Traditional dietary pattern is associated with elevated cholesterol among the Inuit of Nunavik.

Our cross-sectional study assessed the associations between dietary patterns and cardiovascular disease (CVD) risk factors among Nunavik Inuit. This study was conducted as part of the 2004 Nunavik Inuit Health Survey, which included the collection of clinical measurements, plasma samples, and diet information from a food frequency questionnaire. A sample of 666 Inuit aged 18 years and older was included in our analyses. Dietary patterns were generated by principal component analysis. Multivariate general linear models adjusting for sex, age, waist circumference, and other potential confounders were used to examine associations between dietary patterns and CVD risk factors. Four distinct patterns were identified, namely the traditional, Western, nutrient-poor food, and healthy patterns. The traditional pattern showed positive associations with plasma total cholesterol, low-density lipoprotein (LDL) cholesterol, apolipoprotein B100, LDL peak particle diameter, and oxidized LDL (all P values for trend≤0.04), but showed no association with the total cholesterol:high-density lipoprotein cholesterol ratio or with inflammatory biomarkers (all P values for trend ≥0.19). The nutrient-poor food pattern was positively associated with oxidized LDL (P=0.04), but inversely associated with high-sensitivity C-reactive protein (P<0.0001). The Western and healthy patterns showed no association with any CVD risk factor. Our data show that high adherence to a traditional pattern among Nunavik Inuit is not associated with important changes in CVD risk factors, with the exception of a slight elevation in cholesterol concentrations, most likely attributable to increased n-3 fatty acid intake. Dietary patterns reflecting the recent introduction of market foods in the Inuit diet appear to exert a trivial influence on CVD risk factors.

Hemodynamic profiles of intubated and mechanically ventilated carbon monoxide-poisoned patients during systemic hyperbaric oxygen therapy.

BACKGROUND: Carbon monoxide (CO) poisoning can be a life threatening condition. Systemic hyperbaric oxygen (HBO) therapy is used to induce CO detoxification. However, little is known about the hemodynamic response to HBO in severely intoxicated patients. METHODS: We retrospectively analyzed the medical records of 6 CO-poisoned patients treated with propofol, rocuronium bromide, and HBO. The HBO protocol comprised 3 HBO treatments (HBOT1 to HBOT3) within 24 hours. During all HBO sessions heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse blood pressure (ΔBP) were measured every five minutes. Non-parametric tests were used to compare data between HBO sessions. RESULTS: HR increased significantly as the number of HBOT increased, from 68 beats per minute (bpm) during HBOT1 to 77 and 86 bpm during HBOT2 and HBOT3, respectively (p < 0.05). In addition, while no significant change was found for DBP, both SBP and ΔBP showed a transient and significant increase during HBOT2, compared to HBOT1, that did not return to basal values during HBOT3. CONCLUSION: Based on previous studies that have established the respective effects of rocuronium bromide, propofol, HBO, and CO alone on HR, SBP, and ΔBP, it is concluded that the hemodynamic responses observed in the present study are likely to be due to CO. If such, given that neither HR nor SBP and ΔBP returned to basal values by the end of HBOT3, it is suggested that more than 3 HBOT sessions could be necessary to provide full hemodynamic recovery in CO-poisoned patients.

Plantar pressures, plantar forces, and their influence on the pathogenesis of diabetic foot ulcers: a review.

BACKGROUND: Clinical recommendations for the prevention and healing of diabetic foot ulcers (DFUs) are somewhat clear. However, assessment and quantification of the mechanical stress responsible for DFU remain complex. Different pressure variables have been described in the literature to better understand plantar tissue stress exposure. This article reviews the role of pressure and shear forces in the pathogenesis of plantar DFU. METHODS: We performed systematic searches of the PubMed and Embase databases, completed by a manual search of the selected studies. From 535 potentially relevant references, 70 studies were included in the full-text review. RESULTS: Variables of plantar mechanical stress relate to vertical pressure, shear stress, and temporality of loading. At this time, in-shoe peak plantar pressure (PPP) is the only reliable variable that can be used to prevent DFU. Although it is a poor predictor of in-shoe PPP, barefoot PPP seems complementary and may be more suitable when evaluating patients with diabetes mellitus and peripheral neuropathy who seem noncompliant with footwear. An in-shoe PPP threshold value of 200 kPa has been suggested to prevent DFU. Other variables, such as peak pressure gradient and peak maximal subsurface shear stress and its depth, seem to be of additional utility. CONCLUSIONS: To better assess the at-risk foot and to prevent ulceration, the practitioner should integrate quantitative models of dynamic foot plantar pressures, such as in-shoe and barefoot PPPs, with the regular clinical screening examination. Prospective studies are needed to evaluate causality between other variables of mechanical stress and DFUs.

