Association of n-3 polyunsaturated fatty acids and inflammatory indicators with renal function decline in type 2 diabetes.
OBJECTIVE
The n-3 polyunsaturated fatty acids (PUFAs) and the inflammatory indicator, interleukin-6 (IL-6), have been implied in the development of renal dysfunction. This longitudinal study examined the effect of n-3 PUFAs and IL-6 on the risk of renal function decline and explored whether n-3 PUFAs modify the effect of inflammatory indicators on renal dysfunction risk in type 2 diabetes.


METHODS
Studying 676 type 2 diabetic patients, we analyzed erythrocyte fatty acids and inflammatory markers in 2008 and estimated glomerular filtration rate (eGFR) in 2008 and 2012. Renal function decline was defined as an eGFR decline of ≥25% over a 4-year period.


RESULTS
Multivariable logistic regression revealed erythrocyte total PUFAs, n-3 PUFAs, and n-3/n-6 PUFA ratio correlated negatively with risk of renal function decline (OR = 0.75, 0.78, and 0.61, respectively, all p < 0.01), while n-6 PUFAs did not. IL-6 independently predicted risk of renal dysfunction (OR = 1.18, p = 0.015). Stratifying erythrocyte PUFAs into low (<50(th) percentile) or high group (≥50(th) percentile), we found a positive association between IL-6 and risk of renal dysfunction only in the low n-3 PUFA (OR = 1.27, p = 0.035), low n-3/n-6 PUFA (OR = 1.27, p = 0.034), and low total PUFA groups (OR = 1.36, p = 0.005), but not in the high groups.


CONCLUSIONS
High PUFA concentrations, especially n-3 or higher n-3/n-6 PUFA ratio, may exert protective effects against renal function impairment in type 2 diabetic patients. Whether the effect is mediated via modification of inflammatory biomarker such as IL-6 by high n-3 PUFA status warrants further investigation.
School of Population Health, University of Queensland, Brisbane, Queensland, Australia.
Hsin-Fang
HF
Chung
School of Population Health, University of Queensland, Brisbane, Queensland, Australia.
Kurt Z
KZ
Long
Division of Preventive Medicine and Health Services Research, Institute of Population Health Sciences, National Health Research Institutes, Zhunan, Taiwan.
Chih-Cheng
CC
Hsu
School of Population Health, University of Queensland, Brisbane, Queensland, Australia.
Abdullah
A
Al Mamun
Department of Nutrition and Dietetics, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
Huei-Ru
HR
Jhang
Division of Endocrinology and Metabolism, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
Shyi-Jang
SJ
Shin
Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
Shang-Jyh
SJ
Hwang
Department of Nutrition and Dietetics, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Department of Public Health and Environmental Medicine, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan. Electronic address: mechhu@cc.kmu.edu.tw.
Meng-Chuan
MC
Huang
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D004912:Erythrocytes / Q000378:metabolism*; D015525:Fatty Acids, Omega-3 / Q000032:analysis; D043371:Fatty Acids, Omega-6 / Q000032:analysis; D005231:Fatty Acids, Unsaturated / Q000032:analysis*; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D007668:Kidney / Q000276:immunology / Q000502:physiology*; D007677:Kidney Function Tests / Q000379:methods; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D051437:Renal Insufficiency / Q000175:diagnosis* / Q000209:etiology; D012307:Risk Factors
D015415:Biomarkers; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D005231:Fatty Acids, Unsaturated; D015850:Interleukin-6
IL-6; Inflammation; Polyunsaturated fatty acids; Renal function; Type 2 diabetes