Reference values of bone mineral density and prevalence of osteoporosis in Chinese adults.

UNLABELLED: We pooled bone mineral density (BMD) data published in 91 articles including 139,912 Chinese adults and then established a national-wide BMD reference database at the lumbar spine and femur neck for Chinese adults. The prevalence of osteoporosis in the middle-aged and elderly Chinese population was also estimated. INTRODUCTION: Well-accepted reference value of BMD is lacking in Chinese. We established the reference database and assessed osteoporosis prevalence based on published literature conducted in the Mainland China, Taiwan, and Hong Kong Chinese. METHODS: We searched for all published articles indexed in MEDLINE, PubMed, CNKI, and SinoMed up to January 2013. We included cross-sectional studies that examined BMD using a dual-energy X-ray absorptiometry at the femur neck (FN) and/or lumbar spine (LS) in healthy adults. Overall age-specific mean (SD) BMD were pooled after standardization. RESULTS: Ninety-one studies including 51,906 males and 88,006 females (≥ 20 years) in 38 cities in China were included in this pooling study. Gender- and age-specific reference curves of standardized BMD (sBMD) at the LS and FN were constructed. The sBMD cutoffs for osteoporosis classification were 0.746 and 0.549 in women, and 0.680 and 0.568 g/cm(2) in men; age-standardized prevalence of osteoporosis was 23.9 % and 12.5 % in women and 3.2 % and 5.3 % in men aged ≥ 50 years at the LS and FN, respectively. Meta-regression analysis showed that greater age and altitude, lower latitude, smaller city size, earlier detection time, and random sample were correlated to lower sBMD in at least one gender-specific bone sites; the Hologic DXA produced a higher value of FN sBMD than the other two devices (Lunar and Norland). CONCLUSION: We have established a national-wide BMD reference database at the LS and FN for Chinese adults and estimated the prevalence of osteoporosis in the middle-aged and elderly Chinese population.

Longitudinal changes in physical activity levels over 5 years and relationship to cardiorespiratory fitness in Chinese midlife women.

AIM: Better understanding the impact of changes in physical activity levels on cardiorespiratory fitness, as measured by maximal oxygen uptake (VO(2max)) may inform preventive interventions. We aimed to determine longitudinal changes in physical activity levels over 5 years and the relationship between these changes with VO(2max) in a sample of Chinese midlife women. METHODS: A total of 184 Chinese women aged 50-64 years in Hong Kong were enrolled for this study. Physical activity was assessed with the modified Chinese Baecke questionnaire at baseline (2002-2004) and follow-up (2008-2009). VO(2max) was measured with a symptom-limited maximal exercise test on an electrically braked cycle ergometer at follow-up. RESULTS: Compared with subjects who were persistently inactive, those who were increasingly/persistently active had significantly higher levels of VO(2max) (P<0.05). Being persistently active was also independently associated with a high level of VO(2max) (OR: 4.4, 95%CI: 1.0-19.2). However, the rate of decline in VO(2max) with age was apparently greater in persistently active subjects compared with their persistently inactive peers, but the differences were not statistically significant. CONCLUSION: Our findings suggest that maintaining a high level of physical activity may lead to higher levels of VO(2max).

Sex differences in stroke incidence and survival in Hong Kong, 2000-2007.

BACKGROUND: Few studies have examined the impact of sex across different age groups and over time on chronic diseases in Asia. The objective of this study was to explore the effect of sex across different age groups and over time on stroke incidence and 30-day case fatality in Hong Kong. METHODS: Over 90% first hospitalizations for stroke in Hong Kong (from 2000 to 2007) were identified from the Clinical Management System of the Hospital Authority. Age-specific rate ratios (RRs; women to men) for incidence of first hospitalization and the 30-day case fatality were estimated based on Poisson regression models after adjustment for year of hospitalization. RESULTS: Women below the age of 85 years had a lower incidence of first hospitalization than men, and the effect size varied with age [35-44 years: RR = 0.56, 95% confidence interval (CI) = 0.49-0.64; 45-54 years: 0.65, 0.53-0.79; 55-64 years: 0.58, 0.48-0.71; 65-74 years: 0.71, 0.58-0.85; 75-84 years: 0.83, 0.68-1.00)]. Women aged ≥85 years had a stroke incidence similar to men, but the adjusted 30-day case fatality was significantly higher than that of men aged ≥85 years (RR = 1.14, 95% CI = 1.05-1.23). CONCLUSIONS: Lower rates of incidence were observed in women than men aged 35-84 years in Hong Kong but short-term case fatality is greater in women aged ≥85 years.