Omega-3 fatty acids, polymorphisms and lipid related cardiovascular disease risk factors in the Inuit population.

BACKGROUND: Tissue concentrations of fatty acids (FAs) and genetic variations are well-known factors which affect the cardiovascular disease (CVD) risk. The objective was to examine whether the genetic variability of 20 candidate genes and red blood cells (RBCs) percentage of total n-3 polyunsaturated fatty acids (PUFA), a biomarker of dietary n-3 PUFA intake, modulate lipid related CVD risk factors in the Inuit population. METHODS: Data from the Qanuippitaa Nunavik Health Survey (n = 553) were analysed via multivariate regression models with 40 known polymorphisms, RBCs percentage of n-3 PUFA, and the interaction term to take into account the effect on plasma lipid and apolipoporotein levels. RESULTS: Individuals being heterozygotes for CETP C-4502T (rs183130) or G-971A (rs4783961) together with higher n-3 PUFA had lower triacylglycerol (TG) concentrations compared to homozygotes for the minor allele. Further, effects of a stronger beneficial association between n-3 PUFA in RBCs and plasma lipid parameters- including lower total cholesterol (TC), lower low-density lipoprotein cholesterol (LDL-C) or higher high-density lipoprotein cholesterol (HDL-C) concentrations- were associated with AGT M235T (rs699) TT genotype, CETP G-971A (rs4783961) AG genotype, T allele carriers of CETP C-4502T (rs183130), and T allele carriers of CETP Ile405Val (rs5882). In contrast, higher n-3 PUFA in RBCs were associated with adverse lipid profiles- including increased LDL-C, increased apolipoprotein B100 or decreased HDL-C concentrations- in G allele carriers of the APOA5 -3 A/G (rs651821), C allele carriers of APOA5 T-1131C (rs662799), G carriers of APOC3 SstI (rs5128) and G carriers of APOA4 Asn147Ser (rs5104). CONCLUSION: Overall, these results suggest that percentage of total n-3 PUFA of RBCs are associated with lipids related CVD risk factors conferred by genetic variations in the Inuit population.

Gene-diet interactions on plasma lipid levels in the Inuit population.

The Inuit population is often described as being protected against CVD due to their traditional dietary patterns and their unique genetic background. The objective of the present study was to examine gene-diet interaction effects on plasma lipid levels in the Inuit population. Data from the Qanuippitaa Nunavik Health Survey (n 553) were analysed via regression models which included the following: genotypes for thirty-five known polymorphisms (SNP) from twenty genes related to lipid metabolism; dietary fat intake including total fat (TotFat) and saturated fat (SatFat) estimated from a FFQ; plasma lipid levels, namely total cholesterol (TC), LDL-cholesterol (LDL-C), HDL-cholesterol (HDL-C) and TAG. The results demonstrate that allele frequencies were different in the Inuit population compared with the Caucasian population. Further, seven SNP (APOA1 - 75G/A (rs670), APOB XbAI (rs693), AGT M235T (rs699), LIPC 480C/T (rs1800588), APOA1 84T/C (rs5070), PPARG2 - 618C/G (rs10865710) and APOE 219G/T (rs405509)) in interaction with TotFat and SatFat were significantly associated with one or two plasma lipid parameters. Another four SNP (APOC3 3238C>G (rs5128), CETP I405V (rs5882), CYP1A1 A4889G (rs1048943) and ABCA1 Arg219Lys (rs2230806)) in interaction with either TotFat or SatFat intake were significantly associated with one plasma lipid variable. Further, an additive effect of these SNP in interaction with TotFat or SatFat intake was significantly associated with higher TC, LDL-C or TAG levels, as well as with lower HDL-C levels. In conclusion, the present study supports the notion that gene-diet interactions play an important role in modifying plasma lipid levels in the Inuit population.

Population-based study of high plasma C-reactive protein concentrations among the Inuit of Nunavik.

