Differences in red blood cell fatty acid profiles by type 2 diabetes status in early-stage chronic kidney disease

BACKGROUND: Red blood cell (RBC) membrane fatty acid composition may reflect early metabolic disturbances linked to chronic kidney disease (CKD) and type 2 diabetes (T2D), offering insights into shared pathophysiological mechanisms. This study aimed to characterise RBC membrane fatty acid profiles in individuals with early-stage CKD, comparing those with and without T2D to identify disease-specific patterns. METHODS: The cross-sectional analysis comprised 893 participants (290 with T2D and 603 deemed at high risk of T2D by the African Diabetes Risk Score), aged ≥ 18 years, recruited from 16 communities in Cape Town, South Africa, between 2017 and 2019. RBC membrane fatty acids were extracted and analysed using gas chromatography. CKD was defined as an estimated glomerular filtration rate < 60 ml/min/1.73 m² and/or albumin-to-creatinine ratio > 3 mg/mmol. RESULTS: In total, 25.9% presented with CKD, 36.1% with T2D, and 15.6% presented with comorbid CKD and T2D. A higher lipogenic index was associated with an increased odds of prevalent CKD [OR (95% CI): 2.73 (1.22-6.12); p = 0.015], with 18:2n-6 (linoleic acid) [OR (95% CI): 0.81 (0.67-0.99); p = 0.035], total n-6 polyunsaturated fatty acids (PUFA) [OR (95% CI): 0.86 (0.76-0.98); p = 0.025], and total PUFA [OR (95% CI): 0.88 (0.77-0.99); p = 0.041] associated with reduced odds of prevalent CKD, with the associations between the PUFAs modified by T2D status (interaction p < 0.070). CONCLUSION: Our findings showed that comorbid CKD and T2D exacerbates changes in PUFAs, suggesting complex metabolic interactions. These fatty acids may be of clinical value adding to already existing biomarkers to improve early detection or monitoring of these diseases. Furthermore, promoting appropriately balanced dietary intake of n-6 and n-3 PUFAs, could support metabolic health, contributing to more personalized patient care.