Disparities in Lifestyle Habits and Health Related Factors of Montreal Immigrants: Is Immigration an Important Exposure Variable in Public Health?

Study disparities in lifestyle habits and health characteristics of Canadian born population and immigrants with different duration of residence. Data are extracted from 2009 to 2010 public use micro-data files of Canadian Community Health Survey representing about 1.5 million people. Sixty-one percent of the study sample was born in Canada; 49 % males and 59 % below age 50. Amongst lifestyle habits, recent immigrants were less likely to be regular smokers, RR (95 % CI) 0.56 (0.36–0.88) and frequent consumers of alcohol 0.49 (0.27–0.89), but more likely to consume less fruits and vegetables 1.26 (1.04–1.53) than those born in Canada. Amongst health related factors, recent immigrants were less likely to be overweight 0.79 (0.62–0.99) and suffer from chronic diseases 0.59 (0.44–0.80), but more likely to have limited access to family medicine 1.24 (1.04–1.47) than Canada-born population. Immigration status is an important population characteristic which influenced distribution of health indicators. Prevention and promotion strategies should consider immigration status as an exposure variable in the development and implementation of public health programs.     

Population pharmacokinetic analysis of oseltamivir and oseltamivir carboxylate following intravenous and oral administration to patients with and without renal impairment

This work characterizes the pharmacokinetics (PK) of oseltamivir phosphate (OP) and its active metabolite, oseltamivir carboxylate (OC), and investigates oseltamivir i.v. dosing regimens for treatment of influenza in patients with normal renal function and with various degrees of renal impairment. Initially, data collected from 149 subjects with normal renal function and mild to severe renal impairment who were administered 40–200 mg oseltamivir i.v. were described by a four-compartment model. Two compartments described OP, one compartment described OC and one compartment described OP to OC metabolism. Then, data of 128 subjects administered 20–1,000 mg oseltamivir orally were added. The absorption model included three first-order processes with direct (via first-pass) input in the OC compartment and two (direct and delayed) inputs in the OP compartment. Simulations and PK bridging were used to recommend i.v. dosing regimens. The analysis demonstrated that renal function had a major effect on OC clearance (CL _M ) and exposure. CL _M for subjects with mild, moderate and severe renal impairment was 18, 50, and 84 % lower than for subjects with normal renal function. Simulations were used to select i.v. dosing regimens that provide OC C_min coverage and exposures comparable to those achieved in subjects with normal renal function administered 75 mg b.i.d. orally. The oseltamivir dose depended on the degree of renal impairment and was independent of route of administration. Specifically, 75 mg b.i.d. is recommended for subjects with normal renal function or mild renal impairment, 30 mg b.i.d. for subjects with moderate renal impairment, and 30 mg q.d. for subjects with severe renal impairment. Recommended i.v. doses were the same as those recommended for oral administration in corresponding renal impairment groups.     

Household Crowding and Food Insecurity Among Inuit Families With School-Aged Children in the Canadian Arctic

