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Biomedical subjects

Yuqing Zhang

Publications and source records attributed to Yuqing Zhang.

At least 37 records · Page 2Linked to original sources
PubMed2005

Relation of the metabolic syndrome to calcified atherosclerotic plaque in the coronary arteries and aorta.

The metabolic syndrome is a clustering of low levels of high-density lipoprotein cholesterol, hyperglycemia, high waist circumference, hypertension, and elevated triglycerides, and is associated with cardiovascular disease. Calcified atherosclerotic plaque in the coronary arteries (CAC), measured by cardiac tomographic scans, is a marker for atherosclerosis and relates to mortality. The investigators examined the relation of the metabolic syndrome, and each of its components, to the prevalence of CAC, measured from 2002 to 2004 in 3,166 white and African-American subjects in the National Heart, Lung, & Blood Institute Family Heart Study. Adjusting for age, race, center, smoking, and alcohol consumption, odds ratios and 95% confidence intervals (CI) for a CAC score >100 for subjects with metabolic syndrome were 1.7 (95% CI 1.3 to 2.3) for men and 1.6 (95% CI 1.2 to 2.1) for women. Associations were found for most of the components of the metabolic syndrome with CAC. Associations with the metabolic syndrome were similar for calcified atherosclerotic plaque in the abdominal aorta among 3,173 subjects, with adjusted odds ratios for a score >1,000 of 2.1 (95% CI 1.5 to 3.1) for men and 1.8 (95% CI 1.4 to 2.4) for women. We conclude that the metabolic syndrome and most of its components are associated with a higher prevalence of calcified atherosclerotic plaque in the coronary arteries and abdominal aorta in white and African-American men and women.

Aorta, Abdominal↗
PubMed2005

Bone mineral density and the risk of Alzheimer disease.

BACKGROUND: Some, but not all, studies have suggested that estrogen replacement therapy has a beneficial effect on cognition in postmenopausal women. Bone mineral density (BMD) is a potential surrogate marker for cumulative estrogen exposure and has been associated with cognitive performance and risk of cognitive deterioration. OBJECTIVE: To examine whether low BMD in elderly individuals is associated with an increased risk of developing Alzheimer disease (AD). DESIGN, SETTING, AND PARTICIPANTS: Community-based prospective cohort study of 987 subjects (610 women) who were cognitively intact and had baseline BMD measured at the femoral neck, the trochanter, and the radial shaft between 1988 and 1989. MAIN OUTCOME MEASURES: Incidence of AD and all-cause dementia during an 8-year follow-up period. RESULTS: Women in the lowest quartile of femoral neck BMD had more than twice the incidence of AD (hazard ratio, 2.04; 95% confidence interval, 1.11-3.75) and all-cause dementia (hazard ratio, 2.01; 95% confidence interval, 1.16-3.49) compared with those in higher quartiles after adjusting for age, sex, apolipoprotein E epsilon4, baseline homocysteine level, education, estrogen use, smoking, and stroke. A similar but statistically nonsignificant relationship was observed between BMD of the femoral trochanter and AD, while no such relationship was seen between radial BMD and AD or all-cause dementia. In men, there was a trend toward an inverse relationship between BMD and the risk of AD, but the relationship was not statistically significant at any of the 3 sites. CONCLUSIONS: Low femoral neck BMD was associated with approximately 2 times the risk of AD and all-cause dementia in women but not men, suggesting the possibility that cumulative estrogen exposure may influence the risk of developing AD. Additional studies are needed to confirm this correlation.

Aged↗
PubMed2005

Knee height, knee pain, and knee osteoarthritis: the Beijing Osteoarthritis Study.

