Glycemic Fluctuations in Healthy Pediatric Residents During 24-Hr Emergency Shifts: A Hidden Metabolic Risk for Health Care Workers

The metabolic effect of prolonged shift work (increased risk for insulin resistance, hypertension, dyslipidemia, obesity) among several occupations, including health care workers, has been highlighted in several studies and metanalyses.^1-4 In this context, we conducted a prospective cohort study from February to May of 2024 to assess glycemic fluctuations, as recorded with continuous glucose monitoring systems (CGMS), in young and healthy pediatric residents working in a tertiary hospital, during various duty conditions.

Thirteen residents (84.6% female) wore CGM sensors (Dexcom One and Freestyle Libre 1) across 35 days of 24-hour Emergency Department (ED) duty, 35 days “after” ED duty, and 114 regular 8-hour working days. A total of 23 975 glucose measurements were analyzed. Notably, mean glucose values were significantly higher during 24-hour ED shifts compared to post-duty and regular days (99.69 vs 97.67 and 97.14 mg/dL, respectively; P < .001). Time in normoglycemia (70-140 mg/dL) significantly declined during ED duty shifts, accompanied by increased time above 140 mg/dL, suggesting acute dysglycemia even in healthy individuals (Fig. 1). Glucose variability (CV) was also elevated (20.37% vs 17.49% on regular days). During night hours (00:00-06:00), glucose levels remained higher on ED duty nights (99.53 mg/dL), reflecting possible circadian rhythm disruption. Interestingly, male residents demonstrated higher glucose values than females during ED duties (101.22 vs 99.17 mg/dL, P = .006), a difference reversing on regular days.

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Figure 1.

Significantly lower time in normoglycemia (TING, 70-140 mg/dl) and higher time in the interval 141 to 180 mg/dl on 24 h during ED duty shifts compared to 24 h “after” and 24 h “away” from ED duty shifts, in total (P < .001).

Our findings during regular working days align with the multicenter CGM study by Shah et al, ⁵ who reported a 96% time in normoglycemia in healthy adults. However, in our cohort, time in normoglycemia fell to 92.37% during ED shifts, indicating their metabolic burden on residents. Spartano et al, ⁶ using CGM in a larger community sample, noted an impressive percentage of 12.1% above 140 mg/dl among nondiabetic individuals. While Spartano’s cohort was relatively older and more heterogeneous in terms of weight, our young, healthy, normal-body mass index (BMI) physicians still showed acute metabolic alterations.

Overall, prolonged and irregular shift work in medical trainees induces transient dysglycemia, likely mediated by circadian misalignment, poor sleep, irregular meals, and psychological stress. These effects may accumulate over time, potentially predisposing even healthy individuals to metabolic disorders.

We suggest that continuous glucose monitoring could be a valuable research tool in terms of occupational and preventive medicine, especially among high-risk groups such as health care workers. Our preliminary data could be a stimulus for further larger studies, and a basis for discussion among institutions and policymakers about regulatory interventions, including shift duration limits, structured rest, and access to healthy meals during overnight shifts, to minimize preventable metabolic harm. Medical training must prioritize not only patient safety but also physician well-being.