The hefty fetal phenotype hypothesis revisited: high birth weight, type 2 diabetes and gestational diabetes in a Saskatchewan cohort of First Nations and non-First Nations women.

Although low birth weight (LBW) increases the risk for type 2 diabetes (T2DM), the relationship between high birth weight (HBW) and T2DM is less definitive and largely confined to North American Indigenous populations. We re-examined the relationship between LBW (4000 g) and both T2DM and gestational diabetes (GDM) among First Nations and non-First Nations women in Saskatchewan. We analyzed new data for female subjects from a 2001 case-control study that led to our hefty fetal phenotype hypothesis. Using survival analysis techniques and a validated algorithm for identifying diabetes in health care administrative data, we followed a 1950-1984 birth cohort of 2003 women until March 31, 2013. Cox regression analysis determined the time to occurrence of first episode of GDM and diagnosis of T2DM by birth weight and ethnicity. First Nations women with HBW demonstrated a greater risk for developing both T2DM [hazard ratios (HR) 1.568; 95% confidence interval (CI) 1.188, 2.069] and GDM (HR 1.468; 95% CI 1.016, 2.121) than those with normal birth weight (NBW). Non-First Nations women with LBW had a greater risk of developing GDM than those with NBW (HR 1.585; 95% CI 1.001, 2.512). HBW is a risk factor for GDM and T2DM among First Nations women. This is likely due to exposure of these women to their own mothers' diabetic pregnancies or gestational impaired glucose tolerance. This inter-generational amplification of T2DM risk mediated through prenatal exposures appears to play a substantial role in the epidemic of T2DM among First Nations peoples.

Application of dynamic modelling techniques to the problem of antibacterial use and resistance: a scoping review.

Selective pressure exerted by the widespread use of antibacterial drugs is accelerating the development of resistant bacterial populations. The purpose of this scoping review was to summarise the range of studies that use dynamic models to analyse the problem of bacterial resistance in relation to antibacterial use in human and animal populations. A comprehensive search of the peer-reviewed literature was performed and non-duplicate articles (n = 1486) were screened in several stages. Charting questions were used to extract information from the articles included in the final subset (n = 81). Most studies (86%) represent the system of interest with an aggregate model; individual-based models are constructed in only seven articles. There are few examples of inter-host models outside of human healthcare (41%) and community settings (38%). Resistance is modelled for a non-specific bacterial organism and/or antibiotic in 40% and 74% of the included articles, respectively. Interventions with implications for antibacterial use were investigated in 67 articles and included changes to total antibiotic consumption, strategies for drug management and shifts in category/class use. The quality of documentation related to model assumptions and uncertainty varies considerably across this subset of articles. There is substantial room to improve the transparency of reporting in the antibacterial resistance modelling literature as is recommended by best practice guidelines.

Decreased urine albumin:creatinine ratios in infants of diabetic mothers: does exposure to diabetic pregnancies alter fetal renal development?

Offspring of diabetic mothers experience an increased risk for type 2 diabetes but it is not known whether diabetic pregnancies also confer a higher inter-generational risk for diabetic complications. Because microalbuminuria is a sensitive indicator of glomerular damage, we compared the urine albumin:creatinine ratios (ACRs) between 65 infants of diabetic mothers (InfDM+) and 59 infants of non-diabetic mothers (InfDM-), and repeated the comparisons in 21 InfDM+ and 19 InfDM- when children were 5-19 months old. ACRs were higher among neonates compared with normal reference values for adults, but declined with increasing age. The only independent predictor of higher ACRs in a logistic regression model (⩾13 mg/mmol v. <13 mg/mmol) was the presence of delivery complications (odds ratio 2.95; P = 0.015). Neither high nor low birth weight was associated with higher neonatal ACRs. The most unique finding of the study was that InfDM+ had significantly lower ACRs than InfDM- [mean = 12.9 (median = 6.0) v. mean = 16.6 (median = 11.5), respectively at P = 0.05] even after adjusting for other variables using logistic regression (odds ratio 0.25; P = 0.001). In contrast, by 5-19 months, there was a trend toward higher ACRs among InfDM+ compared with InfDM- [mean = 6.3 mg/mmol (median = 1.9) v. mean = 3.0 mg/mmol (median = 2.5), respectively at P = 0.25]. Lower ACRs in InfDM+ may be due to developmental changes in fetal kidneys induced by hyperinsulinemia. Although the implications of this observation are unclear, it is possible that exposure to a diabetic intrauterine environment might influence the later risk for renal disease.

Comparison of multiple environmental factors for asthmatic children in public housing.