OBJECTIVE: Few risk factors for knee osteoarthritis (OA) are appreciated, and the discordance between symptoms and the severity of structural disease has not been explained. Knee height contributes to moments around the knee. The longer the leg, the more torque is present. Although this would suggest that having long legs would be related to the occurrence of knee OA and pain, this issue has not been studied. Our aim was to explore the association between knee height, knee pain, and knee OA. METHODS: We recruited a random sample of Beijing residents ages 60 years and older. Subjects answered questions about joint symptoms, and radiographs of their knees were obtained. A knee joint with a Kellgren/Lawrence grade of >/=2 was defined as having radiographic OA. Patellofemoral OA was defined as being present when grade >/=1 osteophytes or grade >/=1 joint space narrowing was observed on skyline views of the patella or anterior femur. Subjects were considered to have symptomatic OA when both radiographic OA and self-reported pain were present in the same joint. Knee height was measured on the right leg using a sliding broad-blade caliper; the subject was seated, and the subject's feet were bare. We used logistic regression analyses to assess whether knee height was associated with prevalent radiographic and symptomatic OA. We then assessed whether knee height was associated with knee symptoms independently of structural change. RESULTS: A total of 1,006 men (mean +/- SD age 68.4 +/- 6.4 years) and 1,500 women (mean +/- SD age 67.5 +/- 6.1 years) participated in this study. Higher knee height was associated with an increasing prevalence of both radiographic and symptomatic OA, especially among women. For radiographic OA, the magnitude of association was similar for the patellofemoral and tibiofemoral compartments. Among women with knee pain, higher knee height was associated with more severe knee pain (P = 0.0004 for the highest quartile versus the lowest quartile of knee height) independently of the severity of radiographic OA. CONCLUSION: Knee height is associated with prevalent radiographic and symptomatic knee OA. It may also play an important role in knee symptoms. This study highlights the importance of mechanical forces in the determination of OA and knee symptoms.

Anthropometry↗
PubMed2005

Bone marrow lesions in the knee are associated with increased local bone density.

OBJECTIVE: Bone marrow lesions are associated with pain and compartment-specific progression of joint space narrowing in patients with knee osteoarthritis (OA). Bone marrow lesions occur in regions under increased loading, and excess loading produces increased bone mineral density (BMD). The ratio of BMD in the medial tibial plateau compared with that in the lateral tibial plateau (M:L BMD ratio) reflects loading in the knee. Therefore, we hypothesized that a higher M:L BMD ratio would be associated with medial bone marrow lesions, and that lower ratios would be associated with lateral bone marrow lesions. METHODS: Participants in the Framingham Osteoarthritis Study underwent magnetic resonance imaging (MRI), measurement of bone mineral density (BMD), and knee radiography between 2002 and 2004. MRI was used to define medial and lateral bone marrow lesions in the medial and lateral tibiofemoral compartments, respectively. We performed a logistic regression analysis with medial bone marrow lesions as the outcome, testing M:L BMD ratio groups as predictor variables. We adjusted for age, sex, body mass index, and systemic BMD, using generalized estimating equations to adjust for correlations between knees. An identical analysis evaluating lateral bone marrow lesions was performed. RESULTS: Medial bone marrow lesions were strongly associated with a high M:L BMD ratio. The odds ratios (ORs) for prevalent medial bone marrow lesions, for the lowest to the highest quartile of M:L BMD ratios, were 1.0 (referent), 1.3, 5.0, and infinity (P for trend < 0.0001). Lateral bone marrow lesions were strongly associated with low M:L BMD ratios (the ORs for prevalent lateral bone marrow lesions, for the highest to the lowest quartile, were 1.0 [referent], 3.0, 26.8, and 54.0 [P for trend < 0.0001]). CONCLUSION: Medial bone marrow lesions occur in knees with relatively higher local medial tibial bone density, and lateral bone marrow lesions occur in knees with relatively higher lateral tibial bone density, supporting the hypothesis that local BMD reflects loading within the knee. Our findings emphasize the importance of loading in the pathophysiology of OA.

Aged↗
PubMed2005

Sex differences in musculoskeletal pain in older adults.

