Association Between Chronic Osteomyelitis and Risk of End-Stage Renal Disease: A Nationwide Population-Based Cohort Study

Chronic osteomyelitis risk is associated with NLRP3 gene rs10754558 polymorphism in a Chinese Han Population

BACKGROUND

Single nucleotide polymorphisms (SNPs) in the nucleotide-binding domain leucine-rich repeat protein-3 (NLRP3) gene are reported to be linked to many inflammatory disorders. However, uncertainty persists over the associations between these SNPs and susceptibilities to chronic osteomyelitis (COM). This study aimed to investigate potential relationships between NLRP3 gene SNPs and the risks of developing COM in a Chinese Han cohort.

METHODS

The four tag SNPs of the NLRP3 gene were genotyped in a total of 428 COM patients and 368 healthy controlsusing the SNapShot technique. The genotype distribution, mutant allele frequency, and the four genetic models (dominant, recessive, homozygous, and heterozygous) of the four SNPs were compared between the two groups.

RESULTS

A significant association was found between rs10754558 polymorphism and the probability of COM occurence by the heterozygous model (P = 0.037, odds ratio [OR] = 1.541, 95% confidence interval [CI] = 1.025-2.319), indicating that rs10754558 may be associated with a higher risk of developing COM.In addition, possible relationship was found between rs7525979 polymorphism and the risk of COM development by the outcomes of homozygous (P = 0.073, OR = 0.453, 95% CI = 0.187-1.097) and recessive (P = 0.093, OR = 0.478, 95% CI = 0.198-1.151) models, though no statistical differences were obtained.

CONCLUSIONS

Outcomes of the present study showed, for the first time, that rs10754558 polymorphism of the NLRP3 gene may increase the risk of COM development in this Chinese Han population, with genotype CG as a risk factor. Nonetheless, this conclusion requires verification from further studies with a larger sample size.

Silver ion-doped calcium phosphate-based bone-graft substitute eliminates chronic osteomyelitis: An experimental study in animals

Despite the latest technologies and advances in microbiology and orthopedic surgery, chronic osteomyelitis is still a challenging disorder. Antibiotic resistance and bacterially induced bone destruction can have very serious consequences. We hypothesized that calcium phosphate-based bone graft substitution with silver ion doping would simultaneously treat bone infection and the bony defect in the chronic osteomyelitis. An unicortical 10-mm-diameter bone was harvested in the proximal tibial metaphysis of 24 rabbits. After contaminating the wounds with an infective dose of methicillin-resistant Staphylococcus aureus (MRSA), osteomyelitis was proven radiographically and microbiologically in all rabbits. Animals were than divided into three groups. The first group received vancomycin-impregnated bone cement beads (comparative control group), the second/experimental group received silver ion-doped calcium phosphate beads and the third group received pure calcium phosphate beads (negative controls). Radiographs, intraosseous cultures, and histopathological examinations were performed on postoperative Week 10. The cultures showed no evidence of intramedullary infection in the silver ion-doped calcium phosphate beads group, but they were positive for MRSA in four of the six rabbits in the vancomycin- impregnated bone cement beads group and in all of the eight rabbits in the pure calcium phosphate beads group. Quantitative assessment of histopathological examination showed lowest total damage score in silver ion-doped calcium phosphate beads group (p < .001). Percentage of osteoid tissue + bony tissue was also higher in this group compared with other groups. In the final radiological examinations, it was observed that the changes caused by osteomyelitis in the bone tissue in the silver ion-doped calcium phosphate beads group were much improved compared with the vancomycin-impregnated bone cement beads group. Silver ion doped calcium phosphate-based bone-graft substitute offer the ability to stimulate bone growth, combat infection, and, ultimately, treat experimental chronic osteomyelitis in an animal model.

