Table 2.
Association between SOx and coronary artery calcification score ≥ 1000 by logistic regression analysis.
| Univariable analysis | Multivariable analysis | Variable selection (AIC) | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Odds ratio | 95% CI | P | Odds ratio | 95% CI | P | Odds ratio | 95% CI | P | |
| SOx (µmol/L) | 1.01 | 1.00–1.02 | 0.038 | 1.01 | 1.00–1.03 | 0.099 | 1.01 | 1.00–1.02 | 0.168 |
| Age (years) | 1.00 | 0.95–1.05 | 0.854 | ||||||
| Male | 3.44 | 0.91–17.02 | 0.089 | 24.29 | 1.14–1672.3 | 0.076 | 6.90 | 1.10–77.5 | 0.065 |
| HD duration (months) | 1.00 | 1.00–1.01 | 0.235 | ||||||
| Diabetes mellitus | 0.95 | 0.27–3.20 | 0.941 | ||||||
| BMI (kg/m2) | 1.12 | 0.95–1.36 | 0.196 | 1.38 | 0.94–2.25 | 0.128 | |||
| Ankle-brachial index | 0.80 | 0.01–92.26 | 0.923 | ||||||
| aCa (mg/dL) | 1.36 | 0.43–4.63 | 0.604 | ||||||
| Phosphate (mg/dL) | 3.40 | 1.48–10.04 | 0.011 | 2.95 | 0.84–14.0 | 0.127 | 2.82 | 1.17–8.94 | 0.033 |
| iPTH (pg/dL) | 1.01 | 1.00–1.01 | 0.054 | 1.01 | 1.00–1.03 | 0.025 | 1.01 | 1.00–1.01 | 0.058 |
| ALP (U/mL) | 1.00 | 0.99–1.00 | 0.773 | ||||||
| Magnesium (mg/dL) | 0.46 | 0.05–3.62 | 0.467 | ||||||
| Triglyceride (mg/dL) | 1.01 | 1.00–1.02 | 0.105 | 0.98 | 0.96–1.00 | 0.116 | |||
| LDL-C (mg/dL) | 1.03 | 1.00–1.06 | 0.088 | 1.07 | 1.01–1.14 | 0.031 | 1.04 | 1.00–1.10 | 0.055 |
| HDL-C (mg/dL) | 0.96 | 0.92–1.01 | 0.126 | 0.95 | 0.83–1.04 | 0.337 | |||
| Uric acid (mg/dL) | 1.60 | 0.79–3.39 | 0.198 | 2.85 | 0.55–20.2 | 0.239 | |||
| β2MG (µg/L) | 1.08 | 0.95–1.27 | 0.277 | ||||||
| BUN (mg/dL) | 1.04 | 0.98–1.11 | 0.190 | 0.92 | 0.79–1.04 | 0.211 | |||
| Hemoglobin (g/dL) | 0.77 | 0.32–1.62 | 0.519 | ||||||
| Serum albumin (g/dL) | 1.11 | 0.12–9.93 | 0.927 | ||||||
| CaCO3 intake | 3.56 | 0.54–70.37 | 0.260 | ||||||
| Vitamin D medication | 1.40 | 0.41–4.70 | 0.585 | ||||||
| Statin intake | 0.75 | 0.10–3.94 | 0.744 | ||||||
In the analysis, we divided subjects into two groups: those with CAC score < 1000 and those with CAC score ≥ 1000. A logistic regression analysis was performed for the association between SOx and CAC. The explanatory variable was SOx, and the covariates were factors that are reported to be associated with vascular calcification8,25,32,33 or CVD29,34–36. A univariable analysis was performed first, and factors with a two-tailed P value < 0.2 were used for a multivariable analysis. For variable selection, we used Akaike’s information criteria with stepwise backward elimination. A two-tailed P value of < 0.05 was considered to indicate statistical significance.
aCa albumin-adjusted calcium, AIC Akaike’s information criteria, ALP alkaline phosphatase, β2MG beta-2 microglobulin, BUN blood urea nitrogen, BMI body mass index, CaCO3 calcium carbonate, CI confidence interval, HD hemodialysis, HDL-C high-density lipoprotein cholesterol, iPTH intact parathyroid hormone, LDL-C low-density lipoprotein cholesterol, SOx serum oxalate concentration.