The Relationship between Physical Activity and Depressive Symptoms in Middle-Aged and Elderly People Controlling for Demographic and Health Status Variables
Round 1
Reviewer 1 Report
Dear Authors,
To improve the quality of the paper, I would suggest following issues.
1) Please clarify the aim of the study in Introduction. Based on the introduction, it is not fully understandable what is really the purpose of the study.
2) Please add some data from global problems with aging in Introduction. As I see, only data from China is there.
3) Please mention the number of participants in the Method.
4) What about the reliability and validity of the physical activity questionnaire?
5) Results are really interesting.
6) In first sentence of Discussion, you do not need to mention again the statistical test used in the study. Otherwise, you could talk about the aim of this study and tell us about the most important findings.
7) Lack of using accelerometer for measuring physical activity could be another important limitation to this study.
Good luck
Author Response
Response to Reviewer 1 Comments
We feel great thanks for your professional review work on our article. As you are concerned, there are several problems that need to be addressed. According to your nice suggestions, we have made extensive corrections to our previous draft, the detailed corrections are listed below. Our response is given in normal font and changes/additions to the manuscript are given in the red text.
Comment 1. Please clarify the aim of the study in Introduction. Based on the introduction, it is not fully understandable what is really the purpose of the study.
Response: We sincerely thank you for your valuable comments. We have added the research purpose of this study to the introduction. The purpose of my addition is already indicated in red in the introduction.
The contents I added are as follows:
and to provide new evidence for the prevention and treatment of depression by physical activity.
Comment 2. Please add some data from global problems with aging in Introduction. As I see, only data from China is there.
Response: We sincerely thank you for your valuable comments. We have added the aging problem in Japan and Germany to the introduction.
The contents I added are as follows:
Japan has entered a hyper-aged culture and is one of the nations with the greatest rates of population aging in the world, with 27% of the population being over 65 [1]. Germany's population is one of the oldest in Europe with a proportion of 21.12% [2].
Comment 3. Please mention the number of participants in the Method.
Response: We sincerely thank you for your valuable comments. We have added the number of people included in this study to the method.
The contents I added are as follows:
A total of 6,128 respondents were included in this study.
Comment 4. What about the reliability and validity of the physical activity questionnaire?
Response: We sincerely thank you for your valuable comments. We added a description of the reliability and validity of IPAQ in the method.
The contents I added are as follows:
and IPAQ has good reliability and validity[20].
Comment 5. Results are really interesting.
Response: We appreciate your liking of the results.
Comment 6. In first sentence of Discussion, you do not need to mention again the statistical test used in the study. Otherwise, you could talk about the aim of this study and tell us about the most important findings.
Response: We appreciate your comments, and we have made changes according to your comments. We deleted the statistical tests and discussed the most important findings of this study.
The contents I revised are as follows:
This study demonstrated a negative correlation between depression symptoms and physical activity levels in middle-aged and elderly people. After adjusting the demographic characteristics (registered residence type, education level, gender, age, widows) and health status characteristics (diabetes, disability, self-rated health status, hypertension, stroke, hyperlipidemia, arthritis, walking 1 km), this negative correlation still exists. This shows that high physical activity can reduce the risk of depressive symptoms in middle-aged and elderly people.
Comment 7. Lack of using accelerometer for measuring physical activity could be another important limitation to this study.
Response: We think this is an excellent comments. We have added your comments to the fourth part of the limitation.
The contents I added are as follows:
Fourth, the lack of use of accelerometry to measure physical activity and the lack of a moderate intensity physical activity group are two other important limitations of this study. The use of accelerometers to measure physical activity in middle-aged and older adults is more accurate; The lack of a moderate physical activity group would lead to chance that there is a boundary in the assessment of the high-intensity physical activity group versus the low physical activity group.
We tried our best to improve the manuscript and made some changes marked in red in revised paper which will not influence the content and framework of the paper. We appreciate for your warm work earnestly, and hope the correction will meet with approval. Once again, thank you very much for your comments and suggestions.
Reviewer 2 Report
author did good attempt need some minor correction before publication.
1. author should add methodology figure
2. author should add some more description in results section
3. what is novelty of method used in this study?
4. author should add some latest article
5. conclusion section should be revised via adding some numeric data
Author Response
We feel great thanks for your professional review work on our article. As you are concerned, there are several problems that need to be addressed. According to your nice suggestions, we have made extensive corrections to our previous draft, the detailed corrections are listed below. Our response is given in normal font and changes/additions to the manuscript are given in the red text.
Comment 1. author should add methodology figure
Response: We appreciate your comments very much. The methodology figure is shown in Figure 1. Figure 1 shows how to filter participants, finally, 6128 participants were included in the study. The research methods are described in detail in the method section.
Comment 2. author should add some more description in results section
Response: We think this is an excellent comments. We have added more descriptions in the results section according to your comments.
