Iris Koreana NAKAI Inhibits Osteoclast Formation via p38-Mediated Nuclear Factor of Activated T Cells 1 Signaling Pathway

BACKGROUND

Iris Koreana NAKAI (IKN) is a flowering perennial plant that belongs to the Iridaceae family. In this study, we aimed to demonstrate the effects of IKN on osteoclast differentiation in vitro and in vivo. We also sought to verify the molecular mechanisms underlying its anti-osteoclastogenic effects.

METHODS

Osteoclasts were formed by culturing mouse bone marrow macrophage (BMM) cells with macrophage colony-stimulating factor and receptor activator of nuclear factor-κB ligand (RANKL). Bone resorption assays were performed on dentin slices. mRNA expression levels were analyzed by quantitative polymerase chain reaction. Western blotting was performed to detect protein expression or activation. Lipopolysaccharide (LPS)-induced osteoclast formation was performed using a mouse calvarial model.

RESULTS

In BMM cultures, an ethanol extract of the root part of IKN suppressed RANKL-induced osteoclast formation and bone resorptive activity. In contrast, an ethanol extract of the aerial parts of IKN had a minor effect on RANKL-induced osteoclast formation. Mechanistically, the root part of IKN suppressed RANKL-induced p38 mitogen-activated protein kinase (MAPK) activation, effectively abrogating the induction of c-Fos and nuclear factor of activated T cells 1 (NFATc1) expression. IKN administration decreased LPS-induced osteoclast formation in a calvarial osteolysis model in vivo.

CONCLUSIONS

Our study suggested that the ethanol extract of the root part of IKN suppressed osteoclast differentiation and function partly by downregulating the p38 MAPK/c-Fos/NFATc1 signaling pathways. Thus, the root part.

Bone Mineral Density Screening Interval and Transition to Osteoporosis in Asian Women

BACKGRUOUND

Bone mineral density (BMD) testing is indicated for women aged 65 years, but screening strategies for osteoporosis are controversial. Currently, there is no study focusing on the BMD testing interval in Asian populations. The current study aimed to evaluate the estimated time interval for screening osteoporosis.

METHODS

We conducted a study of 6,385 subjects aged 50 years and older who underwent dual-energy X-ray absorptiometry screening more than twice at Samsung Medical Center as participants in a routine health checkup. Subjects were divided based on baseline T-score into mild osteopenia (T-score, <-1.0 to >-1.5), moderate osteopenia (T-score, ≤-1.5 to >-2.0), and severe osteopenia (T-score, ≤-2.0 to >-2.5). Information about personal medical and social history was collected by a structured questionnaire.

RESULTS

The adjusted estimated BMD testing interval for 10% of the subjects to develop osteoporosis was 13.2 years in mild osteopenia, 5.0 years in moderate osteopenia, and 1.5 years in severe osteopenia.

CONCLUSION

Our study provides extended information about BMD screening intervals in Asian female population. Baseline T-score was important for predicting BMD screening interval, and repeat BMD testing within 5 years might not be necessary in mild osteopenia subjects.

10-Year Fracture Risk in Postmenopausal Women with Osteopenia and Osteoporosis in South Korea

BACKGROUND

In South Korea, women aged 66 years are eligible for complimentary bone mineral density (BMD) screening via the National Screening Program for Transitional Ages. We aimed to evaluate the 10-year fracture risk in women receiving BMD screening between January 2008 and December 2015.

METHODS

BMD was classified as normal (T-score ≥-1.0 standard deviation [SD]), osteopenia (T-score <-1.0 SD and >-2.5 SD), and osteoporosis (T score ≤-2.5 SD) from dual-energy X-ray absorptiometry. Follow-up continued from the screening date until a diagnosis for clinical fragility fracture (including sites of the vertebrae, hip, pelvis, clavicle, humerus, forearm, wrist, lower leg, and ankle), censored at the earliest date of trauma, death, or December 2017; fracture was ascertained using diagnostic codes from the National Health Insurance Service database. A multivariable Cox proportional hazard model was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the risk of fracture in women with osteopenia or osteoporosis relative to women with normal BMD.

RESULTS

Among the 271,197 women screened, 44.0% had osteopenia and 35.2% had osteoporosis. The 10 year cumulative incidence of fragility fractures was 31.1%, 37.5%, and 44.3% in women with normal BMD, osteopenia, and osteoporosis, respectively. Fracture risk was higher in women with osteopenia (HR, 1.31; 95% CI, 1.28 to 1.34) and osteoporosis (HR, 1.68; 95% CI, 1.64 to 1.72) than in women with normal BMD.

CONCLUSION

Women with osteopenia and women with osteoporosis, identified by the national BMD screening program, demonstrated a substantially elevated risk of fracture.

