Relationship of serum and dietary vitamin D with high cardiometabolic risk in Mexican systemic lupus erythematosus patients: A cross-sectional study

Objetive: Serum and dietary vitamin D could influence clinical disease activity and cardiometabolic outcomes in systemic lupus erythematosus (SLE). This study aimed to assess the relationship of serum and dietary vitamin D with cardiometabolic risk in Mexican SLE patients and healthy subjects (HS).Methods: 224 SLE patients and 201 HS were included in this cross-sectional study. Serum calcidiol was measured using a competitive enzyme-linked immunosorbent assay (ELISA). Vitamin D dietary intake was assessed by collecting three 24h food records. Dietary patterns (DPs) were identified using principal component analysis (PCA). Cardiometabolic status was analyzed through biochemical measurements and cardiometabolic indexes.Results: Calcidiol deficiency (<20 ng/mL) was associated with 1.66-fold higher risk of excess weight by body mass index (BMI) (≥25 kg/m2) (p = .02), 2.25-fold higher risk to low high-density lipoprotein-cholesterol (HDL-C) (<40 mg/dL) (p < .001), and 1.74-fold higher risk to high triglycerides (TG) ≥150 mg/dL (p = .02). Inadequate vitamin D dietary intake was associated with 1.92-fold higher risk of presenting non-healthy waist circumference (WC) (>80 cm) (p < .01), 2.05-fold higher risk of android waist to hip ratio (WHR ≥85) (p < .01), and 1.72-fold higher risk to excess weight (p = .02). Non-adherence to a DP rich in vitamin D food sources was associated with higher WC, WHR, triglycerides, and lower high-density lipoprotein-cholesterol (HDL-C); furthermore, in HS, non-adherence to the DP rich in vitamin D food sources provided 2.11-fold higher risk to calcidiol deficiency.In Cconclusion: A pattern of Calcidiol deficiency, inadequate vitamin D dietary intake, and non-adherence to a DP rich in vitamin D food sources was related to high cardiometabolic risk in SLE patients and HS.

Analysis of Potential Vitamin D Molecule Biomarkers: Association of Calcitriol and Its Hydroxylation Efficiency Ratio with Cardiovascular Disease Risk in Rheumatoid Arthritis Patients

Rheumatoid arthritis (RA) is a multifactorial autoimmune disease in which hypovitaminosis D by calcidiol quantification has been associated with disease severity. However, other vitamin D molecules could be implicated in RA pathophysiology and its comorbidities such as cardiovascular disease (CVD), which impacts the severity and mortality of RA patients. This study aimed to assess the relationship between calcidiol, calcitriol, its hydroxylation efficiency ratio, and the soluble vitamin D receptor (sVDR) and clinical and CVD risk variables to propose potential vitamin D molecule biomarkers for RA. A cross-sectional study of females was conducted on 154 RA patients and 201 healthy subjects (HS). Calcidiol, calcitriol, and the sVDR were measured in blood serum, and vitamin D hydroxylation efficiency was estimated using the calcitriol/calcidiol ratio score. CVD risk was calculated by the high-sensitivity C-reactive protein (hs-CRP) cutoff values. Disease activity was evaluated with the Disease Activity Score for 28 standard joints (DAS28-CRP). Results: The hydroxylation efficiency ratio and calcitriol serum levels were higher in RA patients with hypovitaminosis D (p < 0.001). Moreover, RA patients had a higher probability of a high hydroxylation efficiency ratio (OR = 2.02; p = 0.02), calcitriol serum levels (OR = 2.95; p < 0.001), and sVDR serum levels (OR = 5.57; p < 0.001) than HS. This same pattern was also observed in RA patients with high CVD risk using CRP serum levels; they showed a higher hydroxylation efficiency ratio (OR = 4.51; p = 0.04) and higher calcitriol levels (OR = 5.6; p < 0.01). Calcitriol correlates positively with the sVDR (r = 0.21, p = 0.03), CRP (r = 0.28, p < 0.001), and cardiometabolic indexes (p < 0.001) also showed discrimination capacity for CVD risk in RA patients with CRP ≥ 3 mg/L (AUC = 0.72, p < 0.01). In conclusion, hypovitaminosis D in RA patients was characterized by a pattern of a higher hydroxylation efficiency ratio and higher calcitriol and sVDR serum levels. Notably, higher calcitriol serum levels and a higher vitamin D hydroxylation efficiency ratio were associated with higher CVD risk in RA patients.

