## 3 Results
\begin{table}
\begin{tabular}{c c c} \hline
**Variables** & **Overall (\(\mathbf{u=92}\))** & **\(\mathbf{p\ Value}\)** \\ \hline Ferritin (ng/mL) & 612.1 \(\pm\) 315.2 \\ Hemoglobin (g/dL) & 10.7 \(\pm\) 1.4 \\ Hematocrit (\%) & 32.0 \(\pm\) 4.3 \\ Platelet (k/\(\mu\)L) & 193.8 \(\pm\) 64.1 \\ \hline \end{tabular} Continuous variables were abbreviated as mean \(\pm\) SD. Categorical variables are abbreviated as \(n\) (\%). SpO2 = pulse oximeter saturation.  
\end{table} 
Table 1: _Cont._ \begin{table}
\begin{tabular}{c c c c} \hline
**Variables** & **Survivors (\(\mathbf{u=69}\))** & **Deceased (\(\mathbf{u=23}\))** & \(\mathbf{p\ Value}\) \\ \hline Age (years) & 62.6 \(\pm\) 9.8 & 63.6 \(\pm\) 11.5 & 0.684 \\ Male, \(n\) (\%) & 32 (46.4) & 11 (47.8) & 0.905 \\ Diabetes mellitus, \(n\) (\%) & 23 (33.3) & 15 (65.2) & \textless{}0.01 \\ Obstructive sleep apnea, \(n\) (\%) & 4 (5.8) & 6 (26.1) & \textless{}0.05 \\ Hypertension, \(n\) (\%) & 27 (39.1) & 13 (56.5) & 0.148 \\ Prior coronary artery disease, \(n\) (\%) & 23 (33.3) & 13 (56.5) & \textless{}0.05 \\ Pre-dialytic SpO2 (\%) & 95.2 \(\pm\) 2.2 & 93.0 \(\pm\) 5.0 & \textless{}0.05 \\ Body weight (kg) & 61.3 \(\pm\) 10.1 & 59.6 \(\pm\) 9.2 & 0.482 \\ Body mass index (kg/m\({}^{2}\)) & 24.0 \(\pm\) 2.8 & 23.5 \(\pm\) 2.8 & 0.549 \\ Systolic blood pressure (mmHg) & 136 \(\pm\) 23 & 148 \(\pm\) 32 & 0.063 \\ Diastolic blood pressure (mmHg) & 78 \(\pm\) 14 & 85 \(\pm\) 24 & 0.056 \\ Aspartate aminotransferase (IU/L) & 16.4 \(\pm\) 7.4 & 17.4 \(\pm\) 9.1 & 0.597 \\ Albumin (g/dL) & 3.9 \(\pm\) 0.5 & 3.8 \(\pm\) 0.4 & 0.508 \\ Total cholesterol (mg/dL) & 192.3 \(\pm\) 52.8 & 212.3 \(\pm\) 45.0 & 0.110 \\ Triglyceride (mg/dL) & 182.4 \(\pm\) 137.0 & 207.4 \(\pm\) 107.0 & 0.429 \\ Blood urea nitrogen (mg/dL) & 66.1 \(\pm\) 15.7 & 63.8 \(\pm\) 17.1 & 0.556 \\ Creatinine (mg/dL) & 10.1 \(\pm\) 1.7 & 10.7 \(\pm\) 1.5 & 0.210 \\ Uric acid (mg/dL) & 7.5 \(\pm\) 1.4 & 7.7 \(\pm\) 1.5 & 0.624 \\ Potassium (mmol L\({}^{-1}\)) & 4.6 \(\pm\) 0.9 & 4.4 \(\pm\) 0.8 & 0.371 \\ Adjusted calcium (mg/dL) & 9.4 \(\pm\) 0.8 & 9.2 \(\pm\) 0.8 & 0.185 \\ Phosphate (mg/dL) & 4.6 \(\pm\) 1.6 & 4.7 \(\pm\) 1.2 & 0.699 \\ Iron (ug/dL) & 79.7 \(\pm\) 34.3 & 75.0 \(\pm\) 23.7 & 0.549 \\ Ferritin (ng/mL) & 596.1 \(\pm\) 285.0 & 657.4 \(\pm\) 392.2 & 0.426 \\ Hemoglobin (g/dL) & 10.8 \(\pm\) 1.4 & 10.2 \(\pm\) 14 & 0.116 \\ Hematocrit (\%) & 32.4 \(\pm\) 4.3 & 31.0 \(\pm\) 4.3 & 0.166 \\ Platelet (k/\(\mu\)L) & 195.3 \(\pm\) 67.1 & 189.2 \(\pm\) 55.3 & 0.694 \\ \hline \end{tabular} Continuous variables were abbreviated as mean \(\pm\) SD. Categorical variables are abbreviated as \(n\) (\%). SpO2 = pulse oximeter saturation.  
\end{table} 
Table 2: Comparisons of bio-clinical parameters between survivors and non-survivors according to all-cause mortality. \(p\) = 0.166), respectively. The similar results were found in the comparison between CV event and non-CV event groups according to CV mortality (Table 3). In summary, DM, prior CAD history, OSA, and pre-dialytic SpO2 values differed significantly between event and non-event groups with respect to all-cause and CV mortality. The Lower Pre-Dialytic Level of SPO2 and OSA Group Were Associated with an Incremental Risk for All-Cause and CV Mortality  
Table 4 summarized the results in the univariate Cox regression analysis for potential prognostic factors with respective to all-cause and CV mortality. A history of DM, lower pre-dialytic levels of SPO2, lower serum concentrations of albumin, and lower levels of hemoglobin were significantly associated with all-cause mortality (all \(p\) values < 0.05). Furthermore, prior history of CAD, DM, lower pre-dialytic levels of SPO2, prevalent OSA and lower serum concentrations of albumin were significantly associated with CV mortality (all \(p\) values < 0.05). However, the prevalent OSA was associated with CV mortality rather than all-cause death.