Little is known about sex differences in musculoskeletal pain in older persons. There were 682 women and 380 men aged 72 years and older who participated in the 22nd biennial exam of the Framingham Study (1992-1993). Participants were asked to identify pain locations on a homunculus showing all regions of the body. Pain was categorized according to number of regions, with the most disseminated pain classified as widespread pain (back pain and upper and lower extremity pain with bilaterality). Among the women, 63% reported pain in one or more regions, compared to 52% of men. Widespread pain was more prevalent among women than men (15 versus 5%, respectively). In both men and women, pain was associated with fair or poor self-rated health, history of back pain before age 65, and disability. Factors associated with pain only in women included body mass index, systolic blood pressure, and depressive symptoms. In men but not women, pain was associated with polyarticular radiographic osteoarthritis. In conclusion, musculoskeletal pain was more prevalent and more widespread in older women than older men. Men and women differ in the factors associated with musculoskeletal pain in older ages. Further research is needed to understand sex differences in musculoskeletal pain the older population.

Aged↗
PubMed2005

The Felodipine Event Reduction (FEVER) Study: a randomized long-term placebo-controlled trial in Chinese hypertensive patients.

OBJECTIVE: To compare the incidence of stroke and other cardiovascular events in hypertensive patients receiving a low-dose diuretic and low-dose calcium antagonist combination with those receiving low-dose diuretic monotherapy, and assess the effects of a small blood pressure difference at achieved levels lower than those achieved in previous placebo-controlled trials. METHODS: The Felodipine Event Reduction (FEVER) trial was an investigator-designed, prospective, multicentre, double-blind, randomized, placebo-controlled, parallel group trial. It enrolled 9800 Chinese patients, of either sex, aged 50-79 years, with one or two additional cardiovascular risk factors or disease, whose blood pressure, 6 weeks after switching from previous antihypertensive therapy to low-dose (12.5 mg a day) hydrochlorothiazide, was in the range 140-180 mmHg (systolic) or 90-100 mmHg (diastolic). These patients were randomly assigned either to low-dose felodipine extended release or placebo, and followed at 3-month intervals for an average of 40 months. RESULTS: The intention-to-treat analysis included 9711 randomly selected patients with only 30 (0.3%) lost to follow-up. A total of 31 842 patient-years of follow-up were accumulated, with 85.9% of patients remaining on blinded randomized treatment. Add-on therapy was given to 33.9% of the hydrochlorothiazide-felodipine patients and to 42.3% of the hydrochlorothiazide-placebo patients. In the felodipine group, systolic blood pressure (SBP)/diastolic blood pressure (DBP) decreased (from randomization to study end) from 154.2/91.0 to 137.3/82.5 mmHg, and in the placebo group from 154.4/91.3 to 142.5/85.0 mmHg, with an average difference throughout the trial of 4.2/2.1 mmHg. In the felodipine group, the primary endpoint (fatal and non-fatal stroke) was reduced by 27% (P = 0.001). Among secondary endpoints, all cardiovascular events were reduced by 27% (P < 0.001), all cardiac events by 35% (P = 0.012), death by any cause by 31% (P = 0.006), coronary events by 32% (P = 0.024), heart failure by 30% (P = 0.239), cardiovascular death by 33% (P = 0.019), cancer by 36% (P = 0.017) in the felodipine group. No significant differences were found in new-onset diabetes. Both treatments were very well tolerated. CONCLUSIONS: In moderately complicated hypertensive patients from China even a difference in SBP/DBP as small as 4/2 mmHg, such as that induced by adding low-dose felodipine to low-dose hydrochlorothiazide, is associated with very substantial reductions in the incidence of most types of cardiovascular events. As the SBP achieved in the felodipine group was below the recommended goal of less than 140 mmHg, and SBP in the placebo group was slightly above that level, FEVER provides the required evidence in support of the guidelines recommended goal, even for a hypertensive population not entirely consisting of patients with diabetes or previous cardiovascular events.

Aged↗
PubMed2005

Cimetidine and other histamine2-receptor antagonist use in relation to risk of breast cancer.

