Repeated vaccination is required to optimize seroprotection against H1N1 in the immunocompromised host

Background

In 2009 the declaration by the World Health Organization of a global pandemic of influenza-H1N1 virus led to a vaccination campaign to ensure protection for immunocompromised patients. The goal of this study was to determine the efficacy of the 2009 H1N1 vaccine in patients with hematologic malignancies.

Design and Methods

We evaluated humoral and cellular immune responses to 2009 H1N1 vaccine in 97 adults with hematologic malignancies and compared these responses with those in 25 adult controls. Patients received two injections of vaccine 21 days apart and the controls received one dose. Antibody titers were measured using a hemagglutination-inhibition assay on days 0, 21 and 49 after injection of the first dose. Cellular immune responses to H1N1 were determined on days 0 and 49.

Results

By day 21 post-vaccination, protective antibody titers of 1:32 or more were seen in 100% of controls compared to 39% of patients with B-cell malignancies (P<0.001), 46% of allogeneic stem cell transplant recipients (P<0.001) and 85% of patients with chronic myeloid leukemia (P=0.086). After a second dose, seroprotection rates increased to 68%, (P=0.008), 73%, (P=0.031), and 95% (P=0.5) in patients with B-cell malignancies, after allogeneic stem cell transplantation and with chronic myeloid leukemia, respectively. On the other hand, T-cell responses to H1N1 vaccine were not significantly different between patients and controls.

Conclusions

These data demonstrate the efficacy of H1N1 vaccine in most patients with hematologic malignancies and support the recommendation for the administration of two doses of vaccine in immunocompromised patients. These results may contribute towards the development of evidence-based guidelines for influenza vaccination in such patients in the future.     

Physical activity, smoking, and obesity among Canadian school youth. Comparison between urban and rural schools

BACKGROUND: More information is needed to document the prevalence of health risk factors in youth. The purpose of this study is to compare the prevalence of physical inactivity, smoking and overweight/obesity among youth in urban and rural schools. METHODS: Data were obtained from a Student Physical Activity and Smoking Survey of 2,697 high school students in four urban schools in Ontario and four rural schools in Alberta. Prevalence of physical inactivity was assessed by examining compliance with Canada's Physical Activity Guide to Healthy Active Living, and with daily energy expenditure classification values. Prevalence of smoking was assessed by examining current smoking status. Overweight and obesity prevalences were examined by comparing BMI values to the BMI index for age and sex percentiles set by the Centers for Disease Control and Prevention. RESULTS: Physical activity prevalence was found to be low in our study, with only 57.0% of youth achieving Canada's Physical Activity Guidelines, and with 26.0% classified as sedentary based on the daily energy expenditure classification values. A higher proportion of rural students reported "trying smoking" than urban school students (73.0% versus 64.4%, p<0.001). A significantly higher proportion of rural males were 'overweight' than urban males, and a significantly higher proportion of rural females were 'obese' in comparison to urban females. CONCLUSION: Our findings add further support for an urgent need to promote physical activity among Canadian youth. Additionally, our results suggest that it is especially important to target rural students, particularly girls, for smoking prevention programs. Future studies are required to examine such rural and urban differences within provinces.     

Efficacy of an E-mail intervention for the promotion of physical activity and nutrition behavior in the workplace context

PURPOSE: The purpose of this study was to evaluate a 12-week workplace e-mail intervention designed to promote physical activity and nutrition behavior. DESIGN: A pre- and post-test design was conducted to compare the effects of e-mail messages between intervention and control groups. SETTING: Five large workplaces in Alberta, Canada. SUBJECTS: Employees with access to a personal e-mail address (N = 2121) were randomly assigned to an intervention (n = 1566) or a control group (n = 555). INTERVENTION: Physical activity and nutrition messages were based on social-cognitive theories. The intervention group received one physical activity and one parallel nutrition message per week for 12 weeks. The control group received no weekly messages. MEASURES: Each participant completed self-report measures of physical activity and nutrition related to knowledge, attitudes, and behaviors 1 week before (time 1) and 1 week after (time 2) the intervention. RESULTS: The intervention group was more efficacious at time 2 on measures of self-efficacy, pros, cons, intentions, and behavior related to physical activity. This group also reported more favorable changes in practicing healthy eating, balancing food intake with activity level, cooking meals with techniques to reduce fat, and avoiding eating high-fat foods. Effect sizes for all significant differences were small. CONCLUSION: E-mail is a promising mode of delivery for promoting physical activity and nutrition in the workplace. Further theoretically driven studies are needed.     

Differences in physical activity levels between urban and rural school children in Cyprus

This study attempted to examine differences in physical activity levels between urban and rural primary school children. The sample consisted of 256 Greek-Cypriot children and their parents from two schools representing urban areas and three schools representing rural areas. Children's activity levels were assessed for 4 weekdays in the winter and for 4 weekdays in the summer using a pedometer (DW-200; Yamax, Tokyo, Japan). Daily step counts were used to describe children's activity levels. Parents completed a questionnaire assessing environmental variables in both seasons. Two-way ANOVAs indicated that urban school children were significantly more active in winter than rural school children (means = 13,583 +/- 4,313 versus 12 436 +/- 3610, P < 0.001) and that rural school children were significantly more active in the summer (means = 16,450 +/- 5134 versus 14,531 +/- 4,901, P < 0.001). Parents of children in rural schools reported more space available in the garden and in the neighbourhoods, and safer neighbourhoods than parents of children in urban schools, whereas children in urban schools had more exercise equipment available at home and were transported more frequently to places where they could be physically active. Results of this study suggest that intervention programmes to promote physical activity need to consider seasonal and geographical location differences in physical activity levels.     

