The Prevalence of Osteoporosis in an Iranian Population

Iranian Multicenter Osteoporosis Studies (IMOS) during last decade: rationale, main findings, lessons learned and the way forward

Purpose

Osteoporosis remains a major public health concern, considering its high prevalence along with its association with osteoporotic fractures. It imposes a heavy burden on the society worldwide as the population ages. This paper aims to provide a brief review on Iranian multicenter osteoporosis studies (IMOS) studies and provide some recommendations for improvement.

Methods

IMOS studies were conducted to investigate the prevalence of osteoporosis and related risk factors. This paper provides a general view on the Iranian multicenter osteoporosis studies (IMOS), conducted during last decades.

Results

The results showed a high prevalence of osteoporosis and vitamin D deficiency in the Iranian population. Although the study protocols were mainly similar, some differences were observed in terms of the study population and design. The protocol of IMOS-3 was modified to overcome the setbacks noted in the previous studies; however, it was implemented in two cities with noticeably different socioeconomic and geographical characteristics from five cities where the first phase was conducted, resulting in different lifestyles and habits. Although previous IMOS studies have raised major concerns regarding the high prevalence of osteoporosis and vitamin D deficiency, interpretation should be made with caution given the differences, especially in the surveyed cities. Such discrepancies cause problems in trend analysis, and nationally representative samplings are preferably needed to correctly compare the prevalence of osteoporosis and related risk factors.

Conclusions

Considering the aging population and the importance of osteoporosis and its complication, developing a standard surveillance system to obtain valid and nationally representative estimates is recommended.

Semiautomated Electrochemical Melting Curve Analysis Device for the Detection of an Osteoporosis Associated Single Nucleotide Polymorphism in Blood

The detection of single nucleotide polymorphisms (SNPs) is of increasing importance in many areas including clinical diagnostics, patient stratification for pharmacogenomics, and advanced forensic analysis. In the work reported, we apply a semiautomated system for solid-phase electrochemical melting curve analysis (éMCA) for the identification of the allele present at a specific SNP site associated with an increased risk of bone fracture and predisposition to osteoporosis. Asymmetric isothermal recombinase polymerase amplification using ferrocene labeled forward primers was employed to generate single stranded redox labeled amplicons. In a first approach to demonstrate the proof of concept of combining asymmetric RPA with solid-phase éMCA, a simplified system housing a multielectrode array within a polymeric microsystem, sandwiched between two aluminum plates of a heater device, was used. Sample manipulation through the microfluidic channel was controlled by a syringe pump, and an external Ag/AgCl reference electrode was employed. Individual electrodes of the array were functionalized with four different oligonucleotide probes, each probe equivalent in design with the exception of the middle nucleotide. The isothermally generated amplicons were allowed to hybridize to the surface-tethered probes and subsequently subjected to a controlled temperature ramp, and the melting of the duplex was monitored electrochemically. A clear difference between the fully complementary and a single mismatch was observed. Having demonstrated the proof-of-concept, a device for automated éMCA with increased flexibility to house diverse electrode arrays with internal quasi-gold reference electrodes, higher resolution, and broader melting temperature range was developed and exploited for the detection of SNP hetero/homozygosity. Using the optimized conditions, the system was applied to the identification of the allele present at an osteoporosis associated SNP site, rs2741856, in 10 real fingerprick/venous blood samples, with results validated using Sanger sequencing.

FRAX-based intervention and assessment thresholds for osteoporosis in Iran

We compared the utility of the current Iranian guidelines that recommend treatment in women with a T-score ≤ - 2.5 SD with a FRAX-based intervention threshold equivalent to women of average BMI with a prior fragility fracture. Whereas the FRAX-based intervention threshold identified women at high fracture probability, the T-score threshold was less sensitive, and the associated fracture risk decreased markedly with age.

INTRODUCTION

The fracture risk assessment algorithm FRAX® has been recently calibrated for Iran, but guidance is needed on how to apply fracture probabilities to clinical practice.

METHODS

The age-specific ten-year probabilities of a major osteoporotic fracture were calculated in women with average BMI to determine fracture probabilities at two potential intervention thresholds. The first comprised the age-specific fracture probabilities associated with a femoral neck T-score of - 2.5 SD, in line with current guidelines in Iran. The second approach determined age-specific fracture probabilities that were equivalent to a woman with a prior fragility fracture, without BMD. The parsimonious use of BMD was additionally explored by the computation of upper and lower assessment thresholds for BMD testing.

RESULTS

When a BMD T-score ≤ - 2.5 SD was used as an intervention threshold, FRAX probabilities in women aged 50 years was approximately two-fold higher than in women of the same age but with an average BMD and no risk factors. The relative increase in risk associated with the BMD threshold decreased progressively with age such that, at the age of 80 years or more, a T-score of - 2.5 SD was actually protective. The 10-year probability of a major osteoporotic fracture by age, equivalent to women with a previous fracture rose with age from 4.9% at the age of 50 years to 17%, at the age of 80 years, and identified women at increased risk at all ages.

CONCLUSION

Intervention thresholds based on BMD alone do not effectively target women at high fracture risk, particularly in the elderly. In contrast, intervention thresholds based on fracture probabilities equivalent to a "fracture threshold" target women at high fracture risk.

A highly sensitive electrochemical biosensor based on AuNP-modified gold electrodes for selective determination of serum levels of crosslaps

This article explains a step-wise protocol to develop an electrochemical sensor to quantify serum levels of C-telopeptide (CTX) crosslinks also known as crosslaps in a matter of minutes and with high level of accuracy. The technique needs only one-step (incubation) and can thus be used for point of care screening. Due to the excellent electrical properties of the as-prepared immunosensor, CTX levels were successfully measured from 1 to 1000 pg/mL. This is while the normal reference of the marker is 50-450 pg/mL, suggesting that the sensor can acceptably detect CTX. The results also showed a good correlation with ECLIA in measuring serum levels of CTX.

The risk of osteoporotic fractures and its associating risk factors according to the FRAX model in the Iranian patients: a follow-up cohort

BACKGROUND

The present study is designed to assess the incidence rate of osteoporotic fracture and its risk factors, particularly those used to predict the 10-year risk of osteoporotic fracture in FRAX based on the data gathered through a follow up cohort initiated in 2000.

METHODS

The present retrospective cohort was conducted on men and women from 40 to 90 years of age enrolled in the IROSTEOPs study. A phone survey was conducted during 2013 and beginning of 2014 to assess the fractures (traumatic/osteoporotic) occurring at the time of inclusion until the date of the telephone survey, its type and mechanism, and the patient's age at the time of accident. Survival analysis using Kaplan-Meier product-limit method was performed with the time of fracture as the study outcome.

RESULTS

Final study population consisted of 1233 individuals, translated in to 9133 person years. The incidence rate of osteoporotic fracture was reported to be 359.1 cases in every 10,000 person years. The 10-year Kaplan-Meier estimate of any kind of major osteoporotic fractures for all the subcohort population was 10.75%. Osteoporosis (HR = 0.75), Discordance between femoral neck and spine (HR = 1.45), Diabetes (HR = 1.81), IBD (HR = 1.84), immobility more than 90 days (HR = 2.19), and personal history of fracture (HR = 7.75) had a considerable effect on the 10-year risk of major osteoporotic fractures.

CONCLUSIONS

Adding new clinical risk factors to FRAX® may help improve fracture prediction in the Iranian population.