BACKGROUND: The shift away from traditional lifestyle in the Inuit population over the past few decades has been associated with an increased prevalence of coronary heart disease (CHD) risk factors such as obesity, high blood pressure (BP) and diabetes. However, the impact of this transition on the pro-inflammatory marker high-sensitivity C-reactive protein (hs-CRP) has not been documented. OBJECTIVES: To examine the prevalence of elevated plasma hs-CRP concentrations in Inuit from Nunavik in the province of Quebec (Canada) and identify anthropometric, biochemical and lifestyle risk factors associated with elevated hs-CRP. DESIGN: A population-representative sample of 801 Inuit residents from 14 villages of Nunavik, aged between 18 and 74 years, was included in the analyses. Subjects participated in a clinical session and completed questionnaires on lifestyle. Multivariate logistic regression was used to determine risk factors for elevated hs-CRP. RESULTS: Elevated plasma hs-CRP concentrations (≥ 2 mg/L) were present in 32.7% (95% confidence interval (CI) 29.5-35.8) of the Inuit adult population and were more prevalent among women than among men (36.7% vs. 29.0%, p=0.007). Multivariate logistic regression analysis indicated that every 1 mmHg increase in systolic BP was associated with a 3% increase in the odds of having hs-CRP concentrations ≥ 2 mg/L in the Inuit population (95% CI 1.01-1.04). The combination of older age (≥ 50 vs. <30 years) and elevated waist circumference (gender-specific cut-off values) in a multivariate logistic model was also associated with a 13.3-fold increase in the odds of having plasma hs-CRP concentrations ≥ 2 mg/L (95% CI 5.8-30.9). CONCLUSIONS: These data indicate that elevated hs-CRP is relatively prevalent among Inuit with values that are similar to those seen in Canadian Caucasian populations. Sex, age, waist circumference and systolic BP are major factors that increase the risk of this inflammatory phenotype among Inuit from Nunavik, despite their different lifestyle background compared with Caucasians.

Hyperbaric oxygen therapy decreases blood pressure in patients with chronic wounds.

INTRODUCTION: A single session of hyperbaric oxygen therapy (HBO2T) is known to act on the parasympathetic system and also increase the production of reactive oxygen species. However, the impact of a treatment series consisting of 20 to 40 sessions on blood pressure (BP) remains unknown. Thus, the current study aimed to assess the effect of this type of treatment in patients administered HBO2T as an adjunct therapy for wound healing. METHODS: We retrospectively analyzed data from 93 patients treated for wound healing. All patients were treated in the Perry Sigma Plus DuoPlace hyperbaric chamber at the CSSS Alphonse Desjardins Centre Hospitalier Affilié Universitaire/CHAU de Lévis (Québec, Canada) between 2003 and 2010. They were exposed daily to 100% oxygen at 2.5 atmospheres absolute (atm abs) for 90 minutes. The systolic BP (SBP), diastolic BP (DBP) and heart rate (HR) were measured before each HBO2T session, and patient age and sex were also recorded. The impact of HBO2T on BP was evaluated using linear mixed models. RESULTS: The mean age of the patients was 66.6 years (standard deviation: 10.8). The majority of the subjects was male (79.6%) and suffered from Type 2 diabetes (71.9%) and hypertension (65.6%). These patients received an average of 25 HBO2T sessions. Before the first treatment, the mean SBP and DBP measurements were 145 (24.8) mmHg and 78 (13.1) mmHg, respectively; the median recorded HR was 69.0 beats/minute (interquartile range: 63.0-81.5). The age- and sex-adjusted mixed models revealed that HBO2T was significantly associated with a decrease in the HR and SBP measurements; the greatest impact was observed during the first 20 treatments for HR (p-value < 0.5) and the last 20 treatments for SBP (p-value < 0.0001). No effects of HBO2T on DBP were detected (p-value = 0.36). CONCLUSIONS: In patients with chronic wounds requiring HBO2T, successive HBO2T treatments affect HR and SBP measurements. However, further prospective clinical investigations are required to evaluate the prolonged effects of HBO2T.

Is severe obesity a cardiovascular health concern in the Inuit population?