Differences in the correlates of physical activity between urban and rural Canadian youth

BACKGROUND: Despite the benefits of physical activity (PA), a significant proportion of youth remains inactive. Studies assessing differences in the correlates of PA among urban and rural youth are scarce, and such investigations can help identify subgroups of the population that may need to be targeted for special intervention programs. The purpose of this study was to assess differences in the correlates of PA between Canadian urban and rural youth. METHODS: The sample consisted of 1398 adolescents from 4 urban schools and 1290 adolescents from 4 rural schools. Mean age of the participants was 15.6 +/- 1.3 years. Hierarchical regression analyses were used to examine the association between self-reported PA and a number of demographic, psychological, behavioral, and social correlates. RESULTS: Common correlates between the 2 locations included gender (with girls being less active than boys) perceptions of athletic/physical ability, self-efficacy, interest in organized group activities, use of recreation time, and friends' and siblings' frequency of participation in PA. Active commuting to school and taking a physical education class were unique correlates of PA at the multivariate level in urban and rural students, respectively. Variance explained in PA ranged from 43% for urban school students to 38% for rural school students. CONCLUSIONS: Although more similarities than discrepancies were found in the correlates of PA between the 2 geographical locations, findings from this study strengthen the policies that argue for a coordinated multisector approach to the promotion of PA in youth, which include the family, school, and community.     

Prevalence and correlates of active traveling to school among adolescents in Cyprus

More data regarding prevalence and correlates of active travel to school are needed from different parts of the world. The purpose of this study was to examine prevalence and correlates of active travel to school among adolescents in Cyprus. A cross-sectional study was conducted among 1966 adolescents attending grade 6, grades 7-9, grades 10-12 and technical/vocational schools in Cyprus. Overall prevalence of active travel to school was 19.4%. Parental perceptions of safe route to school, other children walking to school from the child's neighborhood and school location (urban versus rural) were associated with active travel across different levels of education. Having enough time to walk to school in the moming was the most consistent correlate of active travel. Low prevalence estimates of active traveling to school among adolescents in Cyprus raise the need to promote this source of daily physical activity.     

The synergistic effect between the Mediterranean diet and <Emphasis Type="Italic">GSTP1</Emphasis> or <Emphasis Type="Italic">NAT2</Emphasis> SNPs decreases breast cancer risk in Greek-Cypriot women

Purpose

Xenobiotic metabolism is related to the interplay between diet and breast cancer (BC) risk. This involves detoxification enzymes, which are polymorphic and metabolise various dietary metabolites. An important characteristic of this pathway is that chemoprotective micronutrients can act not only as substrates but also as inducers for these enzymes. We investigated whether functional GSTP1 (p.Ile105Val-rs1695), NAT2 (590G>A-rs1799930) SNPs and GSTM1 and GSTT1 deletion polymorphisms could modulate the effect of the Mediterranean diet (MD) on BC risk, in Greek-Cypriot women.

Methods

Genotyping was performed on women from the MASTOS case–control study of BC in Cyprus. A 32-item food-frequency questionnaire was used to obtain dietary intake information. A dietary pattern, which closely resembles the MD (high loadings of vegetables, fruit, legumes and fish), was previously derived with principal component analysis and was used as our dietary variable.

Results

GSTT1 null genotype increased BC risk compared with the homozygous non-null GSTT1 genotype (OR 1.21, 95 % CI 1.01–1.45). Increasing adherence to the MD reduced BC risk in women with at least one GSTP1 Ile allele (OR for Ile/Ile = 0.84, 95 % CI 0.74–0.95, for Ile/Val = 0.73, 95 % CI 0.62–0.85) or one NAT2 590G allele (OR for 590 GG = 0.73, 95 % CI 0.63–0.83, for 590 GA = 0.81, 95 % CI 0.70–0.94). p interaction values were not, however, statistically significant.

Conclusion

The homozygous null GSTT1 genotype could be a risk allele for BC among Greek-Cypriot women. The anticarcinogenic effects of the high adherence to MD against BC risk could also be further enhanced when combined with the wild-type alleles of the detoxification GSTP1 or NAT2 SNPs.

     

Age, gender, and urban-rural differences in the correlates of physical activity

BACKGROUND: The majority of the population is inactive, and strategies to date for promoting regular physical activity have been limited in their effectiveness. Further research is needed to identify correlates of physical activity in different subgroups to design more efficacious interventions. This study sought to identify correlates of physical activity across men and women, urban and rural geographical locations, and four distinct age groups (18-25; 26-45; 46-59; and 60+). METHODS: This study employed data from a large provincial household random sample (N = 20,606) of Canadians. Analyses were utilized to examine the amount of variance explained in self-reported physical activity by a number of demographic and/or biological, psychological, behavioral, social, and environmental variables within each subgroup. RESULTS: Proportion of friends who exercise, injury from past physical activity, educational level, perceived health status, and alcohol consumption were among the strongest correlates across subgroups. CONCLUSIONS: A number of correlates were identified as being significant across all subgroups examined. Most differences in the correlates of physical activity were found within different age groups rather than among urban and rural residents and gender.