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.

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

End-stage renal disease (ESRD) patients are vulnerable to vitamin D deficiency due to impaired renal hydroxylation, low dietary intake and inadequate sun exposure. Vitamin D plays a role in innate and adaptive immunity and its seasonal variation has been linked to mortality. ESRD is associated with inadequate removal of pro-inflammatory cytokines regulating acute phase protein (APP) synthesis. Our aim was to look for associations between lifestyle factors, diet, and vitamin D seasonal variation and their relationship with selected APPs and calcium-phosphate metabolism. The study included 59 ESRD patients treated with maintenance hemodialysis. A 24-hour dietary recall was conducted in the post-summer (November 2018, PS) and post-winter (February/March 2019, PW) period, and blood was collected for the measurements of serum total vitamin D, α1-acid glycoprotein (AGP), C-reactive protein (CRP), albumin, prealbumin (PRE), parathormone, calcium and phosphate. A self-constructed questionnaire gathered information on vitamin D supplementation, sun exposure and physical activity. Higher caloric intake was observed PW compared PS. Less than 15% of participants met the dietary recommendations for energy, protein, fiber, vitamin D and magnesium intake. Vitamin D supplementation was associated with higher serum vitamin D regardless of season. AGP, PRE, albumin, and vitamin D presented seasonal changes (higher values PS). In patients with serum vitamin D below 25 ng/mL, vitamin D seasonal change correlated with CRP and prealbumin change. Phosphate and Ca × P correlated positively with AGP. A low vitamin D serum level could impact the inflammatory process; however, more studies are needed to confirm the relationship.