Lifestyle mediates seasonal changes in metabolic health among the yakut (sakha) of northeastern siberia.

OBJECTIVES: Among indigenous circumpolar populations, extreme seasonality influences food availability and energy metabolism. Furthermore, subsistence patterns and wage labor opportunities shift with season. Thus, health measures among circumpolar populations likely exhibit seasonal changes that are influenced by lifestyle factors. This study examines how markers of cardio-metabolic health vary between summer and winter as a function of an individual's lifestyle and sex among the Yakut of northeastern Siberia. METHODS: Anthropometric dimensions, serum lipids and glucose levels, blood pressure, and lifestyle data were collected for a sample of 115 Yakut participants (71 women, 44 men) in Berdygestiakh, Sakha Republic, Russia in the summer of 2009 and winter of 2011. RESULTS: Men and women experienced significant increases in total and HDL cholesterol and triglyceride levels from summer to winter. Women exhibited winter-time increases in adiposity and glucose levels. Men who reported greater market integration were more likely to have lower winter blood pressure levels. Additionally, time spent fishing was associated with lower winter-time LDL cholesterol, while foraging time was associated with higher HDL cholesterol. CONCLUSIONS: While seasonal changes in anthropometric dimensions were modest, Yakut men and women experienced significant increases in total cholesterol and HDL cholesterol from summer to winter. These results also suggest that while Yakut individuals with greater subsistence participation are more buffered from adverse seasonal changes in cholesterol levels, they may be at a greater risk for winter increases in blood pressure. Furthermore, the interactions between lifestyle and seasonal change in metabolic health appear to differ between Yakut women and men. Am. J. Hum. Biol. 28:868-878, 2016. © 2016Wiley Periodicals, Inc.

Adiponectin, hemoglobin, and cardiovascular risk in an indigenous siberian population.

OBJECTIVES: Adipose tissue hypoxia appears to play a role in promoting chronic inflammation and the development of obesity-related cardiovascular and metabolic diseases, yet the underlying mechanisms are not well understood. The aim of the present research is to examine whether adiponectin levels (an adipocyte-derived hormone with anti-inflammatory properties) are inversely correlated with hemoglobin levels in an indigenous Siberian population. METHODS: The study was conducted among 252 Yakut adults (≥18 years; 135 females) from Berdygestiakh, Sakha Republic, Russia. Measurements included anthropometric dimensions (body mass index [BMI], waist circumference [WC], and percent body fat) and blood levels of hemoglobin and adiponectin. RESULTS: Yakut females had higher adiponectin concentrations than males (15.1 ± 9.8 vs. 11.7 ± 10.6 µg/ml; P < 0.001), whereas males had higher hemoglobin levels (14.4 ± 1.4 vs. 12.6 ± 1.5 g/dL; P < 0.001). Body composition measures in both sexes were negatively associated with adiponectin and positively associated with hemoglobin. After adjusting for central adiposity and smoking, adiponectin levels were negatively correlated with hemoglobin levels in men (P < 0.05), but not in women (P = 0.511). CONCLUSIONS: This investigation provides some support for the involvement of hypoxia-related dysregulation of adiponectin associated with obesity and potentially cardiovascular disease. Am. J. Hum. Biol. 28:580-583, 2016. © 2015 Wiley Periodicals, Inc.