Serum 25-hydroxy vitamin D levels in Egyptian patients with rheumatoid arthritis: Association with disease activity, functional disability and radiological damage

Genetic Risk of Rheumatoid Arthritis: A Case Control Study

Vitamin D effects are mediated by vitamin D receptors (VDRs), which are influenced by various genetic polymorphisms, including ApaI and BsmI. These polymorphisms have been linked to several diseases, including rheumatoid arthritis (RA). This study aimed to compare the frequency and association of VDR ApaI and BsmI gene polymorphisms, serum 25-hydroxy vitamin D (25-(OH)-D) levels, and calcium (Ca) levels between a RA group and a matched healthy control group. In one hundred RA patients and fifty healthy controls, the genotypes of the VDR ApaI and BsmI gene polymorphisms were analyzed using polymerase chain reaction restriction fragment length polymorphisms (PCR-RFLP). Both Serum 25-(OH)-D level and calcium level were measured in the two groups. There was no significant difference between the cases and controls regarding the VDR ApaI gene polymorphism (p = 0.89). A significant difference was observed between the cases and controls in terms of the VDR BsmI gene polymorphism (p = < 0.001). The serum levels of 25-(OH)-D and calcium were significantly lower in the RA group compared to the control group (p = 0.04 and < 0.001 respectively). Significantly higher serum vitamin D levels were associated with the aa genotype (p = 0.007). Significantly increased calcium levels were associated with the AA genotype (p = 0.02). No significant difference was found among BsmI polymorphisms regarding vitamin D and Ca levels (p = 0.25 and 0.87 respectively). Vitamin D receptor gene BsmI polymorphism but not ApaI polymorphism could be a marker of RA susceptibility. Vitamin D and Ca levels are negatively affected by RA. Vitamin D receptor gene ApaI polymorphism contributes to vitamin D and Ca levels.

Bone mineral density, vitamin D receptor (VDR) gene polymorphisms, fracture risk assessment (FRAX), and trabecular bone score (TBS) in rheumatoid arthritis patients: connecting pieces of the puzzle

Purpose

To assess vitamin D receptor (VDR) gene polymorphisms and bone mineral density and to investigate the possible risk factors of osteoporosis and fracture in rheumatoid arthritis (RA).

Methods

A total of 97 RA patients and 45 matched controls were enrolled. Serum vitamin D level, VDR genotyping, dual-energy X-ray absorptiometry (DEXA) scan, trabecular bone score (TBS), and fracture risk assessment (FRAX) in 10 years were assessed. Disease activity score (DAS28) and modified health assessment questionnaire (MHAQ) were measured.

Results

The mean age of the patients was 47.9 ± 8.9 years; 85 females, 12 males (F:M 7.1:1) and mean disease duration 9.4 ± 6.2 years. DAS28 was 4.52 ± 1.04 and MHAQ 0.6 ± 0.4. There was a significant difference between cases and controls as regards DEXA and FRAX (p < 0.0001) but the TBS and VDR genotyping were comparable (p = 0.29 and p = 0.12, respectively). The vitamin D level was comparable with the control (9.3 ± 6.5 vs 10.4 ± 7.5 ng/mL, p = 0.4). None of the patients was receiving anti-osteoporotic therapy or biologic therapy. There was a significant association between the presence of osteoporosis and age, disease duration, menopause, and rheumatoid factor (RF) positivity. The TBS was significantly lower and FRAX higher in patients with positive RF and anti-CCP. FRAX was significantly related and the TBS inversely with the age, disease duration, serum uric acid, alkaline phosphatase, and MHAQ.

Conclusions

Reduced BMD and increased tendency to fractures are remarkable in RA patients. Vitamin D level was decreased in patients and control, and VDR gene polymorphisms were not linked to RA. TBS and FRAX are effective tools to assess osteoporotic fractures in RA.

Key Points • Reduced bone mineral density (BMD) and increased tendency to fractures are remarkable in rheumatoid arthritis (RA) patients. • Vitamin D level was decreased in patients and control, and VDR gene polymorphisms were not linked to RA. • Trabecular bone score (TBS) and fracture risk assessment (FRAX) in 10 years are effective tools to assess osteoporotic fractures in RA.

