Polymorphisms at the Osteoprotegerin and Interleukin-6 Genes in Relation to First-Ever Stroke

Osteoprotegerin and MTHFR gene variations in rheumatoid arthritis: association with disease susceptibility and markers of subclinical atherosclerosis

We aimed to explore whether the rs2073618 variant (G1181C) of the osteoprotegerin (OPG) gene and the methylenetetrahydrofolate reductase (MTHFR) rs1801131 (A1298AC) and rs1801133 (C677T) gene polymorphisms contribute to rheumatoid arthritis (RA) susceptibility and RA related subclinical atherosclerosis. Overall 283 RA patients and 595 healthy controls (HC) were genotyped for common variants of the OPG and MTHFR genes using PCR based assays. Clinical and laboratory parameters were recorded following thorough chart review. Surrogate markers of subclinical atherosclerosis (Carotid/Femoral intima media thickness/plaque formation) along with traditional risk factors for atherosclerosis were assessed in all RA patients and 280HC. Increased prevalence of the CC genotype of the rs2073618 variant was detected in RA patients vs HC (42.4% vs. 33%, p-value: 0.04). RA patients with high serum titers of rheumatoid factor (RF) or anti-cyclic citrullinated peptide (CCP) antibodies displayed increased prevalence of the CC genotype of the rs2073618 variant of the OPG gene compared to HC (48.6% and 47.5 vs 33.3%, p-values: 0.0029and 0.0077 respectively). Of interest, this genotype turned to be associated with higher carotid IMT scores (0.872 ± 0.264 vs 0.816 ± 0.284, p-value: 0.01) and marginally with higher rates of carotid plaque formation (66% vs 54.1%, p = 0.06). The MTHFR 1298CC genotype was more prevalent only in the anti-CCP positive group compared to HC, with no associations detected with markers of subclinical atherosclerosis, following adjustment for traditional cardiovascular (CVD) risk factors. Reduced rates of carotid/femoral plaque formation were detected among RA patients harboring the MTHFR TT genotype (52.4 vs 72.7, p-value: 0.009, respectively). This association remained significant following adjustment for classical CVD risk factors (OR [95% CI 0.364 [0.173–0.765], p-value: 0.008). Genetic variations of the osteoprotegerin and MTHFR genes seem to increase susceptibility for seropositive RA and potentially contribute to subclinical atherosclerosis linked to RA. Larger studies are needed to confirm these findings.

Effects of Neurological Disorders on Bone Health

Neurological diseases, particularly in the context of aging, have serious impacts on quality of life and can negatively affect bone health. The brain-bone axis is critically important for skeletal metabolism, sensory innervation, and endocrine cross-talk between these organs. This review discusses current evidence for the cellular and molecular mechanisms by which various neurological disease categories, including autoimmune, developmental, dementia-related, movement, neuromuscular, stroke, trauma, and psychological, impart changes in bone homeostasis and mass, as well as fracture risk. Likewise, how bone may affect neurological function is discussed. Gaining a better understanding of brain-bone interactions, particularly in patients with underlying neurological disorders, may lead to development of novel therapies and discovery of shared risk factors, as well as highlight the need for broad, whole-health clinical approaches toward treatment.

Effect of osteoprotegerin gene polymorphisms on the risk of cervical spondylotic myelopathy in a Chinese population

OBJECTIVE

Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord dysfunction. Our study aims to explore the correlation of osteoprotegerin (OPG) gene polymorphisms and the risk factors and severity of CSM.

PATIENTS AND METHODS

The peripheral blood samples from 494 CSM patients and 515 healthy individuals were collected for detecting the 950T/C, 1181G/C and 163A/G genotypes and genetic equilibrium of OPG in the CSM and control groups and analyzing the genotype distribution and allele frequency. The severity of CSM and the impaired segments were evaluated by the Japanese Orthopedic Association (JOA) scoring combined with cervical magnetic resonance imaging (MRI), in order to investigate the relations between the three genotypes of OPG promoter gene loci (950T/C, 163A/G and 1181G/C) and occurrence as well as severity of CSM.

RESULTS

The risk rate of TC genotype carrier suffered from CSM was 0.46, of TT genotype carrier was 0.27. The risk rate of T allele carrier suffered from CSM was 0.37. In 950T/C single nucleotide polymorphism (SNP), patients with TC, TT and T genotypes had lower risk to suffer from CSM.

CONCLUSION

Taken together, OPG 950T/C SNP protects against CSM, and it is correlated with the severity of CSM, providing a new idea for the prevention and treatment of CSM.