The effects of isoflavones combined with soy protein on lipid profiles, C-reactive protein and cardiovascular risk among postmenopausal Chinese women.

BACKGROUND & AIMS: Observational studies note that regular dietary soy protein intake (6-11 g day(-1)) has a significant association with lower blood lipids; however, these observations have not been confirmed by clinical trials. This study aimed to ascertain the effects of moderate intake of soy protein (15 g) with isoflavones or isoflavones alone on serum lipid profiles, inflammatory markers (C-reactive protein and uric acid) and composite cardiovascular risk in Chinese postmenopausal, prediabetic women. METHODS AND RESULTS: A double-blind randomised, placebo-controlled trial was conducted among 180 postmenopausal Chinese women with prediabetes or early untreated diabetes, aged 46-70 years and, on average, 6.0 years since menopause. Participants were randomly assigned to one of the three arms to receive 15-g soy protein and 100-mg isoflavone (Soy group), or 15-g milk protein and 100 mg isoflavone (Iso group) or 15-g milk protein (placebo group) on a daily basis for 6 months. The results showed that no significant difference was observed in serum high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), total cholesterol (TC), triaclyglycerol (TG), high sensitive C-reactive protein and a composite 10-year cardiovascular risk between the three groups at both 3 and 6 months. Serum uric acid marginally increased by 1.22% in the Soy group and decreased by 4.28% and 4.82% in the Iso and placebo groups at 3 months (P = 0.087), but no difference was observed at 6 months (P = 0.264). CONCLUSION: Soy protein with isoflavones or isoflavones alone at the provided dosage showed no significantly beneficial effects on measured cardiovascular risk factors in postmenopausal Chinese women with early hyperglycaemia.

Predictive Value of the GLIM Criteria in Chinese Community-Dwelling and Institutionalized Older Adults Aged 70 Years and Over.

OBJECTIVES: The Global Leadership Initiative on Malnutrition (GLIM) has recently published criteria for classifying malnutrition. This study investigated the associations between malnutrition and adverse outcomes, and identified which component(s) of the GLIM criteria is/are risk factor(s) of adverse outcomes in Chinese older adults. DESIGN: A prospective cohort study of Chinese older adults in a healthy ageing study. SETTING: Participants' place of residence. PARTICIPANTS: Community-dwelling and institutionalized Chinese older adults aged ≥70 years living in Hong Kong. MEASUREMENTS: Malnutrition at baseline was classified according to selected GLIM criteria. Adverse outcomes including poor self-rated health, functional limitation (Barthel Index), falls, frailty (FRAIL scale), hospitalization and mortality were assessed after a 3-year follow-up. Associations between malnutrition and components of selected GLIM criteria (weight loss, low body mass index (BMI), low muscle mass and disease burden) and each adverse outcome were examined using adjusted binary logistic regression and Cox proportional hazards model. Odds ratio (OR) or hazard ratio (HR) and 95% confidence interval (CI) are presented. RESULTS: Data of 1576 community-dwelling (45.5% female, 78.1±6.5 years) and 427 institutionalized (69.6% female, 85.5±6.4 years) older adults were included at baseline. Among community-dwelling older adults, malnutrition was associated with frailty (n=899, OR: 2.44, 95% CI: 1.05-5.70) and mortality (n=1007, HR: 1.37, 95% CI: 1.12-1.66). No association was found for other outcomes. Among institutionalized older adults, malnutrition was not associated with any outcomes. Low BMI and low muscle mass were risk factors of frailty; while weight loss was a risk factor of mortality in community-dwelling older adults. Weight loss and disease burden were risk factors of mortality among institutionalized older adults. CONCLUSION: The association between malnutrition and frailty and mortality was observed in community but not in institutional settings. Further studies are required to draw more definitive conclusions on the use of GLIM criteria in institutional settings.

