Anti-diabetic effect of anthocyanin cyanidin-3-O-glucoside: data from insulin resistant hepatocyte and diabetic mouse

BACKGROUND

Anthocyanins are a group of natural products widely found in plants. They have been found to alleviate the disorders of glucose metabolism in type 2 diabetes mellitus (T2DM), while the underlying mechanisms remain unclear.

METHODS

HepG2 and L02 cells were incubated with 0.2 mM PA and 30 mM glucose for 24 h to induce IR, and cells treated with 5 mM glucose were used as the control. C57BL/6 J male mice and db/db male mice were fed with a chow diet and gavaged with pure water or cyanidin-3-O-glucoside (C3G) solution (150 mg/kg/day) for 6 weeks.

RESULTS

In this study, the anthocyanin C3G, extracted from red bayberry, was found to alleviate disorders of glucose metabolism, which resulted in increased insulin sensitivity in hepatocytes, and achieved by enhancing the glucose consumption as well as glycogen synthesis in insulin resistance (IR) hepatpcytes. Subsequently, the expression of key proteins involved in IR was detected by western blotting analysis. Protein tyrosine phosphatase-1B (PTP1B), a negative regulator of insulin signaling, could reduce cellular sensitivity to insulin by inhibiting the phosphorylation of insulin receptor substrate-2 (IRS-2). Results of this study showed that C3G inhibited the increase in PTP1B after high glucose and palmitic acid treatment. And this inhibition was accompanied by increased phosphorylation of IRS proteins. Furthermore, the effect of C3G on improving IR in vivo was validated by using a diabetic db/db mouse model.

CONCLUSION

These findings demonstrated that C3G could alleviate IR in vitro and in vivo to increase insulin sensitivity, which may offer a new insight for regulating glucose metabolism during T2DM by using the natural dietary bioactive components. C3G promotes the phosphorylation of IRS-2 proteins by suppressing the expression of PTP1B, and then enhances the sensitivity of hepatocyte to insulin.

Exploring the Effects of Cyanidin-3-O-Glucoside on Type 2 Diabetes Mellitus: Insights into Gut Microbiome Modulation and Potential Antidiabetic Benefits

Berries and their functional components have been put forward as an alternative to pharmacological treatments of type 2 diabetes mellitus (T2DM), and more attention has been paid to the gut microbiome in the pathophysiology of T2DM. Thus, we tried to examine the metabolic impact of red bayberry-derived cyanidin-3-O-glucoside (C3G) and investigate whether the antidiabetic effects of C3G were associated with the gut microbiome. As a result, C3G administration was found to reduce blood glucose levels of diabetic db/db mice, accompanied by increased levels of glucagon-like peptide (GLP-1) and insulin. Moreover, 16S rRNA analysis showed that the dominant microbiota modulated by C3G were pivotal in the glucose metabolism. Furthermore, the modulation of C3G on metabolic activities of gut bacteria leads to an increase in intestinal levels of key metabolites, particularly short-chain fatty acids. This contribution helps in promoting the secretion of GLP-1, which in turn increases insulin release with the purpose of reducing blood glucose levels. Overall, these findings may offer new thoughts concerning C3G against metabolic disorders in T2DM.

The burden of fracture in China from 1990 to 2019

PURPOSE

Osteoporosis is one of the most common clinical problems among the elderly population. China is one of the countries most threatened by osteoporosis and fragility fracture, because of its large population and aging population trends during recent decades. We aimed to estimate the disease burden of fracture from 1990 to 2019 in China.

METHODS

We performed a secondary analysis of fractures using detailed information for China from the Global Burden of Disease Study 2019. Fracture incidence and prevalence, rate of years lost to disability from fractures, and term secular trends in China from 1990 to 2019 were compared by sex, age, cause, and nature of fracture.

RESULTS

The numbers for incidence and prevalence of fracture and years lived with disability (YLDs) from fractures in China increased from 12.54 million, 28.35 million, and 1.71 million in 1990 to 21.27 million, 67.85 million, and 3.79 million in 2019, respectively, increases of 70%, 139%, and 122%, respectively. In 2019, falls was the leading cause of fractures, with an age-standardized incidence rate (ASIR) of 762 per 100 000 (95% uncertainty interval [UI] 629-906), an age-standardized prevalence rate (ASPR) of 1863 per 100 000 (95% UI 1663-2094), and an age-standardized YLD rate (ASYR) of 103 per 100 000 (95% UI 69-147). Fall-associated deaths and disability-adjusted life-years (DALYs) from low bone mineral density increased greatly during the most recent three decades. Fracture of patella, tibia or fibula, and ankle were the most frequent fracture types, with an ASYR of 116 per 100 000 (95% UI 75-169). Hip fracture had more incident cases in adults ≥ 60 years old, and was more frequent for females.

CONCLUSIONS

The burden from fractures has increased significantly since 1990 in China. Falls and road injuries are the main causes of the increase. The fall-associated health burden from osteoporosis needs to be prioritized, with longer-term commitment to its reduction required.

Population serum proteomics uncovers a prognostic protein classifier for metabolic syndrome

Metabolic syndrome (MetS) is a complex metabolic disorder with a global prevalence of 20%-25%. Early identification and intervention would help minimize the global burden on healthcare systems. Here, we measured over 400 proteins from ∼20,000 proteomes using data-independent acquisition mass spectrometry for 7,890 serum samples from a longitudinal cohort of 3,840 participants with two follow-up time points over 10 years. We then built a machine-learning model for predicting the risk of developing MetS within 10 years. Our model, composed of 11 proteins and the age of the individuals, achieved an area under the curve of 0.774 in the validation cohort (n = 242). Using linear mixed models, we found that apolipoproteins, immune-related proteins, and coagulation-related proteins best correlated with MetS development. This population-scale proteomics study broadens our understanding of MetS and may guide the development of prevention and targeted therapies for MetS.

Global, regional and national burden of endocrine, metabolic, blood and immune disorders 1990-2019: a systematic analysis of the Global Burden of Disease study 2019

Background

Endocrine, metabolic, blood and immune disorders (EMBID) is a vital public health problem globally, but the study on its burden and global trends was scarce. We aimed to evaluate the global burden of disease and trends in EMBID from 1990 to 2019.

Methods

We extracted the data of EMBID-related on death cases, Age-standardized death rates (ASDRs), disability-adjusted life-years (DALYs), Age-standardized DALY rates, years of life lost (YLLs), Age-standardized YLL rates, years lived with disability (YLDs) and Age-standardized YLD rates between 1990 and 2019 from the Global Burden of Disease 2019, by sex, age, and year at the global and geographical region levels. The Annual rate of change was directly extracted from Global Health Data Exchange (GHDx) and we also calculated the age-related age-standardized rate (ASR) to quantify trends in EMBID-related deaths, DALYs, YLLs and YLDs.

Result

Globally, the EMBID-related ASDRs showed an increasing trend, whereas the DALYs ASR, YLLs ASR and YLDs ASR were decreased between 1990 to 2019. Furthermore, High-income North America and Southern Sub-Saharan Africa had the highest both ASDRs and DALYs ASR, and Southern Sub-Saharan Africa and Caribbean had the highest both YLDs ASR and YLLs ASR in 2019. Males had a higher EMBID-related ASDRs than females, but the DALYs ASR in females were higher than males. The burden of EMBID was higher in older-aged compared to other age groups, especially in developed regions.

Conclusion

Although EMBID-related ASRs for DALYs-, YLLs- and YLDs declined at the global level from 1990 to 2019, but the ASDRs was increasing. This implied high healthcare costs and more burden of ASDRs due to EMBID in the future. Therefore, there was an urgent need to adopt geographic targets, age-specific targets, prevention strategies and treatments for EMBID to reduce negative health outcomes globally.