Association of - 717 A > G (rs2794521) CRP polymorphism with high cardiovascular risk by C-reactive protein in systemic lupus erythematosus patients

INTRODUCTION

Systemic lupus erythematosus (SLE) is an autoimmune disease where genetic factors have been related to SLE susceptibility and disease severity. CRP polymorphisms have been associated with high C-reactive protein (CRP) serum levels, cardiovascular disease (CVD), and high clinical disease activity in SLE patients; however, the evidence is still inconclusive.

OBJECTIVE

This study was aimed to assess the association of the - 717 A > G, - 409 G > A, + 1444 C > T, and + 1846 C > T CRP polymorphisms with genetic susceptibility, clinical disease activity, and CVD risk in Mexican-mestizo SLE patients.

METHODS

A comparative cross-sectional study was conducted on 369 unrelated women: 183 with SLE according to the 1997 SLE-ACR criteria and 186 healthy subjects (HS). The clinical disease activity was assessed by the Mex-SLEDAI score; CRP and lipid profile were quantified by turbidimetry and colorimetric-enzymatic assays, respectively. The CRP polymorphisms genotyping was carried out by allelic discrimination.

RESULTS

SLE patients with - 717 AA genotype had higher CRP serum levels than SLE carriers of AG and GG genotypes (AA = 5 mg/L vs. AG = 3.2 mg/L vs. GG = 2.4 mg/L; p = 0.01), and the AA genotype was associated with high CVD risk by CRP in SLE patients (OR = 3; CI: 1.2-7.6; p < 0.01).

CONCLUSIONS

The - 717 A > G CRP polymorphism is a risk factor for high CRP levels and high CVD risk in Mexican-mestizo SLE patients. Key Points • Cardiovascular disease is one of the major causes of death in SLE patients due to the higher prevalence of traditional and non-traditional cardiovascular risk factors. • C-reactive protein is a liver-derived acute-phase protein suggested as one powerful independent risk predictor factor for cardiovascular disease. • Single nucleotide polymorphisms in CRP have been suggested as genetic susceptibility factors that could modify the SLE pathophysiology outcomes. • Mexican-mestizo SLE patients carrying the -717 A>G CRP AA genotype had 3-fold high cardiovascular disease risk than SLE patients with AG or GG genotypes.

Nutritional, biochemical, and clinical determinants of hyperuricemia in systemic lupus erythematosus patients: Relationship with clinical and renal disease activity

Systemic lupus erythematosus (SLE) is the prototypical autoimmune disease considered as an independent risk factor for mortality by cardiovascular disease. Currently, uric acid is described as a novel biomarker associated with cardiometabolic risk. However, nutritional and serum determinants that influence hyperuricemia development in autoimmune diseases have not been fully elucidated. This study aimed to assess the nutritional, biochemical, and cardiometabolic determinants of hyperuricemia and its relationship with clinical variables in SLE patients. A cross-sectional study was conducted in 167 SLE patients and 195 control subjects (CS). Nutrient intake, anthropometry, biochemical, and cardiometabolic indexes were evaluated. In SLE patients, adequate protein (OR = 0.4; p = 0.04) and carbohydrate (OR = 0.2; p = 0.01) intakes were associated with a lower risk of hyperuricemia. SLE patients with hyperuricemia presented a higher risk of clinical (OR = 2.2; p = 0.03) and renal activity (OR = 3.4; p < 0.01), as well as triglycerides ≥150 mg/dL (OR = 3.6; p < 0.01), hs-CRP ≥1 mg/L (OR = 3.1; p < 0.01), Kannel score ≥3 (OR = 2.5; p = 0.02), and BMI ≥25 kg/m² (OR = 2.2; p = 0.02). Oppositely, serum levels of HDL-C ≥40 mg/dL (OR = 0.2; p < 0.01) were associated with a lower risk of hyperuricemia. According to the pharmacotherapy administered, prednisone treatment was associated with a high risk of hyperuricemia (OR = 4.7; p < 0.001). In contrast, the hydroxychloroquine treatment was associated with a lower risk of hyperuricemia (OR = 0.4; p = 0.02). In conclusion, SLE patients with hyperuricemia presented a high risk of clinical and renal activity as well as worse cardiometabolic status. Notably, an adequate intake of protein, carbohydrates, healthy HDL-C serum levels, and hydroxychloroquine treatment could be determinants of lower risk of hyperuricemia.