Differential effects of anti-B7-1 and anti-B7-2 monoclonal antibody treatment on the development of diabetes in the nonobese diabetic mouse.

Insulin-dependent diabetes mellitus (IDDM) is thought to be an immunologically mediated disease resulting in the complete destruction of the insulin-producing islets of Langerhans. It has become increasingly clear that autoreactive T cells play a major role in the development and progression of this disease. In this study, we examined the role of the CD28/B7 costimulation pathway in the development and progression of autoimmune diabetes in the nonobese diabetic (NOD) mouse model. Female NOD mice treated at the onset of insulitis (2-4 wk of age) with CTLA4Ig immunoglobulin (Ig) (a soluble CD28 antagonist) or a monoclonal antibody (mAb) specific for B7-2 (a CD28 ligand) did not develop diabetes. However, neither of these treatments altered the disease process when administered late, at > 10 wk of age. Histological examination of islets from the various treatment groups showed that while CTLA4Ig and anti-B7-2 mAb treatment blocked the development of diabetes, these reagents had little effect on the development or severity of insulitis. Together these results suggest that blockade of costimulatory signals by CTLA4Ig or anti-B7-2 acts early in disease development, after insulitis but before the onset of frank diabetes. NOD mice were also treated with mAbs to another CD28 ligand, B7-1. In contrast to the previous results, the anti-B7-1 treatment significantly accelerated the development of disease in female mice and, most interestingly, induced diabetes in normally resistant male mice. A combination of anti-B7-1 and anti-B7-2 mAbs also resulted in an accelerated onset of diabetes, similar to that observed with anti-B7-1 mAb treatment alone, suggesting that anti-B7-1 mAb's effect was dominant. Furthermore, treatment with anti-B7-1 mAbs resulted in a more rapid and severe infiltrate. Finally, T cells isolated from the pancreas of these anti-B7-1-treated animals exhibited a more activated phenotype than T cells isolated from any of the other treatment groups. These studies demonstrate that costimulatory signals play an important role in the autoimmune process, and that different members of the B7 family have distinct regulatory functions during the development of autoimmune diabetes.

Menopausal transition and changes of body composition: a prospective study in Chinese perimenopausal women.

OBJECTIVES: Whether age or menopause per se influences fat distribution remains controversial. This study aimed to investigate the change of body composition, particularly body fat distribution, in relation to menopausal transition in a 30-month prospective study of perimenopausal women. METHODS: A total of 438 community-based healthy women aged 44-55 years participated in the Hong Kong Perimenopausal Women Osteoporosis Study. Data were obtained at baseline, and at 9-, 18- and 30-month during the follow-up. Soft tissue measurements consisting of fat mass and lean muscle mass of the trunk and whole body were obtained by the dual energy X-ray absorptiometry. Percentage change of body measurements over the follow-up period was compared between women who remained premenopausal, those who went through menopausal transition, and those who were menopausal since baseline. RESULTS: A slight decrease in the lean mass but an increase in the total fat mass and trunk fat mass (TFM) over the follow-up period were noted. Multivariate linear regression analysis showed that age was negatively associated with an increase in central obesity. Adjusted for the important predictors--age, age of menarche and education level, menopausal status was a significant and independent predictor of the decrease in lean mass and the increase in percent of body fat, TFM and trunk-leg fat mass ratio. CONCLUSION: Our 30-month longitudinal study showed that menopause has an independent effect on an increase in fat mass, and an increase in central obesity in perimenopausal Chinese women.

A mild favorable effect of soy protein with isoflavones on body composition--a 6-month double-blind randomized placebo-controlled trial among Chinese postmenopausal women.