Objectives. We examined the relation of household crowding to food insecurity among Inuit families with school-aged children in Arctic Quebec.Methods. We analyzed data collected between October 2005 and February 2010 from 292 primary caregiver–child dyads from 14 Inuit communities. We collected information about household conditions, food security, and family socioeconomic characteristics by interviews. We used logistic regression models to examine the association between household crowding and food insecurity.Results. Nearly 62% of Inuit families in the Canadian Arctic resided in more crowded households, placing them at risk for food insecurity. About 27% of the families reported reducing the size of their children’s meals because of lack of money. The likelihood of reducing the size of children’s meals was greater in crowded households (odds ratio = 3.73; 95% confidence interval = 1.96, 7.12). After we adjusted for different socioeconomic characteristics, results remained statistically significant.Conclusions. Interventions operating across different levels (community, regional, national) are needed to ensure food security in the region. Targeting families living in crowded conditions as part of social and public health policies aiming to reduce food insecurity in the Arctic could be beneficial.Inadequate housing conditions (e.g., crowding and structural damage) are prevalent among First Nations and Inuit communities in Canada and elsewhere.1 In Nunavik, the Inuit homeland in Arctic Quebec, Canada, the government promoted the relocation of many Inuit families to fledgling communities during the 1950s. Relocated families were moved to small, poorly heated and insulated accommodations. Since then, different programs have been designed by the federal, provincial, territorial, and regional governments to address the housing problem in Nunavik and across the Canadian Arctic.2 At present, more than 90% of the Nunavik population has reported living in social (subsidized) housing.3 In this region, social housing units are allocated locally through a point-based system set according to specific criteria, so that applicants most in need are given first priority (e.g., families with lower income, with young children, and living in overcrowded dwellings).2 Rent is set according to household income, while also considering the cost of living.4 Thus, in Nunavik, housing tenure does not differentiate between households on the basis of financial security or income level, given that nearly all of the population resides in social housing. Such organization rather highlights the high degree of financial need throughout this population and a limited private residential market unattainable by most of the population.Household overcrowding, generally defined as more than 1 person per room,5 is particularly problematic in Nunavik. According to Statistics Canada, 49% of the 2006 population lived in overcrowded houses.5 Often, overcrowding is approached as a consequence of economic difficulties. Living in smaller homes or in shared accommodation has been known as a way to lower living costs to dedicate the available financial resources to other basic necessities.6 In such situations, overcrowded households may experience higher food insecurity as a result of a precarious economic situation. In the particular case of Nunavik, however, crowding is a direct consequence of an underlying, and persistent, lack of housing. Household crowding in Nunavik is not only a product of financial difficulties but also an effect of the rapidly growing and young population. Between 2001 and 2006, the population in Nunavik increased by 12% compared with 4% for the province of Quebec. During the past 3 decades, the population has doubled from 5860 in 1986 to 12 090 in 2011.7 In 2008, it was estimated that more than 900 new housing units were needed, but only 239 units were constructed.8 The housing backlog is further compounded by high costs of construction and short building seasons.The housing situation in Nunavik and throughout the Canadian Arctic raises concerns, in terms of both public health and the health of each individual resident, especially that of children.9–14 Indeed, studies have shown that household crowding is associated with poorer respiratory health, especially among children.12,15 In crowded dwellings, the lack of privacy and the difficulty of withdrawing from (unwanted) social interactions may limit the ability of controlling one’s home situation and lead to “overarousal.”16 Household crowding also has been identified as eliciting chronic stress responses in adults,17 anger and depression18 with possible repercussions on behaviors,19–22 withdrawal,23 and reduced social support24 that, we contend, could influence household food insecurity.Food insecurity occurs when it is not possible to obtain safe, sufficient, and nutritiously adequate foods for a healthy life in socially and culturally acceptable ways.25–27 Studies have shown that in a situation of food insecurity, adults generally first reduce their own food consumption. As the situation becomes more severe, children’s diets also will be reduced, particularly in low-income households with single mothers.28,29 In 2012, 14% of the households in Canada experienced food insecurity.30 In Canadian Arctic communities, food insecurity is high: 62.2% and 31.6% of children live in food-insecure households in Nunavut and Northwest Territories, respectively.30 In Nunavik, the proportion of Inuit children experiencing food insecurity reached 30% in 2006.31 Studies emphasize that a reduction of the quality in diet and nutrient intake resulting from food insecurity is linked to various health issues in children, including poor health,25,32–34 developmental delays,35 and poor mental health.36Access to food products supplied from southern regions of Quebec comes at a very high cost to Nunavik, with an average price 57% higher than in the provincial capital.37 Despite efforts to redress this situation, food costs remain very high and often inaccessible to many Nunavik families who must resort to reducing the amount of food supplies or buying products of lower nutritional quality,38 which compromises health and well-being.36,37,39In a study conducted among low-income families in the United States, Cutts et al.40 found a higher risk of food insecurity and child food insecurity in households with higher housing insecurity. In their study, crowding and multiple moves were considered as indicators of housing insecurity. This association was independent of maternal and family characteristics such as education and household employment. In a recent study involving Inuit households from Nunavut, in the eastern Canadian Arctic, Huet et al.41 reported higher food insecurity among Inuit living in overcrowded households and in houses requiring major repairs. This observation, however, was based on bivariate associations between housing conditions and food insecurity and did not account for other factors such as socioeconomic conditions. These studies nonetheless suggest that food insecurity is not only explained in terms of low socioeconomic status and poverty.40,42We examined whether household crowding was associated with food insecurity among Inuit families with school-aged children, independently of socioeconomic disadvantage.     

Implementation of human biomonitoring in the Dehcho region of the Northwest Territories,Canada (2016–2017)

Background

Human biomonitoring represents an important tool for health risk assessment, supporting the characterization of contaminant exposure and nutrient status. In communities where country foods (locally harvested foods: land animals, fish, birds, plants) are integrated in the daily diet, as is the case in remote northern regions where food security is a challenge, such foods can potentially be a significant route of contaminant exposure. To assess this issue, a biomonitoring project was implemented among Dene/Métis communities of the Dehcho region of the Northwest Territories, Canada.

Methods

Participants completed dietary surveys (i.e., a food frequency questionnaire and 24-h recall) to estimate food consumption patterns as well as a Health Messages Survey to evaluate the awareness and perception of contaminants and consumption notices. Biological sampling of hair, urine and blood was conducted. Toxic metals (e.g., mercury, lead, cadmium), essential metals (e.g., copper, nickel, zinc), fatty acids, and persistent organic pollutants (POPs) were measured in samples.

Results

The levels of contaminants in blood, hair and urine for the majority of participants were below the available guidance values for mercury, cadmium, lead and uranium. However, from the 279 participants, approximately 2% were invited to provide follow up samples, mainly for elevated mercury level. Also, at the population level, blood lead (GM: 11 μg/L) and blood cadmium (GM: 0.53 μg/L) were slightly above the Canadian Health Measures Survey data. Therefore, although country foods occasionally contain elevated levels of particular contaminants, human exposures to these metals remained similar to those seen in the Canadian general population. In addition, dietary data showed the importance and diversity of country foods across participating communities, with the consumption of an average of 5.1% of total calories from wild-harvested country foods.