Associations between OPG and RANKL polymorphisms, vertebral fractures, and abdominal aortic calcification in community-dwelling older subjects: the Sao Paulo Ageing & Health Study (SPAH)

This is the first study analyzing concomitantly osteoprotegerin (OPG)/receptor activator of nuclear factor kappa B ligand (RANKL) polymorphisms and OPG/RANKL serum levels and their association with bone mineral density (BMD), vertebral fractures, and vascular aortic calcification in a cohort of 800 subjects in community-dwelling older individuals.

INTRODUCTION

Osteoprotegerin (OPG) and RANKL play an important role in osteoclast activation and differentiation as well as in vascular calcification. At present, there are no studies of OPG or RANKL gene polymorphisms in Brazilian older populations. The aim of this study was to evaluate OPG/RANKL polymorphism and their association with vertebral fractures (VFs) and aortic calcification.

METHODS

Eight hundred subjects (497 women/303 men) were genotyped for the OPG 1181G>C (rs2073618), 163C>T (rs3102735), 245T>G (rs3134069), and 209G>A (rs3134070) and RANKL A>G (rs2277438) single-nucleotide polymorphisms (SNPs). VFs were evaluated by spine radiography (Genant's method). Aortic calcification was quantified using Kauppila's method.

RESULTS

The isolated genotype analyses and single-allele frequency data showed association of OPG 163C, 245G, and 209A alleles with presence of VFs (P < 0.05). Multiple logistic regression of subjects with absence of VFs vs. those with VFs (grades II/III) revealed only OPG 209A homozygosity as a risk factor for higher-grade VFs (odds ratio (OR) = 4.17, 95 % CI 1.03-16.93, P = 0.046). Regarding aortic calcification, the isolated genotype analysis frequency data revealed a significant association of OPG 1181G, 163C, 245G, and 209A alleles with absent aortic calcification (P < 0.05). Multiple logistic regression data confirmed that the OPG 209A allele was protective for aortic calcification (OR = 0.63, 95 % CI 0.45-0.88, P = 0.007) and the OPG 1181C allele was a risk factor for aortic calcification (OR = 1.26, 95 % CI 1.00-1.58, P = 0.046).

CONCLUSION

This study showed that the OPG 209AA genotype was a risk factor for higher-grade VFs, the OPG 209A allele was protective for aortic calcification, and the OPG 1181C was a risk factor for aortic calcification, supporting the involvement of OPG polymorphisms in the analyzed phenotypes and the concept that the related pathogenesis is multifactorial.

Polymorphisms in three genes are associated with hemorrhagic stroke

BACKGROUND

Multiligand receptor for advanced glycation end products (RAGE), osteoprotegerin, and Golgb1 genes may be implicated in atherosclerosis and vascular diseases. Single nucleotide polymorphisms (SNPs) rs1035798 in RAGE gene, rs2073617 and rs2073618 in TNFRSF11B, and rs3732410 in Golgb1 will be investigated on whether there is an association with hemorrhagic stroke (HS) in Chinese population.

METHODS

A total of 600 subjects including 199 HS patients and 401 controls were assayed. These samples were divided into two groups: the ≤50 year and >50 year groups. Genotyping of SNPs was determined using the SEQUENOM MassARRAY matrix-assisted laser desorption ionization-time-of-flight-mass spectrometry. The association between genotype and HS risk was evaluated by computing the odds ratio (OR) and 95% confidence interval (CI) with multivariate unconditional logistic regression analyses.

RESULTS

Our data showed that in the ≤50 year group, the rs1035798 major allele homozygote C/C in RAGE gene was associated with an increased risk of HS, while Golgb1 rs3732410 minor allele homozygote G/G was associated with a decreased risk of HS. In the >50 year group, the major allele homozygote G/G of rs2073618 was found to be associated with an increased risk of HS.

CONCLUSIONS

The polymorphisms rs1035798 of RAGE gene, rs2073618 of TNFRSF11B, and rs3732410 of Golgb1 might be involved in the risk of HS at different stage of ages.

Association of IL-6-174G > C and -572C > G polymorphisms with risk of young ischemic stroke patients

AIM

To investigate the association between interleukin-6 (IL-6) -174G>C and -572C>G polymorphisms and risk for ischemic stroke (IS) in young patients.

METHODS

We genotyped IL-6 -174G>C and -572C>G in a case-control study of 430 young IS patients and 461 control subjects. An unconditional multiple logistical regression model was used to calculate the effects of IL-6-174G>C and -572C>G polymorphisms on IS risk.