BACKGROUND: In vitro and animal studies suggested that soy protein and isoflavones promote weight and body fat loss. However, clinical trials in humans were few and the effects remained uncertain. OBJECTIVES: To examine whether soy protein with isoflavones and isoflavone extracts exert beneficial effects on body composition among postmenopausal women. DESIGN: A double-blind randomized placebo-controlled trial was conducted among 180 postmenopausal Chinese women with mild hyperglycemia. After a 2-week adaptation, participants were randomly assigned to one of the three arms to receive 15 g soy protein and 100 mg isoflavones (Soy group), or 15 g milk protein and 100 mg isoflavones (Iso group), or 15 g milk protein (placebo group) on a daily basis for 6 months. RESULTS: We observed a mild but significant favorable effect of soy protein with isoflavones on the changes of body weight (BW), body mass index, and body fat percentage relative to isoflavone extracts and milk protein after 6-month supplementation. The mean differences of BW between the Soy and the Iso groups were -0.75 kg (95% CI: -1.363 to -0.136, P=0.017), and between the Soy and the placebo groups were -0.60 kg (95% CI: -1.209 to -0.019, P=0.047). The mean difference of change percentage in body fat percentage between the Soy and the Iso groups was -3.74% (95% CI: -6.88 to -0.60%, P=0.02), and between the Soy and the placebo groups was -2.54% (95% CI: -5.69 to 0.12%. P=0.08). CONCLUSIONS: Six-month supplementation of soy protein with isoflavones had a mild favorable effect on body composition in postmenopausal women.

Higher sea fish intake is associated with greater bone mass and lower osteoporosis risk in postmenopausal Chinese women.

SUMMARY: We examined the cross-sectional association of the intakes of different types of fishes with bone mass and osteoporosis risk in postmenopausal Chinese women. We found that higher intake of sea fish is independently associated with greater bone mass and lower osteoporosis risk among postmenopausal Chinese women. INTRODUCTION: Fish contains many important nutrients that are beneficial on bone health, but limited data on the relationship between fish intake and bone health are available. We examined the association of the intakes of different types of fishes with bone mineral density (BMD) and bone mineral content (BMC) and osteoporosis risk. METHODS: This population-based cross-sectional study was conducted among 685 postmenopausal Chinese women. Habitual dietary intakes were assessed using food frequency questionnaire. BMD and BMC at the whole body, lumbar spine, and left hip were measured with dual-energy x-ray absorptiometry. RESULTS: After adjusting for the potential confounders, we observed dose-dependent relations between sea fish intake and BMDs, BMCs, and osteoporosis risk; the mean BMDs were 3.2-6.8% higher, and BMCs 5.1-9.4% higher in the top quintile groups (Q5) of sea fish intake than in the bottom quintile (Q1) at the whole body and hip sites (p < 0.05); the odds ratios (95% confidence interval (CI)) for osteoporosis (T-score < -2.5) in Q5 were 0.23 (0.08-0.66), 0.12 (0.03-0.59), and 0.06 (0.01-0.44) compared with those in Q1 at the whole body, total hip, and femur neck, respectively. No independent association between consumption of freshwater fish or shellfish and bone mass was observed. CONCLUSION: Higher intake of sea fish is independently associated with greater bone mass and lower osteoporosis risk among postmenopausal Chinese women.

Acute gastroenteritis in Hong Kong: a population-based telephone survey.

A population-based telephone survey of acute gastroenteritis (AG) was conducted in Hong Kong from August 2006 to July 2007. Study subjects were recruited through random digit-dialing with recruitments evenly distributed weekly over the 1-year period. In total, 3743 completed questionnaires were obtained. An AG episode is defined as diarrhoea >or=3 times or any vomiting in a 24-h period during the 4 weeks prior to interview, in the absence of known non-infectious causes. The prevalence of AG reporting was 7%. An overall rate of 0.91 (95% CI 0.81-1.01) episodes per person-year was observed with women having a slightly higher rate (0.94, 95% CI 0.79-1.08) than men (0.88, 95% CI 0.73-1.04). The mean duration of illness was 3.6 days (S.D.=5.52). Thirty-nine percent consulted a physician, 1.9% submitted a stool sample for testing, and 2.6% were admitted to hospital. Of the subjects aged >or=15 years, significantly more of those with AG reported eating raw oysters (OR 2.4, 95% CI 1.3-4.4), buffet meals (OR 1.8, 95% CI 1.3-2.5), and partially cooked beef (OR 1.8, 95% CI 1.2-2.7) in the previous 4 weeks compared to the subjects who did not report AG. AG subjects were also more likely to have had hot pot, salad, partially cooked or raw egg or fish, sushi, sashimi, and 'snacks bought at roadside' in the previous 4 weeks. This first population-based study on the disease burden of AG in Asia showed that the prevalence of AG in Hong Kong is comparable to that experienced in the West. The study also revealed some 'risky' eating practices that are more prevalent in those affected with AG.