OBJECTIVES: Obesity is rising globally and severe obesity (SO) [body mass index (BMI) = 40 kg/m(2) or = 35 kg/m(2) with co-morbidity] is growing at a much faster rate. Amongst the Inuit, evolution of SO remains unknown. We investigated whether the level of SO changed and whether the cardio-metabolic profile improved or deteriorated in Nunavik Inuit between 1992 and 2004. METHODS: SO subjects were selected from two comparable population-based studies. These studies were undertaken in Nunavik (Quebec, Canada), and were performed in two different time frames, separated by 12 years. Physiological (lipid profile, fasting insulin, fasting glucose, and blood pressure) as well as anthropometric data (BMI, waist circumference, and waist to hip ratio) were collected in both studies. RESUTLS: There was approximately a fourfold increase in the prevalence of SO in comparable age groups. This increase affected both genders between 1992 and 2004. Smoking rates in SO populations have significantly decreased during this period, from 85% to 41% (P < 0.0001). Overall, there were no statistically significant differences in the cardio-metabolic profile (insulin, total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, systolic and diastolic blood pressures, BMI, and waist to hip ratio). There was, however, a significant increase in waist circumference (P < 0.001), especially in women (P < 0.01). Type 2 diabetes remained stable, at around 40% in this population. CONCLUSION: Although the prevalence of SO increased, the cardio-metabolic profile remained stable. Nevertheless, regular monitoring of chronic disease in this population remains crucial.

Cardiovascular risk factors and subclinical atherosclerosis among Nunavik Inuit.

OBJECTIVE: To evaluate subclinical atherosclerosis in Nunavik Inuit and its correlation to traditional cardiovascular disease risk factor. METHOD: The intima-media thickness (IMT) of 12 segments of the carotid arteries (IMT(12_seg)) free of plaque were assessed in randomly selected 40 years old and older Inuit from. Clinical assessment was performed which included fasting plasma glucose, fasting insulin, systemic blood pressure, body mass index, smoking, circulating blood lipids and oral glucose tolerance test. In addition, documented presence of ischemic heart disease (IHD), stroke, diabetes mellitus, hypertension and dyslipidemia were determined from medical files. RESULTS: The average age of the 287 participants was 51.2 ± 0.6 years (56.8% women). Mean IMT(12_seg) was 0.80 ± 0.17 mm (range: 0.55-1.47 mm). Compared with disease free Inuit, individuals with history of stroke showed greater carotid internal IMT (0.68 ± 0.01 mm vs. 0.96 ± 0.15 mm respectively; p<0.005) but no difference was observed for IHD. Hypertensive and dyslipidemic Inuit had higher IMT(12_seg) compared to risk factor free individuals but no difference was observed in diabetics. None of the clinical assessments were associated with IMT(12_seg). In a multivariate backward elimination model, only age, gender, and medically documented history of hypertension were found to be predictors of IMT(12_seg) (adjusted r-square of 0.54; p<0.0001). CONCLUSION: Compared with disease free Nunavik Inuit, subclinical signs of atherosclerosis determined by IMT was higher in individual diagnosed with stroke. Independent predictors of IMT(12_seg) in our group were age, gender and history of hypertension. No other traditional risk factors imparted IMT.

Tissue-specific responses of lipoprotein lipase to dietary macronutrient composition as a predictor of weight gain over 4 years.

This study evaluated if the effect of dietary macronutrient composition on adipose tissue lipoprotein lipase (ATLPL) and skeletal muscle lipoprotein lipase (SMLPL) predicted the long-term (over 4 years) changes in body weight and composition in free-living adults. Using a crossover design, 39 healthy subjects (n = 24 normal weight, n = 7 overweight, n = 8 obese) each followed a 2-week isocaloric high-carbohydrate (HC; 55% CHO:25% fat) and high-fat (HF; 30% CHO:50% fat) diet. On day 15 of each diet, biopsies were performed in the fasted state and 6 h after a meal. Body weight and composition were measured annually over 4 years. The outcomes for body weight, fat mass and % body fat were assessed using a linear two-stage mixed model. The mean (±SEM) increase in body weight and fat mass over 4 years was 0.29 ± 0.15 kg/year (P = 0.063) and 0.31 ± 0.15 kg/year (P = 0.051), respectively. The most consistent predictors of future body weight and fat changes were the ΔATLPL and ΔSMLPL responses (0-6 h) to a HC diet/meal. For the HC diet/meal, the subjects who had an increase in ATLPL activity/cell gained more % body fat over 4 years (P = 0.006) whereas subjects who had a decrease in SMLPL activity/g also had an increase in fat mass (P = 0.021). No significant relationships were observed between fasting ATLPL and SMLPL or enzyme responses to meals and any of the outcomes following the HF diet. In free-living adults the variability in tissue-specific lipoprotein lipase (LPL) responsiveness to a HC diet/meal predicts longitudinal changes in body composition.

