Zhiyong Zou

Prevalence and risk factors of arthritis in a middle-aged and older Chinese population: the China Health and Retirement Longitudinal Study

OBJECTIVES The aims of this study were to estimate the prevalence of arthritis and to identify risk factors of arthritis in a middle-aged and older Chinese adult population. METHODS The China Health and Retirement Longitudinal Study (CHARLS) national survey data were used to estimate overall arthritis prevalence and prevalence by age and gender groups taking into account the complex survey design and response rate. The PROC SURVEYLOGISTIC procedure (SAS 9.3; SAS Institute, Cary, NC, USA) was applied to identify factors associated with arthritis using the CHARLS national survey data. Significant factors were further evaluated in the longitudinal CHARLS pilot study. RESULTS The overall prevalence of arthritis among middle-aged and older Chinese adults was 31.4% (95% CI 30.3, 32.4). Prevalence increased with age. Females had a higher prevalence of arthritis than males in each age group. In the cross-sectional analysis, age, gender, education, BMI, sleep duration, vigorous physical activity and self-reported doctor-diagnosed chronic lung disease, hypertension, chronic liver disease, cardiovascular disease, stroke, chronic kidney disease and chronic digestive disease were associated with arthritis. Age, gender, vigorous physical activity and cardiovascular disease were confirmed to be risk factors of arthritis in the longitudinal analysis. Participants with cardiovascular disease were 1.67 times (95% CI 1.02, 2.74) more likely to have self-reported arthritis in a 4-year period of follow-up in the CHARLS pilot study. CONCLUSION Middle-aged and older Chinese adults had a high prevalence of arthritis. Cardiovascular disease is a novel risk factor for arthritis in this population.

Validity of self-reported diabetes among middle-aged and older Chinese adults: the China Health and Retirement Longitudinal Study

Background Self-reported diabetes has been found to be valid to evaluate peoples diabetes status in the population of several countries. However, no such study has been conducted to assess the validity of self-reported diabetes in the Chinese population, the largest population with the highest rate of diabetes. The aim of our study is to evaluate the validity of self-reported diabetes among the middle-aged and older Chinese population. Methods Data from 11 601 participants, aged ≥45, of the China Health and Retirement Longitudinal Study (CHARLS) during 2011–2012, were analysed. Prevalent self-reported diabetes was compared with reference definition defined by fasting glucose, glycated haemoglobin and medication use. Sensitivity, specificity, positive predicted value, negative predicted value and κ value were calculated overall, by 5-year age groups, by education levels and by living areas. Results The sensitivity of prevalent self-reported diabetes was 41.5%, and the specificity was 98.6%. The sensitivity of self-reported diabetes increased with education levels, and was much higher among urban residents than rural residents (58.2% vs 35.0%). The specificity was above 98% among all age groups, in different education levels, and in rural and urban areas. Self-reported diabetes had substantial agreement with reference definition among participants with above vocational school education or those living in urban areas (κ=0.658 and 0.646, respectively). Conclusions Although the sensitivity of self-reported diabetes was poor among middle-aged and older Chinese adults, the specificity and positive predictive values were fairly good. Furthermore, self-reported diabetes performed well among those with more than vocational school educations or those living in urban areas.

The Prevalence and Determinants of Using Traditional Chinese Medicine Among Middle-aged and Older Chinese Adults: Results From the China Health and Retirement Longitudinal Study

BACKGROUND Although traditional Chinese medicine (TCM) is known as an integrative part of Chinas health care system, little is known on the prevalence and determinants of using TCM among the middle-aged and older Chinese population, especially among those with chronic conditions. METHODS The nationwide survey data of 17,708 Chinese adults aged 45 and older from the China Health and Retirement Longitudinal Study were used to estimate the prevalence of TCM. SAS SURVEYLOGISTIC procedure was applied to identify factors associated with using TCM. Analysis took into account the complex survey design and nonresponse rate. RESULTS The prevalence of using TCM was 19.3% (95% CI 18.4%-20.1%) among the overall participants and 24.5% (95% CI 23.4%-25.5%) among those with self-reported chronic conditions. Participants with stroke, cardiovascular disease, and chronic kidney diseases were the most frequent users of TCM to treat their conditions. Age, individual income, and family income were associated with TCM use; however, when further controlling for chronic diseases, these variables became nonsignificant. Besides TCM, 4.4% (3.8%-5.0%) and 4.6% (4.0%-5.2%) of the overall participants and those with chronic conditions, respectively, used other forms of complementary and alternative medicine. CONCLUSIONS The prevalence of using TCM was high among the middle-aged and older Chinese population. The use of TCM was mainly driven by chronic conditions. The main conditions that patients used TCM to treat were stroke, cardiovascular disease, and chronic kidney disease.

