The relationship between dietary inflammatory index (DII) and early renal injury in population with/without hypertension: analysis of the National health and nutrition examination survey 2001–2002

Abstract

Background

Inflammation plays a crucial role in occurrence of kidney injury, and specific dietary patterns can influence systemic inflammation levels. However, the relationship between dietary inflammatory potential and early-stage kidney damage remains unclear.

Method

2,108 participants was recruited from 2001–2002 National Health and Nutrition Examination Survey (NHANES). Dietary Inflammatory Index (DII) is utilized to assess dietary inflammatory potential, calculated through a 24-h dietary recall questionnaire. Early renal injury was evaluated using urinary albumin to creatinine (UACR), cystatin C (CysC), β-2 microglobulin (β2M), and estimated glomerular filtration rate (eGFR) based on serum creatinine (eGFRs), cystatin C (eGFRc), and both Scr and CysC (eGFRs&c). Participant characteristics were analyzed, and association between DII, hypertension, and early renal injury markers was explored using multiple linear and logistic regression models.

Results

The average age of participants was 53.9 years. DII exhibited a positive correlation with UACR (β = −0.048[0.017,0.078]), β2M (β = 0.019[0.010,0.027]), CysC (β = 0.012 [0.004,0.021]). Conversely, a negative correlation was observed between DII and eGFRc (β = −1.126[−1.554, −0.699]), eGFRs&c (β=-1.101[−1.653, −0.549]). A significant association was observed between hypertension and abnormality of early kidney damage markers. Subgroup analysis reveals that the positive correlation between DII and the occurrence of abnormal markers of early kidney damage is only observed in individuals with hypertension. Furthermore, an interaction between DII and hypertension was detected in eGFRs&c (OR:1.250[1.042, 1.499], p for interaction = 0.03).

Conclusion

Higher levels of DII may be associated with occurrence of early kidney damage. For individuals with hypertension, avoiding excessive consumption of pro-inflammatory foods may reduce the risk of renal injury.

Keywords:

• Dietary inflammatory index
• dietary patterns
• early renal injury
• hypertension
• inflammation
• cross-sectional study
• NHANES

Acknowledgments

We thank to the National Center for Health Statistics at the CDC for their excellent work in collecting the NHANES data and for making it accessible to the public.

Ethics approval and consent to participate

The CDC/NCHS Research Ethics Review Board granted approval for the detailed methods and protocols employed in the NHANES study. These procedures, including informed consent protocols for participants, can be accessed on the CDC.gov website. All methods adhered to the applicable guidelines and regulations. Since the data used in this study are publicly available, it was exempt from ethical review involving human subjects.

Consent for publication

Not applicable.

Authors’ contributions

JD.H and MD.S conceptualized the research topic and framework; JD.H and YH.W identified the methodological details of the research; JD.H, HM.L and X.Y used statistical software for data analysis; JD.H, HM.L and CY.Q wrote the main manuscript text; JD.H and MD.S conducted Writing-review and editing. All authors reviewed the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s). The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Data availability statement

All data can be downloaded from the NHANES website (https://www.cdc.gov/nchs/nhanes/about_nhanes.htm).

Additional information

Funding

This study was supported by The Jilin Tianhua Health Public Welfare Foundation, No. Z2022LJL009.