OBJECTIVE: Cimetidine, a histamine2-receptor antagonist (H2 blocker) commonly used to treat symptoms of peptic and duodenal ulcer, influences both hormonal and immune pathways. We investigated the influence of cimetidine use on the risk of breast cancer in our hospital-based case control surveillance study. METHODS: Data on medication use and other factors were elicited from patients admitted to hospitals from 1977 to 2002. We compared 6,994 breast cancer cases with a control group comprising cancer (n = 2,478) and noncancer (n = 6,004) diagnoses. Conditional logistic regression models were used to estimate odds ratios for H2 blocker use that began at least 1 year prior to admission. Regular use was defined as use for at least 4 days per week for at least 3 continuous months. RESULTS: The odds ratio for breast cancer among regular users of cimetidine was 0.9 (95% confidence interval, 0.6-1.2) using a combined cancer and noncancer control group. For use of 4 or more years' duration, the odds ratio was < 1.0 but was not statistically significant. The odds ratio for the regular use of other H2 blockers was 0.9 (95% confidence interval, 0.6-1.3). CONCLUSIONS: Our data agree with data from three prior studies which indicate that cimetidine is not associated with the risk of breast cancer. Other H2 blockers were also unrelated to the risk of breast cancer.

Adult↗
PubMed2005

T1198C polymorphism of the angiotensinogen gene and antihypertensive response to angiotensin-converting enzyme inhibitors.

This study examined the association between T1198C polymorphism of the angiotensinogen (AGT) gene and the blood pressure response to ACE inhibitors in a Chinese hypertensive cohort. After a 2-week single-blind placebo run-in period, benazepril (10-20 mg/day) or imidapril (5-10 mg/day) was administered for 6 weeks to 509 patients with mild-to-moderate essential hypertension. Polymerase chain reaction combined with restriction enzyme digestion was used to detect the polymorphism, and the patients were classified as having the TT, TC, or CC genotype. The achieved changes in systolic and diastolic blood pressure (SBP and DBP) were analyzed to determine their association with genotypes at the AGT gene locus. In the total 509 patients, the TT genotype was observed in 44 patients (8.7%), the TC genotype in 214 patients (42.0%), and the CC genotype in 251 patients (49.3%). The SBP reductions in patients with the TT genotype, TC genotype, and CC genotype were -15.3+/-12.7 mmHg, -14.0+/-12.7 mmHg, and -14.4+/-12.4 mmHg, respectively (p=0.809). The DBP reductions in patients with the TT genotype, TC genotype, and CC genotype were -8.5+/-8.1 mmHg, -8.3+/-7.5 mmHg, and -8.9+/-6.6 mmHg, respectively (p=0.638). There were no significant differences in the changes in SBP or DBP after treatment among the three genotype groups. In conclusion, these results suggest that the AGT genotype does not predict the blood pressure-lowering response to antihypertensive treatment with ACE inhibitors in Chinese hypertensive patients.

Adult↗
PubMed2005

Structural factors associated with malalignment in knee osteoarthritis: the Boston osteoarthritis knee study.

OBJECTIVE: Osteoarthritis (OA) is a multifactorial condition. The progression of knee OA is determined in part by mechanical effects on local structures. One of the mechanical influences on cartilage loss is limb alignment. We explored the structural factors associated with malalignment in subjects with symptomatic OA. METHODS: We conducted a cross-sectional assessment using The Boston Osteoarthritis of the Knee Study, a natural history study of symptomatic knee OA. Baseline assessments included knee magnetic resonance imaging (MRI) and information on weight and height. Long-limb radiographs to assess mechanical alignment were obtained at 15 months. Subarticular bone attrition, meniscal degeneration, anterior and posterior cruciate ligament integrity, medial and lateral collateral ligament integrity, marginal osteophytes, and cartilage morphology were assessed on MRI using a semiquantitative, multi-feature scoring method (Whole-Organ MRI Score) for whole-organ evaluation of the knee that is applicable to conventional MRI techniques. We also quantified the following meniscal position measures on coronal MRI images in both medial and lateral compartments: subluxation, meniscal height, and meniscal covering of the tibial plateau. Using the long-limb radiographs, mechanical alignment was measured in degrees on a continuous scale. The purpose of this cross-sectional analysis was to determine the individual and relative contribution of various structural factors to alignment of the lower extremity. We assessed the cross-sectional association between various structural factors and alignment of the lower extremity using a linear regression model. RESULTS: The 162 subjects with all measures acquired had a mean age of 67.0 years (SD 9.2), body mass index 31.4 (SD 5.6); 30% were female and 77% of knees had a Kellgren-Lawrence grade > or = 2. The main univariate determinants of varus alignment in decreasing order of influence were medial bone attrition, medial meniscal degeneration, medial meniscal subluxation, and medial tibiofemoral cartilage loss. Multivariable analysis revealed that medial bone attrition and medial tibiofemoral cartilage loss explained more of the variance in varus malalignment than other variables. The main univariate determinants of valgus malalignment in decreasing order of influence were lateral tibiofemoral cartilage loss, lateral osteophyte score, and lateral meniscal degeneration. CONCLUSION: Cartilage loss has been thought to be the major determinant of alignment. We found that other factors including meniscal degeneration and position, bone attrition, osteophytes, and ligament damage contribute to the variance of malalignment. Further longitudinal analysis is required to determine cause and effect relationships. This should assist researchers in determining strategies to ameliorate the potent effects of this mechanical disturbance.

