Abstract:
Background and aim: Recently Brown Adipose Tissue (BAT), a type of fat that functions to burn energy as heat, has emerged as a novel anti-obesity target due to its highly thermogenic capability that contributes to energy expenditure. This heat production can be measured by infrared thermography of the temperature of skin in the supraclavicular area overlying the most metabolically active brown fat depot. Current evidence suggests both age and adiposity have an affect on brown fat activity. The central aim was to assess the influence of age on supraclavicular skin temperature and energy expenditure in a New Zealand context, with a secondary aim of investigating the relationship with body composition. Supraclavicular skin temperature and energy expenditure were used as indicators for brown adipose tissue activity. Method: 37 females took party in the study: 17 children (aged 11-15), 10 young adults (aged 23-25) and 10 old adults (aged 52-66). Participants underwent infrared thermography imaging of supraclavicular skin temperature at baseline and in response to cool stimulus (submersion of hand in water cooled to 16°C). Measurement of resting energy expenditure (REE) in fasted participants was collected over a baseline period and with submersion of feet into water cooled to 16°C. Body composition analysis was completed using Dual X-ray Absorptiometry. The effect of age and body composition on the response of supraclavicular skin temperature and energy expenditure in response to cooling was then explored. Results: Age-related trends in supraclavicular temperature were observed between children and old adults, however these findings were not significant. Application of cold stimulus increased energy expenditure in all age groups, with children showing higher energy expenditure than adults; but did not elicit change in supraclavicular skin temperature for any age group. No relationship between body fat content and cold-induced response of supraclavicular skin temperature and energy expenditure was found.