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.

Does sitting height ratio affect estimates of obesity prevalence among Canadian Inuit? Results from the 2007-2008 Inuit Health Survey.

OBJECTIVES: High sitting height ratio (SHR) is a characteristic commonly associated with Inuit morphology. Inuit are described as having short leg lengths and high trunk-to-stature proportions such that cutoffs for obesity derived from European populations may not adequately describe thresholds of disease risk. Further, high SHR may help explain the reduced impact of BMI on metabolic risk factors among Inuit relative to comparison populations. This study investigates the relationship between SHR and body mass index (BMI) in Inuit. METHODS: Subjects are 2,168 individuals (837 males and 1,331 females) from 36 Inuit communities in the Canadian Arctic. Mean age is 42.63 ± 14.86 years in males and 41.71 ± 14.83 years in females. We use linear regression to examine the association between age, sex, height, sitting height, SHR, waist circumference (WC), and BMI. We then evaluate the efficacy of the relative sitting height adjustment as a method of correcting observed BMI to a population-standardized SHR. RESULTS: Mean BMI is significantly higher than among non-Inuit Canadians. Obesity prevalence is high, particularly among Inuit women. In the regression, only age and WC are significant predictors of BMI. While SHR is significantly greater than that of the US population, there is substantial agreement between overweight and obesity prevalence using observed and corrected BMI. CONCLUSIONS: We find no consistent relationship between SHR and BMI and suggest the unique anthropometric and metabolic profile observed in Inuit arise from factors not yet delineated. More complex anthropometric and imaging studies in Inuit are needed.

Relation between methylmercury exposure and plasma paraoxonase activity in inuit adults from Nunavik.

BACKGROUND: Methylmercury (MeHg) exposure has been linked to an increased risk of coronary heart disease (CHD). Paraoxonase 1 (PON1), an enzyme located in the high-density-lipoprotein (HDL) fraction of blood lipids, may protect against CHD by metabolizing toxic oxidized lipids associated with low-density liproprotein and HDL. MeHg has been shown to inhibit PON1 activity in vitro, but this effect has not been studied in human populations. OBJECTIVES: This study was conducted to determine whether blood mercury levels are linked to decreased plasma PON1 activities in Inuit people who are highly exposed to MeHg through their seafood-based diet. METHODS: We measured plasma PON1 activity using a fluorogenic substrate and blood concentrations of mercury and selenium by inductively coupled plasma mass spectrometry in 896 Inuit adults. Sociodemographic, anthropometric, clinical, dietary, and lifestyle variables as well as PON1 gene variants (rs705379, rs662, rs854560) were considered as possible confounders or modifiers of the mercury-PON1 relation in multivariate analyses. RESULTS: In a multiple regression model adjusted for age, HDL cholesterol levels, omega-3 fatty acid content of erythrocyte membranes, and PON1 variants, blood mercury concentrations were inversely associated with PON1 activities [ß-coefficient = -0.063; 95% confidence interval (CI), -0.091 to -0.035; p < 0.001], whereas blood selenium concentrations were positively associated with PON1 activities (ß-coefficient = 0.067; 95% CI, 0.045-0.088; p < 0.001). We found no interaction between blood mercury levels and PON1 genotypes. CONCLUSIONS: Our results suggest that MeHg exposure exerts an inhibitory effect on PON1 activity, which seems to be offset by selenium intake.

A comparison of the metabolic response to abdominal obesity in two Canadian Inuit and First Nations population.

Inuit and Cree populations are known for high obesity rates despite markedly different rates of type 2 diabetes (T2DM). To document this apparent discrepancy we evaluated the impact of body size parameters and fasting insulin (FI) on several T2DM risk factors among Inuit and Cree populations (Québec, Canada). A total of 1,104 adults (≥18 years) Inuit and Cree individuals participated in a cross-sectional investigation. Interestingly, across both genders, across all levels of waist circumference (WC), Inuit showed lower levels of FI (age-adjusted, P < 0.0001) and fasting glucose (P < 0.0001) than Cree individuals. In both groups, a comparison of multi-sample structural equation models confirmed the predominant influence of WC on other traditional risk factors, compared to BMI. A preponderant direct impact of WC was observed on blood pressure (BP) parameters (P < 0.0001), high-density lipoprotein cholesterol (HDL-C) (P < 0.0001), and FI (P < 0.0001). Fasting glucose level appear to be influenced by WC via FI in both ethnic groups (P < 0.0001), while triacylglycerol (TAG) level was predominantly impacted by WC via FI, but only in Cree individuals (P < 0.0001). The main ethnic difference found was the strength of the impact of WC on FI, which was considerably higher among the Cree (λ = 2.4, P < 0.0001) than the Inuit (λ = 1.8, P < 0.0001). These results confirm the predominant role of abdominal adiposity in the complex and tenuous links of different traditional T2DM determinants. However, the ethnic difference in the impact of abdominal obesity on insulin levels across all WCs needs to be explored further.

