Associations of Serum High-Sensitivity C-Reactive Protein (hs-CRP) And Insulin Resistance With Early Renal Impairment...

Early diabetic kidney disease in type 2 diabetes is characterized by increased urinary albumin excretion despite preserved estimated glomerular filtration rate (eGFR). The roles of systemic inflammation and insulin resistance at this stage remain incompletely defined. This study evaluated the associations of high-sensitivity C-reactive protein (hs-CRP) and insulin resistance (HOMA-IR) with early renal impairment. In this single-center retrospective cross-sectional study, 126 patients with type 2 diabetes and eGFR ≥60 mL/min/1.73 m² were included; patients not using exogenous insulin formed a subgroup (n=97). The primary outcome was natural log-transformed urine albumin-to-creatinine ratio (ln-UACR). Associations were assessed using Spearman correlation and multivariable linear regression adjusted for age, sex, diabetes duration, systolic blood pressure, and glycated hemoglobin (HbA1c). Dose-response relationships, joint exposure effects, surrogate outcomes, and sensitivity analyses were also examined. Statistical analyses were performed using R (version 4.3.2). ln-UACR was positively correlated with hs-CRP in the overall sample (ρ=0.28, p=0.001) and with HOMA-IR in the subgroup (ρ=0.26, p=0.009). After adjustment, hs-CRP remained associated with ln-UACR in both the overall sample (βstd=0.23) and subgroup (βstd=0.22), and HOMA-IR remained associated in the subgroup (βstd=0.17, p=0.018). ln-UACR increased across tertiles of both exposures (p for trend <0.01). The high hs-CRP/high HOMA-IR group showed higher ln-UACR compared with the low/low group (mean difference 0.64, 95% CI 0.37-0.88), without significant interaction (p=0.173). Associations were consistent across surrogate outcomes and sensitivity analyses. In patients with type 2 diabetes and preserved eGFR, hs-CRP and HOMA-IR were independently associated with markers of early renal impairment. These findings suggest potential relevance for early risk characterization, although prospective studies are required to confirm clinical utility.