## 3 Results and Discussion
### Identification of Potential Predictors and Their Association with CKD
\begin{table}
\begin{tabular}{l c c c c} \hline \hline \multicolumn{1}{c}{**Variable**} & **Total (_n_ = 12,189)** & **NCKD (_n_ = 9691)** & **CKD (_n_ = 2498)** & _p-Value_ \\ \hline Age (years) & 37 (31–43) & 36 (31–42) & 40 (34–48) & \(<\)0.001 \\ Sex & 8457 (69\%) & 7740 (80\%) & 717 (29\%) & \(<\)0.001 \\ Male & 3732 (31\%) & 1951 (20\%) & 1781 (71\%) & \(<\)0.001 \\ Female & 3732 (31\%) & 1951 (20\%) & 1781 (71\%) & \(<\)0.001 \\ Smoking status & & & & \\ Not smoking & 9847 (84\%) & 7648 (79\%) & 2199 (88\%) & \(<\)0.001 \\ Smoking & 2342 (19\%) & 2043 (21\%) & 299 (12\%) & \(<\)0.001 \\ Alcohol & & & & \\ Not drinking & 10,289 (84\%) & 8035 (83\%) & 2254 (90\%) & \(<\)0.001 \\ Drinking & 1900 (16\%) & 1656 (17\%) & 244 (10\%) & \(<\)0.001 \\ Comorbidities & & & & \\ Hypertension & 157 (1.3\%) & 55 (0.6\%) & 102 (4.1\%) & \(<\)0.001 \\ Diabetes & 51 (0.4\%) & 21 (0.2\%) & 30 (1.2\%) & \(<\)0.001 \\ Physical examination & & & & \\ BMI (kg/m\({}^{2}\)) & 22.0 (20–24.5) & 21.7 (19.8–24.2) & 23.1 (21.0–25.4) & \(<\)0.001 \\ Body fat (\%) & 27.1 (22.9–32.0) & 27.6 (23.5–32.4) & 24.9 (21.0–29.5) & \(<\)0.001 \\ Waist circumference (cm) & 72 (67–79) & 71 (66–77) & 77 (71–84) & \(<\)0.001 \\ Systolic BP (right arm, mmHg) & 113 (103–125) & 112 (102–124) & 117 (107–128) & \(<\)0.001 \\ Diastolic BP (right arm, mmHg) & 67 (60–75) & 67 (60–74) & 70 (64–77) & \(<\)0.001 \\ Blood lipids & & & & \\ Triglyceride (mmol/L) & 0.9 (0.7–1.3) & 0.9 (0.6–1.3) & 1.1 (0.8–1.5) & \(<\)0.001 \\ Cholesterol (mmol/L) & 4.9 (4.3–5.5) & 4.9 (4.3–5.5) & 5.0 (4.4–5.6) & \(<\)0.001 \\ HDL-cholesterol (mmol/L) & 1.5 (1.3–1.8) & 1.6 (1.3–1.8) & 1.4 (1.2–1.7) & \(<\)0.001 \\ LDL-cholesterol (mmol/L) & 2.8 (2.3–3.4) & 2.8 (2.3–3.3) & 3.0 (2.5–3.5) & \(<\)0.001 \\ Renal function & & & & \\ Blood urea nitrogen (BUN, mg/dL) & 12.4 (10.5–14.8) & 12.1 (10.2–14.4) & 13.4 (11.5–15.7) & \(<\)0.001 \\ Creatinine (mg/dL) & 0.8 (0.7–0.95) & 0.8 (0.7–0.89) & 1.08 (0.92–1.19) & \(<\)0.001 \\ eGFR (mL/min/1.73 m\({}^{2}\)) & 78.8 (63.1–94.4) & 84.9 (73.0–98.3) & 52.9 (47.2–56.8) & \(<\)0.001 \\ Metabolic indices & & & & \\ Ty-Index & 4.5 (4.3–4.7) & 4.5 (4.3–4.7) & 4.6 (4.4–4.8) & \(<\)0.001 \\ TG/HDL-C ratio & 1.3 (0.9–2.2) & 1.3 (0.9–2.0) & 1.7 (1.1–2.8) & \(<\)0.001 \\ VAI & 0.8 (0.5–1.3) & 0.7 (0.4–1.1) & 1.2 (0.8–2.0) & \(<\)0.001 \\ \hline \hline \end{tabular} Data are represented as median (IQR, inter quartile range) for continuous variables, n (%) for categorical variables and \(p\)-value < 0.05 was considered significant. BMI, body mass index; Systolic BP, systolic blood pressure; Diastolic BP, diastolic blood pressure; HDL-cholesterol, high-density lipoprotein cholesterol; LDL-cholesterol, low-density lipoprotein cholesterol; eGFR, estimated glomerular filtration; TgG-Index, triglyceride glucose index; TG/HDL-C ratio, triglyceride to high-density lipoprotein cholesterol ratio; VAI, visceral adiposity index.  
\end{table} 
Table 1: Baseline characteristics. reported in previous population-based longitudinal studies, which used only conventional statistics to investigate [16; 17; 18].