Aged↗
PubMed2004

Cyclooxygenase-2 activity contributes to neuronal expression of cyclin D1 after anoxia/ischemia in vitro and in vivo.

Cyclooxygenase-2 (COX-2) activity has been implicated in the pathogenesis of neuronal cell death in ischemia and other diseases, but the mechanism by which COX-2 exacerbates cell death is unknown. COX-2 activity is known to induce expression of cyclin D1 in neoplastic cells, and cyclin D1 expression can induce cell death in postmitotic neurons. In the present study, the role of COX-2 and cyclin D1 in neuronal cell death induced by anoxia and ischemia was examined. Treatment with the COX-2 specific inhibitor (NS 398 25 microM) and cyclin D1 inhibitor (flavopiridol 1 microM) increased neuronal survival and inhibited DNA fragmentation after anoxia. NS-398 suppressed anoxia-induced expression of cyclin D1. Flavopiridol inhibited the anoxia-induced increased expression of cyclin D1, but had no effect on COX-2 expression. Treatment with the selective COX-2 inhibitor, SC58125, had no affect on COX-2 expression but partially suppressed cyclin D1 expression in the cortex following middle cerebral artery occlusion in vivo. These results show that COX-2 activity is required for cyclin D1 expression after ischemia in vivo and anoxia in vitro. These data provide support for the hypothesis that cyclin D1 expression is an important mechanism by which COX-2 activity exacerbates ischemic neuronal death.

Animals↗
PubMed2004

A hybrid protein of the amino-terminal fragment of urokinase and mutant plasminogen activator inhibitor-2 efficiently inhibits tumor cell invasion and metastasis.

The urokinase plasminogen activator(uPA) system plays important roles in tumor cell invasion and metastasis. In the present study, we evaluated the effects of ATF-PAI2CD, a hybrid protein of the amino-terminal fragment of urokinase and mutant plasminogen activator inhibitor-2, on 95D cells in vitro and in vivo. Furthermore, our results support a current hypothesis that fusion protein blocks tumor invasion and motility by inhibiting localized pericellular proteolysis. Treatment of 95D cells with ATF-PAI2CD resulted in a dose-dependent decrease in tumor-cell invasion through matrigel, and ATF-PAI2CD was much more effective than PAI-2CD. In addition, extracellular regular protein kinase (ERK1/2) expression was downregulated and the adhesion ability to fibronectin was increased in 95D cells treated with the fusion protein, which was confirmed by cell adhesion assay. A high-concentration of ATF-PAI2CD caused a significant reduction in tumor volume and weight in BALB/c (nu/nu) mice female inoculated with human 95D cells (5 x 10(6)); the antitumor effects were significant, which demonstrated a 67.9+/-4.2% reduction in tumor growth compared with control mice. The number of lymphatic metastasis was significantly reduced in mice treated with high- and middle- concentrations of ATF-PAI2CD, whereas a low-concentration of ATF-PAI2CD failed to exhibit any antimetastatic effects. In conclusion, the results suggested that the hybrid protein has therapeutic potential for lung carcinoma and other tumors to inhibit tumor invasion and metastasis.