Association between exposure to the Chinese famine during infancy and the risk of self-reported chronic lung diseases in adulthood: a cross-sectional study

Objective To examine the association between early-life exposure to the Chinese famine and the risk of chronic lung diseases in adulthood. Design Data analysis from a cross-sectional survey. Setting and participants 4135 subjects were enrolled into the study from the China Health and Retirement Longitudinal Study (CHARLS) 2011–2012 baseline survey to analyse the associations between prenatal and early postnatal famine exposure and the risk of chronic lung diseases in adulthood. Main outcome measures Chronic lung diseases were defined based on self-reported information. Results The prevalence of self-reported chronic lung diseases in fetus-exposed, infant-exposed, preschool-exposed, and non-exposed groups was 6.5%, 7.9%, 6.8%, and 6.1%, respectively. The risk of chronic lung diseases in the infant-exposed group was significantly higher (OR 1.95, 95% CI 1.10 to 3.44) than the non-exposed group in severely affected areas, even after adjusting for gender, smoking, and drinking, family economic status, and the highest educational attainment of the parents (OR 2.57, 95% CI 1.26 to 5.25). In addition, after stratification by gender and famine severity, we found that only infant exposure to the severe famine was associated with the elevated risk of chronic lung diseases among male adults (OR 3.16, 95% CI 1.17 to 8.51). Conclusions Severe famine exposure during the period of infancy might increase the risk of chronic lung diseases in male adults.

Association between the Great China Famine exposure in early life and risk of arthritis in adulthood

Background The association between famine exposure in early life and risk of arthritis (combination of osteoarthritis and inflammatory arthritis) in adulthood is unclear. The aim of this study is to explore the association. Methods A total of 4124 subjects were selected from the national data of the China Health and Retirement Longitudinal Study in 2011–2012. Doctor-diagnosed arthritis was self-reported in participants’ questionnaire. Birthdates were used to categorise participants into famine-exposed and non-exposed groups. Logistic regression model was used to explore the association of famine exposure in early life with the risk of arthritis in adulthood. Results The prevalence of arthritis in both infant-exposed and preschool-exposed groups was significantly higher than those in the non-exposed group (35.0% and 30.6% vs 27.3%; p<0.05). Compared with the non-exposed group, the infant-exposed group showed a significantly elevated risk of arthritis in adulthood after adjusting for confounding factors (OR=1.65; 95% CI 1.29 to 2.11; p<0.001). In the stratified analysis, we found that participants who lived in severely affected areas (OR=1.91; 95% CI 1.41 to 2.59; p<0.001), who are female (OR=2.21; 95% CI 1.57 to 3.11; p<0.001) and those with a body mass index ≥24.0 kg/m2 (OR=2.46; 95% CI 1.70 to 3.55; p<0.001) in the infant-exposed group had increased risk of arthritis in adulthood. Similar results were additionally observed when age-balanced control group was used. Conclusion Great China Famine exposure in infancy may be associated with an elevated risk of arthritis in adulthood, particularly in women and participants with adiposity. These findings suggest nutrition intervention in infancy and weight control in later life may reduce the risk of arthritis in adulthood.

Chinese famine exposure in infancy and metabolic syndrome in adulthood: results from the China health and retirement longitudinal study

Background/objectivesTo explore the association between famine exposure in early life and the risk of metabolic syndrome in the Chinese adults.Subjects/methodsA total of 2148 participants aged 50s were selected from a large national epidemiological survey in the China. The logistic regression models were used to analyze the association between famine exposure in early life and risk of metabolic syndrome in adulthood.ResultsThe prevalence of metabolic syndrome among individuals in the preschool exposed group, infant exposed group, fetal exposed group, and the non-exposed group was 37.9, 43.5, 37.5, and 34.0%, respectively. The prevalence of metabolic syndrome in the infant exposed group was significantly higher than the non-exposed group (43.5 vs. 34.0%, P = 0.006). Compared with the non-exposed group, individuals who exposed to the famine in infancy significantly increased the risk of metabolic syndrome (OR = 1.83; 95% CI: 1.24, 2.70) after adjusting for gender, smoking status, drinking status, physical activity, and the educational levels of participants and their parents. However, similar results were not observed in the fetal (OR = 1.25; 95% CI: 0.89, 1.74) or the preschool (OR = 1.30; 95% CI: 0.97, 1.75) exposed groups.ConclusionsThe Great China famine exposure during infancy was linked with the elevated risk of metabolic syndrome in adults aged 50s, which provided further evidence for the developmental origins hypothesis.