Hyoung-Moo Park

Calcium from plant sources is beneficial to lowering the risk of osteoporosis in postmenopausal Korean women

Osteoporosis, which has become a serious public health concern, is influenced by diet, especially calcium intake. Dairy products are a good source of calcium, but plant calcium may also be important in populations that do not consume a large amount of milk. The purpose of the present study was to examine the hypothesis that calcium from vegetable sources is associated with osteoporosis risk and bone mineral density in postmenopausal Korean women with osteoporosis and age-matched controls (N = 144). The results of multivariate-adjusted regression analyses indicated that the intake of calcium, plant calcium, potassium, vitamin A, carotene, vitamin B(1), niacin, vitamin E, vitamin C, and vegetables was associated with significantly reduced risk of osteoporosis after adjusting for age, body mass index, hormone replacement therapy, and energy intake. In addition, intake of vegetables alone, as well as calcium, plant calcium, potassium, and antioxidant vitamins (vitamin C, vitamin E, β-carotene), which are abundant in vegetables, was significantly and positively associated with bone mineral density. However, in this population of low-dairy consumers, intake of calcium from meat and dairy products was not related to risk of osteoporosis and bone mineral density. Our results suggest that high dietary intake of calcium, especially plant calcium, reduces the risk of osteoporosis and increased bone mineral density in postmenopausal Korean women. Vegetables may be an important source of calcium and may also provide vitamins and minerals that exert additional beneficial effects on the bone.

The Reference Value of Skeletal Muscle Mass Index for Defining the Sarcopenia of Women in Korea

Background Sarcopenia is considering important disease entity in elderly. Several study groups define the sum of the muscle masses of the four limbs as appendicular skeletal mass (ASM) to calculate skeletal muscle index (SMI). The purpose of this study was to determine cut point of SMI for sarcopenia in Korean women. Methods This study was based on data obtained from the 2008 to 2011 Korean National Health and Nutrition Examination Survey (KNHANES) IV and V. A whole body dual energy X-ray absorptiometry scan were performed on individuals of ≥10 years old from July 2008 to May 2011. In the analysis, 11,633 women were included. ASM was calculated and SMI was obtained as ASM/height2. Cutoff value was defined two standard deviations below mean values for young reference group. Results Of 11,633 women aged 10 to 97 years, mean and standard deviation of year was 46.73±18.54 years. The highest level of height was noted in 20s and the highest total sum of skeletal mass was seen 14.87 kg in 40s. The highest value of SMI was noted in 60s in Korean women. Cutoff value as mean value of young women was decided with SMI of 30s and 40s that have peak ASM. Mean and standard deviation of SMI in those ages was 5.9±0.7 kg/m2. A SMI of two standard deviations below the mean SMI of reference groups was 4.4 kg/m2 as cutoff value. Conclusions This study shows that 4.4 kg/m2 of SMI in Korean women was cutoff value of sarcopenia. Further study is clearly required to decide cutoff value of SMI for sarcopenia, especially for Korean women.

Efficacy of risedronate with cholecalciferol on 25‐hydroxyvitamin D level and bone turnover in Korean patients with osteoporosis

Background  We performed a randomized, double‐blind, prospective, 16‐week clinical trial to evaluate the efficacy and safety of risedronate with and without cholecalciferol on 25‐hydroxyvitamin D [25(OH)D] levels and bone markers in Korean patients with osteoporosis.

Prevalence of Sarcopenia in the Korean Woman Based on the Korean National Health and Nutritional Examination Surveys

Background The criteria for defining sarcopenia vary among studies and confusion has arisen when defining the cutoff value. As a result, the prevalence of sarcopenia differs markedly depending on the definition. This study used the Asian Working Group for Sarcopenia (AWGS) definition to determine the prevalence of sarcopenia among Korean women. Methods This study was based on data obtained from the 2008 to 2011 Korean National Health and Nutrition Examination Surveys IV and V. We used the AWGS recommended cutoff value of 5.4 kg/m2 to determine the prevalence of sarcopenia in Korean women. Results The prevalence rates of sarcopenia using a cutoff value of 5.4 kg/m2 were 385 (19.5%) in women in their 50s, 286 (16.6%) in women in their 60s, 293 (23.7%) in women in their 70s, and 91 (30.8%) in women ≥80 years. The prevalence rates of sarcopenia were 307 (19.0%) in women 65 to 74 years, 194 (27.4%) in women 75 to 84 years, and 32 (40.5%) in women ≥85 years. The overall prevalence among women >50 years was 20.2%. The prevalence of sarcopenia in women >65 years was 22.1%. Conclusions The prevalence of sarcopenia among Korean women was within the range of values of previous research about sarcopenia. Furthermore, using 5.4 kg/m2 as the cutoff value was useful to compare various studies about sarcopenia in Koreans.