Shorter Telomere Length in Peripheral Blood Leukocytes Is Associated with Post-Traumatic Chronic Osteomyelitis

Background: This study investigated the association between post-traumatic chronic osteomyelitis (COM) and peripheral leukocyte telomere length (PLTL) and explored factors associated with PLTL in COM. Methods: A total of 56 patients with post-traumatic COM of the extremity and 62 healthy control subjects were recruited. The PLTL was measured by real-time PCR. Binary logistic regression analysis was used to identify factors in correlation with telomere length. Sex, age, white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and infection duration were included as independent variables in the logistic regression model. Results: Post-traumatic COM patients had significantly shorter PLTLs (5.39 ± 0.40) than healthy control subjects (5.69 ± 0.46; p < 0.001). Binary logistic regression analysis showed that PLTL had a statistically significant association with age (B = -0.072; p = 0.013) and CRP (B = -0.061; p = 0.033). The logistic regression model was statistically significant and explained 31.4% (Nagelkerke R²) of the change in telomere length and correctly classified 69.6% of the cases. Conclusions: Patients with post-traumatic COM have shorter PLTLs than healthy subjects. The PLTL erosion of post-traumatic COM was partially explained by age and CRP.

Health Care Costs of Post-traumatic Osteomyelitis in China: Current Situation and Influencing Factors

BACKGROUND

Currently, very limited information is available regarding the economic burdens of patients with extremity post-traumatic osteomyelitis (OM). This study aimed to investigate direct health care costs and utilization for inpatients with extremity post-traumatic OM and analyze its constituent ratios and influencing factors in Southern China.

METHODS

We searched in the electronic medical record system for inpatients who had received surgical interventions at our department between 2013 and 2016 for extremity post-traumatic OM. Data of direct health care costs incurred during their hospitalizations were collected in six main categories (service, diagnosis, treatment, materials, pharmaceuticals, and miscellaneous expenses). In addition, data of total medical costs for contemporaneous inpatients with non-post-traumatic OM were also collected as controls.

RESULTS

A total of 278 post-traumatic OM and 10,420 controls were included. The median cost for the post-traumatic OM inpatients was $10,504 US dollars, 4.8-fold higher than that for those with non-post-traumatic OM ($2189, P < 0.001). The direct cost in the category of materials accounted for the largest proportion (61%), followed by that in pharmaceuticals (12%) and treatment (11%). The median number of hospital admissions for post-traumatic OM patients was 1 time, with a median length-of-stay of 22 d. The most influencing factors for the health care costs of the post-traumatic OM inpatients were use of an external fixator ($16,016 for those who used versus $4956 for those who did not, P < 0.001), external fixator type ($19,563 for ring fixator versus $14,966 for rail fixator, P < 0.001), infection site ($13,755 for tibia, $14,216 for femur and $5673 for calcaneus, P < 0.001), and infection-associated injury type ($12,890 for infection after open fracture versus $8087 for infection after closed fracture, P = 0.001).

CONCLUSIONS

An unexpectedly large proportion of the direct health care costs for inpatients with extremity post-traumatic OM went to cover an external fixator, with expenses for pharmaceuticals and treatment accounting for only a little more than the tenth of the total health care costs. Use of external fixator, external fixator type, infection site, and infection-associated injury type directly influenced the health care costs.

Interleukin-1 Beta Gene Polymorphism rs16944 May Associate with Increased Susceptibility to Extremity Chronic Osteomyelitis in Chinese Han Population

Background

Previous studies had indicated that interleukin-1 beta (IL-1β) gene single nucleotide polymorphisms (SNPs) associate with different inflammatory diseases. However, potential links between these polymorphisms and susceptibility to extremity chronic osteomyelitis (COM) remain unclear. This study aimed to investigate relationships between IL-1β gene polymorphisms (rs16944, rs1143627, rs1143634, and rs2853550) and risks of developing extremity COM in Chinese Han population.