A Novel Predictive Model for Adrenocortical Carcinoma Based on Hypoxia- and Ferroptosis-Related Gene Expression

Background

The impact of hypoxia on ferroptosis is important in cancer proliferation, but no predictive model combining hypoxia and ferroptosis for adrenocortical carcinoma (ACC) has been reported. The purpose of this study was to construct a predictive model based on hypoxia- and ferroptosis-related gene expression in ACC.

Methods

We assessed hypoxia- and ferroptosis-related gene expression using data from 79 patients with ACC in The Cancer Genome Atlas (TCGA). Then, a predictive model was constructed to stratify patient survival using least absolute contraction and selection operation regression. Gene expression profiles of patients with ACC in the Gene Expression Omnibus (GEO) database were used to verify the predictive model.

Results

Based on hypoxia-related gene expression, 79 patients with ACC in the TCGA database were divided into three molecular subtypes (C1, C2, and C3) with different clinical outcomes. Patients with the C3 subtype had the shortest survival. Ferroptosis-related genes exhibited distinct expression patterns in the three subtypes. A predictive model combining hypoxia- and ferroptosis-related gene expression was constructed. A nomogram was constructed using age, sex, tumor stage, and the predictive gene model. Gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses revealed that the gene signature was mainly related to the cell cycle and organelle fission.

Conclusion

This hypoxia-and ferroptosis-related gene signature displayed excellent predictive performance for ACC and could serve as an emerging source of novel therapeutic targets in ACC.

Pressure-Induced Superconductivity up to 9 K in the Quasi-One-Dimensional KMn_{6}Bi_{5}

The Mn-based superconductor is rare owing to the strong magnetic pair-breaking effect. Here we report on the discovery of pressure-induced superconductivity in KMn_{6}Bi_{5}, which becomes the first ternary Mn-based superconductor. At ambient pressure, the quasi-one-dimensional KMn_{6}Bi_{5} is an antiferromagnetic metal with T_{N}≈75  K. By measuring resistance and ac magnetic susceptibility under hydrostatic pressures up to 14.2 GPa in a cubic anvil cell apparatus, we find that its antiferromagnetic transition can be suppressed completely at a critical pressure of P_{c}≈13  GPa, around which bulk superconductivity emerges and displays a superconducting dome with the maximal T_{c}^{onset}=9.3  K achieved at about 14 GPa. The close proximity of superconductivity to a magnetic instability in the temperature-pressure phase diagram of KMn_{6}Bi_{5} and an unusually large μ_{0}H_{c2}(0) exceeding the Pauli paramagnetic limit suggests an unconventional magnetism-mediated paring mechanism. In contrast to the binary MnP, the flexibility of the crystal structure and chemical compositions in the ternary AMn_{6}Bi_{5} (A=alkali metal) can open a new avenue for finding more Mn-based superconductors.

The Burden of Diabetes-Related Chronic Kidney Disease in China From 1990 to 2019

OBJECTIVE

To analyze the trends in disease burden of diabetes-related chronic kidney disease (CKD) by year, age, gender and types of diabetes in China from 1990 to 2019.

METHODS

Data on prevalence, deaths and disability-adjusted life years (DALYs) for diabetes-related CKD were extracted from the Global Burden of Disease (GBD) 2019 study. Analyses were performed by year, age, gender and types of diabetes.

RESULTS

In China, the numbers of deaths and DALYs of diabetes-related CKD continuously increased but the age-standardized rates (per 100,000 population) decreased over 30 years, in which the numbers of deaths and DALYs attributable to type 1 diabetes mellitus (T1DM)-related CKD barely changed and the age-standardized rates decreased over the years; and the number of deaths and DALYs attributable to type 2 diabetes mellitus (T2DM)-related CKD continuously increased, but the age-standardized rates also decreased. In 2019, 76.03 (58.24-95.61) thousand deaths and 2.13 (1.65-2.67) million DALYs were attributable to diabetes-related CKD, of which, T2DM accounted for 83.32% and 77.0% respectively, and T1DM accounted for the rest. Increasing gender disparity was seen, with males being more heavily impacted. The burden of diabetes-related CKD varied among different age groups, with the numbers of deaths and DALYs attributable to T1DM-related CKD peaking between 45 and 54 years of age and T2DM-related CKD peaking between 75 and 79 years of age; and the crude rates of deaths and DALYs attributable to T1DM-related CKD peaking between 70 and 79 years of age and 40 to 54 years of age, respectively, and T2DM-related CKD peaking over 90 years of age. Among neighboring and G20 countries, the burden of diabetes-related CKD in China was relatively controlled reflected by the ranking of adjusted death and DALYs rates.

CONCLUSIONS

The burden of diabetes-related CKD in China worsens and shows gender disparities and different age distribution. Greater efforts are needed to improve the health outcomes of these patients, especially among males.

The Global Burden of Osteoporosis, Low Bone Mass, and Its Related Fracture in 204 Countries and Territories, 1990-2019

BACKGROUND

Low bone mineral density (LBMD), including osteoporosis and low bone mass, has becoming a serious public health concern. We aimed to estimate the disease burden of LBMD and its related fractures in 204 countries and territories over the past 30 years.

METHODS

We collected detailed information and performed a secondary analysis for LBMD and its related fractures from the Global Burden of Disease Study 2019. Numbers and age-standardized rates related to LBMD of disability-adjusted life-years (DALYs) and deaths in 204 countries and territories were compared by age, gender, socio-demographic index (SDI), and location.

RESULTS

Global deaths and DALYs number attributable to LBMD increased from 207 367 and 8 588 936 in 1990 to 437 884 and 16 647 466 in 2019, with a raise of 111.16% and 93.82%, respectively. DALYs and deaths number of LBMD-related fractures increased 121.07% and 148.65% from 4 436 789 and 121248 in 1990 to 9 808 464 and 301 482 in 2019. In 2019, the five countries with the highest disease burden of DALYs number in LBMD-related fractures were India (2 510 288), China (1 839 375), United States of America (819 445), Japan (323 094), and Germany (297 944), accounting for 25.59%, 18.75%, 8.35%, 3.29%, and 3.04%. There was a quadratic correlation between socio-demographic index (SDI) and burden of LBMD-related fractures: DALYs rate was 179.985-420.435SDI+417.936SDI²(R^{2 =} 0.188, p<0.001); Deaths rate was 7.879-13.416SDI+8.839 SDI²(R^{2 =} 0.101, p<0.001).

CONCLUSIONS

The global burden of DALYs and deaths associated with LBMD and its related fractures has increased significantly since 1990. There were differences in disease burden between regions and countries. These estimations could be useful in priority setting, policy-making, and resource allocation in osteoporosis prevention and treatment.

Global burden of non-communicable diseases attributable to dietary risks in 1990-2019

BACKGROUND

Dietary risks have raised attention worldwide during recent decades. The present burden-of-disease study aimed to evaluate the global dietary risks for non-communicable diseases (NCDs) from 1990 to 2019 and quantify their impact on mortality and disability-adjusted life-years (DALYs). Data from the 2019 Global Burden of Disease Study on deaths and DALYs from NCDs attributable to worldwide dietary risks were obtained and underwent deep analysis by year, age, gender, location, leading risks and leading causes, and their associations were examined. The socio-demographic index (SDI) was used as an indicator of national socio-economic status, as well as the relationships between age-standardised rates of deaths or DALYs and socio-economic status.

RESULTS

In 2019, 7.9 million deaths and 187.7 million DALYs were attributable to dietary risk factors. High intake of sodium and low intake of whole grains and fruits were leading dietary risks for deaths and DALYs worldwide. However, both indices showed a decreasing trend by year, an increase by age and a higher disease burden in males. The main distribution of dietary-related NCDs was located in highly populated countries. A negative association between the SDI and disease burden and a positive association between the SDI and male preponderance were found.

