Review for 10.1186/s12876-024-03324-6 (2024)

Title: The relationship between the systemic immune inflammation index and the Nonalcoholic
fatty liver disease in American adolescents
Version: 1 Date: 03 Jun 2024
Reviewer's report:
The research topic is commendable, as it addresses a pertinent area of study with the potential
for significant impact on public health. Understanding the relationship between the Systemic
Immune-Inflammation (SII) index and Non-Alcoholic Fatty Liver Disease (NAFLD) could
provide valuable insights into disease mechanisms and potential interventions. However, there
are several critical issues that need to be addressed.
Abstract:
The study aims to explore the relationship between the SII index and NAFLD in the general
U.S. population. It is crucial to explicitly state why this investigation is necessary, in particular
the adolescence settings. The abstract should provide a clear rationale for why examining this
relationship in the adolescent population is essential.
Introduction:
The prevalence of NAFLD is a global issue, not confined to Western countries. High prevalence
rates are also reported in countries like India, Pakistan, and Japan. Therefore, the statement "with
higher rates reported in Western countries" should be removed from the first paragraph.
Methods:
- The collinearity analysis was performed to evaluate and exclude variables with a variance
inflation factor (VIF) > 5 considered to be collinear [PMC10352838]. The reference should be
formatted using numbered citation.
- The stratification factors included gender (male/female), asthma (yes/no), and physical activity
(yes/no). The inclusion of asthma as a stratification factor is unclear. It would be more
appropriate to include race/ethnicity, as these factors are more closely related to NAFLD.
- The terms alanine aminotransferase, aspartate aminotransferase, and blood urea nitrogen
should be abbreviated as ALT, AST, and BUN, respectively, for consistency.
- The age range of the study population is unclear. It is not specified whether the study includes
only adolescents or if pediatric patients (under 12 years old) are also included.
The use of CAP for diagnosing NAFLD is validated in adults but not in pediatric/adolescent
populations. The current evidence does not support its use for NAFLD diagnosis in children
and adolescents (P V Alves V, et al. Clinical Performance of Transient Elastography
With Comparison to Quantitative Magnetic Resonance Imaging, Ultrasound, and Biopsy in
Children and Adolescents With Known or Suspected Fatty Liver Disease. Child Obes. 2023
Oct;19(7):461-469).
Specific Concerns:
The main concern is the rationale for selecting the adolescent population for this study.
While previous studies have examined the relationship between SII and NAFLD in adults, the
justification for focusing on adolescents is not adequately addressed in the background section.
Furthermore, the association between CAP and NAFLD steatosis is not well established in
pediatric and adolescent populations, which raises questions about the appropriateness of this
diagnostic approach.
Conclusion:
Although the study addresses an important topic, the current manuscript has significant
methodological and conceptual issues that need to be resolved. The rationale for focusing on
adolescents, the selection of stratification factors, and the use of CAP in diagnosing NAFLD in
this age group need to be thoroughly justified and supported by existing literature.
Given these substantial concerns, I regret to inform you that the manuscript, in its current form,
does not meet the standards for publication in this journal. I recommend that the authors address
these issues and consider resubmitting after making the necessary revisions.