Comparison of dietary intake, and continuous blood glucose measurement in nurses working either 12-hour day shifts or night shifts

Abstract: Title: Dietary intake and continuous blood glucose measurement in nurses working either 12-hour day shifts or night shifts Sushana Sudhi, Andrew Browning, Megan Kevil, Teresa Rangel, Rachel Carlson, Lindsey Miller Background: Nursing night shift work is essential in the hospital yet is linked to negative outcomes such as cardiometabolic illnesses including type 2 diabetes. Short-term studies (lasting a few days) of simulated night shift work have identified night-time decreases in insulin sensitivity and glucose tolerance as potential causes of negative cardiometabolic health outcomes. However, the long-term effect of regular night shift work on glucose regulation among nurses remains unknown. Purpose: To determine whether night shift nurses have altered glucose levels and dietary intake compared to day shift nurses. Methods/Approach: Frontline nurses regularly working full time, 12-hour night (n=12) or day shifts (n = 9) for at least three months were recruited from an intensive care unit of a large medical center. During the 6-day study period, all nurses worked the first 3 days, followed by 3 days off. A continuous blood glucose monitor was applied the day before the first on-shift day. Participants reported all food and beverages consumed using the Automated Self-Administered 24-hour dietary assessment tool. Glucose and dietary intakes were averaged to tabulate mean values for 3 conditions: overall, on-shift, and off-shift. Independent t-tests were conducted using SPSS to determine group differences. Results: No significant differences were found between day and night shift for average glucose levels during the 6-day period, during on-shift days, or during off-shift days (p\u3e0.05). Of clinical significance, night shift nurses spent more time with glucose ≥ 140mg/dL (day = 136.2 minutes/day, night = 169 minutes/day) and had higher variability over the 6-day period. No significant differences were detected in dietary intakes, although several clinically significant differences were detected. Night versus day shift nurses reported lower caloric intake while on-shift, (1752.5 vs. 2129.4kcals, p = 0.073) yet more while off-shift (2266 vs. 2021.7kcals, p = 0.421). Sodium intake exceeded recommended daily intake of ≤ 2,300mg per day in both groups yet was highest in night shift (day = 3383.9mg, night = 3796.8mg). Additionally, average fiber intake was lower than recommendations of 25g in both groups (day = 16.2g, night = 17.5g). Conclusion: Results should be interpreted with caution due to the small sample size. However, night shift nurses in our sample consumed less calories while on-shift, more calories while off-shift, and reported more sodium intake than recommended. Additionally, our study indicates that night shift nurses experience greater glucose variability and spend more time in higher glucose ranges compared to day shift nurses. Future work is needed with larger sample sizes to verify findings. Implications for practice: Per our findings, dietary interventions may be needed to decrease sodium and increase fiber intake among nurses to reduce risk for cardiometabolic illnesses. Additionally, despite lower caloric intake when on-shift, night shift nurses spent more time on average than day shift nurses with glucose ≥ 140mg/dL, increasing risk for type 2 diabetes. Nurses, particularly when working night shift, should work closely with medical professionals to monitor diet and blood glucose trends to reduce risk for cardiometabolic illness like type 2 diabetes