Parity and risk of ovarian cysts: Cross-sectional evidence from the Dongfeng-Tongji cohort study.

Little is known about the association between parity and the risk of ovarian cysts. The aim of this study was to examine the association between parity and the risk of ovarian cysts among a population of Chinese women. A total of 20 502 women aged 45-86 years from the Dongfeng-Tongji Cohort study completed baseline questionnaires, medical examination and provided baseline blood samples. Participants were categorized into four groups according to parity (one, two, three, and four or more live births). Logistic regression models were used to investigate the association between parity and the risk of ovarian cysts. The prevalence of ovarian cysts in the study population was 4.0% (816/20 502). Increasing parity was associated with decreasing risk of ovarian cysts without adjustment for any covariates and after age-adjusted model (P<0.001). After adjusting for potential confounders, women who had had four or more live births had lower risk of ovarian cysts (OR: 0.51; 95% CI: 0.27-0.96) compared with women who had had one live birth. There was a consistent but non-significant decreased risk of ovarian cysts for women who had had two, and three live births (OR: 0.85; 95% CI: 0.68-1.05) and (OR: 0.84; 95% CI: 0.59-1.20) respectively compared with women who had had one live birth. It was concluded that higher parity was associated with decreasing risk of ovarian cysts in this population of Chinese women. These findings could be helpful in decision making in clinical practice for gynecologists when evaluating women suspected to have ovarian cysts.

Parity and Risk of Stroke among Chinese Women: Cross-sectional Evidence from the Dongfeng-Tongji Cohort Study.

Epidemiological studies have investigated the association between parity and the risk of stroke, but the results have been inconsistent. The objective of this study was to assess the association among middle-aged and older Chinese women. We used data from the Dongfeng-Tongji Cohort Study. In total, 14,277 women were included in the analysis. Participants were classified into four groups according to parity. Stroke cases were self-reported during face-to-face interviews. Multivariable logistic regression models were used to investigate the association between parity and the risk of stroke while controlling for potential confounders. The prevalence of stroke among the study subjects was 2.7% (380 of 14,277). In the fully adjusted model, women who had experienced two, three, or four or more live births had 1.24 times (95% CI, 0.85-1.81), 1.97 times (95% CI, 1.30-2.98) and 1.86 times (95% CI, 1.14-3.03), higher risk of stroke, respectively, compared with women who had experienced one live birth. High parity was associated with an increasing risk of stroke in the present study. Further longitudinal studies are needed to confirm the association and to explore the unclear mechanism underlying the link between parity and stroke risk.

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 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.

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.

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

BACKGROUND: Evidence 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. METHODS: A 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. RESULTS: Of 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. CONCLUSIONS: Our 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.