Carbohydrate binding activities of Bradyrhizobium japonicum. I. Saccharide-specific inhibition of homotypic and heterotypic adhesion.

Bradyrhizobium japonicum (R110d) exhibited four saccharide-specific binding activities: (a) adsorption to Sepharose beads containing covalently coupled lactose; (b) homotypic agglutination through one pole of the cell (star formation); (c) heterotypic adhesion to the cultured soybean cell line, SB-1; and (d) attachment to roots of soybean plants. Each of these binding activities can be inhibited by the addition of galactose or lactose, but not by derivatives such as N-acetyl-D-galactosamine or melibiose. Treatment of wild-type bacteria with N-methyl-N'-nitro-N-nitrosoguanidine followed by selection on the basis of reduced binding to SB-1 cells, resulted in two specific mutants, designated N4 and N6. Compared to wild type, these two mutants also exhibited decreased binding activity in: (a) adsorption to lactose-Sepharose beads; (b) homotypic star formation; and (c) heterotypic attachment to roots of soybeans plants. These results suggest that all four of the saccharide-inhibitable binding activities of Bradyrhizobium japonicum may be mediated by the same mechanism(s) or molecular component(s).

Carbohydrate binding activities of Bradyrhizobium japonicum. II. Isolation and characterization of a galactose-specific lectin.

Extracts of Bradyrhizobium japonicum were fractionated on Sepharose columns covalently derivatized with lactose. Elution of the material that was specifically bound to the affinity column with lactose yielded a protein of Mr approximately 38,000. Isoelectric focusing of this sample yielded two spots with pI values of 6.4 and 6.8. This protein specifically bound to galactose-containing glycoconjugates, but did not bind either to glucose or mannose. Derivatives of galactose at the C-2 position showed much weaker binding; there was an 18-fold difference in the relative binding affinities of galactose versus N-acetyl-D-galactosamine. These results indicate that we have purified a newly identified carbohydrate-binding protein from Bradyrhizobium japonicum, that can exquisitely distinguish galactose from its derivatives at the C-2 position.

Endogenous lectins from cultured soybean cells: isolation of a protein immunologically cross-reactive with seed soybean agglutinin and analysis of its role in binding of Rhizobium japonicum.

Incubation of Rhizobium japonicum with the cultured soybean cell line SB-1, originally derived from the roots of Glycine max, resulted in specific adhesion of the bacteria to the plant cells. This binding interaction appears to be mediated via carbohydrate recognition, since galactose can inhibit the heterotypic adhesion but glucose cannot. Affinity chromatography, on a Sepharose column derivatized with N-caproyl-galactosamine, of the supernatant fraction of a SB-1 cell suspension after enzymatic removal of cell wall yielded a single polypeptide (Mr approximately 30,000) on immunoblotting analysis with rabbit antibodies directed against seed soybean agglutinin. Fluorescently labeled rabbit anti-seed soybean agglutinin also yielded specific immunofluorescent staining on the cell wall and plasma membrane of the SB-1 cells. These results suggest that one likely candidate that may mediate the recognition between the Rhizobium and the soybean cells is the endogenously produced SB-1 lectin. This notion is supported by the observation that rabbit anti-seed soybean agglutinin blocked the Rhizobium-soybean cell adhesion, whereas control antibodies did not.

Change in bone mineral density and its determinants in pre- and perimenopausal Chinese women: the Hong Kong Perimenopausal Women Osteoporosis Study.

UNLABELLED: This 30-month study investigating bone change and its determinants in 438 perimenopausal Chinese women revealed that the fastest bone loss occurred in women undergoing menopausal transition but maintenance of body weight and physical fitness were beneficial for bone health. Soy protein intake also seemed to exert a protective effect. INTRODUCTION: This 30-month follow-up study aims to investigate change in bone mineral density and its determinants in Hong Kong Chinese perimenopausal women. METHODS: Four hundred and thirty-eight women aged 45 to 55 years were recruited through random telephone dialing and primary care clinic. Bone mass, body composition, lifestyle measurements were obtained at baseline and at 9-, 18- and 30-month follow-ups. Univariate and stepwise multiple regression analyses were performed with the regression coefficients of BMD/C (derived from baseline and follow-up measurements) as the outcome variables. Menopausal status was classified as pre- or postmenopausal or transitional. RESULTS: Menopausal status was the strongest determinant of bone changes. An annual bone loss of about 0.5% was observed among premenopausal, 2% to 2.5% among transitional, and about 1.5% in postmenopausal women. Multiple regression analyses, revealed that a positive regression slope of body weight was protective for follow-up bone loss at all sites. Number of pregnancy, soy protein intake and walking were protective for total body BMC. Higher baseline LM was also protective for neck of femur BMD. CONCLUSION: Maintenance of body weight and physical fitness were observed to have a protective effect on for bone loss in Chinese perimenopausal women.

