); two CPIs, OR 2.5 (95% CI 1.2 to 5.1); and three or more CPIs, OR 4.8 (95% CI 1.9 to 12.2). CONCLUSIONS: This study offers evidence of a dose-response relation between the number of CPIs owned by adolescents and higher likelihood of experimental and established smoking. The dose-response relation persists after controlling for confounding influences. These data provide further support of a causal relation between tobacco promotional campaigns and smoking behaviour among adolescents.     

Human aflatoxin exposure in Kenya, 2007: a cross-sectional study

Aflatoxins contaminate approximately 25% of agricultural products worldwide. They can cause liver failure and liver cancer. Kenya has experienced multiple aflatoxicosis outbreaks in recent years, often resulting in fatalities. However, the full extent of aflatoxin exposure in Kenya has been unknown. Our objective was to quantify aflatoxin exposure across Kenya. We analysed aflatoxin levels in serum specimens from the 2007 Kenya AIDS Indicator Survey – a nationally representative, cross-sectional serosurvey. KAIS collected 15,853 blood specimens. Of the 3180 human immunodeficiency virus-negative specimens with ≥1 mL sera, we randomly selected 600 specimens stratified by province and sex. We analysed serum specimens for aflatoxin albumin adducts by using isotope dilution MS/MS to quantify aflatoxin B1-lysine, and normalised with serum albumin. Aflatoxin concentrations were then compared by demographic, socioeconomic and geographic characteristics. We detected serum aflatoxin B1-lysine in 78% of serum specimens (range = <LOD–211 pg/mg albumin, median = 1.78 pg/mg albumin). Aflatoxin exposure did not vary by sex, age group, marital status, religion or socioeconomic characteristics. Aflatoxin exposure varied by province (p < 0.05); it was highest in Eastern (median = 7.87 pg/mg albumin) and Coast (median = 3.70 pg/mg albumin) provinces and lowest in Nyanza (median = <LOD) and Rift Valley (median = 0.70 pg/mg albumin) provinces. Our findings suggest that aflatoxin exposure is a public health problem throughout Kenya, and it could be substantially impacting human health. Wide-scale, evidence-based interventions are urgently needed to decrease exposure and subsequent health effects.     

Prevalence of smoking and its relationship with carotid atherosclerosis in Alaskan Eskimos of the Norton Sound region: the GOCADAN study.

Since 2000, the Genetics of Coronary Artery Disease in Alaska Natives (GOCADAN) study has been collecting information on cardiovascular disease (CVD) and its risk factors from 1,214 Alaska Natives of the Norton Sound region, a population with increasing rates of heart disease and stroke. Because smoking was reported in a large proportion of the participants, this analysis was undertaken to evaluate smoking patterns and their relation to other risk factors and to CVD. The relationships among smoking habits and demographic factors, body mass index, plasma fibrinogen, prevalent hypertension, and carotid plaque were evaluated. Eighty percent of participants had smoked 100+ cigarettes in their lifetime. Fifty-seven percent of women and 63% of men (p = .12) were current smokers: one in four smokers had quit. Current smokers (OR = 2.1; 95% CI = 1.1-3.8) and those who had quit <5 years ago (OR = 1.6; 95% CI = 1.1-2.2) were more likely than non-smokers to have carotid plaque. Pack-years smoked also were correlated with carotid plaque. The high prevalence of smoking and low rates of cessation in this population demonstrate an urgent need for smoking prevention and cessation programs among Alaskan Eskimos of the Norton Sound region and other Alaska Native groups.