Animals↗
PubMed2004

Education modifies the effect of alcohol on memory impairment: the third national health and nutrition examination survey.

We examined whether the relation of alcohol consumption to prevalence of verbal memory impairment was modified by education among 4,804 elderly subjects in the Third National Health and Nutrition Examination Survey. Verbal memory was assessed using delayed recall, with impairment defined as a combined score <4. Alcohol consumption over the previous month prior to the interview was assessed using a food frequency questionnaire. Prevalence of verbal memory impairment decreased from 11.3 to 7.2, 5.7, 5.1 and 4.4% in increasing categories of alcohol consumption (none, 1-4, 5-14, 15-30 and >30 drinks per month) in men, and from 7.2 to 3.5 and 2.8% (for none, 1-14, and >14 per month) in women, respectively. Adjusting for age, race, and other factors, prevalence ratios of verbal memory impairment decreased with each increasing alcohol category, but the effect was attenuated when further adjusted for education. There was a much stronger protection from alcohol among subjects with more education: prevalence ratios were reduced from 1.0 to 0.2 to 0.1 for non-drinkers, 1-14, and >14 drinks/month, respectively (p for trend = 0.007). Our results suggest that alcohol intake is associated with a greater decrease in the prevalence of verbal memory impairment among more educated subjects than among those with less education, possibly related to differences in drinking patterns.

Aged↗
PubMed2004

Metacarpal cortical area and risk of coronary heart disease: the Framingham Study.

The objective of this study was to determine the relation between bone mass and the incidence of coronary heart disease in women and men. Participants included 2,059 cohort members of the Framingham Study (1,236 women and 823 men aged 47-80 years) who underwent posteroanterior hand radiography and were free from cardiovascular disease at baseline (1967-1970) and who were then followed for 30 years through the end of 1997 for the incidence of coronary heart disease. The incidence of coronary heart disease decreased from 15.65/1,000 person-years among women in the lowest metacarpal cortical area quartile to 11.76/1,000 person-years among women in the highest quartile (p(trend) = 0.03), and the inverse relation persisted after adjustment for confounders (highest vs. lowest quartile of metacarpal cortical area: hazard ratio = 0.73, 95% confidence interval: 0.53, 1.00; p(trend) = 0.03). In contrast, no association was present in men (highest vs. lowest quartile of metacarpal cortical area: hazard ratio = 1.14, 95% confidence interval: 0.84, 1.56; p(trend) = 0.55).

Aged↗
PubMed2004

Cigarette smoking and increased risk of mucinous epithelial ovarian cancer.

Several studies have reported that cigarette smoking is associated with an increased risk of mucinous ovarian cancer, but other studies have failed to find such a relation. Using data from the Case-Control Surveillance Study, begun in four US cities in 1976, the authors conducted a case-control study (1976-2001) to examine the association between cigarette smoking and the risk of ovarian cancer of different cell types. Among 709 incident cases of epithelial ovarian cancer, 402 were serous, 74 were mucinous, 106 were endometrioid, and 127 were of other cell types. For mucinous ovarian cancer, the odds ratios were 1.5 (95% confidence interval (CI): 0.7, 3.4) among women who smoked less than one pack of cigarettes per day, 1.4 (95% CI: 0.6, 3.5) among women who smoked one pack per day, and 2.9 (95% CI: 1.2, 7.5) among women who smoked more than one pack per day, relative to never smokers. The odds ratios were 2.5 (95% CI: 1.1, 5.4) for ex-smokers and 1.4 (95% CI: 0.7, 2.9) for current smokers. While women with up to 15 pack-years of smoking had an almost 2.5 times' increased risk of mucinous ovarian cancer, such an increased risk was not found among those with more than 15 pack-years of smoking. There was no association between cigarette smoking and epithelial ovarian cancer of other cell types. Despite inconsistencies in the data, these results strengthen the evidence that cigarette smoking may play a role in the development of mucinous ovarian cancer but not ovarian cancer of other cell types.