RESULTS

Higher body mass index, diabetes, hypertension, obesity, and smoking were associated with risk of ischemic stroke. Multivariate regression analyses showed that subjects carrying the -174CC genotype (OR=1.69, 95% CI=1.16-2.57) and C allele (OR=1.37, 95% CI=1.09-1.67) had a small but significant increased risk of IS. Similarly, those carrying the -572GG genotype (OR=2.12, 95% CI=1.18-3.82) and G allele (OR=1.43, 95% CI=1.14-1.83) had a moderate increased risk of IS. We found the -174G>C and -572C>G polymorphisms interact with hypertension and obesity.

CONCLUSION

Our results suggest that polymorphisms in IL-6-174G>C and -572C>G are associated with IS risk in young patients, and that these polymorphisms interact with hypertension, obesity and etiologic subtypes. These findings could be helpful in identifying individuals at increased risk for developing IS.

Bone mineral density and incidence of stroke: European prospective investigation into cancer-norfolk population-based study, systematic review, and meta-analysis

BACKGROUND AND PURPOSE

The prospective link between osteoporosis and future risk of stroke requires evidence from large-scale population-based long-term studies.

METHODS

Calcaneum broadband ultrasound attenuation was measured in the Norfolk cohort of the European Prospective Investigation into Cancer-Norfolk between 1997 and 2000. Incident strokes were ascertained by hospital record linkage and death certificates in March 2009 and December 2011, respectively. A search of MEDLINE and EMBASE was performed to evaluate the relationship between bone mineral density and incident stroke. After data extraction of relevant studies, pooled risk of stroke was estimated using meta-analysis.

RESULTS

In 14 290 participants (mean follow-up of 9.3 years; total person-years 132 574), there were 599 incident strokes. Participants in the lowest 10% of the calcaneum broadband ultrasound attenuation distribution had an increased stroke risk (hazard ratio 1.41; 95% confidence intervals, 1.02-1.94) compared with those in the top 30% of the distribution after adjustments. A decrease of ~1 standard deviation in broadband ultrasound attenuation (20 db/MHz) was associated with a 17% increase in relative risk of stroke (95% confidence intervals, 5%-30%). Meta-analysis of 4 studies (25 760 participants, 1237 cases of stroke) found that for every decrease in 1 standard deviation in bone mineral density, there was an increased risk of incident stroke among women (pooled relative risk 1.22; 95% confidence intervals, 1.09-1.37; I2=0%, 3 studies) but not in men (pooled relative risk 1.05; 95% confidence intervals, 0.94-1.17; I(2)=0%, 2 studies).

CONCLUSIONS

Bone mineral density predicts total stroke risk. The evidence is stronger in women with regard to the continuous relationship.

T Allele of nonsense polymorphism (rs2039381, Gln71Stop) of interferon-ε is a risk factor for the development of intracerebral hemorrhage

Interferons (IFNs) play key roles in various biologic responses including antiviral and immune reactions. We evaluated one possible risk factor in nonsense polymorphism (rs2039381, Gln71Stop) of interferon-ε (IFNE). We recruited stroke [119 ischemic stroke (IS) and 145 intracerebral hemorrhage (ICH)] and control (401), respectively. The nonsense SNP (rs2039381, Gln71Stop) of IFNE was selected. We identified individual genotype using sequencing. SNPStats and SPSS 18.0 programs were used to analyze genetic data. Genotype frequencies (C/C:C/T:T/T) in the ICH group and control group were 59.3:37.9:2.8 and 73.6:23.4:3.0, respectively. We found that rs2039381 was associated with ICH (OR = 2.01, 95% CI = 1.33-3.03, p = 0.001 in codominant1 model; OR = 1.91, 95% CI = 1.28-2.84, p = 0.0016 in dominant model; OR = 1.60, 95% CI = 1.14-2.26, p = 0.0074 in log-additive model). T allele frequency of rs2039381 was significantly higher in ICH than in controls. The nonsense SNP (rs2039381, Gln71Stop) of IFNE was associated with ICH (OR = 1.61, 95% CI = 1.14-2.26, p = 0.006). A nonsense SNP (rs2039381, Gln71Stop) of IFNE was associated with ICH in Korean population. Our findings raise the possibility that the T allele of rs2039381 is a risk factor which is susceptible to ICH.

(Sub)clinical cardiovascular disease is associated with increased bone loss and fracture risk; a systematic review of the association between cardiovascular disease and osteoporosis

Introduction

Both cardiovascular disease and osteoporosis are important causes of morbidity and mortality in the elderly. The co-occurrence of cardiovascular disease and osteoporosis prompted us to review the evidence of an association between cardiovascular (CV) disease and osteoporosis and potential shared common pathophysiological mechanisms.

