Lijun Shen

The effects of midday nap duration on the risk of hypertension in a middle-aged and older Chinese population: a preliminary evidence from the Tongji-Dongfeng Cohort Study, China.

Objective: Evidence from epidemiological studies suggested that shorter and longer duration of nocturnal sleeping may increase the risk of hypertension for older adults. Little is known about the duration of midday nap on the variability of blood pressure among older adults. In this study, we examined whether duration of habitual midday nap is associated with level of blood pressure or the risk of hypertension in a middle-aged and older Chinese population. Methods: A total of 27 009 participants (mean age 63.6 years) from Dongfeng-Tongji Cohort Study received baseline examination including physical examination and laboratory tests, and a face-to-face-interview including demographic information, disease history, and lifestyle. Participants were categorized into five groups according to nap duration, such as no napping, less than 30 min, 30∼60 min, 60∼90 min, and at least 90 min. A series of categorical logistic regression models was used to examine the odd ratios of nap duration with hypertension. Results: The level of SBP and DBP increased significantly with longer duration of habitual midday napping. Nappers with longer nap duration had considerably higher rate of hypertension. The longer duration of napping was related to higher blood pressure level and was associated with a higher risk of hypertension. After adjusting for possible confounders, the longer duration (>60 min) of napping was still associated with hypertension Conclusion: Our findings showed that the practice of longer afternoon nap is associated with a higher increased risk of hypertension, independent of several covariates. Further prospective researches are needed to examine the midday nap duration for development of hypertension.

Daily sleep duration and risk of metabolic syndrome among middle-aged and older Chinese adults: cross-sectional evidence from the Dongfeng–Tongji cohort study

BackgroundEvidence from epidemiological studies has demonstrated that a shorter or longer duration of nighttime sleep may increase the risk of metabolic syndrome. Little is known about the association between daily sleep duration, including nighttime sleep and daytime napping duration, and metabolic syndrome. We aimed to examine the association between daily sleep duration and metabolic syndrome and its components in middle-aged and older Chinese adults using data from the Dongfeng-Tongji Cohort study.MethodsA total of 25,184 participants (mean age 63.6 years) who completed the baseline questionnaire, physical examination and laboratory tests were included in this analysis. Daily sleep duration was calculated by summing up nighttime sleep duration and daytime napping duration. The metabolic syndrome was defined using the International Diabetes Federation criteria. Logistic regression models were used to investigate the association between daily sleep duration and the risk of metabolic syndrome and its components.ResultsOf the participants, 8,046 (31.9%) had metabolic syndrome. Females had a higher prevalence (38.6%) of metabolic syndrome than males (23.9%). Female participants with longer daily sleep duration (≥8 hours, all P < 0.05) per day had a higher risk of metabolic syndrome compared with those sleeping 7–7.9 hours, adjusting for potential confounders. Longer daily sleep was positively associated with individual components of metabolic syndrome except central obesity in females, and was only positively associated with HDL-C in males. Further analysis revealed that a longer duration of daytime napping (≥90 minutes, P < 0.05) was associated with the risk of metabolic syndrome in females. However, nighttime sleep duration was not associated with the risk of metabolic syndrome in either males or females.ConclusionsOur findings suggested that longer daytime napping duration rather than nighttime sleeping duration was associated with increased risk of metabolic syndrome in females. The findings have significant implications for further studies to explore the appropriate sleep duration for middle-aged and older adults.

Parity and the Risk of Diabetes Mellitus among Chinese Women: A Cross-Sectional Evidence from the Tongji-Dongfeng Cohort Study

Objectives Little is known about the long-term health impact of pregnancy on women. The objective of this study was to examine the association between parity and the risk of diabetes among a population of Chinese women. Study design A total of 14,196 women (aged ≥45 years) from the Dongfeng-Tongji Cohort study who had experienced at least one live birth completed baseline questionnaires, medical examinations, and provided baseline blood samples. Participants were categorized into four groups according to parity (one, two, three, or four or more live births). Logistic regression models were used to investigate the association between parity and the risk of diabetes after controlling potential confounders. Results The prevalence of diabetes in the study population was 18.0% (2,552/14,196). Fasting plasma glucose levels increased with the increasing number of live births (P<0.001) and parity had a positive graded association with diabetes without adjustment for any covariates (P for trend <0.001). After adjusting for potential confounders, women who had had two, three, and four or more live births had 1.35 times (95% CI, 1.20–1.52), 1.59 times (95% CI, 1.39–1.82) and 1.44 times (95% CI, 1.21–1.71), respectively, higher risk of diabetes compared with women who had had one live birth. Conclusion Multiparity was associated with increasing risk of diabetes in this population of Chinese women. These findings suggested that multiparity may be a risk factor for the development of diabetes among Chinese women. Future studies are needed to examine the physiological changes during pregnancy for risk of diabetes in later life.

