Blood glucose variance measured by continuous glucose monitors across the menstrual cycle

Abstract

Past studies on how blood glucose levels vary across the menstrual cycle have largely shown inconsistent results based on limited blood draws. In this study, 49 individuals wore a Dexcom G6 continuous glucose monitor and a Fitbit Sense smartwatch while measuring their menstrual hormones and self-reporting characteristics of their menstrual cycles daily. The average duration of participation was 79.3 ± 21.2 days, leading to a total of 149 cycles and 554 phases in our dataset. We use periodic restricted cubic splines to evaluate the relationship between blood glucose and the menstrual cycle, after which we assess phase-based changes in daily median glucose level and associated physiological parameters using mixed-effects models. Results indicate that daily median glucose levels increase and decrease in a biphasic pattern, with maximum levels occurring during the luteal phase and minimum levels occurring during the late-follicular phase. These trends are robust to adjustments for participant characteristics (e.g., age, BMI, weight) and self-reported menstrual experiences (e.g., food cravings, bloating, fatigue). We identify negative associations between each of daily estrogen level, step count, and low degrees of fatigue with higher median glucose levels. Conversely, we find positive associations between higher food cravings and higher median glucose levels. This study suggests that blood glucose could be an important parameter for understanding menstrual health, prompting further investigation into how the menstrual cycle influences glucose fluctuation.

Impact of Physiological Fluctuations of Sex Hormones During the Menstrual Cycle on Glucose Metabolism and the Gut Microbiota

“…Lin et al addressed the issue of limited blood sampling time points by analyzing glucose variance in the course of the menstrual cycle using continuous glucose measurement. While not performing an OGTT, their results support the findings of Jarrett and Graver, Peppler et al, and Brennan et al, as they found that glucose values were the lowest during late FP, increased during ovulation, and peaked in the LP phase 75 .…”

Case report: catamenial hyperglycemia: the trigger of recurrent DKA in a female patient with three-year follow-up

“…The precise mechanism behind catamenial hyperglycemia remains uncertain, but it is likely associated with decreased insulin sensitivity caused by elevated levels of circulating progesterone. Basic research in rats has indicated that progesterone can reduce glucose uptake in skeletal and adipose tissues ( 17 ). According to the findings of Cawood et al., approximately 67% of women with diabetes encountered fluctuations in their blood glucose levels during the premenstrual period ( 18 ).…”

In vivo techniques for assessment of insulin sensitivity and glucose metabolism

“…While the menstrual cycle lasts ~28 days, the estrous cycle is shorter, lasting 4–5 days ( Ajayi & Akhigbe 2020 , Gutierrez-Castellanos et al 2022 ). Blood glucose concentrations have been found to change throughout the menstrual cycle ( Lin et al 2023 ). It could be argued that the estrous cycle increases variance of metabolic studies; therefore, data from female rodents should be presented by estrous phase ( Della Torre et al 2016 ).…”