Methods

A systematic literature search (Medline, Pubmed and Embase) was conducted to identify all clinical studies that investigated the association between cardiovascular disease and osteoporosis. Relevant studies were screened for quality according to guidelines as proposed by the Dutch Cochrane Centre and evidence was summarized.

Results

Seventy studies were included in this review. Due to a large heterogeneity in study population, design and outcome measures a formal meta-analysis was not possible. Six of the highest ranked studies (mean n = 2,000) showed that individuals with prevalent subclinical CV disease had higher risk for increased bone loss and fractures during follow-up compared to persons without CV disease (range of reported risk: hazard ratio (HR) 1.5; odds ratio (OR) 2.3 to 3.0). The largest study (n = 31,936) reported a more than four times higher risk in women and more than six times higher risk in men. There is moderate evidence that individuals with low bone mass had higher CV mortality rates and incident CV events than subjects with normal bone mass (risk rates 1.2 to 1.4). Although the shared common pathophysiological mechanisms are not fully elucidated, the most important factors that might explain this association appear to be, besides age, estrogen deficiency and inflammation.

Conclusions

The current evidence indicates that individuals with prevalent subclinical CV disease are at increased risk for bone loss and subsequent fractures. Presently no firm conclusions can be drawn as to what extent low bone mineral density might be associated with increased cardiovascular risk.

Osteoprotegerin levels in patients with severe mental disorders

BACKGROUND

Severe mental disorders are associated with elevated levels of inflammatory markers. In the present study, we investigated whether osteoprotegerin (OPG), a member of the tumour necrosis factor receptor family involved in calcification and inflammation, is elevated in patients with severe mental disorders.

METHODS

We measured the plasma levels of OPG in patients with severe mental disorders (n = 312; 125 with bipolar disorder and 187 with schizophrenia) and healthy volunteers (n = 239).

RESULTS

The mean plasma levels of OPG were significantly higher in patients than in controls (t531 = 2.6, p = 0.01), with the same pattern in bipolar disorder and schizophrenia. The increase was significant after adjustment for possible confounding variables, including age, sex, ethnic background, alcohol consumption, liver and kidney function, diabetes, cardiovascular disease, autoimmune diseases and levels of cholesterol, glucose and C-reactive protein.

LIMITATIONS

Owing to the cross-sectional design, it is difficult to determine causality.

CONCLUSION

Our results indicate that elevated OPG levels are associated with severe mental disorders and suggest that mechanisms related to calcification and inflammation may play a role in disease development.

Lack of Observed Association between High Plasma Osteoprotegerin Concentrations and Ischemic Stroke Risk in a Healthy Population

Background: Several studies suggest that osteoprotegerin (OPG) concentrations may be associated with the risk of ischemic stroke, but no large prospective studies have been conducted. We conducted a nested case-control study within a large cohort to elucidate a possible relation.

Methods: The study was done within a follow-up study including 57 053 men and women. Baseline data included OPG concentrations, lifestyle factors, and medical history. Median length of follow-up was 3.1 years. We assessed the relationship between OPG and stroke risk using conditional logistic regression to adjust for known risk factors (smoking, blood pressure, cholesterol, diabetes, body mass index, alcohol use, polyunsaturated fatty acids, and education).

Results: We identified 254 cases with verified incident acute ischemic stroke and 254 age- and sex-matched controls. Median plasma OPG concentration among cases was 1.84 μg/L (25th–75th percentile 1.45–2.30 μg/L) compared with 1.87 μg/L (1.49–2.27 μg/L) in the control group. The adjusted odds ratio was 0.87 (95% CI 0.46–1.63) comparing participants in the highest quartile of OPG concentrations with those in the lowest quartile.

Conclusions: These findings provide no support for the hypothesis that plasma OPG concentrations are associated with an increased risk of ischemic stroke. This result could indicate a different pathogenic process in stroke development from that in ischemic heart disease, where OPG is a strong predictor.

Advances in the Genetic Basis of Ischemic Stroke

As one of the leading causes of death within both the developed and developing world, stroke is a world-wide problem. About 80% of strokes are ischemic. It is caused by multiple genetic factors, environmental factors, and interactions among these factors. There is a long list of candidate genes that have been studied for a possible association with ischemic stroke. Among the most widely investigated genes are those involved in haemostasis, inflammation, nitric oxide production, homocysteine and lipid metabolism, renin-angiotensin-aldosterone system. Combined link-age/association studies have demonstrated that genes encoding PDE4D and ALOX5AP confer risk for stroke. We review the studies of these genes which may have potential application on the early diagnosis, prevention and treatment ischemic stroke patients.