Methods

Altogether 233 extremity COM patients and 200 healthy controls were genotyped for the four tag SNPs of the IL-1β gene using the SNapShot genotyping method. Comparisons were performed regarding genotype distribution, mutant allele frequency, and four genetic models (dominant, recessive, homozygous, and heterozygous models) of the four SNPs between the two groups.

Results

Significant associations were identified between rs16944 polymorphism and the risk of developing COM by dominant model (P = 0.026, OR = 1.698, 95% CI 1.065-2.707) and heterozygous model (P = 0.030, OR = 1.733, 95% CI 1.055-2.847). Although no statistical differences were found of rs1143627 polymorphism between the two groups, there existed a trend that rs1143627 may be linked to an elevated risk of developing COM by outcomes of dominant (P = 0.061), homozygous (P = 0.080) and heterozygous (P = 0.095) models. However, no statistical correlations were found between rs1143634 and rs2853550 polymorphisms and susceptibility to COM in Chinese Han population.

Conclusions

To our knowledge, we reported for the first time that IL-1β gene rs16944 polymorphism may contribute to the increased susceptibility to extremity COM in Chinese Han population, with genotype of AG as a risk factor.

Risk of posterior circulation stroke in patients with cervical spondylosis: A nationwide, population-based study

BACKGROUND AND AIMS

Cervical spondylosis (CS) is reported to be associated with vertebrobasilar insufficiency. However, few cohort studies have investigated the association between CS and posterior circulation ischemic stroke.

METHODS

The study cohort comprised 27,990 patients aged ≥18 years with a first diagnosis of CS. The controls consisted of patients with propensity score matched for age, sex, and comorbidities at a ratio of 1:1. We investigated the relationships of CS with ischemic stroke and all-cause mortality. Cox regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). The average follow-up duration was 6.13 (SD = 3.18) and 6.07 (SD = 3.19) years in the CS and non-CS cohorts, respectively.

RESULTS

The mean age of CS patients and non-CS patients was 54.9 ± 13.4 and 55.1 ± 14.9 years. Fifty-eight point five percent of CS patients and 59.2% of non-CS patients were women. CS patients were 1.46 folds more likely to develop a posterior circulation ischemic stroke (95% CI, 1.23-1.72) than non-CS patients. CS patients with myelopathy exhibited a 1.50-fold risk (95% CI, 1.21-1.86) of posterior circulation ischemic stroke compared with non-CS patients; CS patients without myelopathy were at a 1.43-fold risk (95% CI, 1.18-1.73) of posterior ischemic stroke compared with non-CS patients. The risk of posterior ischemic stroke was non-significant between non-CS patients and CS patients who had received spinal anterior decompression (adjusted HR, 1.66; 95% CI, 0.78-3.52), while receiving posterior decompression was associated with a 4.23-fold risk of posterior ischemic stroke (95% CI, 1.05-17.0).

CONCLUSIONS

This population-based study showed that CS is associated with an increased risk of posterior circulation ischemic stroke. Surgical posterior decompression was associated with the highest risk of posterior ischemic stroke.

Increasing risk of cataract in HCV patients receiving anti-HCV therapy: A nationwide cohort study

Purpose

Hepatitis C virus (HCV) infection is associated with increased systemic oxidative stress, which leads to cardiovascular events, diabetes, and chronic kidney disease. Similarly, cataract is also associated with increased oxidative stress. The association between HCV infection and increased risk of cataract remains unclear.

Methods

A total of 11,652 HCV-infected patients and 46,608 age- and sex-matched non-HCV infected patients were identified during 2003–2011. All patient data were tracked until a diagnosis of cataract, death, or the end of 2011. Cumulative incidences and hazard ratios (HRs) were calculated.