Vitamin D: does it help Tregs in active rheumatoid arthritis patients

Background Regulatory T cells (Tregs) play an important role in the maintenance of immunological tolerance. Tregs deficiency or suppressor functions reduction may be associated with autoimmune diseases development. Objectives To estimate the effect of vitamin D supplementation on Tregs level in the peripheral blood of active rheumatoid arthritis (RA) patients. Methods 40 active RA patients were randomly assigned into two groups. Group I received methotrexate (MTX) plus hydroxychloroquine, group II received MTX, hydroxychloroquine plus vitamin D supplementation for 3 months, and 30 healthy volunteers as control group. Peripheral blood Tregs were measured at baseline and after 3 months by Flow Cytometry. Results At baseline, Tregs percentage was significantly decreased (p<0.001) in both RA patient groups (13.52±1.95%, 13.65±2.98% respectively), compared to controls (28.44±7.37%) with no significant difference between the two patient groups (p=0.866). After 3 months, there was a significant elevation in Tregs percentage in group II compared to group I (p<0.001). Tregs elevation was associated with significant DAS-28 score reduction (p<0.001). Conclusion Vitamin D appears to have important immunomodulatory functions. Vitamin D supplementation can be combined safely with traditional DMARDs to regulate the immune system. Clinical trial registration Tanta University Protocol Record 33846, Vitamin D Effect in Rheumatoid Arthritis, http://www.clinicaltrials.gov, NCT04472481.

The association of megalin and cubilin genetic variants with serum levels of 25-hydroxvitamin D and the incidence of acute coronary syndrome in Egyptians: A case control study

Megalin and cubilin are two receptors that mediate endocytosis of 25-hydroxyvitamin D (25(OH)D) for its final activation by hydroxylation. The aim of the present study was to evaluate the association of polymorphisms in megalin (rs2075252 and rs4668123) and cubilin (rs1801222 and rs12766939) with the circulating serum levels of 25(OH)D and with the early incidence of acute coronary syndrome (ACS) in Egyptians. The study included 328 subjects; 185 ACS patients aged between 27 and 60 years, and 143 healthy age-matched controls. Genotyping of cubilin rs12766939 Single Nucleotide Polymorphism (SNP) was performed using Real-Time Polymerase Chain Reaction (qPCR) and for megalin rs4668123 and rs2075252 and cubilin rs1801222 by Polymerase Chain Reaction- Restriction Fragment Length Polymorphism (PCR-RFLP). 25(OH)D levels were measured by Ultra Performance Liquid Chromatography- Tandem Mass Spectroscopy (UPLC-MS/MS). Results showed that vitamin D deficiency was highly linked to ACS incidence (P < 0.0001). The megalin rs4668123 CC, cubilin rs1801222 GG and cubilin rs12766939 GG + GA genotypes are associated with a higher ACS incidence and can be considered risk factors, according to Chi-squared test (P = 0.0003, 0.0442, 0.013 respectively). Conversely, the megalin rs2075252 SNP was not associated with increased ACS incidence. However, after performing multiple logistic regression analysis, only the megalin rs4668123 SNP was considered an independent ACS risk factor. Furthermore, the megalin rs4668123 CC genotype was associated with lower 25(OH)D levels (P = 0.0018). In conclusion, megalin rs4668123 (CC) was linked to lower 25(OH)D levels and can be considered an independent risk factor for incidence of ACS.

The association between vitamin D concentration and pain: a systematic review and meta-analysis

Objective

Pain-related conditions, such as chronic widespread pain and fibromyalgia, are major burdens for individuals and the health system. Evidence from previous research on the association between circulating 25-hydroxyvitamin D (25(OH)D) concentrations and pain is conflicting. Thus, we aimed to determine if there is an association between mean 25(OH)D concentration (primary aim), or proportion of hypovitaminosis D (secondary aim), and pain conditions in observational studies.

Design

Published observational research on 25(OH)D concentration and pain-related conditions was systematically searched for in electronic sources (MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials) and a random-effects meta-analysis was conducted on included studies.

Results

Eighty-one observational studies with a total of 50 834 participants were identified. Compared with controls, mean 25(OH)D concentration was significantly lower in patients with arthritis (mean difference (MD): −12·34 nmol/l;P<0·001), muscle pain (MD: −8·97 nmol/l;P=0·003) and chronic widespread pain (MD: −7·77 nmol/l;P<0·001), but not in patients with headache or migraine (MD: −2·53 nmol/l;P=0·06). The odds of vitamin D deficiency was increased for arthritis, muscle pain and chronic widespread pain, but not for headache or migraine, compared with controls. Sensitivity analyses revealed similar results.

Conclusions

A significantly lower 25(OH)D concentration was observed in patients with arthritis, muscle pain and chronic widespread pain, compared with those without. These results suggest that low 25(OH)D concentrations may be associated with pain conditions.