# Exosomal miR-92a Concentration in the Serum of Shift Workers
## 3 Results  
All the workers who participated in the study were females. No significant differences were found in age, job seniority, numbers of smokers, or of alcohol drinkers between DT and SW nurses (Table 1). None of the SW nurses had changed the type of schedule from the beginning of the work as evidenced by the same values of job seniority and shift work seniority. SW nurses worked a median of 6.0 nights per month. No significant difference was found in chronotype (MEQ score), sleep quality (PSQI score), and daytime sleepiness (ESS score) between DT and SW nurses. There were no significant differences in metabolic parameters between DT and SW nurses (Table 2). DT nurses showed a higher median value of total cholesterol, but the difference was not significant. Other blood parameters, systolic/diastolic pressure, BMI, waist circumference, skin thickness, and body fat were also similar in the two groups. \begin{table}
\begin{tabular}{l c c} \hline \hline  & **DT Nurses** & **SW Nurses** \\ \hline Age (years): & 39.0 (37.0–41.5) & 39.0 (35.5–40.5) \\ Median (25 th–75 th percentile) & 14.0 (11.0–18.3) & 13.0 (10.5–16.5) \\ \hline Shift work seniority (years): & - & 13.0 (10.5–16.5) \\ Median (25 th–75 th percentile) & & \\ \hline Night worked per month: & - & 6.0 (5.3–6.0) \\ Median (25 th–75 th percentile) & & \\ \hline Smokers (\%) & 40.0 & 40.0 \\ \hline Alcohol drinkers (\%) & 33.3 & 40.0 \\ \hline Subjects taking physical exercise (\%) & 46.7 & 60.0 \\ \hline Coffee consumption (cups/day): Median (25 th–75 th percentile) & 2.0 (1.0–3.0) & 2.0 (1.5–3.0) \\ \hline Chronotype (MEQ score): & 57.5 (52.5–64.0) & 57.0 (51.3–62.0) \\ Median (25 th–75 th percentile) & & \\ \hline Sleep quality (PSQI score): & 6.0 (3.0–8.0) & 4.0 (2.5–6.5) \\ Median (25 th–75 th percentile) & 4.0 (2.3–8.8) & 5.0 (4.0–9.3) \\ \hline Daytime sleepiness (ESS score): Median (25 th–75 th percentile) & 4.0 (2.3–8.8) & 5.0 (4.0–9.3) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Socio-demographic characteristics of daytime (DT) and shift-working (SW) nurses. MEQ: Morningness–Eveningness Questionnaire; PSQI: Pittsburgh Sleep Quality Index; ESS: Epworth Sleepiness Scale. Data about total energy intake, diet composition, and total energy expenditure were similar in the two groups (Table 3). The statistical analysis did not show significant differences. Levels of miR-92a in serum exosomes are reported in Figure 1. We found significantly higher levels of miR-92a in DT nurses than in SW nurses [median 14.2 versus 4.3 (\(2^{-\Delta\text{CI}}/10^{3}\)), \(p=0.002\)]. Since miR-92a in serum exosomes inversely correlate with BAT activity, results were indicative of a lower BAT activity in DT nurses compared with SW nurses. \begin{table}
\begin{tabular}{l c c} \hline  & **DT Nurses** & **SW Nurses** \\ \hline Fasting glycemia (mg/dL) & 89.5 (86.3–96.3) & 83.0 (78.3–91.0) \\ \hline Total cholesterol (mg/dL) & 206.5 (158.8–225.5) & 186.0 (159.5–196.3) \\ \hline HDL cholesterol (mg/mL) & 52.5 (40.8–61.5) & 49.0 (41.0–57.5) \\ \hline Triglierides (mg/mL) & 70.0 (51.5–106.3) & 67.5 (55.5–114.5) \\ \hline Systolic pressure (mmHg) & 110.0 (105.0–120.0) & 110 (110–117.5) \\ \hline Diastolic pressure (mmHg) & 70.0 (60.0–80.0) & 70.0 (65.0–72.5) \\ \hline BMI (Kg/m\({}^{2}\)) & 23.6 (21.1–25.7) & 22.5 (21.2–29.7) \\ \hline Waist circumference (cm) & 90.0 (83.3–99.0) & 87.0 (81.0–103.0) \\ \hline \multirow{4}{*}{Skin thickness} & Biceps & 11.2 (6.7–11.8) & 11.2 (8.2–15.2) \\  & Triceps & 21.2 (17.2–28.0) & 22.2 (20.0–28.8) \\ \cline{1-1}  & Subscapular & 23.0 (17.5–27.8) & 18.8 (13.4–38.4) \\ \cline{1-1}  & Suprailiac & 31.2 (22.4–33.7) & 24.0 (18.4–35.8) \\ \hline Body fat (\%) & & 37.5 (34.1–41.9) & 35.9 (32.1–40.1) \\ \hline \end{tabular}
\end{table} 
Table 2: Metabolic characteristics of daytime (DT) and shift-working (SW) nurses. Results are expressed as median (25 th–75 th percentile). Figure 1: Box plot of levels of miR-92a in serum exosomes of daytime (DT) and shift-working (SW) nurses. * \(p<0.05\), Mann-Whitney U test.