V. G. Krivoshapkin’s research while affiliated with North-Eastern Federal University and other places

Purpose: Self-report is commonly used to assess physical activity (PA) and dietary behavior, particularly in low resource settings. Globally, many low resource settings do not have a public health emphasis on physical activity and diet. A lack of emphasis on these behaviors may mean that they are less likely to be correctly recalled by participants, weakening their analytical use. Methods: Rural indigenous Siberian adults (Yakut) answered questions for their occupational physical activity requirements (OPA), frequency of leisure time physical activity (LPA), percentage of diet from purchased food, and basic demographics. Anthropometrics (body mass index (BMI), waist circumference (WC)) and blood pressure were used to measure health. Chi square and t-tests assessed sex differences in PA, purchased food and health indicators. OPA and LPA were grouped into three categories and compared to the health indicators using ANOVA. Correlations compared purchased food with health indicators. Results/findings: The final sample size was 164 (47 men), mean age 51.1 (SD 14.5). Women had significantly higher BMIs and WCs and lower systolic blood pressure (SBP) than men with no significant difference in purchased food or frequency of LPA. Heavy manual labor was significantly more common in the men but jobs requiring walking or carrying were significantly more common in the women. OPA, LPA and purchased food were all unrelated to all health indicators in simple and multivariate analyses. Conclusions: Simplified questions of behavior within populations who do not receive messages on the importance of that behavior are likely not useful in predicting chronic disease risk.

According to the results of the cross-sectional study of rural indigenous population of the Republic of Sakha (Yakutia), there has been studied the level of cholesterol and frequency of atherogenic changes of the lipid profile of the blood plasma. It has been found that in 35 % of the surveyed indigenous people, the level of cholesterol was 5.2 mmol/l or more, and in 10.8 % - 6.2 mmol/l or more. Among the persons with high cholesterol, atherogenic changes of the ratio of total cholesterol/HDL-C, LDL-C/HDL-C were observed in 19 % of the men and 8 % of the women (p = 0.014); logarithm (TRG/HDL-C) - in 11 % of the men and women (p = 0.906). Thus, the high levels of the total cholesterol (5.2 mmol/l or more) in 80 % of the men and in 89% of the women was not accompanied by atherogenic changes in the lipid profile. This allows to consider the status of hypercholesterolemia in this population group in most of the cases as a manifestation of adaptive changes in lipid metabolism. The identified changes in atherogenic lipid profile were associated with presence of metabolic risk factors, what proves the need for determination of cholesterol in lipoprotein composition and a ratio of lipid fractions for choice of a right tactics for correction of the lipid risk factors.

Viliuisk encephalomyelitis (VE) is an endemic neurological disease in Northeast Siberia and generally considered to be a chronic encephalomyelitis of unknown origin actually spreading in the Sakha (Yakutian) Republic. In search for the pathophysiology and causative agent of VE, we performed a cross-sectional study on clinical, serological and neuroimaging data on chronic VE patients during two medical expeditions to three villages within the Viliuiski river basin in the Republic of Sakha in 2000 and to the capital Yakutsk in 2006. The severity of the core clinical picture with predominant sensory ataxia, gait apraxia, lower limb spasticity, cognitive impairment and bladder dysfunction correlated with the degree of MRI findings showing enlargement of inner ventricular spaces as in communicating hydrocephalus. Laboratory studies revealed transient eosinophilia during the preceding acute meningitis-like phase, but no ongoing inflammatory process in the CSF. We found immune reactions against Toxocara canis in the majority of chronic VE patients but rarely in controls (P = 0.025; Fisher's exact test). Histological analysis of subacute to subchronic VE brain samples showed eosinophilic infiltrations with no signs of persistent Toxocara canis infection. Our data showed that pressure by the communicating hydrocephalus as a mechanical factor is the major pathogenic mechanism in chronic VE, most likely triggered by eosinophilic meningitis. There are no signs for an ongoing inflammatory process in chronic VE. The past eosinophilic reaction in VE might be caused by Toxocara ssp. infection and might therefore represent the first hint for an initial cause leading to the development of chronic VE. Our data provide a framework for future studies and potential therapeutic interventions for this enigmatic epidemic neurological disease potentially spreading in Sakha Republic.

According to the results of the cross-sectional study of rural indigenous population of the Republic of Sakha (Yakutia), there has been studied the level of cholesterol and frequency of atherogenic changes of the lipid profile of the blood plasma. It has been found that in 35 % of the surveyed indigenous people, the level of cholesterol was 5.2 mmol/l or more, and in 10.8 % - 6.2 mmol/l or more. Among the persons with high cholesterol, atherogenic changes of the ratio of total cholesterol / HDL-C, LDL-C / HDL-C were observed in 19 % of the men and 8 % of the women (р = 0.014); logarithm (TRG / HDL-C ) - in 11 % of the men and women (p = 0.906). Thus, the high levels of the total cholesterol (5.2 mmol /l or more) in 80 % of the men and in 89% of the women was not accompanied by atherogenic changes in the lipid profile. This allows to consider the status of hypercholesterolemia in this population group in most of the cases as a manifestation of adaptive changes in lipid metabolism. The identified changes in atherogenic lipid profile were associated with presence of metabolic risk factors, what proves the need for determination of cholesterol in lipoprotein composition and a ratio of lipid fractions for choice of a right tactics for correction of the lipid risk factors.

