The association of markers of body iron stores with kidney disease in type 1 diabetes (T1D) is complex, with both positive and inverse relationships observed. Little data are available on the relationship of dietary iron (DI) intake with markers of kidney function, prior to occult disease, in youth and young adults with T1D. We tested the association of DI with albumin-to-creatinine ratio (ACR), both measured at multiple time points over a 14-year period in youth and young adults with T1D. Study participants (n=629) were from the Colorado site of the SEARCH for Diabetes in Youth study who completed research visits at baseline and (<1yr diabetes duration) and at least one follow-up visit over 14 years. We applied linear mixed models (repeated measures analysis) to test the hypothesis that higher DI over time is longitudinally associated with a higher ACR, which was natural log-transformed prior to regression analysis. Results: Mean age and diabetes duration at study baseline were 10.2 (std 4.2) years and 10.4 (std 6.8) months, respectively. Older age at baseline (p=0.009), female sex (vs. male, p=0.002), and Black race (vs Non-Hispanic White, p<0.001) were each associated with higher ACR levels across follow-up. Contrary to our hypothesis, average DI intake was inversely associated with ACR levels in analyses adjusted for age, sex, and race (p<0.05). This inverse relationship persisted after further controlling for average body mass index (BMI) over time. However, controlling for average HbA1c levels over time, which were positively associated with ACR (p=0.001), attenuated the relationship between DI intake and ACR (p=0.12). In conclusion, total DI intake in children and young adults was associated with a lower ACR over 14 years, but the association was confounded by HbA1c, suggesting that DI may be a marker of total glycemic load. Whether this relationship varies by heme/non-heme content needs to be further explored. These data highlight the important role of diet in the early years after T1D onset.


R.B.Conway: None. T.L.Crume: None. W.Perng: None. D.A.Mcclain: None. D.Dabelea: None.

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