The influence of urban trees and total vegetation on asthma development in children.

Objective: We aimed to assess whether the influence of urban vegetation on asthma development in children (<13 years) varies by type (e.g., total vegetation, tree type, and grass) and season. Methods: We used a cohort of all children born in Montreal, Canada, between 2000 and 2015. Children and cases were identified from linked medico-administrative databases. Exposure to residential vegetation was estimated using the Normalized Difference Vegetation Index (NDVI) for total vegetation and using the total area covered by deciduous and evergreen crowns for trees in 250 m buffers centered on residential postal codes. Seasonal variations in vegetation were modeled by setting values to zero on days outside of pollen and leaf-on seasons. Cox models with vegetation exposures, age as a time axis, and adjusted for sex, material deprivation, and health region were used to estimate hazard ratios (HR) for asthma development. Results: We followed 352,946 children for a total of 1,732,064 person-years and identified 30,816 incident cases of asthma. While annual vegetation (total and trees) measures did not appear to be associated with asthma development, models for pollen and leaf-on seasons yielded significant nonlinear associations. The risk of developing asthma was lower in children exposed to high levels (>33,300 m2) of deciduous crown area for the leaf-on season (HR = 0.69; 95% confidence interval [CI] = 0.67, 0.72) and increased for the pollen season (HR = 1.07; 95% CI =1.02, 1.12), compared with unexposed children. Similar results were found with the Normalized Difference Vegetation Index. Conclusion: The relationship between urban vegetation and childhood asthma development is nonlinear and influenced by vegetation characteristics, from protective during the leaf-on season to harmful during the pollen season.

Branched-Chain and Aromatic Amino Acids in Relation to Fat Mass and Fat-Free Mass Changes among Adolescents: A School-Based Intervention.

Plasma levels of branched-chain amino acids (BCAA) and aromatic amino acids (AAA) are considered early metabolic markers of obesity and insulin resistance (IR). This study aimed to assess changes in plasma concentrations of BCAA/AAA and HOMA-IR2 (homeostasis model assessment of IR) after intervention-induced modifications in fat mass (FM) and fat-free mass (FFM) among French Polynesian adolescents. FM, FFM, plasma levels of BCAA and AAA, HOMA-IR2 were recorded at baseline and post intervention among 226 adolescents during a 5-month school-based intervention on diet and physical activity. Participants were divided into two subgroups according to their college attendance status which determined their intervention adherence: externs/half-residents (n = 157) and residents (n = 69). Four ordinal categories of body composition changes post-intervention were created for the analysis (FMgain/FFMlost < FMgain/FFMgain < FMlost/FFMlost < FMlost/FFMgain). After 5 months, changes in BCAA (p−trend < 0.001) and AAA (p−trend = 0.007) concentrations were positively associated with ordinal categories of body composition. HOMA-IR2 significantly decreased with FMlost (−0.40; 95% CI, −0.60 to −0.20) and increased with FMgain (0.23; 95% CI, 0.11 to 0.36). Our results suggest that FM loss is associated with a decrease in concentrations of obesity and IR metabolic markers which is more substantial when FM loss is accompanied with FFM gain.

Risk of gestational diabetes mellitus in relation to plasma concentrations of amino acids and acylcarnitines: A nested case-control study.

AIMS: Gestational diabetes mellitus (GDM) affects between 5 and 10% of all pregnancies in Canada and can lead to adverse health outcomes in both the mother and fetus. Amino acids (AA) and acylcarnitines (AC) have been identified as early biomarkers of type 2 diabetes but their usefulness in screening for GDM has yet to be demonstrated. METHODS: We conducted a nested case-control study involving 50 controls and 50 GDM cases diagnosed between the 24th and 28th week of gestation. Heparinized plasma samples were obtained during the first and early second trimester of pregnancy. Case and controls were matched according to date of recruitment, maternal age, gestational age at blood sampling as well as pre-pregnancy body mass index. Eight AA and eight AC were quantified using an ultra-high pressure liquid-chromatography quadrupole time-of-flight mass spectrometry platform. Conditional regression analyses adjusted for matching factors and smoking habits during pregnancy were performed to identify plasma metabolites associated with GDM risk. RESULTS: Odds ratio (OR) and 95% confidence interval (CI) for the prediction of GDM per one standard deviation increase of AA or AC in plasma levels were 0.25 (0.08-0.79) for butyrylcarnitine, 0.31 (0.12-0.79) for glutamic acid, 2.5 (1.2-5.3) for acetylcarnitine, 2.9 (1.3-6.8) for isobutyrylcarnitine and 5.3 (1.7-17.0) for leucine. These five metabolites were selected by stepwise conditional logistic regression to create a predictive model with an OR of 2.7 (1.5-4.9). CONCLUSION: Whether the identified metabolites can predict the risk of developing GDM requires additional studies in a larger sample of pregnant women.