CONCLUSIONS

Dietary risk factors for NCDs increased significantly and varied across regions during 1990-2019. Therefore, greater efforts are needed to raise public awareness of interventions and improve dietary practices aiming to reduce the disease burden caused by suboptimal dietary intake, especially in developing countries and among males.

Population genomic, climatic and anthropogenic evidence suggest the role of human forces in endangerment of green peafowl (Pavo muticus)

Both anthropogenic impacts and historical climate change could contribute to population decline and species extinction, but their relative importance is still unclear. Emerging approaches based on genomic, climatic and anthropogenic data provide a promising analytical framework to address this question. This study applied such an integrative approach to examine potential drivers for the endangerment of the green peafowl (Pavo muticus). Several demographic reconstructions based on population genomes congruently retrieved a drastic population declination since the mid-Holocene. Furthermore, a comparison between historical and modern genomes suggested genetic diversity decrease during the last 50 years. However, climate-based ecological niche models predicted stationary general range during these periods and imply the little impact of climate change. Further analyses suggested that human disturbance intensities were negatively correlated with the green peafowl's effective population sizes and significantly associated with its survival status (extirpation or persistence). Archaeological and historical records corroborate the critical role of humans, leaving the footprint of low genomic diversity and high inbreeding in the survival populations. This study sheds light on the potential deep-time effects of human disturbance on species endangerment and offers a multi-evidential approach in examining underlying forces for population declines.

Age, Gender and Geographic Differences in Global Health Burden of Cirrhosis and Liver Cancer due to Nonalcoholic Steatohepatitis

Objective: Recently, Nonalcoholic Steatohepatitis (NASH) has become a major contributor to cirrhosis and liver cancer. Therefore, the Global Burden of Disease (GBD) 2017 was used to comprehensively analyze the global, regional, and national burden of cirrhosis and liver cancer due to NASH between 1990 and 2017.

Methods: Data for cirrhosis and liver cancer due to NASH were extracted from the GBD study 2017. Socio-demographic Index (SDI) in 2017 was cited as indicators of socioeconomic status. ARIMA model was established to forecast the future health burden. Kruskal-Wallis test and Pearson linear correlation were adopted to evaluate the gender disparity and association with socioeconomic level.

Results: From 1990-2017, the global disability-adjusted life years (DALYs) numbers of liver cancer due to NASH increased from 0.71 million to 1.46 million. The age-standardized DALYs rates of liver cancer due to NASH were negatively associated with SDI levels (r=0.-409, p<0.001). Geographically, Australasia experienced the largest increase in the burden of liver cancer due to NASH, with the age-standardized DALYs rate increasing by 143.54%. The global prevalence number of liver cancer due to NASH peaked at 60-64 years in males and at 65-69 years in females. Globally, the burden was heavier in males compared with females. Male-female-ratio of age-standardized DALYs rates in liver cancer due to NASH were positively related to SDI (r=0.303, P=0.011).

Conclusion: The global burden of NASH-associated liver cancer has increased significantly since 1990, with age, gender and geographic disparity. Public awareness of liver diseases due to NASH should be emphasized.

Global, regional, and national burden and trend of diabetes in 195 countries and territories: an analysis from 1990 to 2025

Diabetes mellitus is a leading cause of mortality and reduced life expectancy. We aim to estimate the burden of diabetes by type, year, regions, and socioeconomic status in 195 countries and territories over the past 28 years, which provide information to achieve the goal of World Health Organization Global Action Plan for the Prevention and Control of Noncommunicable Diseases in 2025. Data were obtained from the Global Burden of Disease Study 2017. Overall, the global burden of diabetes had increased significantly since 1990. Both the trend and magnitude of diabetes related diseases burden varied substantially across regions and countries. In 2017, global incidence, prevalence, death, and disability-adjusted life-years (DALYs) associated with diabetes were 22.9 million, 476.0 million, 1.37 million, and 67.9 million, with a projection to 26.6 million, 570.9 million, 1.59 million, and 79.3 million in 2025, respectively. The trend of global type 2 diabetes burden was similar to that of total diabetes (including type 1 diabetes and type 2 diabetes), while global age-standardized rate of mortality and DALYs for type 1 diabetes declined. Globally, metabolic risks (high BMI) and behavioral factors (inappropriate diet, smoking, and low physical activity) contributed the most attributable death and DALYs of diabetes. These estimations could be useful in policy-making, priority setting, and resource allocation in diabetes prevention and treatment.

Global burden of noncommunicable disease attributable to high body mass index in 195 countries and territories, 1990-2017

PURPOSE

The increasing burden of noncommunicable diseases (NCDs) attributable to high body mass index (BMI) represents both a threat and an opportunity for intervention. Estimates of the global latest trend of high BMI-related NCDs and its association with socioeconomic status can facilitate strategic intervention and inform further research.

METHODS

This global burden of disease study extracted global, regional, and national data on death and disability-adjusted life years (DALYs) attributable to high BMI-related NCDs from the GBD Study 2017. Secondary analyses were performed by year, age, sex, and specific causes of death and DALYs. The 2017 Socio-demographic Index (SDI) was used as an indicator of national socioeconomic status. The association between age-standardized death or DALYs rate and socioeconomic status were analyzed.

RESULTS

Worldwide, 4.7 million deaths and 147.7 million DALYs of NCDs were related to high BMI in 2017, with a projection to 5.5 million deaths and 176.9 million DALYs in 2025. Globally, high BMI-related burden showed an increasing trend with males being more heavily impacted overall. The trend and magnitude of high BMI-related disease burden varied substantially in different geographical and socioeconomic regions. Specifically, the low-middle, middle, and high-middle SDI countries were associated with a higher burden. The leading three causes of DALYs attributable to high BMI in 2017 were ischemic heart diseases, stroke, and diabetes mellitus.

CONCLUSIONS

High BMI-related burden of NCDs is worsening, particularly in developing countries. Our findings may enhance public awareness of interventions to reduce the diseases burden caused by high BMI.

Biallelic loss-of-function mutations in JAM2 cause primary familial brain calcification

Primary familial brain calcification is a monogenic disease characterized by bilateral calcifications in the basal ganglia and other brain regions, and commonly presents motor, psychiatric, and cognitive symptoms. Currently, four autosomal dominant (SLC20A2, PDGFRB, PDGFB, XPR1) and one autosomal recessive (MYORG) causative genes have been identified. Compared with patients with autosomal dominant primary familial brain calcification, patients with the recessive form of the disease present with more severe clinical and imaging phenotypes, and deserve more clinical and research attention. Biallelic mutations in MYORG cannot explain all autosomal recessive primary familial brain calcification cases, indicating the existence of novel autosomal recessive genes. Using homozygosity mapping and whole genome sequencing, we detected a homozygous frameshift mutation (c.140delT, p.L48*) in the JAM2 gene in a consanguineous family with two affected siblings diagnosed with primary familial brain calcification. Further genetic screening in a cohort of 398 probands detected a homozygous start codon mutation (c.1A>G, p.M1?) and compound heterozygous mutations [c.504G>C, p.W168C and c.(67+1_68-1)_(394+1_395-1), p.Y23_V131delinsL], respectively, in two unrelated families. The clinical phenotypes of the four patients included parkinsonism (3/4), dysarthria (3/4), seizures (1/4), and probable asymptomatic (1/4), with diverse onset ages. All patients presented with severe calcifications in the cortex in addition to extensive calcifications in multiple brain areas (lenticular nuclei, caudate nuclei, thalamus, cerebellar hemispheres, ± brainstem; total calcification scores: 43-77). JAM2 encodes junctional adhesion molecule 2, which is highly expressed in neurovascular unit-related cell types (endothelial cells and astrocytes) and is predominantly localized on the plasma membrane. It may be important in cell-cell adhesion and maintaining homeostasis in the CNS. In Chinese hamster ovary cells, truncated His-tagged JAM2 proteins were detected by western blot following transfection of p.Y23_V131delinsL mutant plasmid, while no protein was detected following transfection of p.L48* or p.1M? mutant plasmids. In immunofluorescence experiments, the p.W168C mutant JAM2 protein failed to translocate to the plasma membrane. We speculated that mutant JAM2 protein resulted in impaired cell-cell adhesion functions and reduced integrity of the neurovascular unit. This is similar to the mechanisms of other causative genes for primary familial brain calcification or brain calcification syndromes (e.g. PDGFRB, PDGFB, MYORG, JAM3, and OCLN), all of which are highly expressed and functionally important in the neurovascular unit. Our study identifies a novel causative gene for primary familial brain calcification, whose vital function and high expression in the neurovascular unit further supports impairment of the neurovascular unit as the root of primary familial brain calcification pathogenesis.

