Acute Phase Proteins and Vitamin D Seasonal Variation in End-Stage Renal Disease Patients

Hypocholesterolemia and Inflammatory Biomarkers Act as Predictors of Severe Vitamin D Deficiency in Patients With Crohn’s Disease: A Clinical Analysis of 862 Patients in China

Background

In this study, we enrolled 862 patients with Crohn’s disease (CD) in China to investigate the correlation between serum vitamin D (SVD) and serum lipids, inflammatory biomarkers, and important clinical parameters.

Materials and Methods

25(OH)D was measured by LS/MS/MS. Correlation analysis, chi-square tests, and logistic regression analysis were performed to determine the correlations between vitamin D and potential risk factors when vitamin D levels were lower than 10 ng/mL or 20 ng/mL.

Results

The incidence of severe vitamin D deficiency (SVD < 10 ng/mL) in patients with CD was significantly higher than that in healthy controls (28.9 vs. 9.5%). Multinomial logistic regression analysis showed that penetrating disease [odds ratio (OR) = 2.18], low levels of high-density lipoprotein cholesterol (HDL) (OR = 1.91), high erythrocyte sedimentation rate (OR = 1.73), and platelet count (PLT) (OR = 2.71) were regarded as predictors of severe vitamin D deficiency, while only PLT (OR = 1.90) and HDL (OR = 1.76) were considered as predictors of mild vitamin D deficiency (SVD 10–20 ng/mL).

Conclusion

Our results confirm a higher incidence of severe vitamin D deficiency in patients with CD in China and show that vitamin D deficiency could result from the combined effects of penetrating disease, inflammation, and low levels of HDL.

α1-Acid Glycoprotein and Dietary Intake in End-Stage Renal Disease Patients

Management of end-stage renal disease (ESRD) patients requires monitoring each of the components of malnutrition–inflammation–atherosclerosis (MIA) syndrome. Restrictive diet can negatively affect nutritional status and inflammation. An acute-phase protein—α₁-acid glycoprotein (AGP), has been associated with energy metabolism in animal and human studies. The aim of our study was to look for a relationship between serum AGP concentrations, laboratory parameters, and nutrient intake in ESRD patients. The study included 59 patients treated with maintenance hemodialysis. A 24 h recall assessed dietary intake during four non-consecutive days—two days in the post-summer period, and two post-winter. Selected laboratory tests were performed: complete blood count, serum iron, total iron biding capacity (TIBC) and unsaturated iron biding capacity (UIBC), vitamin D, AGP, C-reactive protein (CRP), albumin, prealbumin, and phosphate–calcium metabolism markers (intact parathyroid hormone, calcium, phosphate). Recorded dietary intake was highly deficient. A majority of patients did not meet recommended daily requirements for energy, protein, fiber, iron, magnesium, folate, and vitamin D. AGP correlated positively with CRP (R = 0.66), platelets (R = 0.29), and negatively with iron (R = −0.27) and TIBC (R = −0.30). AGP correlated negatively with the dietary intake of plant protein (R = −0.40), potassium (R = −0.27), copper (R = −0.30), vitamin B₆ (R = −0.27), and folates (R = −0.27), p < 0.05. However, in multiple regression adjusted for confounders, only CRP was significantly associated with AGP. Our results indicate that in hemodialyzed patients, serum AGP is weakly associated with dietary intake of several nutrients, including plant protein.

Seasonal variation of serum 25-hydroxyvitamin D level in hemodialysis patients in the northernmost island of Japan

BACKGROUND

Serum vitamin D level shows a seasonal variation, being lower in winter than in summer in healthy subjects. The aim of this study was to determine whether there is presence of such a seasonal variation in hemodialysis patients.

METHODS

A total of 102 patients on hemodialysis were enrolled in February 2017 (winter) for analyses of serum levels of 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH)₂D] and treatments for chronic kidney disease-mineral and bone disorder (CKD-MBD). The examinations were repeated in August 2017 (summer). After exclusion of patients with malignancy, loss of follow-up and missing data, 78 patients contributed to the analyses.

RESULTS

Serum level of 25(OH)D, but not that of 1,25(OH)₂D, was significantly lower in winter (14.0 ng/mL) than in summer (15.5 ng/mL), though there was no significant difference in regimen for CKD-MBD treatment including vitamin D receptor activators (VDRAs) between the two seasons. Serum intact parathyroid hormone level tended to be higher and alkaline phosphatase was significantly higher in winter than in summer. Linear mixed-effects model analysis showed that level of 25(OH)D, but not that of 1,25(OH)₂D, was significantly associated with season (winter and summer) after adjustment of age, sex, dialysis vintage, albumin level and use of drugs for CKD-MBD.

CONCLUSION

Serum 25(OH)D has a seasonal variation, being lower in winter than in summer, independent of CKD-MBD treatment including treatment with VDRAs in Japanese hemodialysis patients. The impact of the seasonal variation on risk of vitamin D deficiency and its effect on prognosis remain to be investigated.