Trajectories of Alcohol Use and Binge Drinking Among Pregnant Inuit Women.

BACKGROUND: This study investigated trajectories of alcohol use and binge drinking among Inuit women starting from a year before pregnancy until a year after delivery, examined transition rates between time periods, and established whether specific factors could be identified as predictors of changes in alcohol behaviors. METHODS: Drinking trajectories and movement among alcohol users and binge drinkers (i.e. non-binging and binging) were explored by Markov modeling across time periods. Two hundred and forty-eight Inuit women from Arctic Quebec were interviewed at mid-pregnancy, and at 1 and 11 months postpartum to obtain descriptive data on alcohol use during the year before pregnancy, the conception period, the pregnancy and the year after delivery. RESULTS: The proportions of drinkers and bingers were 73 and 54% during the year prior to pregnancy and 62 and 33% after delivery. Both alcohol use and binge drinking trajectories demonstrated a significant drop in prevalence between the year before conception to the conception period. We also noted high probabilities of becoming an abstainer or not binging at this time. However, up to 60% of women continued to drink alcohol during pregnancy. Women in couples and not consuming marijuana were more likely to decrease their binge drinking at conception. CONCLUSIONS: This study emphasizes the importance of including the period around conception in the definition of drinking patterns during pregnancy. The importance of considering alcohol consumption in a multidimensional way (personal, familial and social determinants) is also addressed while trying to minimize problems both for the fetus and the mother.

Obesity and metabolic parameters in adolescents: a school-based intervention program in French Polynesia.

PURPOSE: The prevalence of overweight/obesity among French Polynesian adolescents is alarming. This study aims to prevent rises in obesity by modifying school food and the physical environment of French Polynesian adolescents. METHODS: During the 5-month study, 240 adolescents from a Tubuai island college (in French Polynesia) received a balanced diet based almost exclusively on local agricultural products and fishing by the island community. They were divided into three subgroups according to their college attendance status: external (n = 14), half residents (n = 155), and residents (n = 71). To increase energy expenditure, weekly physical activity was augmented by 2-4 hours of training in Polynesian Va'a canoes. Anthropometric parameters were recorded, and blood samples collected at baseline and after 5 months. Collegians from Rurutu, a neighboring island, were considered as controls (N = 90). RESULTS: At baseline, overweight/obesity prevalence was 60% (with 28% obesity) in the intervention group. After 5 months, adjusted weight gain was -.76 kg for residents (95% confidence interval [CI], -1.59 to .08), 1.34 kg for half residents (95% CI, .84-1.83), 1.82 kg for externs (95% CI, .66-2.97), and 4.2 kg (95% CI, 3.4-5.0) in the controls. Our results indicate that the more adolescents were subjected to food and physical activity commitments, the higher was the rate among those who lost weight. We noted that the weight change magnitude predicted insulin, glucose, and visceral obesity modifications. CONCLUSIONS: This 5-month school-based intervention slowed weight gain and improved the health of Polynesian collegians. The implementation of longer school-based interventions deserves evaluation.

Prospective study of acute health effects in relation to exposure to cyanobacteria.

We conducted a study to investigate the relationship between exposure to cyanobacteria and microcystins and the incidence of symptoms in humans living in close proximity to lakes affected by cyanobacteria. The design was a prospective study of residents living around three lakes (Canada), one of which has a water treatment plant supplying potable water to local residents. Participants had to keep a daily journal of symptoms and record contact (full or limited) with the water body. Samples were collected to document cyanobacteria and microcystin concentrations. Symptoms potentially associated with cyanobacteria (gastrointestinal: 2 indices (GI1: diarrhea or abdominal pain or nausea or vomiting; GI2: diarrhea or vomiting or [nausea and fever] or [abdominal cramps and fever]); upper and lower respiratory tract; eye; ear; skin; muscle pain; headaches; mouth ulcers) were examined in relation with exposure to cyanobacteria and microcystin by using Poisson regression. Only gastrointestinal symptoms were associated with recreational contact. Globally, there was a significant increase in adjusted relative risk (RR) with higher cyanobacterial cell counts for GI2 (<20,000 cells/mL: RR=1.52, 95% CI=0.65-3.51; 20,000-100,000 cells/mL: RR=2.71, 95% CI=1.02-7.16; >100,000 cells/mL: RR=3.28, 95% CI=1.69-6.37, p-trend=0.001). In participants who received their drinking water supply from a plant whose source was contaminated by cyanobacteria, an increase in muscle pain (RR=5.16; 95% CI=2.93-9.07) and gastrointestinal (GI1: RR=3.87; 95% CI=1.62-9.21; GI2: RR=2.84; 95% CI=0.82-9.79), skin (RR=2.65; 95% CI=1.09-6.44) and ear symptoms (RR=6.10; 95% CI=2.48-15.03) was observed. The population should be made aware of the risks of gastrointestinal symptoms associated with contact (full or limited) with cyanobacteria. A risk management plan is needed for water treatment plants that draw their water from a source contaminated with cyanobacteria.

