Oral Presentation ESA-SRB-ANZBMS 2024 in conjunction with ENSA

Reduced brown adipose tissue activity coincides with propensity to gain weight and impaired glucose metabolism in women across the menopausal transition (#109)

Anne Nicole De Jesus 1 , Michael A. Cowley 1 , Anju Joham 2 , Samantha Hutchison 2 , Amanda Vincent 2 , Belinda A. Henry 1
  1. Monash Biomedicine Discovery Institute, Department of Physiology, Monash University, Clayton, Victoria, Australia
  2. Monash Centre for Health Research and Implementation, Clayton, Victoria, Australia

Women experience fluctuations in glucose tolerance and altered weight regulation across the menstrual cycle. Moreover, at mid-life, the menopausal transition leads to increased weight gain and elevated risk of cardiometabolic disease. The physiological factors that underpin these fundamental changes in metabolic health remain unknown. Recent work shows that functional brown adipose tissue (BAT) is associated with reduced risk of weight gain and type 2 diabetes. We aimed to determine whether: 1.) BAT activity fluctuated across the menstrual cycle and 2.) BAT function changed in peri- and post-menopausal women.

Pre- (ages 18-39y/o), peri- (ages 40-49y/o), and post-menopausal (ages 50-60y/o) women were recruited (n=9-12/group). Studies were performed during the follicular (days 9-12) and luteal phases (days 18-24) of the menstrual cycle in pre-menopausal women. In fasted participants, resting energy expenditure and body composition were measured. Infrared thermography was used to measure cutaneous supraclavicular temperature as an index of BAT activity in response to cold exposure (15oC) and during an oral glucose tolerance test (oGTT). Transcutaneous glucose levels were measured using continuous glucose monitors and basal concentrations of 17β-estradiol, progesterone and insulin were assessed.

In pre-menopausal women, BAT activation was lower in the luteal phase than the follicular phase. This coincided with relative glucose intolerance. Furthermore, BAT temperature was significantly lower in both peri- and post-menopausal women compared to pre-menopausal women; surprisingly this effect was greater in the peri-menopausal group. Reduced BAT temperature in peri-menopausal women coincided with decreased glucose tolerance. Changes in BAT activity were independent of age, body weight and adiposity.

Our data suggests that reduced BAT activity may be an important determinant of weight gain and metabolic health in women across the menopausal transition. Further work will delineate the mechanisms that underpin altered BAT function in women across various stages of reproductive life.