The contents I added are as follows:
In terms of chronic diseases, 11.9% of participants had hypertension and 88.1% of participants did not; 12.6% had hyperlipidemia, and 87.4% of the participants did not have hyperlipidemia; 6.6% of participants had diabetes and 93.4% did not; 6.2% of participants had a stroke, and none of the participants had a stroke; 1.8% of participants had asthma and none of the participants had asthma; Arthritis was present in 7.1% of participants and absent in 92.9% of participants. 26.1% of the participants had a smoking habit and 73.9% did not; 79.8% were able to walk one kilometer and 20.2% of participants could not walk one kilometer.
Comment 3. what is novelty of method used in this study?
Response: Thank you for your question. The novelty of the research method of this study In terms of statistical methods, hierarchical linear regression was used to analyze the relationship between physical activity and depressive symptoms after adjusting demographic characteristics and health status. We think this is the novelty of the research method of this study.
Comment 4. author should add some latest article
Response: We sincerely appreciate the valuable comments. We have added some latest articles, which are references [1], [2], [8], [36].
[1]Bessho Shun-ichiro. Local fiscal multipliers and population aging in Japan. Japan & The World Economy,2021,60,101099.
[2]Vanella Patrizio,Wilke Christina Benita,Söhnlein Doris. Prevalence and Economic Costs of Absenteeism in an Aging Population—A Quasi-Stochastic Projection for Germany. Forecasting,2022, 4(1), 371-393.
[8]Ismail Z, Elbayoumi H, Fischer CE, et al. Prevalence of Depression in Patients With Mild Cognitive Impairment A Systematic Review and Meta-analysis. JAMA psychiatry. 2017(1):74.
[36] Ma C, Zhou W, Jia Y, et al. Effects of home-based Baduanjin combined with elastic band exercise in patients with chronic heart failure. European Journal of Cardiovascular Nursing, 2022(6):6.
Comment 5. conclusion section should be revised via adding some numeric data
Response: We sincerely appreciate the valuable comments. We have added some numerical data to the conclusion to support the conclusion of this study.
The contents I added are as follows:
In this study, the middle-aged and elderly people with high physical activity have a lower risk of depression. Compared with middle-aged and elderly women, middle-aged and elderly men are more likely to suffer from depression OR=1.757(95%CI=1.552-1.990). With the increase of age, the risk of depression in middle-aged and elderly people decreased OR=0.675(95%CI=0.633-0.720). Middle-aged and elderly people with worse self-rated health status have higher risk of depression OR=0.801(95%CI=0.695-0.923). Middle-aged and elderly people with disability OR=1.957(95%CI=1.408-2.719), hypertension OR=1.216(95%CI=1.079-1.380) and arthritis OR=1.681(95%CI=1.539-1.861) are prone to depression symptoms.
We tried our best to improve the manuscript and made some changes marked in red in revised paper which will not influence the content and framework of the paper. We appreciate for your warm work earnestly, and hope the correction will meet with approval. Once again, thank you very much for your comments and suggestions.
Reviewer 3 Report
In the present article authors aimed to explore the relationship between physical activity (PA) intensity and depressive symptoms in Chinese middle-aged and elderly people, in order to provide new evidence for the prevention and treatment of depression by physical activity.
The article is easy to follow and to understand but there are there are several things that call my attention since I do not see them completely correct.
In order to make the article more complete, some comments have to be made to the authors.
- In the abstract the objectives are not the same as in the text, and due to that fact the conclusions do not answer to those objectives. Please correct it.
- Please improve a little bit the introduction, specially the second half in which you talk about different articles. It seems to be more a discussion than an introduction.
- In the methods section (Physical activities) you mention that “the number of days and the duration of daily activities of the participants for each physical activity for at least 10 minutes were evaluated”. Why did the authors evaluate only physical activities above 10 minutes? There is clear evidence for the benefits of physical activity below that amount of time and that the sum of small periods of exercise leads to the same benefits.
- In the same paragraph if you evaluate activities above 10 minutes you should clarify that the first classification for duration of each physical activity should be “>10 minutes to < 0.5h”.
- In the same paragraph you say “According to the International Physical Activity Scale” and it is Physical Activity Questionnaire, please correct that.
- I do not understand why did you calculate the weekly physical activity using one formula with the metabolic equivalent. The IPAQ is used just to obtain that information about weekly amount of PA and you already have it.
- related to the previous comment: Why did you divide the sample into two groups? High PA vs. low PA? One single minute can be determinant and move a participant from one group to the other. Why did the authors not include an intermediate group? Or on the contrary, create the groups based on whether or not they comply with the general PA recommendations of the WHO (2020).
- In the statistical analysis paragraph authors say that model 3 was adjusted by several variables, but some of them (i.e. diabetes, hyperlipidaemias, stroke…) have not been explained previously how you obtained them.
- In the results section you sate that “Widowed participants accounted for 10.7%, and widowed participants accounted for 89.3%”. Widowed participants is repeated in that sentence, please correct that, one of them has to be "not widowed".
- Table 1, and table 3: please correct that mistakes in the colouring of the text.
- Table 2 is missing and does nor appear in the text, only appears the head title.
- In the discussion authors say “Physical exercise has been proved to improve the function of cardiovascular system” please reference that information.