A Case of Teriparatide on Pregnancy-Induced Osteoporosis

Pregnancy-induced osteoporosis is a rare disorder characterized by fragility fracture and low bone mineral density (BMD) during or shortly after pregnancy, and its etiology is still unclear. We experienced a case of a 39-year-old woman who suffered from lumbago 3 months after delivery. Biochemical evidence of increased bone resorption is observed without secondary causes of osteoporosis. Radiologic examination showed multiple compression fractures on her lumbar vertebrae. We report a case of patient with pregnancy-induced osteoporosis improved her clinical symptom, BMD and bone turnover marker after teriparatide therapy.

RHEB: a potential regulator of chondrocyte phenotype for cartilage tissue regeneration

As articular cartilage has a limited ability to self‐repair, successful cartilage regeneration requires clinical‐grade chondrocytes with innate characteristics. However, cartilage regeneration via chondrocyte transplantation is challenging, because chondrocytes lose their innate characteristics during in vitro expansion. Here, we investigated the mechanistic underpinning of the gene Ras homologue enriched in brain (RHEB) in the control of senescence and dedifferentiation through the modulation of oxidative stress in chondrocytes, a hallmark of osteoarthritis. Serial expansion of human chondrocytes led to senescence, dedifferentiation and oxidative stress. RHEB maintained the innate characteristics of chondrocytes by regulating senescence, dedifferentiation and oxidative stress, leading to the upregulation of COL2 expression via SOX9 and the downregulation of p27 expression via MCL1. RHEB also decreased the expression of COL10. RHEB knockdown mimics decreased the expression of SOX9, COL2 and MCL1, while abrogating the suppressive function of RHEB on p27 and COL10 in chondrocytes. RHEB‐overexpressing chondrocytes successfully formed cartilage tissue in vitro as well as in vivo, with increased expression of GAG matrix and chondrogenic markers. RHEB induces a distinct gene expression signature that maintained the innate chondrogenic properties over a long period. Therefore, RHEB expression represents a potentially useful mechanism in terms of cartilage tissue regeneration from chondrocytes, by which chondrocyte phenotypic and molecular characteristics can be retained through the modulation of senescence, dedifferentiation and oxidative stress. Copyright

Early changes in 25-hydroxyvitamin D levels and bone markers after monthly risedronate with cholecalciferol in Korean patients with osteoporosis

Purpose This study investigated the efficacy and safety of monthly risedronate, with and without cholecalciferol, on 25-hydroxyvitamin D (25[OH]D) levels and bone markers in Korean patients with osteoporosis. Methods A randomized, double-blinded, prospective, 16-week clinical trial was conducted in ten hospitals. A total of 150 subjects with osteoporosis were randomized to one of the two treatment groups: RSDM+ (monthly risedronate 150 mg and cholecalciferol 30,000 IU combined in a single pill, n = 74) or RSDM (monthly risedronate 150 mg alone, n = 76). We measured serum levels of 25-hydroxyvitamin D (25[OH]D), parathyroid hormone (PTH), and bone markers, as well as performing muscle-function tests at baseline and after 16 weeks of treatment. Results After 16 weeks, serum 25(OH)D levels significantly increased from 17.8 to 26.8 ng/mL in the RSDM+ group, but did not change in the RSDM group. The RSDM+ group exhibited significantly decreased serum PTH from 46 to 36.7 pg/mL, while the RSDM group showed a tendency for PTH to increase from 38 to 40.6 pg/mL. In both groups, serum bone-specific alkaline phosphatase and C-terminal telopeptide rapidly declined, with significance at 16 weeks; there were no significant differences between the groups. Conclusion A once-monthly pill of risedronate and cholecalciferol provided equivalent antiresorptive efficacy to risedronate alone in terms of bone turnover and improved 25(OH)D levels over the 16-week treatment period without significant adverse events in Korean patients with osteoporosis.