Vitamin D status, serum lipid concentrations, and vitamin D receptor (VDR) gene polymorphisms in Familial Mediterranean fever

Serum endocan, asymmetric dimethylarginine and lipid profile in children with familial Mediterranean fever

BACKGROUND

Familial Mediterranean fever (FMF) is a chronic inflammatory disease, and it is thought that subclinical inflammation persists even when there are no attacks, eventually causing endothelial dysfunction (ED) and atherosclerosis. Limited data are available about serum endocan, asymmetric dimethylarginine (ADMA) and lipid profile in children with FMF, so we aimed to evaluate these markers in children with FMF during the attack-free period.

METHODS

A total of 50 patients diagnosed with FMF and 50 age and sex-matched healthy children were recruited. Serum endocan, ADMA and lipid profiles were measured. Also, atherogenic indices (Castelli's risk indices I and II [CRI I and II], atherogenic index of plasma [AIP] and atherogenic coefficient [AC]) were calculated.

RESULTS

Serum endocan, ADMA levels, low-density lipoprotein cholesterol, triglycerides, CRI II and AIP of the FMF patients were significantly higher than controls (p < 0.001). Unlike serum endocan, serum ADMA showed a positive significant correlation with total cholesterol, non-high density lipoprotein cholesterol, CRI I, AIP and AC (p < 0.001, p < 0.001, p = 0.004, p = 0.028, p = 0.004 respectively).

CONCLUSION

Serum ADMA and lipid profile might be used as potential markers for endothelial dysfunction and increased cardiovascular risk in FMF patients.

IMPACT

Theoretically, serum ADMA may affect lipid profiles and serum endocan represents an intriguing biomarker related to inflammation. Coexistence of dyslipidemia represents an additional risk factor that contributes to the onset of early atherosclerosis. A few studies investigated the role of changes in lipid profile and lipid ratios in accelerated atherosclerosis pathogenesis in FMF patients. The relationship between colchicine and lipid profile is contradictory. Although colchicine can cause dyslipidemia, it also has anti-atherosclerosis effects. Elevated ADMA level and atherogenic indices in FMF children reflect their potential role in the early detection of cardiovascular affection in FMF patients.

The influence of vitamin D administration on the clinical presentation, body mass index, and osteoprotegerin (OPG) level in a sample of Egyptian children with familial Mediterranean fever

Background

Familial Mediterranean fever (FMF) is autosomal recessive chronic disease represents by recurring attacks of polyserositis, fever, and joint pain. Vitamin D deficiency in FMF children has been recently mentioned in literature and linked to delayed physical growth. Osteoporosis in FMF patients can be linked to low levels of vitamin D, too. Osteoprotegerin (OPG) might be used as an indicator for osteoporosis. Therefore, this work aimed to investigate the impact of vitamin D administration on clinical status, BMI, and bone mineral density represented by alterations in the OPG serum levels in a group of Egyptian children with FMF. This was a prospective longitudinal study carried out on 33 children, aged 4–16 years, with FMF cases. Patients were on colchicine 0.5–2 mg/day and received vitamin D3 oral drops 2800 IU/ml; each drop contains 100 IU in a dose of 600 IU/day for 6 months. The effect of vitamin D administration was evaluated clinically, anthropometrically and by assessment of serum vitamin D and osteoprotegerin at baseline and 6 months later.

Results

Serum vitamin D levels were below the normal range before intervention and showed significant improvement (p < 0.001) 6 months after intervention. Significant increase in both BMI Z scores (p < 0.05) and OPG serum levels and improvement in the clinical status as illustrated by significant decrease in the number of cases with fever, arthritis, and abdominal pain and significant decrease in the frequency and duration of the attacks (p < 0.001).

Conclusion

Our results intensely indicate that vitamin D supplementation improved the clinical condition, BMI, and bone mineral density in children with FMF.