Parity and risk of metabolic syndrome among Chinese women.

BACKGROUND Studies regarding the effects of parity on metabolic syndrome in later life have produced conflicting results. The purpose of this study was to explore the association between parity and the risk of metabolic syndrome and its components in a population of Chinese women. METHODS A cross-sectional study was performed in a total of 13,358 women (mean age 61.5 years) with at least one live birth from the Dongfeng-Tongji cohort study. Each woman completed baseline questionnaires and received baseline examination, including a physical examination and laboratory tests. Participants were categorized into four groups according to parity (one, two, three, four or more live births). The metabolic syndrome was defined according to the International Diabetes Foundation criteria. Logistic regression was conducted to examine the association between parity and metabolic syndrome, with adjustment of potential confounders. RESULTS In this study sample, the prevalence of metabolic syndrome was 38.6% (5,156 of 13,358). After adjusting for demographic, lifestyle, and reproduction-related factors, women with two, three, or four or more live births had 1.18 times (95% confidence interval [CI], 1.05-1.32), 1.44 times (95% CI, 1.24-1.67), and 1.52 times (95% CI, 1.26-1.83), respectively, higher odds of having metabolic syndrome compared with those with one live birth. Furthermore, parity showed a positive association with waist circumference and a negative association with high-density lipoprotein cholesterol. CONCLUSIONS Multiparity was associated with increasing risk of metabolic syndrome independent of main covariates in this population of Chinese women. The findings suggested that multiparity may be a risk factor for metabolic syndrome.

Height and prevalence of hypertension in a middle-aged and older Chinese population

Evidence from epidemiological studies reported that height was inversely associated with cardiovascular diseases, but the association between height and hypertension was unclear. The purpose of this study was to explore the association between height and blood pressure or prevalence of hypertension in a middle-aged and older Chinese population. A total of 33,197 participants aged 37 to 94 years were recruited from the Dongfeng-Tongji cohort study in Hubei province, China. All participants completed baseline questionnaires, medical examinations and provided blood samples. Hypertension was define as a systolic blood pressure (SBP) over 140 mmHg or/and a diastolic blood pressure (DBP) over 90 mmHg, or current use of antihypertensive medication, or participants with self-reported physician diagnosis of hypertension. Multivariate linear and logistic regression models were used. The prevalence of hypertension was 69.1% for men and 58.0% for women. Pulse pressure (PP) and SBP, but not DBP decreased linearly with increasing height among men and women. Comparing the highest with the shortest quartile of height, the multivariate-adjusted odds ratios were 0.80 (95% confidence interval, 0.71, 0.91) for men and 0.83 (0.74, 0.92) for women. In conclusion, height was associated with reduced SBP, PP and prevalence of hypertension in a middle-aged and older Chinese population.

Early age at menarche and gestational diabetes mellitus risk: Results from the Healthy Baby Cohort study

AIM Early age at menarche has been reported to increase type 2 diabetes risk, but little is known of its impact on gestational diabetes mellitus (GDM) risk. The aim of this study was to examine the association between age at menarche and plasma glucose levels as well as GDM risk. METHODS A total of 6900 pregnant women from the Healthy Baby Cohort Study were included in our analysis. Age at menarche was self-reported and categorized into five groups (9-11, 12, 13, 14 and 15-18 years of age). GDM was diagnosed using the International Association of Diabetes and Pregnancy Study Groups criteria. Comparisons of plasma glucose levels according to age at menarche categories were performed using analysis of covariance. Logistic regression models were used to estimate the association between age at menarche and GDM risk. RESULTS Of our 6900 participants, 1015 (14.7%) were diagnosed with GDM. Mean age at menarche was 13.1±1.2 years. Early age at menarche (9-11 years) was associated with higher fasting, 1-h and 2-h plasma glucose levels (all P<0.05) compared with menarche at age 13 years. Furthermore, early age at menarche was linked to increased GDM risk after adjusting for potential confounders (OR: 1.41, 95% CI: 1.06-1.87). CONCLUSION Early age at menarche is an independent risk factor for GDM and, as such, may help to identify women at higher GDM risk who would benefit from early preventative strategies.