Results

The mean follow-up durations were 5.29 and 5.86 years for the HCV and non-HCV cohorts, respectively. The overall incidence density rate for cataract was 1.36 times higher in the HCV cohort than in the non-HCV cohort (1.86 and 1.37 per 100 person-y, respectively). After adjusting for age, sex, comorbidities of diabetes, hypertension, hyperlipidemia, asthma, chronic obstructive pulmonary disease, coronary artery disease, and anxiety, patients with HCV infection had an increased risk of cataract compared with those without HCV infection [adjusted HR = 1.23, 95% confidence interval (CI) = 1.14–1.32]. HCV-infected patients receiving interferon–ribavirin therapy had a 1.83 times higher (95% CI = 1.40–2.38) risk of cataract than non-HCV infected patients did.

Conclusion

HCV infection, even without the complication of cirrhosis, is associated with an increased risk of cataract, and this risk is higher in HCV-infected patients undergoing interferon–ribavirin therapy.

Association of statin use and the risk of end-stage renal disease: A nationwide Asian population-based case-control study

BACKGROUND

Although experimental models have shown that statins could alleviate glomerular damage and decrease urinary protein excretion, the renal effects of statins remain unclear. A case-control study was conducted using data from Taiwan's National Health Insurance system.

METHODS

An end-stage renal disease (ESRD) group comprising 11,486 patients was established. Each patient was frequency-matched by age, sex, and comorbidities with one person without ESRD from the general population. Logistic regression analysis was performed to estimate the influence of statin use on ESRD risk.

RESULTS

The overall adjusted odds ratios (ORs) of ESRD among patients who received statins was 1.59 (95% confidence interval=1.50-1.68). The raised ESRD risk of statin remained consolidated regardless of statin type (P<.001), except lovastatin. Further, while stratified by cumulative define daily dose, the risk of ESRD increased with accumulative dosage of statins (P for trend<.001).

CONCLUSION

This population-based case-control study showed that statin use might be associated with increased ESRD risks. Large-scale randomized clinical trial encompassing statins of different kinds and populations of different comorbidities would be helpful to clarify the potential ESRD risks of statin users.

Chronic osteomyelitis increases long-term mortality risk in the elderly: a nationwide population-based cohort study

Background

The elderly are predisposed to chronic osteomyelitis because of the immunocompromised nature of aging and increasing number of chronic comorbidities. Chronic osteomyelitis may significantly affect the health of the elderly; however, its impact on long-term mortality remains unclear. We conceived this retrospective nationwide population-based cohort study to address this issue.

Methods

We identified 10,615 elderly patients (≥65 years) comprising 965 patients with chronic osteomyelitis and 9650 without chronic osteomyelitis matched at a ratio of 1:10 by age and gender between 1999 and 2010 from the Taiwan National Health Insurance Research Database. The risk of chronic osteomyelitis between the two cohorts was compared by a following-up until 2011.

Results

Patients with chronic osteomyelitis had a significantly higher mortality risk than those without chronic osteomyelitis [incidence rate ratio (IRR): 2.29; 95 % confidence interval (CI): 2.01–2.59], particularly the old elderly (≥85 years; IRR: 3.27; 95 % CI: 2.22–4.82) and males (IRR: 2.7; 95 % CI: 2.31–3.16). The highest mortality risk was observed in the first month (IRR: 5.01; 95 % CI: 2.02–12.42), and it remained persistently higher even after 6 years (IRR: 1.53; 95 % CI: 1.13–2.06) of follow-up. Cox proportional hazard regression analysis showed that chronic osteomyelitis [adjusted hazard ratio (AHR): 1.89; 95 % CI: 1.66–2.15], advanced age (≥85 years; AHR: 2.02; 95 % CI: 1.70–2.41), male (AHR: 1.34; 95 % CI: 1.22–1.48), and chronic comorbidities were independent predictors of mortality.

Conclusions

This study demonstrated that chronic osteomyelitis significantly increased the long-term mortality risk in the elderly. Therefore, strategies for prevention and treatment of chronic osteomyelitis and concomitant control of chronic comorbidities are very important for the management of the elderly, particularly for a future with an increasingly aged population worldwide.