Author Response
We feel great thanks for your professional review work on our article. As you are concerned, there are several problems that need to be addressed. According to your nice suggestions, we have made extensive corrections to our previous draft, the detailed corrections are listed below. Our response is given in normal font and changes/additions to the manuscript are given in the red text.
Comment 1. In the abstract the objectives are not the same as in the text, and due to that fact the conclusions do not answer to those objectives. Please correct it.
Response: We sincerely thank you for your valuable comments. We have added the research purpose of this study to the introduction.
The contents I added are as follows:
and to provide new evidence for the prevention and treatment of depression by physical activity.
Comment 2. Please improve a little bit the introduction, specially the second half in which you talk about different articles. It seems to be more a discussion than an introduction.
Response: We sincerely thank you for your valuable comments. This part is really like a discussion rather than an introduction. We have modified it according to your comments.
The contents I revised are as follows:
One study showed that high-intensity physical exercise had a positive effect on reducing depressive symptoms compared with low-intensity physical exercise [15]. Another study showed that high-intensity resistance training was more effective than low-intensity resistance training in improving depression in older adults [16].
Comment 3. In the methods section (Physical activities) you mention that “the number of days and the duration of daily activities of the participants for each physical activity for at least 10 minutes were evaluated”. Why did the authors evaluate only physical activities above 10 minutes? There is clear evidence for the benefits of physical activity below that amount of time and that the sum of small periods of exercise leads to the same benefits.
Response: We sincerely thank you for your valuable comments.This content is determined according to the questionnaire of the China Health and Retirement Permanent Study research team. There is indeed obvious evidence that physical activity less than 10 minutes can also be beneficial to health, and the research team may think that physical activity less than 10 minutes has no significant health benefits. I think this may be the reason for choosing physical activity for at least 10 minutes.
Comment 4. In the same paragraph if you evaluate activities above 10 minutes you should clarify that the first classification for duration of each physical activity should be “>10 minutes to < 0.5h”.
Response: We were really sorry for our careless mistakes. Thank you for your reminder. We have corrected this error. I've marked it in red in my manuscript.
Comment 5. In the same paragraph you say “According to the International Physical Activity Scale” and it is Physical Activity Questionnaire, please correct that.
Response: We were really sorry for our careless mistakes. Thank you for your reminder. We have corrected this error. I've marked it in red in my manuscript.
Comment 6. I do not understand why did you calculate the weekly physical activity using one formula with the metabolic equivalent. The IPAQ is used just to obtain that information about weekly amount of PA and you already have it.
Response: We are very grateful for your question. We calculated weekly physical activity using the formula for one metabolic equivalent to facilitate the classification of participants into a high physical activity group and a low physical activity group.
Comment 7. related to the previous comment: Why did you divide the sample into two groups? High PA vs. low PA? One single minute can be determinant and move a participant from one group to the other. Why did the authors not include an intermediate group? Or on the contrary, create the groups based on whether or not they comply with the general PA recommendations of the WHO (2020).
Response: We sincerely thank you for your valuable comments. As you said, this study did not set up a moderate physical activity group, which may have an impact on the study. This is one of the limitations of this study, and we have added it to the fourth part of the limitation. We will add the moderate physical activity group to the future study.
Comment 8. In the statistical analysis paragraph authors say that model 3 was adjusted by several variables, but some of them (i.e. diabetes, hyperlipidaemias, stroke…) have not been explained previously how you obtained them.
Response: We were really sorry for our careless mistakes. Thank you for your reminder. We have added these variables to the method. These variables are obtained by means of self reporting.
Comment 9. In the results section you sate that “Widowed participants accounted for 10.7%, and widowed participants accounted for 89.3%”. Widowed participants is repeated in that sentence, please correct that, one of them has to be "not widowed".
Response: We were really sorry for our careless mistakes. Thank you for your reminder. We sincerely thank the reviewer for careful reading. As suggested by the reviewer, we have corrected the “Widowed” into “non widowed”. I've marked it in red in my manuscript.
Comment 10. Table 1, and table 3: please correct that mistakes in the colouring of the text.
Response: We were really sorry for our careless mistakes. Thank you for your reminder. We have corrected this error. I've marked it in red in my manuscript.
Comment 11. Table 2 is missing and does nor appear in the text, only appears the head title.
Response: We were really sorry for our careless mistakes. Thank you for your reminder. We have added Table 2 to the latest manuscript.
Comment 12. In the discussion authors say “Physical exercise has been proved to improve the function of cardiovascular system” please reference that information.
Response: We sincerely thank you for your valuable comments. We have added this reference. [36] Ma C, Zhou W, Jia Y, et al. Effects of home-based Baduanjin combined with elastic band exercise in patients with chronic heart failure. European Journal of Cardiovascular Nursing, 2022(6):6.
We tried our best to improve the manuscript and made some changes marked in red in revised paper which will not influence the content and framework of the paper. We appreciate for your warm work earnestly, and hope the correction will meet with approval. Once again, thank you very much for your comments and suggestions.
Round 2
Reviewer 3 Report
Thank you for yor comments and for improving the manuscript