Ongoing green peafowl protection in China

The green peafowl (Pavo muticus) is one of the most threatened pheasants in the world. In China, it is widely appreciated for its beauty as well as historical and cultural value, but current populations number less than 500 individuals. Recently, Tang and colleagues reported in Science that the green peafowl is likely to become extinct due to the construction of the Jiasajiang Level 1 Hydropower Station within the Red River Upstream District (RRUD) and thus called for a stop to this project (Tang et al., 2019). According to our recent surveys, however, this species is still extant in 22 counties of Yunnan Province, China, among which, only two within the RRUD have been predicted to be affected by floods from the hydropower station. Therefore, the conclusion that the species will likely go extinct in China upon completion of the dam is unwarranted. In fact, construction of the Jiasajiang Level 1 Hydropower Station was stopped in August 2017. The main challenge for green peafowl conservation is that over 65% of the population occurs outside of protected reserves in China. Fortunately, the Chinese government has adopted an Ecological Redline (ERL) strategy to achieve ecological civilization plans, thus bringing new hope to the conservation of green peafowls both inside and outside of protected reserves. As a top conservation priority for China, the government is fully committed to conserving this peafowl.

Regulation of Vascular Calcification by Growth Hormone-Releasing Hormone and Its Agonists

RATIONALE

Vascular calcification (VC) is a marker of the severity of atherosclerotic disease. Hormones play important roles in regulating calcification; estrogen and parathyroid hormones exert opposing effects, the former alleviating VC and the latter exacerbating it. To date no treatment strategies have been developed to regulate clinical VC.

OBJECTIVE

The objective of this study was to investigate the effect of growth hormone-releasing hormone (GHRH) and its agonist (GHRH-A) on the blocking of VC in a mouse model.

METHODS AND RESULTS

Young adult osteoprotegerin-deficient mice were given daily subcutaneous injections of GHRH-A (MR409) for 4 weeks. Significant reductions in calcification of the aortas of MR409-treated mice were paralleled by markedly lower alkaline phosphatase activity and a dramatic reduction in the expression of transcription factors, including the osteogenic marker gene Runx2 and its downstream factors, osteonectin and osteocalcin. The mechanism of action of GHRH-A was dissected in smooth muscle cells isolated from human and mouse aortas. Calcification of smooth muscle cells induced by osteogenic medium was inhibited in the presence of GHRH or MR409, as evidenced by reduced alkaline phosphatase activity and Runx2 expression. Inhibition of calcification by MR409 was partially reversed by MIA602, a GHRH antagonist, or a GHRH receptor-selective small interfering RNA. Treatment with MR409 induced elevated cytosolic cAMP and its target, protein kinase A which in turn blocked nicotinamide adenine dinucleotide phosphate oxidase activity and reduced production of reactive oxygen species, thus blocking the phosphorylation of nuclear factor κB (p65), a key intermediate in the ligand of receptor activator for nuclear factor-κ B-Runx2/alkaline phosphatase osteogenesis program. A protein kinase A-selective small interfering RNA or the chemical inhibitor H89 abolished these beneficial effects of MR409.

CONCLUSIONS

GHRH-A controls osteogenesis in smooth muscle cells by targeting cross talk between protein kinase A and nuclear factor κB (p65) and through the suppression of reactive oxygen species production that induces the Runx2 gene and alkaline phosphatase. Inflammation-mediated osteogenesis is thereby blocked. GHRH-A may represent a new pharmacological strategy to regulate VC.

Carotid atherosclerosis and its relationship to coronary heart disease and stroke risk in patients with type 2 diabetes mellitus

Carotid atherosclerosis (CA) and carotid plaque (CP) are highly correlated with cardiovascular disease. We aimed to determine the prevalence of CA and CP and their relationship with 10-year risks of stroke and coronary heart disease (CHD) in type 2 diabetes mellitus (T2DM).We studied 1584 T2DM patients aged 20 years and older. CA and CP were detected using ultrasonography. Ten-year stroke and CHD risk were determined using the United Kingdom Prospective Diabetes Study (UKPDS) risk engine.The prevalence of CA and CP increased gradually with age. Men had a higher prevalence of CA than women (CA: 58.18% vs 51.54%, P < .01). The 10-year CHD risk (27.9% vs 15.4%, P < .001) and stroke risk (15.2% vs 5.70%, P < .001) were higher in patients with CA than that of those without CA. Compared with patients without CA, the odds ratios (ORs) of CHD in CA and CP group were 4.47 and 10.78 for men, and 4.19 and 5.20 for women, respectively; in the case of stroke, the OR in CA and CP group were 8.83 and 12.07 for men, and 4.35 and 4.90 for women, respectively (P < .001 for all). Multivariate binary logistic regression analysis showed that CA was an independent risk factor for CHD [OR = 2.66, 95% confidence interval (95% CI), 2.05-3.46, P < .001] and stroke (OR = 3.11, 95% CI, 2.38-4.07, P < .001).CA and CP were prevalent in patients with T2DM and positively correlated with 10-year CHD and stroke risk. CA was an independent risk factor for 10-year CHD risk.

Association of Chronic Kidney Disease with Coronary Heart Disease and Stroke Risks in Patients with Type 2 Diabetes Mellitus: An Observational Cross-sectional Study in Hangzhou, China

Background:

Chronic kidney disease (CKD) is an independent risk factor for cardiovascular disease (CVD). However, the association between CKD and CVD risk in patients with type 2 diabetes mellitus (T2DM) in China has not yet been well investigated. This study aimed to determine the association of CKD with the risks of coronary heart disease (CHD) and stroke in a Chinese population with T2DM.

Methods:

A total of 1401 inpatients with T2DM at the Second Affiliated Hospital of Zhejiang University School of Medicine between April 2008 and November 2013 were included in this study. The CKD-Epidemiology Collaboration equation for Asians was used to classify CKD. The UK Prospective Diabetes Study risk engine was used to estimate the risks of CHD and stroke.

Results:

CHD risk was significantly increased with CKD stage (20.1%, 24.8%, and 34.3% in T2DM patients with no CKD, CKD Stage 1–2, and Stage 3–5, respectively; P < 0.001 for all). The stroke risk was also increased with CKD stage (8.6%, 12.7%, and 25.4% in T2DM patients with no CKD, CKD Stage 1–2, and Stage 3–5, respectively; P < 0.001 for all). Compared with no-CKD group, the odds ratios (ORs) for high CHD risk were 1.7 (P < 0.001) in the CKD Stage 1–2 group and 3.5 (P < 0.001) in the CKD Stage 3–5 group. The corresponding ORs for high stroke risk were 1.9 (P < 0.001) and 8.2 (P < 0.001), respectively.