Association between earlier age at natural menopause and risk of diabetes in middle-aged and older Chinese women: The Dongfeng–Tongji cohort study

AIM Age at menopause is associated with cardiovascular disease, but little is known of its relationship with diabetes, and previous findings are controversial. The objective of this study was to evaluate the association between earlier menopause (at age ≤45 years) and the prevalence of diabetes in the Chinese population. METHODS A total of 16,299 postmenopausal women, aged 42.0-94.3 years, who completed the study questionnaires, underwent medical examinations and provided blood samples, were included in our analysis. Participants self-reported their age at menopause and were then divided into three age groups (≤45, 46-52, ≥53years). Logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS Of the study participants, 2811 (17.2%) had diabetes. The average age at menopause was 49.5±3.3 years. For each 1-year delay in menopausal age, the presence of diabetes was reduced by 2% (OR: 0.98, 95% CI: 0.97-0.99) after adjusting for potential confounding factors. Compared with those whose menopausal age was 46-52 years, the OR for diabetes was 1.20 (95% CI: 1.03-1.39) for those with an earlier menopausal age (≤45years). CONCLUSION Our findings suggest that earlier menopause may be independently associated with an increased prevalence of diabetes. Future prospective studies are needed to verify this relationship.

Parity and Risk of Coronary Heart Disease in Middle-aged and Older Chinese Women

Pregnancy leads to physiological changes in lipid, glucose levels, and weight, which may increase the risk of coronary heart disease (CHD) in later life. The purpose of this study was to examine whether parity is associated with CHD in middle-aged and older Chinese women. A total of 20,207 women aged 37 to 94 years from Dongfeng-Tongji Cohort who completed the questionnaire, were medically examined and provided blood samples, were included in our analysis. CHD cases were determined by self-report of physician diagnosis through face-to-face interviews. Logistic regression models were used to estimate the association between parity and CHD. The rate of CHD was 15.8%. Parity had a positive association with CHD without adjustment of covariates. After controlling for the potential confounders, increasing risk of coronary heart disease was observed in women who had two (OR, 1.65; 95% CI, 1.41–1.93), three (OR, 1.76; 95% CI, 1.44–2.16), and four or more live births (OR, 1.71; 95% CI, 1.33–2.20) compared with women with just one live birth. High parity was significantly associated with increasing risk of CHD in Chinese women. This suggests that multiparity may be a risk factor for CHD among Chinese women.

Parity and the risk of cataract: a cross-sectional analysis in the Dongfeng-Tongji cohort study

Aims Epidemiological evidence showed that prevalence rates of cataract were higher in women than in men. Female reproductive factors were hypothesised to be linked with this sex difference. In this study, we explored possible effects of parity and reproductive factors on the risk of cataract. Methods Women (14 337 total; aged 45–86 years) were recruited from the Dongfeng-Tongji cohort study. All subjects completed baseline questionnaires and medical examinations and provided baseline blood samples. Cataract was diagnosed by the ophthalmologist in the ocular examination. Logistic regression models were used to evaluate the association between parity and the risk of cataract. Results The prevalence rate of cataract in the study population was 6.8% (972/14 337). After adjustment for potential confounders, women who had undergone two, three, and four or more live births had 1.52 times (95% CI 1.13 to 2.04), 1.67 times (95% CI 1.27 to 2.29) and 1.72 times (95% CI 1.22 to 2.42), respectively, higher risk of cataract compared with women who had undergone one live birth. The risk increased by an estimated 11.3% for each additional live birth. Women who had undergone hormone replacement therapy (OR 1.61; 95% CI 1.05 to 2.47), had diabetes mellitus (OR 1.33; 95% CI 1.11 to 1.58) and/or had the habit of drinking alcohol (OR 1.51; 95% CI 1.08 to 2.10) had a higher risk of cataract. Neither menopause status nor history of contraceptive use was associated with cataract. Conclusions The findings suggested that parity was an independent risk factor for the development of cataract in Chinese women.

Socio-economic status and risk of gestational diabetes mellitus among Chinese women

The relationship between socio‐economic status and gestational diabetes mellitus has received little attention. The purpose of this study was to investigate the association between socio‐economic status and risk of gestational diabetes.