В выборке сельского коренного населения республики Саха (Якутия) изучена частота артериальной гипертензии и ожирения (457 чел. в возрасте 20 лет и старше). Установлено, что 40% обследованного населения имеют артериальную гипертензию. Ожирение выявлено у 14% мужчин и 19% женщин, абдоминальный тип ожирения – у 42 и 55% соответственно. Уровень артериального давления положительно коррелирует с индексом массы тела и окружностью талии. Информативность данных показателей при идентификации лиц с высоким рис-ком развития артериальной гипертензии не различается. Широкая распространенность абдоминального типа ожирения требует изучения его вклада в заболеваемость и смертность населения от хронических неинфекционных заболеваний, конституциональных особенностей данной популяции и в последующем, возможно, разработки специфических этнических критериев ожирения.

Background: Circumpolar regions are undergoing social and economic transition, which often corresponds to a behavioural transition. Yet, physical activity and sedentary behaviour are rarely objectively measured within these groups. Aim: This study aimed to characterize objectively measured physical activity and sedentary behaviour in a sample of indigenous Siberians. Subjects and methods: Yakut (Sakha) adults (n = 68, 32 men) underwent anthropometry, interviews and wore a triaxial accelerometer for two days. Time spent in moderate-to-vigorous physical activity (MVPA) or sedentary behaviour was calculated using a single axis and also all three axes. Results: Men spent significantly more time in MVPA than women, although no sex difference was found in sedentary behaviour. Participants were far more active and less sedentary when classified using all three axes (vector magnitude) than a single axis. Television viewing time significantly related to sedentary behaviour in men only. Conclusion: The Yakut have gender differences in amount and predictors of physical activity and sedentary behaviour. Triaxial accelerometry is more sensitive to daily physical activity in free living populations than single axis.

Previous research has shown that the extreme cold and short day lengths of polar winters promote increased production and uptake of thyroid hormones, resulting in marked declines in free triiodothyronine (fT3). However, this "polar T3 syndrome" has been documented almost exclusively on small samples of male sojourners and little is known about seasonal changes in thyroid function among indigenous circumpolar groups. The present study addresses this gap by examining seasonal changes in thyroid hormone levels among the indigenous Yakut (Sakha) of northeastern Siberia. Anthropometric dimensions and thyroid measures (fT3, free thyroxine [fT4], thyroid-stimulating hormone [TSH]) were obtained on two occasions (July/August, 2009 and January 2011) on a sample of 134 Yakut adults (51 men, 83 women) from the village of Berdygestiakh, Sakha Republic/Yakutia, Russia. Yakut men and women both displayed significant declines in fT3 and fT4, and significant increases in TSH from summer to winter despite showing only modest seasonal changes in body mass and composition. Among men, gains in fat-free mass (FFM) were associated with larger reductions in fT3 and greater increases in TSH. Men living more traditional lifeways showed larger winter declines in fT4 and greater increases in TSH. The Yakut exhibited significant winter declines in fT3 levels similar to other circumpolar groups studied. However, the magnitude of seasonal change was greater in the Yakut, perhaps reflecting their distinctive metabolic physiology. Lifestyle factors play a mediating role in thyroid responses, such that men with more traditional lifeways had more exaggerated seasonal changes. Am. J. Hum. Biol., 2013. © 2013 Wiley Periodicals, Inc.

Physical activity has been linked to improved health among Western populations; however, little is known about the relationship among indigenous populations who combine traditional subsistence activities with more sedentary/market lifestyles. This study examines the relationship between physical activity and selected biomarkers of cardiovascular health in a sample of 75 Yakut adults (41 men) who have been undergoing the transition to a wage/market economy since the fall of the Soviet Union. Physical activity was objectively estimated using indirect calorimetry to predict activity energy expenditure (AEE: kcal/d) and accelerometry. Women had significantly lower AEE but not lower accelerometry counts than men. Multiple linear regressions were performed on men and women separately with biomarkers as the dependent variables and physical activity measures, age and percent body fat as the independent variables. Neither measure of physical activity predicted any of the biomarkers in women. In men, AEE was positively associated with high density lipoproteins (HDL) and inversely related to Epstein-Barr virus (EBV) antibodies. Accelerometry counts were negatively associated with C-reactive protein (CRP) and EBV and positively associated with total, HDL and low density lipoproteins (LDL) cholesterol. In men, physical activity appears to reduce the risk for negative health outcomes, predicting lower immune activity and higher levels of the “good” cholesterol and is linked with lower inflammation, though also predicting higher levels of all plasma cholesterols. Overall, physical activity appears to predict improved health in these Yakut men but not for the women, though the reasons behind this sex difference have yet to be investigated.