Obesity risks: towards an emerging Inuit pattern.

OBJECTIVES: The aim of this study was to provide analytical overviews of anthropometric measurements and their relationships with type 2 diabetes and cardiovascular disease (CVD) risk factors within the Inuit population, given that few studies have focused on this issue. Study design. Cross-sectional study. METHODS: Anthropometric and biological data were obtained from 867 Inuit participants from Nunavik (≥18 years). RESULTS: Obesity prevalence for men and women, respectively, was 25.1% and 31.3% according to body mass index (BMI: >30 kg/m2); 20.2% and 55.3% according to waist circumference (WC: >102 cm for men and >88 cm for women); 22.4% and 22.5% according to body fat percentage (%BF: ≥30 in men and ≥40 in women). There was substantial agreement between anthropometric obesity measurements, except for the waist-to-hip ratio (WHR) which showed the lowest agreement with the other measurements. All risk factors were significantly associated with anthropometry. The prevalence of abnormal values for risk factors increased across quartiles of BMI and WC. Among obese participants, as defined by the WC cutoff, 22% had metabolic syndrome based on the National Cholesterol Education Program in the Adult Treatment Panel III (NCEP-ATPIII) definition and 64.8% of them were also insulin resistant. CONCLUSION: Obesity rates among Inuit are high, especially among women. Inuit women display especially high rates of abdominal obesity. Further longitudinal work is needed to evaluate the effects of central and global obesity among Inuit.

Effects of perfluorooctanesulfonate exposure on plasma lipid levels in the Inuit population of Nunavik (Northern Quebec).

BACKGROUND: Perfluorooctanesulfonate (PFOS) was used as a surfactant in various commercial products. In rodents, exposure to this compound induced various health effects, including hypolipidemia. In human populations, the potential toxicity of PFOS is not yet fully characterized, but indications of effects on lipids are reported. A recent study reported an increase in plasma cholesterol associated with exposure to perfluorinated compounds in humans exposed through drinking water, but similar effects were not reported in all exposed human populations. PFOS is widely distributed in the environment, including the arctic biota. The Inuit of Nunavik are exposed to environmental contaminants through the consumption of fish and game. This diet is also a source of omega3-polyunsaturated fatty acids (n-3 PUFAs) that are known to lower plasma triacylglycerols. OBJECTIVE: This cross-sectional epidemiologic study aims at assessing the relationship between PFOS exposure and plasma lipids, while taking account of the concomitant hypolipidemic effect exerted by n-3 PUFAs. METHODS: Plasma concentrations of PFOS and lipids were assessed in Nunavik Inuit adults (n=723) in the framework of a large-scale environmental health study. Associations of exposure levels to age, gender and selected wild food consumption associated with n-3 PUFAs intake, as well as the exposure on lipid levels were investigated by multivariate linear modeling. RESULTS: In the Inuit population, PFOS exposure and n-3 PUFAs intake are related to traditional food consumption. Triacylglycerol and ratio of total cholesterol to high density lipoprotein cholesterol (HDL-C) levels were negatively associated with PFOS plasma levels, while HDL-C levels were positively associated, after adjustment for circulating levels of n-3 PUFAs and for the interaction between gender and PFOS plasma levels. Other plasma lipids, such as low density lipoprotein-cholesterol and non-HDL-C were not related to PFOS plasma concentrations. CONCLUSION: The results of this study show a relationship between PFOS and plasma lipid levels in an environmentally exposed human population, and this effect appears distinct from that of n-3 PUFAs.

Hypertension among the Inuit from Nunavik: should we expect an increase because of obesity?

