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Study Populations
Indigenous Siberians originally practiced complex and regionally variable subsistence strategies determined by local ecological conditions. Subsistence centered around horse, cattle, and reindeer herding, fishing, hunting, and gathering. With the emergence of the Soviet Union many indigenous groups faced forced collectivization, industrialization, and Russification. Economic self-sufficiency decreased, while adult mortality and morbidity increased. When the Soviet Union collapsed in 1991, they returned to a more subsistence based lifestyle and health has continued to decline. Between 1991 and 1995, life expectancy for indigenous Siberians declined four years for women and six years for men. (Sorensen, 2003). Today, indigenous Siberians are simultaneously experiencing the effects of the collapse of the Soviet Union and economic development associated with the diamond and petroleum industries.
Map of the Russian
Federation
Evenki
Family
Yakut
Gathering
Currants
Basal metabolic rate (BMR) is the minimum amount of energy required to sustain basic biological functions. Our research has shown that indigenous Siberians, including the Yakut, Evenki, and Buryat, have elevated BMRs compared to lower latitude populations, which appears to be an adaptation to chronic cold stress. Our current research, sponsored by NSF as part of the International Polar Year program, is investigating causes and consequences of elevated BMRs among indigenous Siberians.
Bill Leonard measuring BMR
Thyroid Hormones and Metabolic Adaptation
Basal Metabolic Rate and
Cold Stress
Basal metabolic rate (BMR) is the minimum amount of energy required to sustain basic biological functions. Our research has shown that indigenous Siberians, including the Yakut, Evenki, and Buryat, have elevated BMRs compared to lower latitude populations, which appears to be an adaptation to chronic cold stress. Our current research, sponsored by NSF as part of the International Polar Year program, is investigating causes and consequences of elevated BMRs among indigenous Siberians.
Bill Leonard measuring BMR
Thyroid Hormones and Metabolic Adaptation
Thyroid function has been investigated as
a key mechanism for BMR upregulation. Our research among the Yakut and
Evenki has demonstrated a positive relationship between the hormone
levels triiodothyronine (T3) and thyroxine (T4) and BMR. Our current
research is focused thyroid function and basal metabolic rate among the
Yakut. Further, we are investigating the consequences of metabolic
upregulation and changes in thyroid activity by examining the increased
prevalence of autoimmune thyroid disorders.
Laboratory Work
Economic
Development and Changing Chronic Disease Patterns
The prevalence of cardiovascular disease
is rapidly increasing among indigenous populations as they transition
to a more Western lifestyle. Our research has documented relatively low
cholesterol levels among indigenous Siberian populations that are now
rising with economic development and dietary change. Our studies have
also suggested that the relatively high basal metabolic rate among
native Siberians is protective against high cholesterol but contributes
to the extremely high blood pressure levels documented among these
populations. Our research is also investigating how the transition away
from a traditional subsistence economy is changing chronic disease
patterns. Specifically, we are examining the role of altered physical
activity patterns and dietary change on obesity, cardiovascular
disease, and type 2 diabetes.
Interviews are used to assess lifestyle and health
Psychosocial
Stress
Chronic psychosocial stress is a known contributor to the risk of negative health outcomes, including infectious disease and the development and progression of cardiovascular disease. Our research uses biomarkers of stress and immune function to understand how stress ‘gets under the skin’ to affect health. In particular, we are investigating how cultural changes in the region influence stress physiology and lead to altered blood pressure regulation and increased cardiovascular disease risk. We have focused on proxy measures of stress, such as Epstein-Barr virus antibodies. Research in 2001 and 2003 used minimally invasive techniques, including the collection of blood spots from finger prick, and later analysis at Northwestern and Harvard Universities. More recently, changes in Russian laws require all biological samples to remain in the country. As a result, all biomarker analyses are now conducted laboratories in Yakutsk (Yakutsk Medical Center) and Novosibirsk (Institute of Soil Science and Agrochemistry).*
Chronic psychosocial stress is a known contributor to the risk of negative health outcomes, including infectious disease and the development and progression of cardiovascular disease. Our research uses biomarkers of stress and immune function to understand how stress ‘gets under the skin’ to affect health. In particular, we are investigating how cultural changes in the region influence stress physiology and lead to altered blood pressure regulation and increased cardiovascular disease risk. We have focused on proxy measures of stress, such as Epstein-Barr virus antibodies. Research in 2001 and 2003 used minimally invasive techniques, including the collection of blood spots from finger prick, and later analysis at Northwestern and Harvard Universities. More recently, changes in Russian laws require all biological samples to remain in the country. As a result, all biomarker analyses are now conducted laboratories in Yakutsk (Yakutsk Medical Center) and Novosibirsk (Institute of Soil Science and Agrochemistry).*
Indigenous
Siberian diets come from a range of market/processed foods, plant and
animal domestication, hunting and gathering.
| Copyright 2009. James Josh Snodgrass. All Rights Reserved. |