Zoonotic infections in communities of the James Bay Cree territory: An overview of seroprevalence.

The Cree communities of James Bay are at risk for contracting infectious diseases transmitted by wildlife. Data from serological testing for a range of zoonotic infections performed in the general population (six communities), or trappers and their spouses (one community), were abstracted from four population-based studies conducted in Cree territory (Quebec) between 2005 and 2009. Evidence of exposure to Trichinella species, Toxoplasma gondii, Toxocara canis, Echinococcus granulosus, Leptospira species, Coxiella burnetii and Francisella tularensis was verified in all communities, whereas antibodies against Sin Nombre virus and California serogroup viruses (Jamestown Canyon and snowshoe hare viruses) were evaluated in three and six communities, respectively. Seroprevalence varied widely among communities: snowshoe hare virus (1% to 42%), F tularensis (14% to 37%), Leptospira species (10% to 27%), Jamestown Canyon virus (9% to 24%), C burnetii (0% to 18%), T gondii (4% to 12%), T canis (0% to 10%), E granulosus (0% to 4%) and Trichinella species (0% to 1%). No subject had serological evidence of Sin Nombre virus exposure. These data suggest that large proportions of the Cree population have been exposed to at least one of the targeted zoonotic agents. The Cree population, particularly those most heavily exposed to fauna, as well as the medical staff living in these regions, should be aware of these diseases. Greater awareness would not only help to decrease exposures but would also increase the chance of appropriate diagnostic testing.

Les communautés cries de la Baie James sont vulnérables aux maladies infectieuses transmises par les animaux sauvages. Les données tirées des tests sérologiques sur une série de zoonoses effectués dans la population générale (six communautés) ou chez les trappeurs et leur conjointe (une communauté) ont été extraites de quatre études en population menées en territoire cri, au Québec, entre 2005 et 2009. Les manifestations d'exposition aux espèces de Trichinella, au Toxoplasma gondii, au Toxocara canis, à l'Echinococcus granulosus, aux espèces de Leptospira, au Coxiella burnetii et au Francisella tularensis ont été vérifiées dans toutes les communautés, tandis que les anticorps contre le virus Sin Nombre et les virus du sérogroupe Californie (virus Jamestown Canyon et snowshoe hare) ont été évalués dans trois et six communautés, respectivement. La séroprévalence variait considérablement selon les communautés, comme suit : virus snowshoe hare (1 % à 42 %), F tularensis (14 % à 37 %), espèces de Leptospira (10 % à 27 %), virus Jamestown Canyon (9 % à 24 %), C burnetii (0 % à 18 %), T gondii (4 % à 12 %), T canis (0 % à 10 %), E granulosus (0 % à 4 %) et espèces de Trichinella (0 % à 1 %). Aucun sujet n'avait de manifestation sérologique d'exposition au virus Sin Nombre. Ces données laissent supposer que de fortes proportions de la population crie ont été exposées à au moins l'un des agents zoonotiques ciblés. La population crie, notamment les peuples les plus exposés aux animaux sauvages, ainsi que le personnel médical qui habite dans ces régions, devrait connaître ces maladies. Une meilleure sensibilisation contribuerait non seulement à réduire les expositions, mais accroîtrait également la possibilité de tests diagnostiques pertinents.

Zoonotic infections in native communities of James Bay, Canada.

The Cree communities of James Bay might be at risk of contracting zoonoses from their contacts with wildlife. Evidence of exposure to seven zoonotic infections, namely Trichinella spp., Toxoplasma gondii, Toxocara canis, Echinococcus granulosus, Leptospira spp., Coxiella burnetii, and Francisella tularensis, was sought in sera from 267 residents of Chisasibi (166) and Waskaganish (101). Study participants responded to questionnaires documenting socio-demographic characteristics and hunting and trapping activities. Associations were assessed by univariable and multivariable logistic regression analysis. High seroprevalence rates were documented for Leptospira spp. (23%), Francisella tularensis (18%), and Toxoplasma gondii (9%). Seroprevalence rates of less than 5% were observed for Coxiella burnetii, Echinococcus granulosus, and Toxocara canis. No subject exhibited serological proof of Trichinella spp. exposure in either community. Serological evidence of exposure to Leptospira spp. and T. gondii was greater in Chisasibi than in Waskaganish, while the T. canis seroprevalence rate was higher in Waskaganish than in Chisasibi. Handling of rabbits was associated with seropositivity for Leptospira spp. Statistical trends were also detected between the handling of ducks and exposure to Toxoplasma gondii, and between both handling animals without gloves and springtime hunting activities and Leptospira spp. seropositivity in Chisasibi and Waskaganish, respectively. A review of the medical records revealed few clinical events potentially related to zoonotic exposures. However, public health authorities and health care workers in these communities should be alert to the risk of these zoonoses.

