Seasonal variation in basal metabolic rates among the yakut (Sakha) of Northeastern Siberia
Article first published online: 20 FEB 2014
Copyright © 2014 Wiley Periodicals, Inc.
American Journal of Human Biology
Volume 26, Issue 4, pages 437–445, July/August 2014
How to Cite
Leonard, W.R., Levy, S.B., Tarskaia, L.A., Klimova, T.M., Fedorova, V.I., Baltakhinova, M.E., Krivoshapkin, V.G. and Snodgrass, J.J. (2014), Seasonal variation in basal metabolic rates among the yakut (Sakha) of Northeastern Siberia. Am. J. Hum. Biol., 26: 437–445. doi: 10.1002/ajhb.22524
- Issue published online: 4 JUN 2014
- Article first published online: 20 FEB 2014
- Manuscript Accepted: 26 JAN 2014
- Manuscript Revised: 25 JAN 2014
- Manuscript Received: 26 DEC 2013
- National Science Foundation. Grant Number: ARC-0802390
- Northwestern University, University of Oregon, and The Ministry of Education and Science of Russia
Objectives: Previous research has shown that indigenous circumpolar populations have elevated basal metabolic rates (BMRs), yet few studies have explored whether metabolic rates increase during the winter. This study addresses this gap by examining seasonal variation in BMR and its associations with thyroid function and lifestyle factors among the Yakut (Sakha) of Siberia.
Methods: Anthropometric dimensions, BMR, and thyroid hormone levels (free triiodothyronine [fT3], free thyroxine [fT4], thyroid-stimulating hormone [TSH]) were measured on two occasions (July/August, 2009 and January 2011) on a sample of 94 Yakut (Sakha) adults (35 men, 59 women) from the rural village of Berdygestiakh, Sakha Republic, Russia.
Results: Seasonal changes in BMR varied by age. Younger Yakut adults (19–49 years) showed significant elevations in winter-time BMR of 6% (P < 0.05), whereas older individuals (≥50 years) showed modest declines (2%; n.s.). Both younger and older Yakut men and women showed increased respiratory quotients during the winter. FT3 and fT4 levels significantly declined during the winter in both younger and older Yakut men and women (P < 0.05). Lifestyle factors were significant predictors of BMR variation, particularly among older men and women.
Conclusions: Among the Yakut, increased wintertime BMR was observed among younger but not older adults, whereas all adults showed sharp reductions in free thyroid hormone levels during the winter. Among men, greater participation in subsistence activities was associated with increased BMRs and greater fat oxidation. Among women, variation in food use had the strongest impact on metabolic function. Am. J. Hum. Biol. 26:437–445, 2014. © 2014 Wiley Periodicals, Inc.