Interstitial glucose and subsequent affective and physical feeling states: A pilot study combining continuous glucose monitoring and ecological momentary assessment in adolescents

Objective: Circulating glucose may relate to affective and physical feeling states reflective of emotional disorder symptoms. No prior studies have investigated within-day associations between glucose and subsequent affective and physical feeling states (positive affect, negative affect, and fatigue) as they occur naturally among healthy adolescents; this pilot study assessed these associations by combining data collected from ecological momentary assessment (EMA) and continuous glucose monitors (CGM). Methods: Participants (N = 15, mean age = 13.1[+/- 1.0] years, 66.7% female, 40.0% Hispanic, 66.7% healthy weight) wore a CGM for 7-14 days. Simultaneously, participants reported on their current positive affect, negative affect, and fatigue randomly during specified windows up to 7 times daily via EMA. CGM-measured mean interstitial glucose was calculated during the time windows (mean minutes = 122.5[+/- 47.3]) leading up to each EMA prompt. Multilevel models assessed within-subject (WS) associations between mean interstitial glucose since the previous EMA prompt and EMA-reported affective and physical feeling states at the current prompt. Results: Participants provided 532 interstitial glucose-matched EMA reports of affective and physical feeling states. During intervals when interstitial glucose was higher than one's usual, higher positive affect (WS beta = 0.01, p < .0001, f(2) = 0.02) and lower fatigue (WS beta = -0.01, p < .0001, f(2) = 0.09) were subsequently reported. Interstitial glucose was unrelated to negative affect (WS beta = -0.002, p = .10, f(2) = 0.01). Associations were weakened, but remained significant following further adjustment for time of day. Conclusions: Though effect sizes were small, within-person variations in interstitial glucose may relate to subsequent affective and physical feeling states among healthy youth. Investigations using similar methodologies in larger, more diverse samples are warranted.