Nine families of a public housing development in Boston were enrolled in a pilot asthma intervention program designed to gather dense environmental data and generate hypotheses about the relative importance of different contaminants and the viability of interventions. Despite formidable challenges working with this inner-city population, the project team succeeded in gaining active support for the project by forming a partnership with a community-based organization and by building positive relationships between the field team and the residents. Families were provided with physical interventions such as air filters, industrial cleaning and mattress covers to each apartment. Indoor temperature was high and relative humidity low during winter. Insulation of exposed steam pipes did not lower temperature. Cockroach, mouse and pet antigen levels were variable and frequently high in settled dust. Viable fungal spore levels were variable and high in some apartments. Dust-mite allergen levels were below the level of concern. Industrial cleaning led to transient reduction in mouse and cockroach antigen burden. Mattress and pillow covers lowered dust-mite antigen in bedrooms, but not living rooms. Nitrogen dioxide (NO2) levels exceeded ambient concentrations due to use of gas stoves and concentrations of particulate matter with aerodynamic diameter <2.5 microm (PM2.5) were above ambient levels because of smoking. Air filtering systems did not reduce PM levels. Several volatile organic compounds (VOCs) were above adverse risk concentrations. We hypothesize that our findings are consistent with a multifactorial model for exacerbation of asthma in this population and that no single problem dominates.

The cost-effectiveness of intensive national school-based anti-tobacco education: results from the tobacco policy model.

OBJECTIVES: School-based anti-tobacco education using the "social influences" model is known to reduce smoking among youth by 5-56%. Program effectiveness, however, dissipates in 1-4 years. Consequently, opinion leaders have questioned whether a more intensive national educational effort would be economically efficient. To address this question, we evaluated the cost-effectiveness of enhanced nationwide school-based anti-tobacco education relative to the status quo. METHODS: To estimate cost-effectiveness, we created the Tobacco Policy Model, a system dynamics computer simulation model. The model relies on secondary data and is designed to calculate the expected costs and public health gains of any tobacco policy or intervention over any time frame. RESULTS: Over 50 years, cost-effectiveness is estimated to lie between $4,900 and $340,000 per quality-adjusted life-year (QALY), depending on the degree and longevity of program effectiveness. Assuming a 30% effectiveness that dissipates in 4 years, cost-effectiveness is $20,000/QALY. Sensitivity analysis reveals that cost-effectiveness varies with cost, survival, and quality-of-life estimates but cost-effectiveness ratios generally remain favorable. CONCLUSIONS: Although not cost saving, a much more intensive school-based anti-tobacco educational effort would be an economically efficient investment for the nation.

Public health impact of changes in smoking behavior: results from the Tobacco Policy Model.

OBJECTIVES: The relative magnitude of the public health gains from preventing smoking initiation versus encouraging cessation or avoiding relapse in different ages and genders is estimated and compared. METHODS: Health gains are defined as the predicted increase in Quality-Adjusted Life-Years (QALYs) to the US population during a century. To estimate QALYs, we developed the Tobacco Policy Model. The model simulates a 10% reduction in the annual probability of initiation versus a 10% increase in cessation versus a 10% reduction in relapse in males and females in six age groups: 10 to 19, 20 to 29, 30 to 39, 40 to 49, 50 to 59 and 60 to 69. RESULTS: Among youth and young adults, reducing initiation yields far more QALYs than encouraging cessation or averting relapse. In middle-aged adults, cessation yields the most QALYs, followed by averting relapse and reducing initiation. In the oldest age group, averting relapse yields the most QALYs followed by cessation and reducing initiation. In general, increasing cessation and reducing relapse is more beneficial in males than in females whereas reducing initiation is more beneficial in females. CONCLUSIONS: The relative value of preventing initiation, encouraging cessation, and averting relapse differs by age and gender. Reducing initiation in youth is likely to offer the largest public health impact during the next century.

The link between smoking and impotence: two decades of evidence.

BACKGROUND: Anti-tobacco advertisements now feature the risk of impotence as a reason to avoid or cease tobacco use. The scientific evidence, however, is mixed. To shed light on the controversy, we compiled 2 decades of published data on the link between smoking and impotence. METHODS: We searched MEDLINE from 1980 to the present for studies that reported smoking prevalence among impotent male subjects. For each study we recorded the age of subjects, their state of residence, the percentage that were current smokers, and the time period over which study data were collected. For comparison purposes, we estimated age-, state-, and year-specific smoking rates in the general male population using the Behavioral Risk Factors Surveillance System. We performed a meta-analysis using a random effects model. RESULTS: Among the 1008 journal articles examined, we identified 19 studies that reported the smoking habits of 3819 impotent men. Of these 19 studies, 16 indicated a smoking prevalence exceeding that of the general population. The 6 largest studies all revealed a higher prevalence of smoking among impotent men. Meta-analysis reveals that 40% of impotent men were current smokers compared with 28% of men in the general population. CONCLUSIONSBased on almost 2 decades of evidence, tobacco use is an important risk factor for impotence. Anti-tobacco advertisements featuring impotence as a reason to avoid or cease tobacco use are well grounded in scientific fact.