Vitamin D Receptor (VDR) Genetic Variants: Relationship of FokI Genotypes with VDR Expression and Clinical Disease Activity in Systemic Lupus Erythematosus Patients

Vitamin D (VD) deficiency is more frequent in systemic lupus erythematosus (SLE) patients than in control subjects (CS); genetic variants in the VD receptor (VDR) could contribute to the clinical disease activity. This study was aimed to determine the association of the VDR variants FokI (rs2228570), BsmI (rs1544410), ApaI (rs7975232), and TaqI (rs731236) with susceptibility to the disease, VD status, VDR mRNA expression, and clinical disease activity in SLE patients. A cross-sectional study was conducted in 194 SLE and 196 CS Mexican women. Immunoassays quantified serum calcidiol and calcitriol. Genotyping was performed by allelic discrimination assays and mRNA VDR expression by qPCR. The FokI variant was not in linkage disequilibrium with BsmI, ApaI, and TaqI VDR variants. SLE patient carriers of the TT FokI genotype showed higher clinical disease activity scores. Notably, the mRNA VDR expression was higher in SLE patients vs. CS, in active vs. inactive SLE patients, and in participants of both study groups with vitamin D deficiency, higher calcitriol levels, and TT FokI genotype carriers. In conclusion, the TT FokI VDR genotype was related to high VDR expression and clinical disease activity in systemic lupus erythematosus patients.

CRP Serum Levels Are Associated with High Cardiometabolic Risk and Clinical Disease Activity in Systemic Lupus Erythematosus Patients

Systemic lupus erythematosus (SLE) patients have a higher frequency of cardiovascular risk factors such as high C-reactive protein (CRP) levels than the general population. CRP is considered a cardiovascular disease marker that could be related to SLE clinical disease activity. This study aimed to assess the association between CRP with cardiometabolic risk and clinical disease activity in SLE patients. A comparative cross-sectional study was conducted in 176 female SLE patients and 175 control subjects (CS) with median ages of 38 and 33 years, respectively; SLE patients were classified by the 1997 SLE-ACR criteria, and the clinical disease activity by the Mexican-SLEDAI (Mex-SLEDAI). CRP and lipid profile (triglycerides, cholesterol, HDL-C, and LDL-C) were quantified by turbidimetry and colorimetric-enzymatic assays, respectively. SLE patients had higher CRP levels than CS (SLE: 5 mg/L vs. CS = 1.1 mg/L; p < 0.001). In SLE patients, CRP levels ≥ 3 mg/L were associated with a higher risk of cardiometabolic risk status assessed by LAP index (OR = 3.01; IC: 1.04−8.7; p = 0.04), triglycerides/HDL-C index (OR = 5.2; IC: 2.1−12.8; p < 0.001), Kannel index (OR = 3.1; IC: 1.1−8.1; p = 0.03), Castelli index (OR = 6.6; IC: 2.5−17.8; p < 0.001), and high clinical disease activity (OR = 2.5: IC: 1.03−6.2; p = 0.04; and β coefficient = 5.8; IC: 2.5−9.4; R2 = 0.15; p = 0.001). In conclusion, high CRP levels were associated with high cardiometabolic risk and clinical disease activity in SLE patients.

