Title: Positive association of nap duration with risk of non-alcoholic fatty liver disease in an
occupational population in Guangdong Province, China: A cross-sectional study
Version: 1 Date: 08 Jan 2022
Reviewer's report:
Chang Hong et al. performed a cross-sectional study to investigate association of nap duration
with risk of non-alcoholic fatty liver disease in an occupational population in China. This study
encompasses an interesting finding, but it also includes some methodological problems.
Major comments
1. Authors categorized daytime napping duration as none, <30 min, 30–60 min, and #60 min
per day. Other studies use different categories, for example none, #1 h, and >1 h per day. The
reason to choose that category is not unclear.
2. In this study the definition of daytime napping is not written, for example every day, several
times in a week, and so on. It should be showed How did they ask a question about it.
3. The authors assessed exercise habits but not dietary habits. This is a limitation of this study.
4. Authors explain the relationship between daytime napping duration and the risk of NAFLD,
long daytime napping duration could elevate the level of cortisol in the blood. In general, daytime
napping around 60 minutes could reduce the level of cortisol in the blood. They should show
the reason to consider like that.
5. Supplemental Table 1 shows that lower BMI (<18) is associated with risk of NAFLED.
Authors should explain the reason of the result.
Minor comments
1. In Table 1, there is a spelling mistake. Daytime dapping duration#Daytime napping duration
2. In the abstract, the age of participants is 30–79 years, but in the text that is 25–50 years. They
should unify it in either.
Title: Positive association of nap duration with risk of non-alcoholic fatty liver disease in an
occupational population in Guangdong Province, China: A cross-sectional study
Version: 1 Date: 08 Jan 2022
Reviewer's report:
Chang Hong et al. performed a cross-sectional study to investigate association of nap duration
with risk of non-alcoholic fatty liver disease in an occupational population in China. This study
encompasses an interesting finding, but it also includes some methodological problems.
Major comments
1. Authors categorized daytime napping duration as none, <30 min, 30–60 min, and #60 min
per day. Other studies use different categories, for example none, #1 h, and >1 h per day. The
reason to choose that category is not unclear.
2. In this study the definition of daytime napping is not written, for example every day, several
times in a week, and so on. It should be showed How did they ask a question about it.
3. The authors assessed exercise habits but not dietary habits. This is a limitation of this study.
4. Authors explain the relationship between daytime napping duration and the risk of NAFLD,
long daytime napping duration could elevate the level of cortisol in the blood. In general, daytime
napping around 60 minutes could reduce the level of cortisol in the blood. They should show
the reason to consider like that.
5. Supplemental Table 1 shows that lower BMI (<18) is associated with risk of NAFLED.
Authors should explain the reason of the result.
Minor comments
1. In Table 1, there is a spelling mistake. Daytime dapping duration#Daytime napping duration
2. In the abstract, the age of participants is 30–79 years, but in the text that is 25–50 years. They
should unify it in either.
Please review this paper.
user
Title: Positive association of nap duration with risk of non-alcoholic fatty liver disease in an
occupational population in Guangdong Province, China: A cross-sectional study
Version: 1 Date: 08 Jan 2022
Reviewer's report:
Chang Hong et al. performed a cross-sectional study to investigate association of nap duration
with risk of non-alcoholic fatty liver disease in an occupational population in China. This study
encompasses an interesting finding, but it also includes some methodological problems.
Major comments
1. Authors categorized daytime napping duration as none, <30 min, 30–60 min, and #60 min
per day. Other studies use different categories, for example none, #1 h, and >1 h per day. The
reason to choose that category is not unclear.
2. In this study the definition of daytime napping is not written, for example every day, several
times in a week, and so on. It should be showed How did they ask a question about it.
3. The authors assessed exercise habits but not dietary habits. This is a limitation of this study.
4. Authors explain the relationship between daytime napping duration and the risk of NAFLD,
long daytime napping duration could elevate the level of cortisol in the blood. In general, daytime
napping around 60 minutes could reduce the level of cortisol in the blood. They should show
the reason to consider like that.
5. Supplemental Table 1 shows that lower BMI (<18) is associated with risk of NAFLED.
Authors should explain the reason of the result.
Minor comments
1. In Table 1, there is a spelling mistake. Daytime dapping duration#Daytime napping duration
2. In the abstract, the age of participants is 30–79 years, but in the text that is 25–50 years. They
should unify it in either.
assistant