Does Familial Mediterranean Fever Provoke Atherosclerosis in Children? Evaluation of Arterial Stiffness and Serum Endocan Levels

OBJECTIVES

This study aimed to evaluate the risk for atherosclerosis by using echocardiographic arterial stiffness (AS) parameters and serum endocan levels, as a biomarker of endothelial dysfunction (ED) in children with FMF.

METHODS

Seventy-nine children with FMF (12-18 years) and 41 healthy children were included, and clinical features (age at the first attack, age at the time of diagnosis, diagnosis delay time, colchicine dose, biological agent usage, MEFV mutations, and symptoms of attacks) of patients were noted. Arterial stiffness parameters were calculated by using echocardiographic aortic measurements with blood pressure monitoring. Hemogram parameters, acute phase reactants, blood glucose and lipid levels of 12 hours of fasting, and serum endocan levels were evaluated for all participants.

RESULTS

There were no statistically significance regarding demographic features, acute phase reactants, and hemogram parameters. Blood glucose and lipid levels were similar, except for HDL (lower in FMF group, p=0.029). Serum endocan levels did not differ in two groups (p=0.906). Only stiffness of descending aorta was lower in FMF group (p=0.028), and the other AS parameters were similar between two groups (p>0.05 for each parameters).

CONCLUSION

Good disease control could be preventive for atherosclerosis in children with FMF. On the other hand, screening for cardiovascular diseases is essential, particularly for uncontrolled cases. Distribution of MEFV gene mutations KEY POINTS: • Exaggerated inflammation is the prominent feature of FMF attacks; moreover, it is shown that subclinical inflammation might also continue in attack-free periods. • Chronic inflammation contributes to atherosclerotic process in almost all stages by activating endothelial cells, producing reactive oxygen species, and accelerating foam cell and atherosclerotic plaque formations. • However, the results of this study showed that there was no difference in terms of atherosclerotic markers such as serum endocan levels and arterial stiffness parameters between pediatric FMF patients and healthy peers. • Good disease control in pediatric FMF patients may prevent early atherosclerotic changes during childhood, which then may lead a probable decreased risk of subsequent CVD in adulthood.

Vitamin D receptor gene ApaI and FokI polymorphisms and its association with inflammation and oxidative stress in vitamin D sufficient Caucasian Spanish children

BACKGROUND

Vitamin D has gone from being just one vitamin to being an important prohormone with multiple effects on different tissue types. The mechanism of action of the active form or calcitriol is mediated by the intracellular vitamin D receptor (VDR). The interaction of the VDR with calcitriol modulates the expression of target genes involved in cell proliferation and cytokine production. Several studies have explored the effects of vitamin D deficiency in inflammatory disorders. Furthermore, some mutations in the VDR can affect its functionality. The focus of this study was to explore associations between VDR single nucleotide polymorphisms (SNPs) and markers of inflammation and oxidative stress in vitamin D sufficient children.

METHODS

This is a cross-sectional study of a Caucasian Spanish population including 155 healthy children (87 males, 68 females) aged 10 to 14 years. FokI, ApaI and TaqI SNPs of the VDR gene were genotyped. Routine biochemistry, serum levels of interleukin-6, tumor necrosis factor-α, interferon-γ, 8-isoprostaglandin F2α and nitrates were determined.

RESULTS

The homozygous major allele AA in the FokI SNP was associated with increased levels of high-density lipoprotein cholesterol in a recessive inheritance mode (P=0.025). The minor allele A of ApaI was significantly associated with decreased serum tumor necrosis factor-α and 8-isoprostaglandin F2α in an additive mode (P=0.016 and P=0.020 respectively). No significant associations were observed between the TaqI SNP and any of the parameters evaluated. Haplotype analysis confirmed the significance of the relationships between ApaI and FokI SNPs and parameters associated with inflammation and oxidative stress.

CONCLUSIONS

Genetic variations of VDR are associated with subtle changes in metabolic, inflammatory and oxidative stress markers. These results may provide a better understanding of the relationships between vitamin D and these clinical parameters.