Conclusion:

In patients with T2DM, advanced CKD stage was associated with the increased risks of CHD and stroke.

MicroRNAs and Cardiovascular Disease in Diabetes Mellitus

Cardiovascular disease (CVD) is the major macrovascular complication of diabetes mellitus. Recently, although CVD morbidity and mortality have decreased as a result of comprehensive control of CVD risk factors, CVD remains the leading cause of death of patients with diabetes in many countries, indicating the potential underlying pathophysiological mechanisms. MicroRNAs are a class of noncoding, single-stranded RNA molecules that are involved in β-cell function, insulin secretion, insulin resistance, skeletal muscle, and adipose tissue and which play an important role in glucose homeostasis and the pathogenesis of diabetic complications. Here, we review recent progress in research on microRNAs in endothelial cell and vascular smooth muscle cell dysfunction, macrophage and platelet activation, lipid metabolism abnormality, and cardiomyocyte repolarization in diabetes mellitus. We also review the progress of microRNAs as potential biomarkers and therapeutic targets of CVD in patients with diabetes.

Lower Extremity Peripheral Arterial Disease Is an Independent Predictor of Coronary Heart Disease and Stroke Risks in Patients with Type 2 Diabetes Mellitus in China

We aimed to determine the relationship between lower extremity peripheral arterial disease (PAD), 10-year coronary heart disease (CHD), and stroke risks in patients with type 2 diabetes (T2DM) using the UKPDS risk engine. We enrolled 1178 hospitalized T2DM patients. The patients were divided into a lower extremity PAD group (ankle-brachial index ≤ 0.9 or >1.4; 88 patients, 7.5%) and a non-PAD group (ankle-brachial index > 0.9 and ≤1.4; 1090 patients, 92.5%). Age; duration of diabetes; systolic blood pressure; the hypertension rate; the use of hypertension drugs, ACEI /ARB, statins; CHD risk; fatal CHD risk; stroke risk; and fatal stroke risk were significantly higher in the PAD group than in the non-PAD group (P < 0.05 for all). Logistic stepwise regression analysis indicated that ABI was an independent predictor of 10-year CHD and stroke risks in T2DM patients. Compared with those in the T2DM non-PAD group, the odds ratios (ORs) for CHD and stroke risk were 3.6 (95% confidence interval (CI), 2.2-6.0; P < 0.001) and 6.9 (95% CI, 4.0-11.8; P < 0.001) in those with lower extremity PAD, respectively. In conclusion, lower extremity PAD increased coronary heart disease and stroke risks in T2DM.

Gender Differences in Risks of Coronary Heart Disease and Stroke in Patients with Type 2 Diabetes Mellitus and Their Association with Metabolic Syndrome in China

Coronary heart disease (CHD) and stroke are common complications of type 2 diabetes mellitus (T2DM). We aimed to explore the differences in the risks of CHD and stroke between Chinese women and men with T2DM and their association with metabolic syndrome (MS). This study included 1514 patients with T2DM. The Asian Guidelines of ATPIII (2005) were used for MS diagnosis, and the UKPDS risk engine was used to evaluate the 10-year CHD and stroke risks. Women had lower CHD risk (15.3% versus 26.3%), fatal CHD risk (11.8% versus 19.0%), stroke risk (8.4% versus 10.3%), and fatal stroke risk (1.4% versus 1.6%) compared with men with T2DM (p < 0.05-0.001). The CHD risk (28.4% versus 22.6%, p < 0.001) was significantly higher in men with MS than in those without MS. The CHD (16.2% versus 11.0%, p < 0.001) and stroke risks (8.9% versus 5.8%, p < 0.001) were higher in women with MS than in those without MS. In conclusion, our findings indicated that Chinese women with T2DM are less susceptible to CHD and stroke than men. Further, MS increases the risk of both these events, highlighting the need for comprehensive metabolic control in T2DM.

Hepatitis B virus-associated nephropathy in a patient with diabetes mellitus

Hepatitis B virus (HBV)‐associated nephropathy is not a rare manifestation of HBV infection; this could result in diagnostic confusion and the possible misidentification of a diabetic patient with albuminuria. We present the first published case of a HBV‐associated nephropathy occurring in a patient with diabetes. The patient was a 24‐year‐old man who was admitted to hospital with 4 days of generalized swelling and oliguria. He had a 3‐year history of weight loss, and a 1‐year history of polydipsia and polyuria before the symptoms of generalized swelling and oliguria appeared. Laboratory tests showed a fasting blood sugar of 15.1 mmol/L and glycated hemoglobin of 18.1%. The 24‐h urine protein excretion was 2807.8 mg and serum albumin was 19.1 g/L. The diagnosis of HBV‐associated nephropathy was confirmed by serological evaluations of HBV antigen and antibodies, immunohistochemical evidence of HBV‐related antigens, and immune complexes in renal biopsies. The decreased proteinuria was observed after antiviral therapy.

Leptin promotes the osteoblastic differentiation of vascular smooth muscle cells from female mice by increasing RANKL expression

Arterial calcification is a complex and active regulated process, which results from a process of osteoblastic differentiation of vascular smooth muscle cells (VSMCs). Leptin, the product of the ob gene, mainly regulates food intake and energy expenditure and recently has been considered to be correlated with the arterial calcification. However, the mechanisms of the effects of leptin on osteoblastic differentiation of VSMCs are unknown. We used calcifying vascular smooth muscle cells (CVSMCs) as a model to investigate the relationship between leptin and the osteoblastic differentiation of CVSMCs and the signaling pathways involved. Our experiments demonstrated that leptin could increase expression of receptor activator of nuclear factor-κB ligand (RANKL) and bone morphogenetic protein 4 (BMP4), as well as alkaline phosphatase (ALP) activity, runt-related transcription factor 2 expression, calcium deposition, and the formation of mineralized nodules in CVSMCs. Suppression of RANKL with small interfering RNA abolished the leptin-induced ALP activity and BMP4 expression in CVSMCs. Leptin could activate the ERK1/2 and phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. Furthermore, pretreatment with the ERK inhibitor PD98059 and the PI3K inhibitor LY294002 abolished leptin-induced RANKL expression and blocked the promotion of ALP activity of CVSMCs. Silencing of the leptin receptor OB-Rb with small interfering RNA abolished leptin-induced activation of ERK and Akt and the expression of RANKL and reversed the effects of leptin on ALP activity. Meanwhile, addition of Noggin (the BMP4 inhibitor) blunted the effect of leptin on ALP activity. These results show that leptin can promote osteoblastic differentiation of CVSMCs by the OB-Rb/ERK1/2/RANKL-BMP4 and OB-Rb/PI3K/Akt/RANKL-BMP4 pathways.

The efficacy of metformin in pregnant women with polycystic ovary syndrome: a meta-analysis of clinical trials

OBJECTIVES

The role of metformin in the treatment of pregnant women with polycystic ovary syndrome (PCOS) is controversial. Therefore, we evaluated whether the use of metformin during pregnancy in women with PCOS could reduce pregnancy-related complications.

RESEARCH DESIGN AND METHODS

MEDLINE was searched to retrieve relevant trials. In addition, reviews and reference lists of the retrieved articles were scanned for further appropriate studies. The primary outcome measure was the incidence of complications of pregnancy, which included early pregnancy loss (EPL), gestational diabetes (GDM), pre-eclampsia (PE), and pre-term delivery (PD).

RESULTS

In total, eight studies with 1106 patients were included. The pooled odds ratio (OR) (95% confidence interval) of outcome for pregnant women with PCOS prescribed metformin were 0.32 (0.19-0.55) for EPL, 0.37 (0.25-0.56) for GDM, 0.53 (0.30-0.95) for PE and 0.30 (0.13-0.68) for PD.

