At baseline, median [interquartile range; IQR] NfL levels (pg/ml) did not differ by sex (female = 21.7 [16.9–30.6], male = 22.6 [16.5–29.8]; p = 0.88) or kidney disease (present = 22.5 [15.5–26.9], absent = 22.2 [16.9–30.5]; p = 0.70). This evidence concerns the gene NEFL and kidney disorder.