Associations of >1-h compared with 1-h meal timing variability (eating jetlag) with plasma glycemic parameters and continuous glucose monitoring measures among pregnant females: a prospective cohort study.

BACKGROUND

Eating jetlag (EJL), the difference in eating times between weekdays and weekends, disrupts circadian alignment and may affect metabolic health. However, its influence on glucose tolerance and continuous glucose monitoring (CGM) during pregnancy remains unknown.

OBJECTIVES

We aimed to investigate the associations between EJL and glycemic parameters during pregnancy.

METHODS

This secondary analysis was conducted on a cohort of 248 healthy pregnant females from Singapore. EJL, derived from 4-d food diaries at 20-wk of gestation, was the absolute difference in average meal times between weekdays and weekends for the first (EJLfirst) and last (EJLlast) meals and categorized as ≤1-h (reference) or >1-h. Primary outcomes at 25-wk of gestation included results from the 75-g oral glucose tolerance test, fasting insulin, homeostasis model assessment of insulin resistance (HOMA2-IR), and β-cell function (HOMA2-%B). Secondary outcomes at 20-wk of gestation included glycemic control and variability measured over 10-d using CGM. Skewed glycemic variables were log-transformed for normality, and associations between EJL and glycemic outcomes were analyzed using multivariable regressions.

RESULTS

After adjusting for baseline sociodemographic, lifestyle, and dietary factors, EJLlast >1-h was associated with higher fasting insulin [geometric mean ratio (95% confidence intervals): 1.21 (1.05, 1.39)], HOMA2-IR [1.21 (1.05, 1.39)], HOMA2-%B [1.11 (1.01, 1.22)], and CGM-based measures, including mean glucose [1.05 (1.00, 1.09)], J-index [1.11 (1.01, 1.22)], and glucose management indicator [1.03 (1.00, 1.06)]. EJLfirst >1-h was associated with higher CGM-based mean amplitude of glycemic excursions (MAGE) [1.09 (1.01, 1.19)]. For CGM-based glycemic variability outcomes (standard deviation, coefficient of variation [CV], MAGE), there were interactions between EJLfirst and 1) diet quality [adherence to Dietary Approaches to Stop Hypertension (DASH)] (P-interactions = 0.06-0.09), and 2) prepregnancy body mass index (BMI) (P-interaction=0.07 for CV). In females with a prepregnancy BMI ≥23 kg/m2 and low diet quality (DASH score ≤median), EJLfirst >1 h was associated with higher CGM-based glycemic variability.

CONCLUSIONS

EJL was associated with unfavorable glycemic parameters during pregnancy. Dietary interventions could promote consistent meal timing, especially in higher risk groups with suboptimal nutritional status. This trial was registered at clinicaltrials.gov as NCT03803345.