CONCLUSIONS

Metformin therapy throughout pregnancy decreased the OR of EPL, GDM, PE, and PD in pregnant PCOS women with no serious detrimental side effects.

Age- and gender-specific prevalence of carotid atherosclerosis and its association with metabolic syndrome in Hangzhou, China

OBJECTIVE

Because of rapid alterations in lifestyle and the incidence of metabolic syndrome (MetS), the prevalence of carotid atherosclerosis (CA) and carotid plaque (CP) may increase in China. We aimed to evaluate the prevalence of CA and CP as well as its relation to MetS in an East Chinese population.

METHODS

The study included 6142 subjects who underwent general health screening including carotid ultrasonography in 2009. Diagnoses of MetS were made according to the revised Adult Treatment Panel III criteria.

RESULTS

The prevalence of CA and CP increased gradually with age. These conditions were more prevalent in men than in women (CA: 22.1%vs 12.0%, P < 0.001; CP: 12.6%vs 7.2%, P < 0.001). Multivariate logistic regression analysis showed that male gender, age, blood pressure, fasting blood glucose (FBG) and low-density lipoprotein cholesterol were risk factors for CA and CP, while high-density lipoprotein cholesterol was protective for CA. Age ≥ 50 years has the largest impact on CA and CP, followed by elevated blood pressure and elevated blood glucose. Individuals with MetS had a higher prevalence of CA (27.7%vs 20.0% in men, 24.0%vs 10.3% in women; P < 0.001 in both) and CP (16.6%vs 11.2% in men, P < 0.001; 11.8%vs 6.5% in women, P < 0.005) than those without MetS. The prevalence and odds ratios of CA and CP aggregated with an increasing number of MetS components, even in individuals exhibiting only one component.

CONCLUSIONS

These results indicate that CA and CP have become a major public health problem in China. MetS and its components were associated with an increased prevalence of CA and CP.

Age-related bone mineral density, osteoporosis rate and risk of vertebral fracture in mainland Chinese women with type 2 diabetes mellitus

Few data are available regarding bone mineral density (BMD) and the risk of vertebral fracture among mainland Chinese women with type 2 diabetes mellitus (T2DM). A decrease in the bone projective area (BPA) can be an indirect marker reflecting compressed vertebral fracture. We investigated age-related BMD, BPA, and the prevalence of osteoporosis in women with T2DM in mainland China. BMD and BPA of the posteroanterior lumbar spine (L1-L4) and hip were measured by dual-energy X-ray absorptiometry in 1253 women with T2DM and 1194 control subjects without diabetes aged 40-80 yr. BMD of the lumbar spine and hip decreased with age. BMD of the lumbar spine was higher in T2DM than controls (p<0.05-0.001), as was BPA at some vertebral bodies (p<0.05-0.001), whereas no significant intergroup differences in BPA were observed at the hip. The prevalence of osteoporosis in the women with T2DM increased with age: 0-2.58% at age 40-49 yr, 6.94-28.4% at age 50-59 yr, 32.7-76.7% at age 70-80 yr, with the range reflecting differences between skeletal sites. In subjects over 60 yr, the rates of osteoporosis at posteroanterior spine were significantly lower in T2DM patients than in controls (p<0.05-0.001). In conclusion, women with T2DM had higher BMD and lower risk of osteoporosis. Higher BPA of the vertebrae indicated that women with T2DM in mainland China would have a lower risk of vertebral fracture than non-diabetic women.

Bone mineral density and its relationship with body mass index in postmenopausal women with type 2 diabetes mellitus in mainland China

Bone mineral density (BMD) and its association with body mass index (BMI) are uncertain in postmenopausal women with type 2 diabetes mellitus (T2DM) in mainland China. This study was performed to assess this association including 1,042 postmenopausal women with T2DM and 919 non-diabetic control subjects. Bone mineral density of the posteroanterior spine and of the left hip was measured by use of dual-energy X-ray absorptiometry. Diabetic participants were divided into three groups according to BMI, i.e. low BMI (DML < 18.5 kg/m(2)), intermediate BMI (DMM 18.5-24.9 kg/m(2)), and high BMI (DMH >or= 25 kg/m(2)). The BMD values of diabetic subjects between groups exhibited a significant gradient difference, with DML < DMM < DMH. On the fitting curves, where BMD in various skeletal regions varied with age, BMDs of DML were approximately 15% lower than those of DMM, and those of DMM were approximately 10% lower than those of DMH. For prevalence and risks of osteoporosis a gradient difference was observed among diabetic groups, DML > DMM approximately control > DMH. The osteoporosis risk was higher for the hip than for the lumbar spine, especially in DML. This study indicated that postmenopausal women with T2DM had higher BMD and lower osteoporosis risk in the lumbar spine, and that lower BMI was an indicator of osteoporosis in mainland China.

Establishment of BMD reference databases for the diagnosis and evaluation of osteoporosis in central southern Chinese men

Osteoporosis in men is an increasingly important public health problem. This study was designed to establish bone mineral density (BMD) reference databases for central southern Chinese men at multiple skeletal sites. We recruited 2433 native Chinese males for BMD assessment. Of these, 1537 were healthy volunteers (age range, 15-85 years), and 896 were suspected to have osteoporosis. BMD values were measured at the posteroanterior (PA) and lateral spine, hip, and distal forearm using a Delphi A absorptiometer. The quadratic regression model provided the best fit for age-related changes in BMD in the spine and hip. The cubic regression model was the best for describing age-related BMD changes in the distal forearm. Peak BMD in the lumbar spine, femoral neck, and total hip occurred at 15-19 years. Peak BMD at the distal forearm occurred at 40-44 years. The prevalence of primary osteoporosis in subjects ranging from 50-85 years was 4.3%-27.7% at various skeletal sites. Compared to the databases established here, the Hologic databases led to significantly higher osteoporosis detection rates. The BMD reference databases established for central southern Chinese men provide the most reliable diagnostic standards for osteoporosis detection in men of central south China.

Serum concentrations of MMP-1, MMP-2, and TIMP-1 in Chinese women: Age-related changes, and the relationships with bone biochemical markers, bone mineral density

BACKGROUND

Osteoblast-derived matrix metalloproteinse-1 (MMP-1), MMP-2 and tissue inhibitor of metalloproteinase-1 (TIMP-1) play a role in bone metabolism by degrading bone matrix.

METHODS

We measured MMP-1, MMMP-2, TIMP-1 and associated results with age and bone metabolism in 591 Chinese women aged 20-80 y.

RESULTS

Serum MMP-1, MMP-2, and TIMP-1 concentrations exhibited positive correlation with age. Serum concentrations of MMP-1 were higher in 40-69 y old women. The concentrations of MMP-2 were significantly increased in the 50-69 y olds. Serum TIMP-1 concentrations were significantly lower in women aged 30-59 y, and then these were followed by an increase at >60 y olds. We found a significant negative weaker correlation between MMP-2 and BMD. But multiple linear stepwise regression analysis showed that MMP-2 was not a determinant factor for BMD. There were significant positive correlations between MMP-2 and bone alkaline phosphatase (BAP), osteocalcin (OC), and cross-linked N-telopeptides of type I collagen (NTX).

CONCLUSIONS

The serum concentrations of MMP-1, MMP-2, and TIMP-1 exhibit age-related changes, and circulating MMP-2 and bone turnover are related.

Age-related changes of serum bone alkaline phosphatase and cross-linked C-telopeptides of type I collagen and the relationship with bone mineral density in Chinese women

BACKGROUND

Previous studies have shown that bone turnover rate changes with age. At the same time, there is no definitive research regarding age-related changes of bone turnover level and its association with bone mineral density (BMD) in Chinese mainland women.