Conclusion

This project completed in the Mackenzie Valley of the Northwest Territories fills a data gap across other biomonitoring studies in Canada as it integrates community results, will support stakeholders in the development of public health strategies, and will inform environmental health issue prioritization.

     

Transit time ultrasound perivascular flow probe technology is superior to MR imaging on hepatic blood flow measurement in a porcine model

Background: The hepatic hemodynamics is an essential parameter in surgical planning as well as in various disease processes. The transit time ultrasound(TTUS) perivascular flow probe technology is widely used in clinical practice to evaluate the hepatic inflow, yet invasive. The phase-contrast-MRI(PC-MRI) is not invasive and potentially applicable in assessing the hepatic blood flow. In the present study, we compared the hepatic inflow rates using the PC-MRI and the TTUS probe, and evaluated their predictive value of post-hepatectomy adverse events. Methods: Eighteen large white pigs were anaesthetized for PC-MRI and approximately 75% hepatic resection was performed under a unified protocol. The blood flow was measured in the hepatic artery(Qha), the portal vein(Qpv), and the aorta above the celiac trunk(Qca) using PC-MRI, and was compared to the TTUS probe. The Bland-Altman method was conducted and a partial least squares regression(PLS) model was implemented. Results: The mean Qpv measured in PC-MRI was 0.55 ± 0.12 L/min, and in the TTUS probe was 0.74 ± 0.17 L/min. Qca was 1.40 ± 0.47 L/min in the PC-MRI and 2.00 ± 0.60 L/min in the TTUS probe. Qha was 0.17 ± 0.10 L/min in the PC-MRI, and 0.13 ± 0.06 L/min in the TTUS probe. The Bland-Altman method revealed that the estimated bias of Qca in the PC-MRI was 32%(95% CI:-49% to 15%); Qha 17%(95% CI:-15% to 51%); and Qpv 40%(95% CI:-62% to 18%). The TTUS probe had a higher weight in predicting adverse outcomes after 75% resection compared to the PC-MRI( β= 0.35 and 0.43 vs β = 0.22 and 0.07, for tissue changes and premature death, respectively). Conclusions: There is a tendency of the PC-MRI to underestimate the flow measured by the TTUS probes. The TTUS probe measures are more predictive of relevant post-hepatectomy outcomes.     

Follicular dendritic cell tumor of the mediastinum: expression of fractalkine and SDF-1α as mast cell chemoattractants

Follicular dendritic cell tumor (FDCT) is a rare tumor mainly located in laterocervical lymph nodes. We report one case of mediastinal FDCT associated with a history of bullous skin disease and clinically obvious immunosuppression. This tumor was characterized by heavy mast cell infiltration. Mast cells were in close relationship with tumor cells as demonstrated by ultrastructural examination and their presence are probably related with the strong expression of mast cell chemoattractants as fraktalkine and stromal cell-derived factor-1α by tumor cells. The long follow-up period of more than 17 years allowed to us assess the relatively indolent evolution of this tumor characterized by three slowly growing local recurrences without metastasis.     

Ischemic preconditioning for major liver resection under vascular exclusion of the liver preserving the caval flow: a randomized prospective study

BACKGROUND: Two randomized prospective studies suggested that ischemic preconditioning (IP) protects the human liver against ischemia-reperfusion injury after hepatectomy performed under continuous clamping of the portal triad. The primary goal of this study was to determine whether IP protects the human liver against ischemia-reperfusion injury after hepatectomy under continuous vascular exclusion with preservation of the caval flow. STUDY DESIGN: Sixty patients were randomly divided into two groups: with (n=30; preconditioning group) and without (n=30; control group) IP (10 minutes of portal triad clamping and 10 minutes of reperfusion) before major hepatectomy under vascular exclusion of the liver preserving the caval flow. Serum concentrations of aspartate transferase, alanine transferase, glutathione-S-transferase, and bilirubin and prothrombin time were regularly determined until discharge and at 1 month. Morbidity and mortality were determined in both groups. RESULTS: Peak postoperative concentrations of aspartate transferase were similar in the groups with and without IP (851 +/- 1,733 IU/L and 427 +/- 166 IU/L respectively, p=0.2). A similar trend toward a higher peak concentration of alanine transferase and glutathione-S-transferase was indeed observed in the preconditioning group compared with the control group. Morbidity and mortality rates and lengths of ICU and hospitalization stays were similar in both groups. CONCLUSIONS: IP does not improve liver tolerance to ischemia-reperfusion after hepatectomy under vascular exclusion of the liver with preservation of the caval flow. This maneuver does not improve postoperative liver function and does not affect morbidity or mortality rates. The clinical use of IP through 10 minutes of warm ischemia in this technique of hepatectomy is not currently recommended.