CRP and chronic kidney disease: Compared to those without PAS (control group), patients with PAS were older and had higher incidence of diabetes mellitus, higher systolic and diastolic blood pressure, higher levels of intact parathyroid hormone, and C-reactive protein, and lower levels of 25-hydroxyvitamin D. Multivariate logistic regression analysis found 25-hydroxyvitamin D levels (odds ratio [OR]: 0.895, 95% confidence interval [CI] 0.828–0.968, p = 0.005) and old age (OR: 1.140, 95% CI 1.088–1.194, p < 0.001) to be independently associated with PAS in patients with stage 3–5 CKD.