Dairy product intake and its association with body weight and cardiovascular disease risk factors in a population in dietary transition.

OBJECTIVE: Higher dairy product intake has shown beneficial effects on body weight, blood pressure, type 2 diabetes, and cardiovascular disease (CVD) risk factors in Caucasian populations. This study evaluated dairy product intake and its association with body weight and CVD risk profile among a population undergoing a dietary transition in Canada, the Nunavik Inuit. METHODS: Data were collected from August 27 to October 1, 2004, in the 14 villages of Nunavik on a Canadian research icebreaker (Canadian Coast Guard ship Amundsen). Dairy product intake and calcium intake were evaluated in 543 Inuit using a food frequency questionnaire. Physiological (lipid profile, fasting glucose, and insulin) and anthropometrical measurements were also obtained. RESULTS: The range of median dairy product intake extended from 120 g/d in the lowest tertile to 290 g/d in the highest tertile. The median of calcium intake was 524 mg/d. Participants in the highest tertile of dairy product consumption had higher body weight, fat-free mass, waist circumference, waist-to-hip ratio, and fasting glucose concentrations than participants in the lowest tertile (all p < 0.01). After adjustments for potential cofactors, no significant association was observed. A higher prevalence of Inuit participants with metabolic syndrome was observed in the higher tertile compared with the first tertile (10.3% vs 1.6%; p < 0.001). CONCLUSIONS: Higher dairy product intake in Nunavik Inuit is not related to protective effects on body weight and CVD. The consumption of dairy products in Nunavik Inuit is probably not sufficient to withdraw beneficial effects on body weight or CVD risk factors, as observed in North American populations.

Seroprevalence of 10 zoonotic infections in 2 Canadian Cree communities.

We evaluated the seroprevalence of 10 zoonotic agents among the general population (15 years old and over) of Eastmain and Wemindji, James Bay, Quebec, in 2007. Overall seroprevalence rates were similar between the 2 communities. Nearly half the individuals tested (n = 251; 146 women, 105 men) were seropositive (n = 115) for at least one zoonosis. The highest seroprevalence rates were for Leptospira sp. (23%), Francisella tularensis (17%), and the California serogroup viruses (JC and SSH viruses) (10%). The other zoonoses (Toxoplasma gondii, Coxiella burnetii, Echinococcus granulosus, Toxocara canis, and Trichinella sp.) had seroprevalence rates ≤5%; no exposures were identified to hantaviruses (Sin Nombre virus). Overall, seropositivity was related to age, gender, hunting, and owning a dog. There was no medical history suggestive of overt diseases. Nonetheless, physicians should consider these agents when confronted with difficult or confusing diagnoses. In particular, the bacterial zoonoses should be ruled out in individuals with high or prolonged fever.

Influence of n-3 fatty acids on cardiac autonomic activity among Nunavik Inuit adults.

OBJECTIVES: Inuit from Nunavik (northern Quebec) consume large amounts of fish and marine mammals, which are important sources of n-3 polyunsaturated fatty acids (n-3 PUFAs). These substances have a beneficial impact on heart rate (HR) and heart rate variability (HRV). However, it is unknown if this beneficial impact remains significant in populations with high mercury exposure. The study assessed the impact of n-3 PUFAs (Docosahexaenoic [DHA] and Eicosapentaenoic acid [EPA]) on resting HR and HRV among Nunavik Inuit adults considering mercury and other potential confounders. STUDY DESIGN: Cross-sectional study employing clinical measurements. METHODS: Complete data were collected among 181 adults ≥ 40 years old (109 women and 72 men) living in the 14 coastal villages of Nunavik. Several indices of HRV were derived from a 2-hour Holter monitoring assessment. n-3 PUFAs levels were measured in membrane erythrocytes. Simple linear regression was used to analyse the relationship between n-3 PUFAs levels and resting HR and HRV parameters while multiple linear regressions were carried out to control for confounders. RESULTS: In the overall analyses, EPA was associated with SDANN (ß = 0.07, p = 0.04) and LF norm (ß = -1.84, p = 0.03) after adjusting for confounders. Among women, DHA was associated with resting HR (ß =-1.40, p = 0.03) while EPA was associated with SDNN (ß = 0.08, p = 0.03), SDANN (ß = 0.09, p = 0.02) and resting HR (ß = -2.61, p = 0.002). No significant association was observed in men. CONCLUSIONS: These results suggest a beneficial impact of n-3 PUFAs on resting HR and HRV among Nunavik Inuit women.