Adenocarcinoma, Mucinous↗
PubMed2004

Association of squatting with increased prevalence of radiographic tibiofemoral knee osteoarthritis: the Beijing Osteoarthritis Study.

OBJECTIVE: To examine the association between squatting, a common daily posture in China, and the prevalence of radiographic osteoarthritis (OA) in different knee compartments among Chinese subjects from Beijing, and to estimate how much of the difference in prevalence of knee OA between Chinese subjects in Beijing and white subjects in Framingham, Massachusetts is accounted for by the impact of squatting. METHODS: We recruited a random sample of Beijing residents age > or =60 years. Subjects answered questions on joint symptoms, and knee radiographs were obtained. Subjects were also asked to recall the average amount of time spent squatting each day at age 25 years. Radiographic films (weight-bearing anteroposterior and skyline views) were read for Kellgren/Lawrence (K/L) grade and individual radiographic features. Medial disease was defined when radiographs showed a K/L grade of > or =2 at the tibiofemoral joint and a medial joint space narrowing score of > or =1, and lateral disease was assessed in a comparable manner in the lateral compartments. We examined the association of squatting with the prevalence of tibiofemoral OA as well as with the prevalence of patellofemoral knee OA, while adjusting for age and other potential confounding factors. We used the same approach to assess the relationship between squatting and tibiofemoral OA in the medial compartment and in the lateral compartment. Finally, we estimated the impact of squatting at age 25 on the difference in prevalence of knee OA between Chinese subjects in Beijing and white subjects in the Framingham OA Study. RESULTS: Squatting was very common among the Chinese subjects: approximately 40% of men and approximately 68% of women reported squatting > or =1 hour per day at age 25. The prevalence of tibiofemoral OA increased as the time spent squatting at age 25 increased in both the men and the women. Compared with subjects who squatted <30 minutes per day at age 25, the multivariable-adjusted prevalence odds ratios of tibiofemoral OA were 1.1 for time spent squatting of 30-59 minutes/day, 1.0 for 60-119 minutes/day, 1.7 for 120-179 minutes/day, and 2.0 for > or =120 minutes/day among the men (P for trend = 0.074), and the respective odds ratios among the women were 1.4, 1.3, 1.2, and 2.4 (P for trend = 0.077). A weaker association with patellofemoral OA was found. Prolonged squatting in daily life was more strongly associated with medial knee OA than with lateral disease in the men, but had a similar effect on both knee compartments in the women. After adjusting for the impact of squatting, the age-adjusted difference in prevalence of tibiofemoral OA was reduced from an excess of 14.4% to 9.5% in the Chinese women, but the difference in prevalence of tibiofemoral OA in the Chinese men increased after adjustment for age and squatting, from 2.9% lower to 7.0% lower as compared with their white counterparts. CONCLUSION: Prolonged squatting is a strong risk factor for tibiofemoral knee OA among elderly Chinese subjects in Beijing, and accounts for a substantial proportion of the difference in prevalence of tibiofemoral OA between Chinese subjects in Beijing and white subjects in Framingham.

Aged↗
PubMed2004

Chopstick arthropathy: the Beijing Osteoarthritis Study.