METHODS

In a cohort of 663 Chinese mainland women aged 20-70 years, serum bone alkaline phosphatase (BAP) and serum cross-linked C-telopeptides of type I collagen (sCTX) were measured to evaluate the state of bone formation and resorption, respectively. BMD was measured in the posteroanterior spine, supine lateral spine, hip and forearm using a dual-energy X-ray absorptiometry.

RESULTS

The cubic polynomial regression model best fit age-related changes in serum BAP (R2=0.398, p<0.001) and sCTX concentrations (R2=0.148, p<0.001) with largest R2 from comparison 8 different regression models. Their values reached a minimal level in the 30-39 years age group, and increased dramatically in the 40-59 years groups. There was a decreasing trend of BAP in women >60 years. The levels of BAP and sCTX were inversely correlated to BMD in various skeletal regions over the entire population (r=-0.096 to -0.357, p<0.05). sCTX was a significant predictor of a T-score< or =-2.5 of BMD in postmenopausal women with sCTX levels above mean+2 SD of women aged 30-39 years compared with other postmenopausal women, which indicated by odds ratios 1.9-3.7 (p<0.05) for various skeletal regions, especially for the lateral lumbar spine (2.2, p<0.01), Ward's triangle (3.7, p<0.01), and ultradistal end of radius + ulna (2.8, p<0.001).

CONCLUSIONS

Age-dependent serum BAP and sCTX were inversely correlated to BMD, and sCTX was a useful parameter for the prediction of a low T-score of BMD at skeletal sites with abundant cancellous bone in postmenopausal women.

Establishment of BMD reference curves at different skeletal sites in women, using a Cartesian coordinate numeration system

The BMD reference curve is the reference value used for diagnosing osteoporosis and assessing bone mass changes. Its accuracy would affect the correctness of T-score and Z-score values and thus the reliability of diagnostic results. In this paper, we report the use of a new method, a Cartesian coordinate numeration system, to establish BMD reference curves at different skeletal sites in women. In a reference population of 3,919 women ranging in age from 5-85 years, we used the dual X-ray absorptiometry (DXA) bone densitometer to measure BMD at the posteroanterior spine (PA; vertebrae L1-L4), followed by a paired PA/lateral spine scan of the vertebral bodies of L2-L4, expressed in g/cm2 and g/cm3, and of the hip and forearm. We chose the cubic regression model to best fit BMD curves that varied with age at different skeletal sites. We then referred the BMD of the fitting curves established by the method of the coordinate numeration system as reference curves, compared them to BMD reference curves derived from the fitting curve equation or age cross-section, and calculated the deflection degrees of the BMD reference curves acquired from the fitting curve equation. At the PA spine, lateral spine (expressed in g/cm3), femoral neck, Ward's triangle and radius + ulna ultradistal, the reference curves calculated from the equation were significantly lower than those confirmed by the method of the coordinate numeration system; whereas, at the lateral spine (expressed in g/cm2), total hip, and radius + ulna 1/3 sites, the reference curves derived from the equation were markedly higher than those acquired from the coordinate numeration system. The differences in the two kinds of reference curves calculated by these two different methods gradually increased along with the increment in ages of the women. At the peak value of the reference curves, the BMD calculated from the equation deflected from 2.02% to -10.0% from the BMD acquired from the coordinate numeration system at different skeletal sites, and from 21.5% to -121.8% until the age of 85 years. The highest positive deflection of 65.2% existed at the lateral spine (expressed in g/cm2) and the lowest positive deflection of 21.5% at the total hip. The maximum negative deflection of -121.8% was at the radius + ulna ultradistal, and the minimum negative deflection of -32.6% at the PA spine. The BMD curve acquired from age cross-section was highly positive compared with the one derived from the coordinate numeration system (r=0.955-0.985 p=0.000) with no significant difference between them. Various analysts used such a method to obtain the coefficient of variance (CV) in BMD precision on each curve that was from 0.05-0.19%. Our study shows that the Cartesian coordinate numeration system is an accurate, precise and reliable method and can serve to reveal the serious drawbacks of using the fitting curve equation to calculate BMD. The BMD reference curves established by this coordinate numeration system maintained the authenticity of the fitting curve, whereas, using the fitting curve equation to obtain BMD reference curves at different skeletal sites led to distortion, and resulted in false increases or decreases in T-score and Z-score values.

Comparison of spine and femur reference data in native Chinese women from different regions of China

The aim of this study is to explore the differences of BMD reference curves at various skeletal sites among Chinese women from different regions of China and to investigate the feasibility of establishing a unified national BMD reference database for Chinese women. We measured BMD at the posteroanterior (PA) lumbar spine, femoral neck, trochanter and Ward's triangle by dual-energy X-ray absorptiometry bone densitometer in 3,422 Changsha women of South Central China, aged 20-84 years. The documented BMDs of reference populations of women in all other areas included Shanghai ( n =2,111) and Nanjing ( n =3,174) in the East, Shenyang ( n =1,213) in the Northeast, Kunming ( n =523) in the Southwest, Chongqing ( n =811) in the Midwest and Xian ( n =1,320) in the Northwest. We adopted the cubic regression as the fitting model for reference curves of BMD that varied with age, conducted conversions of BMD measured by various bone densitometers from different manufacturers and compared the differences between standardized BMD (sBMD) reference curves and combined ones for women from different areas. Our results revealed that by comparing variances in women from different areas, the average variances of non-standard BMD were 0.8-30.8% at the PA spine, 0.7-24.5% at the femoral neck, 0.6-29.9% at the trochanter and 1.1-54.7% at Ward's triangle, while average variances of sBMD either significantly decreased or disappeared (0.8-3.9% at the PA spine, 0.7-8.6% at the femoral neck, 0.6-8.3% at the trochanter and 1.1-29.9% at Ward's triangle). The sBMD reference curves were highly positive-dependent with combined ones ( r =0.913-0.999, P =0.000). At the PA spine and trochanter, the effect of combined sBMD curves presented well in women from different areas, except for those from Shanghai at the PA spine and Shenyang at the trochanter, indicating that sBMD curves were significantly different from pooled ones; at the femoral neck and Ward's triangle, the effect of combined sBMD reference curves was poor, indicating that sBMD curves demonstrated significant differences from pooled ones in women from a majority of these areas. We conclude that, in high density population areas, sBMD reference curves showed no significant geographic differences in women from various regions. In women from different areas, sBMD reference curves present good pooled results at the PA spine and trochanter. The less ideal combining effect of the sBMD curves at both femoral neck and Ward's triangle might be caused by the intrinsic differences from the different measuring instruments.

Relationship of serum leptin with age, body weight, body mass index, and bone mineral density in healthy mainland Chinese women

BACKGROUND

Serum leptin concentration is associated with age, fat and bone mineral density (BMD), and there are ethnic differences in physique and BMD values. The relationship between serum leptin concentration and BMD in Chinese women is presently unknown. We examined the relationship of serum leptin concentration with age, body weight, BMI and BMD in mainland Chinese women.

METHODS

Serum leptin concentration in a population of 676 Chinese females, aged 20-80 years (45.4+/-14.8 years, mean+/-S.D.), was measured using an enzyme-linked immunosorbent assay (ELISA). BMD values were measured by dual-energy X-ray absorptiometry (DXA) at a number of sites: the posteroanterior lumbar spine (PA, L1-L4), lateral lumbar spine (Lat, L2-L4), hip (including the femoral neck (FN) and total hip (T-hip)), and forearm (one-third region (RU1/3) and total region (RUT)). The relationship between changes in serum leptin concentration with age, body weight, height, body mass index (BMI) and BMD values at six sites were analyzed using 10 different regression models, and the models giving the best fit were selected.