Functional effects of vitamin D: From nutrient to immunomodulator

Vitamin D can be obtained from the endogenous synthesis in the epidermis by exposure to UVB light, and from foods and supplements in the form of ergocalciferol (vitamin D₂) and cholecalciferol (vitamin D₃). The main metabolite used to measure vitamin D serum status is calcidiol [25(OH)D]. However, its active metabolite calcitriol [1α,25(OH)₂D] performs pleiotropic effects in the cardiovascular, neurological, and adipose tissue as well as immune cells. Calcitriol exerts its effects through genomic mechanisms modulated by the nuclear vitamin D receptor (VDR)/retinoid X receptor (RXR) complex, to bind to vitamin D response elements (VDRE) in target genes of several cells such as activated T and B lymphocytes, neutrophils, macrophages, and dendritic cells; besides of its genomic mechanisms, VDR performs novel non-genomic mechanisms that involve its membrane expression and soluble form; highlighting that vitamin D could be an immunomodulatory nutrient that plays a key role during physiological and pathological events. Therefore, the aim of this comprehensive literature review was to describe the most relevant findings of vitamin D dietary sources, absorption, synthesis, metabolism, and factors that influence its serum status, signaling pathways, and biological effects of this immunonutrient in the health and disease.

Association of Vitamin D Metabolism Gene Polymorphisms with Autoimmunity: Evidence in Population Genetic Studies

A high prevalence of vitamin D (calcidiol) serum deficiency has been described in several autoimmune diseases, including multiple sclerosis (MS), rheumatoid arthritis (AR), and systemic lupus erythematosus (SLE). Vitamin D is a potent immunonutrient that through its main metabolite calcitriol, regulates the immunomodulation of macrophages, dendritic cells, T and B lymphocytes, which express the vitamin D receptor (VDR), and they produce and respond to calcitriol. Genetic association studies have shown that up to 65% of vitamin D serum variance may be explained due to genetic background. The 90% of genetic variability takes place in the form of single nucleotide polymorphisms (SNPs), and SNPs in genes related to vitamin D metabolism have been linked to influence the calcidiol serum levels, such as in the vitamin D binding protein (VDBP; rs2282679 GC), 25-hydroxylase (rs10751657 CYP2R1), 1α-hydroxylase (rs10877012, CYP27B1) and the vitamin D receptor (FokI (rs2228570), BsmI (rs1544410), ApaI (rs7975232), and TaqI (rs731236) VDR). Therefore, the aim of this comprehensive literature review was to discuss the current findings of functional SNPs in GC, CYP2R1, CYP27B1, and VDR associated to genetic risk, and the most common clinical features of MS, RA, and SLE.

Association of cardiometabolic risk status with clinical activity and damage in systemic lupus erythematosus patients: A cross-sectional study

Cardiometabolic status is a key factor in mortality by cardiovascular disease (CVD) in systemic lupus erythematosus (SLE). This study evaluated the association of cardiometabolic risk status with clinical activity and damage in SLE patients. A cross-sectional study was conducted in 158 SLE patients and 123 healthy subjects (HS). Anthropometry, glucose, hs-CRP, lipid profile, oxLDL, sCD36, anti-oxLDL antibodies, and cardiometabolic indexes were evaluated. SLE patients had dyslipidemia, higher sCD36, anti-oxLDL antibodies, hs-CRP, and risk (OR > 2) to present Castelli score ≥ 4.5, HDL-C < 40 mg/dL and LDL-C ≥ 100 mg/dL. Disease evolution time was correlated with glucose and BMI, damage with TG, and clinical activity with TG, TG/HDL-C ratio, and Kannel index. Active SLE patients had risk (OR > 2) to present a Castelli score ≥ 4.5, Kannel score ≥ 3, TG/HDL-C ratio ≥ 3 and HDL-C < 40 mg/dL. In conclusion, SLE patients have high cardiometabolic risk to CVD related to disease evolution time, and clinical activity.