OBJECTIVE: Several investigators have speculated that mechanical stress might play an important role in the development of hand osteoarthritis (OA). Chopsticks, used universally as eating utensils in China, increase joint loading in the first through third fingers. We conducted a population-based survey among elderly Chinese individuals living in Beijing, to explore whether chopsticks use is associated with prevalent hand OA. METHODS: We recruited a sample of persons ages 60 years and older, using door-to-door enumeration in randomly selected neighborhoods in Beijing. Subjects answered questions about the hand with which they use chopsticks, handedness, and pincer grip activities. Bilateral posteroanterior hand radiographs were obtained, and each joint was graded according to the Kellgren/Lawrence (K/L) scale. We defined a subject as having radiographic OA if at least 1 of his or her hand joints had radiographic OA (K/L score of > or =2). We defined a particular hand group (i.e., distal interphalangeal [DIP] joints, proximal interphalangeal [PIP] joints, or metacarpophalangeal [MCP] joints) as having OA if at least 1 joint of the group had radiographic OA. We calculated the prevalence of OA for each hand joint and, according to the status of chopsticks use, performed a matched analysis to examine the relationship between chopsticks use and the prevalence of hand OA. In the analysis, we excluded persons who reported a previous hand injury. Because most subjects used chopsticks with their dominant hand (a hand they would be expected to use more for all manual tasks), we also performed the analysis among subjects who reported that they had no hand preference when performing other activities and subjects who denied other pincer grip activities. RESULTS: A total of 1,008 men and 1,499 women were assessed. The prevalence ratio for OA of the thumb IP joint in the chopsticks hand was 1.2 (range 1.1-1.4) in men and 1.6 (range 1.4-1.7) in women; the prevalence ratio for OA of the second and third PIP joints was 1.5 (range 1.1-2.2) in men and 1.4 (range 1.2-1.7) in women; and the prevalence ratio for OA of the second and third MCP joints was 1.4 (range 1.2-1.6) in men and 1.4 (range 1.2-1.6) in women. The prevalence ratios in these joints were greater than the ratios in other MCP, PIP, or DIP joints from the same hand that were unlikely to be involved by chopsticks use, especially among women. Similar results were observed when the analyses were limited to ambidextrous subjects and subjects who did not engage in any other pincer grip activities. Thumb IP joint OA affected 26% of the entire population studied, and chopsticks use accounted for 19% of the risk of OA developing in this joint in men and 36% of the risk in women. CONCLUSION: This epidemiologic study investigated the relationship of chopsticks use to hand arthropathy. The results suggest that chopsticks use is associated with an increased prevalence of OA in the IP joint of the thumb, and in the second and third PIP and MCP joints.

Aged↗
PubMed2004

Quadriceps weakness and its relationship to tibiofemoral and patellofemoral knee osteoarthritis in Chinese: the Beijing osteoarthritis study.

OBJECTIVE: Weakness has been documented as a feature of tibiofemoral knee osteoarthritis (OA) and may cause disease in this compartment by shock absorption during impulse loading at heel strike, when the patellofemoral joint is not engaged. Our objective was to determine the association of muscle weakness with compartment-specific knee OA, to evaluate sex-specific differences in this relationship, and to determine, by evaluating asymptomatic individuals with OA, whether symptoms may produce the weakness seen in OA. METHODS: This cross-sectional study involved 2,472 subjects (1,475 women and 997 men) ages 60 years or older from 4 central districts of Beijing, China. For all subjects, a skyline view of each knee and an anteroposterior (AP) or posteroanterior (PA) radiograph of both knees were obtained during weight bearing. Radiographs were read by one reader for Kellgren/Lawrence (K/L) grade, joint space narrowing (JSN), and osteophytes. We defined a subject as having tibiofemoral OA when the K/L grade was > or =2 on AP/PA view, patellofemoral OA on skyline view when the osteophyte score was > or =2 (or when the JSN score was > or =2 and the osteophyte score was > or =1), and mixed OA when the knee had both patellofemoral and tibiofemoral radiographic OA. Strength was measured isometrically for each leg separately, and knee pain was evaluated by questionnaire. RESULTS: In women, quadriceps weakness was associated with tibiofemoral OA (odds ratio [OR] 0.7, 95% confidence interval [95% CI] 0.4-1.0), patellofemoral OA (OR 0.6, 95% CI 0.4-0.9), and mixed OA (OR 0.4, 95% CI 0.3-0.6). In men, weakness was associated with mixed OA (OR 0.5, 95% CI 0.3-0.8), and the ORs suggesting an association of patellofemoral OA with weakness were the same as those in women, although in men this trend did not reach statistical significance (P = 0.12). In men, isolated tibiofemoral disease was not associated with weakness; however, the sample size in this analysis was limited. When subjects with knee symptoms were excluded, the relationship of quadriceps weakness to OA was attenuated, with only the relationship between muscle weakness and mixed OA remaining significant. CONCLUSION: There is a relationship between quadriceps weakness and knee OA in all compartments, with the strongest association in mixed disease. Pain may contribute to some of this weakness.

Aged↗