highly significantp < 0.001
For patients with normal creatinine levels, the intergroup differences in secondary sample SDMA levels remained highly significant in both analyses: 5.68 (5.32–6.42) for IS vs. 4.93 (4.19–5.34) A.U. for HS in MS analysis ( n = 85, p < 0.001), and 0.78 (0.69–0.93) for IS vs. 0.68 (0.56–0.81) nmol/mL for HS in ELISA analysis ( n = 248, p < 0.001).