OBJECTIVES: Because of their recent adoption of a Westernized lifestyle, an increased risk of developing hypertension (HTN) is suspected among Inuit populations. This study aimed to assess the exact prevalence of HTN in Nunavik Inuit and to examine its association with other major risk factors of cardiovascular disease. STUDY DESIGN: A cross-sectional population-based study. METHODS: We analysed biological and anthropometric data and the medical history of 832 Inuit. RESULTS: The overall prevalence of HTN (≥140/90 mmHg or the use of medication) was 19% with no gender difference. Obesity (body mass index [BMI] ≥30 kg/m(2)) was the highest prevalent cardiovascular risk factor (23%), and was significantly associated with HTN (OR for BMI<25 kg/m(2) vs. BMI 30-34 kg/m(2): 7.9 [3.5-17.9]; OR for BMI<25 kg/m(2) vs. BMI ≥35 kg/m(2): 14.4 [5.6-36.7]). An increase in odds of prehypertension (preHTN) (130-139/80-89 mmHg) was also observed as the BMI increased (p for trend, p<0.0001). CONCLUSION: The prevalence of HTN in the Inuit populations has reached values similar to those of their Westernized counterparts. Furthermore, not only HTN but also preHTN states are significantly associated with obesity even after adjusting for confounding variables. These results clearly indicate that HTN is becoming a growing health challenge in Nunavik because of pandemic obesity.

Cardiovascular burden and related risk factors among Nunavik (Quebec) Inuit: insights from baseline findings in the circumpolar Inuit health in transition cohort study.

BACKGROUND: The Inuit are commonly portrayed to be somehow protected from cardiovascular diseases (CVDs) through their traditional lifestyle and diet. However, actual sociocultural transition and related major, modifiable risk factors have scarcely been quantified in the Inuit population. Such knowledge is extremely valuable in terms of public health intervention. METHODS: A total of 887 Inuit residents from Nunavik, Quebec, participated in a cohort study. The estimates presented were derived from anthropometric and biological measurements gathered at the time of recruitment and enhanced by information collected in the medical file of each participant. All estimates were corrected for a complex sampling strategy and bootstrapped to ensure the representativeness of the general Nunavik population. RESULTS: Overall, 19% of Inuit had a disease of the circulatory system according to the International Statistical Classification of Diseases and Related Health Problems, 10th revision. Among all disorders, peripheral circulatory system disease was the most prevalent (9%). Prevalences of ischemic heart disease and cerebrovascular disease were of similar magnitude (2.5%). No significant difference in disease prevalence was noted between sexes. The major modifiable CVD risk factors were smoking (84%), obesity (49%) [corrected] (body mass index of greater than 30 kgm2) and elevated blood pressure (13085 mmHg or greater) (18%). Prevalences were globally higher among women. CONCLUSION: The current belief that the Inuit are protected from CVD is seriously questioned by the results of the present study. Considering the extremely high prevalence of CVD risk factors, a population-based intervention reinforced for women is urgently needed to reduce their risk.

Association between trans-fatty acids in erythrocytes and pro-atherogenic lipid profiles among Canadian Inuit of Nunavik: possible influences of sex and age.

Dietary exposure to trans-fatty acids (TFA) is likely to be high among Canadian Inuit; yet no data are available on the physiological effects of TFA in this population. The purpose of the present study was to assess the association between TFA and plasma lipid profiles in Inuit men and women living in Nunavik (Québec, Canada). In a cross-sectional, population-based survey, a total of 795 Nunavik Inuit eligible participants gave a blood sample. Exposure to TFA was assessed by their relative proportion in erythrocyte membrane. We performed multiple regression analysis using plasma lipids or their linear combinations as the dependent variables and TFA as the main predictor, adjusting for potential confounders. The associations varied markedly between the sexes and according to age. In men (n 357, aged 36.3 (sd 14.3) years, TFA 1.24 (sd 0.54) %), TFA tended to be negatively associated with HDL-cholesterol (HDL-C), apoA1 and LDL particle size, and positively associated with non-HDL-C, LDL-cholesterol (LDL-C), apoB100, the apoB100:apoA1 ratio and the ratios of total cholesterol (TC), LDL-C and TAG to HDL-C. No such trends were observed in women (n 438, aged 37.0 (sd 14.1) years, TFA 1.16 (sd 0.54) %), except for HDL-C and apoA1 in women aged 50 years and more. These results suggest that TFA could raise the risk of CHD in Inuit men at least through their physiological effects on plasma lipids. The differential associations reported in pre- and postmenopausal women need to be reproduced in other populations and in experimental studies addressing the influence of sex hormones in response to dietary fats.