RESULTS

The cubic regression model best described the changes in serum leptin concentration with age (R(2)=0.048, p<0.001) and body weight (R(2)=0.352, p<0.001), while the quadratic regression model was best for serum leptin concentration changes with BMI (R(2)=0.410, p<0.001); serum leptin concentration was not correlated with height. Serum leptin concentration was significantly higher in postmenopausal than premenopausal women (p<0.001). Serum leptin concentration was correlated with Lat BMD (R(2)=0.012, p<0.018), FN BMD (R(2)=0.006, p<0.041) and T-hip BMD (R(2)=0.013, p<0.004) in the whole population. In premenopausal women, leptin was positively associated with BMD except for Lat (R(2)=0.029-0.055, p<0.008); in postmenopausal women, leptin was also positively associated with AP, FN, T-hip BMD (R(2)=0.026-0.042, p<0.007). However, after adjusting for BMI not for body weight, there was no association between serum leptin concentration and age. Meanwhile, after adjustment for age, body weight and BMI, there was no association between serum leptin concentration and BMD values in premenopausal and postmenopausal women.

CONCLUSIONS

Age-related changes in serum leptin concentration is dependent on BMI, but not a direct determinant of BMD in Chinese females.

Relationship of body surface area with bone density and its risk of osteoporosis at various skeletal regions in women of mainland China

The aim of this study was to investigate the relationship between body surface area (BS) and bone mineral density (BMD) and the associated osteoporosis risk at various skeletal regions in women from mainland China. BMD was measured at the posteroanterior (PA) spine (L1-L4), supine lateral spine (L2-L4) including volumetric BMD (vBMD), hip including femoral neck, trochanter and total hip, and forearm, including radius + ulna ultradistal (R + UUD), 1/3 site (R + U1/3) and total region (R + UT) using a dual-energy X-ray absorptiometry (DXA) fan-beam bone densitometer (Hologic QDR 4500A) in 3418 females aged from 18 to 75 years. Data analysis revealed a positive correlation between BS and BMD at the various skeletal regions (r = 0.114-0.373, all P = 0.000), but no correlation with vBMD (r = 0.000, P = 0.934). Using the stepwise regression model, BMDs at various skeletal regions were dependent variables while height, weight, body mass index (BMI), BS and projective bone area (BA) were independent variables; BS was determined to be the most important variable that affected the PA spine, hip and forearm BMDs. Subjects were divided into three groups according to size: large BS group (LBSG), intermediate BS group (IBSG) and small BS group (SBSG). The BMD at different skeletal regions of subjects between groups exhibited a significant gradient difference, with LBSG > IBSG > SBSG, but this was not seen for vBMD. On the fitting curves where BMD varied with age at the PA spine, femoral neck, total hip and R + UUD, BMDs of LBSG were 6.93-9.29% higher than those of IBSG and 12.1-16.9 % higher than those of SBSG, whereas those of SBSG were 6.12-9.59% lower than those of IBSG at various skeletal regions, respectively. The prevalence rates and risks of osteoporosis of LBSG were significantly lower than those of SBSG and IBSG, whereas those of IBSG were obviously lower than those of SBSG at various skeletal regions, respectively, presenting a gradient difference among the three study groups, LBSG < IBSG < SBSG. Our study shows that the relationship between BS and BMD exceeds that between BMD and height or weight in women in mainland China. When areal BMD is employed, those with a larger BS have higher areal BMD and lower risks of osteoporosis while, conversely, those with a smaller BS have lower areal BMD, and therefore higher risk for osteoporosis. However, when vBMD is used, these differences diminish or even disappear.

Determination of age-specific bone mineral density and comparison of diagnosis and prevalence of primary osteoporosis in Chinese women based on both Chinese and World Health Organization criteria

The aim of this study was to determine age-specific bone mineral density (BMD) at various skeletal regions in a native Chinese reference population, and to explore the differences in the diagnosis of primary osteoporosis and estimated prevalence of osteoporosis based on both Chinese criteria (BMD of subjects, 25% lower than the peak BMD) and WHO criteria (BMD of subjects, 2.5 SD [T-score < or = -2.5] lower than the young adult mean [YAM]). There were 3,406 subjects in our female reference population, ranging in age from 10 to 90 years. A dual-energy X-ray absorptiometry (DXA) fan-beam bone densitometer (Hologic QDR 4500A) was used to measure the BMD in subjects at the posteroanterior (PA) spine (L1-L4), supine lateral spine (L2-L4 including areal BMD [aBMD] and volumetric BMD [vBMD]), hip (including femoral neck and total hip), and radius + ulna ultradistal (R + UUD) of the forearm. Cross-sectional data analysis in stratified 5-year age intervals revealed that the peak BMD (PBMD) at various skeletal regions occurred within the age range of 30-44 years, with PBMD at the lateral spine and femoral neck occurring at 30-34 years, posteroanterior spine and total hip at 35-39 years, and ultradistal forearm at 35-44 years. The reference values of BMD (PBMD) calculated using Chinese criteria for the diagnosis of primary osteoporosis were significantly higher than the young adult mean (YAM) using WHO criteria for all skeletal regions except for the total hip, at a range of 0.9%-3.8% higher. The BMD cutoff values using Chinese criteria for the diagnosis of osteoporosis were 3.7%-10.9% higher than those using WHO criteria for various skeletal regions. The prevalence rate of primary osteoporosis according to Chinese criteria in subjects ranging from 50 to 90 years was 41.5% at the PA spine, 53.9% at the lateral spine, 34.2% at the femoral neck, 30.7% for total hip, and 51.4% at R + UUD; while according to WHO criteria, this rate was 32.1% at the PA spine, 34.9% at the lateral spine, 16.3% at the femoral neck, 18.9% for total hip, and 45.2% at R + UUD. The prevalence of primary osteoporosis according to both criteria varied with the age and skeletal region of the subjects. The prevalence of primary osteoporosis using Chinese criteria, compared with WHO criteria was 31% higher at the lumbar spine, 109% higher at the femoral neck, and 14% higher at the ultradistal forearm. In conclusion, PBMD occurs in the age range of 30-44 years in native Chinese females. The BMD reference values, BMD cutoff values, and prevalence of primary osteoporosis determined by Chinese criteria are all higher than those determined by the WHO criteria; thus, the application of Chinese criteria may overestimate the number of patients with primary osteoporosis.

Establishment of BMD reference plots and determination of peak BMD at multiple skeletal regions in mainland Chinese women and the diagnosis of osteoporosis

Osteoporosis is a major public health problem, particularly in women. Bone mineral density (BMD) reference plot is a basic, and the peak BMD (PBMD) an important, parameter in the diagnosis of osteoporosis. In order to establish reference plots of BMD at multiple skeletal sites in Chinese women and improve the diagnostic accuracy for osteoporosis, we measured BMDs at several skeletal regions in 3,378 Chinese women, aged 5-96 years, using a dual-energy X-ray absorptiometry fan-beam bone densitometer. After determining that the cubic regression model best fit all skeletal regions, we utilized the curve-fitting to establish BMD reference plots and utilized the curve-fitting equation to calculate the highest BMDs at all skeletal regions using three different methods of calculation--actual PBMD (method A), PBMD of each 5-year age group (method B), and a cross-section of age (method C). When the three methods were compared, we found significant differences among them at the majority of skeletal regions studied. When we utilized these three methods to determine the prevalence of osteoporosis in 2,120 women aged 40 years and older, except for the Ward's triangle, we observed significant differences among them at all skeletal regions. In the present study, we established new BMD reference plots at multiple skeletal regions for women of mainland China. Our findings also indicate that curve-fitting equations can be employed to calculate actual PBMDs specific to individual regions, and that the use of different methods to calculate PBMD may have a significant impact on both PBMD and the diagnosis of osteoporosis. Therefore, we suggest that a standardized method be established to calculate site-specific PBMDs based on the peak values of best-fit reference curves in appropriate age groups.