Abstract
After reading “The association between sarcopenic obesity and depression in middle-aged and elderly U.S. adults: insights from the NHANES study”, we sincerely appreciate Zhang et al.‘s exploration of the relationship between sarcopenic obesity and depression in middle-aged and elderly populations, which provides new clinical perspectives for preventing sarcopenic obesity and depression. However, to more rigorously and clearly elucidate this relationship, several concerns must be addressed.
To the Editor:
After reading “The association between sarcopenic obesity and depression in middle-aged and elderly U.S. adults: insights from the NHANES study”, we sincerely appreciate Zhang et al.‘s exploration of the relationship between sarcopenic obesity and depression in middle-aged and elderly populations, which provides new clinical perspectives for preventing sarcopenic obesity and depression. However, to more rigorously and clearly elucidate this relationship, several concerns must be addressed.
First, NHANES data utilizes stratified multistage probability sampling to represent the nutritional and health status of the U.S. population. Therefore, in data analysis, weighting adjustments are essential to improve the study’s representativeness, especially when analyzing baseline characteristics and conducting logistic regression to examine the correlation between sarcopenic obesity and depression. However, the authors did not clarify whether weights were applied in their “Statistical Analysis” section. If weights were used, this should be explicitly stated; if not, the results lack accuracy and credibility.
Second, the authors used univariate analyses to screen variables significantly associated with depression and included them in the final multivariate model. While this approach is commendable, we note that the variable “Cancer or malignancy” showed significant associations with depression in univariate analysis but was not included in the final multivariate model. This omission may mask or even reverse the true relationship between sarcopenic obesity and depression. We urge the authors to include “Cancer or malignancy” in the multivariate analysis.
Third, in the “Subgroup analysis” section, the authors only stratified by age and sex. We believe this is insufficient. To ensure robustness and identify underlying heterogeneity, additional subgroup analyses (e.g., by race, education level, alcohol intake, current smoking, cardiovascular diseases, and cancer) are necessary.
Fourth, potential confounders such as diabetes and hypertension may influence both sarcopenic obesity [1, 2] and depression [3]. NHANES data has provided diagnostic information for these conditions through physical examinations, biochemical markers, and self-reports. To comprehensively assess the sarcopenic obesity and depression relationship, these variables should first undergo univariate screening and then be considered for inclusion in multivariate analyses.
Finally, as a cross-sectional observational study, the design inherently limits causal inference. This limitation must be explicitly acknowledged in the “Limitations” section to prevent misinterpretation.
Zhang et al.‘s investigation into sarcopenic obesity and depression in aging populations offers novel insights, suggesting that weight control or muscle strength enhancement may reduce depression risk. Addressing the above concerns would enhance the accuracy, robustness, and clinical applicability of their conclusions.
Author contributions
Jiang-yu Tu.wrote the main manuscript text.
Funding
None.
Data availability
No datasets were generated or analysed during the current study.
Declarations
Ethical approval
This study is “Letter to the Editor” and no patients are involved. Therefore, ethical approval is not necessary.
Informed consent
As no patients were included in this study, informed consent was not necessary.
Competing interests
The authors declare no competing interests.
Conflict of interest
The author declares that he has no conflict of interest in this study.
Human and animal rights
There are no needs of presenting statement of human and animal rights in this study.
Footnotes
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References
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Associated Data
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Data Availability Statement
No datasets were generated or analysed during the current study.