The 2nd Metacarpal Cortical Index as a Simple Screening Tool for Osteopenia

Background

Osteopenia is a known risk factor for sustaining skeletal fractures. Prevention of fragility fractures has obvious clinical and economic advantages, however screening all patients using a dual energy X-ray absorptiometry (DXA) is controversial not only because of the cost implications but also because it would potentially involve exposing a percentage of normal patients to unnecessary radiation. We wished to assess whether a simple hand X-ray measuring the 2nd metacarpal cortical index (2MCI) could be used as a simple screening tool for identifying patients with osteopenia.

Methods

We retrospectively collected the radiographic data of 206 patients who had a simple radiograph of the hand and a DXA scan within one year of each other from our picture archiving and communication system database. The 2MCI was calculated for all patients. As data was parametric, a Pearson’s correlation was performed to assess association between T-scores and 2MCI. Further analysis involved the construction of receiver operating characteristic (ROC) curves to identify a 2MCI index, which would give the most appropriate sensitivity and specificity values for identifying the presence of osteopenia.

Results

A statistically significant and moderate correlation between DXA T-scores and 2MCI values was found (r=0.54, n=206, P<0.001). Further ROC curve analysis of normal and osteopenic subjects identified that a 2MCI of 41.5 had a sensitivity of 100% and specificity of 53% for detecting osteopenia.

Conclusions

Our results support the use of the 2MCI as a simple screening tool for identifying patients with osteopenia.

Clinical Implication of Sarcopenia in Patients with Inflammatory Bowel Disease

Recent studies have shown that inflammatory bowel disease (IBD) patients are affected by altered body composition, especially low muscle mass or sarcopenia. Detection of sarcopenia is important, as it can independently predict osteopenia, sarcopenic obesity, and poor disease outcomes during IBD progress. The challenges are needed to identify diagnostic and managing strategies for sarcopenia in IBD to improve disease outcomes and increase the quality of life in patients with IBD.

PREVALENCE OF OSTEOPOROSIS AND HYPOVITAMINOSIS D AT SIRIRAJ METABOLIC BONE DISEASE CLINIC

OBJECTIVE

To identify the prevalence of osteoporosis and hypovitaminosis D among patients at the Siriraj Metabolic Bone Disease (MBD) Clinic, and to compare initial vitamin D levels in patients with and without a history of fragility fractures.

METHODS

Medical records of patients who attended our MBD clinic between 2012 and 2015 were retrospectively reviewed. Patient baseline demographic, clinical, bone mineral density (BMD), and laboratory data were collected and analyzed. Osteoporosis was diagnosed when patients had a BMD T-score <-2.5 or presented with fragility fractures.

RESULTS

There were 761 patients included in this study. Of these, 627 patients (82.4%) were diagnosed with osteoporosis and 508 patients (66.8%) had fragility fractures. Baseline serum 25-hydroxyvitamin D (25(OH)D) levels were available in 685 patients. Of these, 391 patients (57.1%) were diagnosed with hypovitaminosis D. When evaluated only in patients with fragility fractures, the average initial 25(OH)D level was 28.2±11.6 ng/mL, and the prevalence of hypovitaminosis D was 57.6%.

CONCLUSION

A high prevalence of osteoporosis and hypovitaminosis D was found among patients at our clinic; two-thirds of patients had a history of fragility fractures, and no difference in initial 25(OH)D levels was seen between patients with and without fragility fractures. Level ofEvidence III, Retrospective Study.

Age-Related Changes in the Prevalence of Osteoporosis according to Gender and Skeletal Site: The Korea National Health and Nutrition Examination Survey 2008-2010

BACKGROUND

The incidence of osteoporosis and its related fractures are expected to increase significantly in the rapidly aging Korean population. Reliable data on the prevalence of this disease is essential for treatment planning. However, sparse data on Korean patients is available.

METHODS

We analyzed data from the Korea National Health and Nutrition Examination Survey (KNHANES) 2008 to 2010. Bone mineral density (BMD) was measured at the femoral neck and lumbar spine using dual-energy X-ray absorptiometry. Osteopenia and osteoporosis were diagnosed according to the World Health Organization T-score criteria. We analyzed the BMD data of 17,208 people (men, 7,837; women, 9,368).

RESULTS

The adjusted prevalence of osteoporosis was 7.8% in men versus 37.0% in women. No significant difference was observed in the prevalence of osteopenia between genders (men, 47.0%; women, 48.7%). The prevalence of osteoporosis in men in their 50s was 4.0%, in their 60s was 7.2%, in their 70s was 15.1%, and in their 80s was 26.7%. The figures in women were 15.2%, 36.5%, 62.7%, and 85.8%, respectively. The age group with the maximal BMD differed between genders. In the men, 20s had the highest value in all the skeletal sites. However, in the women, the maximal BMD in the femoral neck, lumbar spine, and the total hip was observed in their 20s, 30s, and 40s, respectively. The onset age of osteoporosis differed between genders. Osteoporosis in the femoral neck began at 55 years in the women and at 60 years in the men.

CONCLUSION

The prevalence of osteoporosis in Korea was significantly high. In addition, the age-related changes in the prevalence of osteoporosis differed according to gender and skeletal site.