Public health significance of the frailty index.

BACKGROUND: A quantifiable indicator of frailty would be very useful in assessing the health state of older populations, as well as enable the effect of interventions to be evaluated over time. METHODS: A total of 2032 people aged 70 years and over recruited by stratified random sampling, and information obtained regarding physical and functional health, and psychological factors. The frailty index (FI) was constructed from 62 variables. Associations between the FI, and changes in ADL score, mental score, and hospitalization days over a 10-year period were evaluated. RESULTS: For the baseline to 3-year changes, a 0.10 increase in baseline FI is accompanied by a 0.499-point faster drop in ADL score, a 0.223-point faster decline in mental score, and 4.57-day faster increase in hospital days. For 3-10-year changes, frailty was a significant predictor only of changes in mental score, with results indicating that, on average, each increase of 0.10 in the baseline frailty index was associated with 0.613-point drop in mental score during this period. Chronological age and frailty had differential associations with those changes. CONCLUSION: The FI is a valid indicator of morbidity and requirement for health and social services for ageing populations.

The purification and characterization of multiple forms of mouse submaxillary gland renin.

Five forms of renin, A0, A, C, D and E, from mouse submaxillary gland were purified by a two-step procedure including chromatography on the immunoaffinity column and CM-cellulose column. Four renin fractions, A0, A, C and E were purified to homogeneity by the criteria of polyacrylamide gel electrophoresis, analytical isoelectric focusing and Ouchterlony double immunodiffusion. All these forms of renin have molecular weights of 40 000 as determined by gel filtration on Sephadex G-100 column. No high molecular weight renin could be demonstrated. Individual renin fractions showed similar angiotensin I formation activity, 52-158 ng angiotensin I/ng protein per h. No other protease activity could be detected with hemoglobin or casein as substrate. These purified proteins showed a discrete pattern of migration under polyacrylamide gel electrophoresis. Under denaturing condition in SDS-gel electrophoresis, all but fraction D showed a protein band with a molecular weight of 30 000. Fraction D showed a major component with molecular weight of 33 000. The isoelectric points of these renin forms varied from 5.46 to 5.76. They all reacted with antibody raised against renin A and showed similar pressor response activity with 20 ng quantities of the purified proteins. The closely related characteristics of these five forms of renin were further demonstrated by their similarity in peptide mapping patterns after limited digestion with Staphylococcus aureus V8 protease. The data suggest that these proteins are homologous proteins.

Membrane anchoring of calnexin facilitates its interaction with its targets.

Calnexin, a chaperone that resides in the endoplasmic reticulum, participates in the quality control function of this compartment. Many glycoproteins in the process of folding associate transiently with this chaperone via interactions involving the recognition of their mono-glucosylated glycans. Some misfolded proteins which are retained in the endoplasmic reticulum exhibit prolonged association with calnexin. We have examined whether the transmembrane and cytoplasmic domains of calnexin influence the association of this chaperone with its targets. Interactions of wild type and truncated calnexin with a glycoprotein that is retained in the endoplasmic reticulum (the lymphocyte tyrosine kinase, Ltk), with membrane IgM heavy chains, and with the MHC class I heavy chain protein were investigated. A soluble calnexin molecule lacking the transmembrane domain and cytoplasmic tail does not associate with any of these proteins. When a heterologous transmembrane domain is fused to the lumenal portion of calnexin, this membrane-bound protein can bind Ltk, IgM heavy chains, and MHC class I heavy chain proteins. These results suggest that calnexin must be membrane-anchored in order to recognize its substrates.