(P13-006-24) Impact of Diet Composition and Quality on Continuous Glucose Monitor-Derived Measures of Glycemic Variability in Free-Living Adults

Objectives: Continuous Glucose Monitors (CGMs) offer a detailed assessment of dynamic glucose fluctuations. However, the impact of diet composition and quality on CGM-derived glycemic traits among free-living individuals without diabetes remains unclear. We evaluated the association of macronutrient intake and diet quality indices with CGM-derived glycemic variability in individuals without diabetes.

Methods: Participants from the Framingham Heart Study Third Generation Cohort, free of diabetes (HbA1c < 6.5%, fasting glucose < 126mg/dL, no glucose-lowering medication) with ≥3 days of Dexcom G6 Pro CGM data and ≥2 days of dietary records, were included in this analysis. CGM-derived metrics, including mean glucose, continuous overall net glycemic action (CONGA), mean of daily differences (MODD), and mean amplitude of glycemic excursions (MAGE) were calculated using the “cgmanalysis” R package. Multivariable linear regression models were used to assess the association between macronutrient composition (% energy intake (EI)) and diet quality with CGM measures, adjusting for age, sex, race, energy intake, smoking, alcohol, medication use, average daily steps, and body mass index.

Results: We included data from 682 participants (59.2% female, mean age 60.3y, 56% normoglycemic).  In multivariable-adjusted models, higher %EI from carbohydrate was positively associated with CGM metrics (per 5% change: mean glucose: Beta±SE=0.63±0.28, p=0.024; CONGA: 0.44 ± 0.10,p < 0.001; MAGE:  0.52 ± 0.22,p=0.026). In contrast, a higher %EI from protein was associated with lower CONGA, MODD, and MAGE; and a higher %EI from fat was only associated with lower CONGA. Furthermore, greater adherence to the alternative healthy eating index [AHEI] was associated with better CGM metrics (per 5-unit increase in AHEI: mean glucose: -0.41 ± 0.18, p=0.023, CONGA: -0.23 ± 0.07, p=0.001, MODD:-0.21 ± 0.06, p < 0.001, MAGE: -0.47 ± 0.16, p < 0.001).

Conclusions: Higher %EI from carbohydrates and lower diet quality was associated with higher mean CGM glucose and overall poorer glycemic control. Future investigations should explore the interactions between diet quality, other lifestyle factors, and glycemic traits.

Funding Sources: NHLBI, NIDDK