(P08-021-23) Taste Sensitivity to a Caloric Sweetener Varies With Menstrual Cycle Hormones

Objectives:

Background: The human sweet taste receptor, T1R2/T1R3, found within taste buds is prevalent in all metabolic organs and is believed to play a functional role in sensing sugars and maintaining blood glucose homeostasis. Nutritive sugars such as glucose are also sensed in the mouth via the oral metabolic signaling pathway, which involves the sodium-glucose cotransporter (SGLT1) and ATP-sensitive potassium channel (K_ATP). Prior in vitro studies showed that 17-β-estradiol is a positive modifier for the K_ATP channel in pancreatic beta islet cells. Studies also show that many ovulating females experience gustatory and food habit changes throughout the menstrual cycle, which is associated with fluctuations of estrogens.

Hypothesis: We hypothesize that oral glucose detection thresholds in humans will decrease as a function of increasing 17-β-estradiol (ovulation), but sucralose (the non-caloric sweetener) thresholds will not.

Methods: Oral glucose and sucralose detection thresholds in eumenorrheic humans (n=10) were collected during menstruation and ovulation using a modified staircase method and compared to non-ovulating humans (n= 6).  Luteinizing hormone (LH), estrone-glucuronide-3 (E3G) [estrogen metabolite], and pregnanediol (PdG) [progesterone metabolite] were measured in urine during the follicular phase using a digital fertility device, Mira. Ovulation was additionally confirmed with LH Modern Fertility strips. Liking ratings of 450 and 900 mM glucose solutions were also measured on a labeled hedonic scale.

Results: Oral glucose detection thresholds showed a downward trend (increased sensitivity) during ovulation (elevated estrogen) compared to menstruation.  Sucralose detection thresholds, however, did not change.

Conclusions: Individual participants showed a large reliable decrease in detection threshold changes, whereas others did not. Individual variation of the magnitude of change in estrogen during the follicular phase is related to oral glucose sensitivity changes. Hormone fluctuation during the menstrual cycle influences oral glucose but not sucralose detection, which implicates the K_ATP channel and may impact insulin release, food preference, and gustation.

Funding Sources: NIH R21 and Busch Biomedical Grant to PASB