However, the prevalence of CKD 3–4 (defined as eGFR< 60 ml·min−1·(1.73 m2)−1) and elevated liver function (defined as alanine aminotransferase and/or aspartate aminotransferase is elevated ≥ 3 times the upper limit of normal and combined with elevated total bilirubin) were only 3.2% and 0.3% in 2002 visit in CMCS; thus their impact on our results would be minimal. Here, GPT is linked to chronic kidney disease.