A prospective study of the transient decrease in ovarian cancer risk following childbirth

Epidemiologic evidence shows that the risk of ovarian cancer is decreased following childbirth. We examined the time points when the decreased risk of postpartum maternal ovarian cancer reaches the lowest point and whether the protective effect diminishes over time. A case-control study nested within the Swedish Fertility Register included 10,086 cases of epithelial ovarian cancer recorded in the Swedish Cancer Register from 1961 to 2001. From the Fertility Register, 49,249 eligible subjects matched to the cases by age were selected as controls. The analysis contrasted risk between adjacent parities through logistic regression models that included indicator variables representing each year of age, age at delivery, and time since delivery. Compared with nulliparous women, uniparous women had a transient decrease in maternal ovarian cancer risk at 2 years after delivery (spline-derived odds ratio, 0.71; 95% confidence interval, 0.53-0.95, for those delivered at age 25 years) and maintained a lower risk for 4 years postpartum. Similar transient decreases were observed in biparous women compared with uniparous women and in women with three parities compared with biparous women. The protective effect of childbearing seemed to diminish with time. The transient decrease in postpartum ovarian cancer risk may define the latent period required for pregnancy hormones in clearing out ovarian cells that have undergone early stages of malignant transformation. The period before the risk increases again could indicate the period required for ovarian cancer induction

Interactions between the FTO rs9939609 polymorphism, body mass index, and lifestyle-related factors on metabolic syndrome risk

Whether the FTO polymorphisms interact with environmental factors has not yet been evaluated in associations with metabolic syndrome (MS) risk. The present study investigated the association of the FTO rs9939609 genotypes, body mass index (BMI), and lifestyle-related factors including smoking, alcohol drinking, physical activity, and diet with MS incidence. A population-based prospective cohort study comprised 3,504 male and female Koreans aged 40 to 69 years. At the beginning of the study, all individuals were free of MS and known cardiovascular disease. Incident cases of MS were identified by biennial health examinations during a follow-up period from April 17, 2003 to April 15, 2009. Pooled logistic regression analysis was applied to obtain relative odds (RO) of MS with its 95% confidence interval (CI). After controlling for potential MS risk factors, we observed no association between the rs9939609 genotypes and MS incidence. In analysis stratified by BMI, however, carriers with the FTO risk allele whose BMI is 29 kg/m2 or greater showed an approximately 6-fold higher RO (95% CI: 3.82 to 9.30) compared with non-carriers with BMI less than 25 kg/m2. In particular, the association between the rs9939609 variants and MS risk was significantly modified by high BMI (P-value for interaction < 0.05). Such significant interaction appeared in associations with central obesity and high blood pressure among the MS components. Because carriers of the FTO risk alleles who had BMI of 29 kg/m2 or greater are considered a high risk population, we suggest that they may need intensive weight loss regimens to prevent MS development

Projection of Diabetes Prevalence in Korean Adults for the Year 2030 Using Risk Factors Identified from National Data

BackgroundA number of studies have reported future prevalence estimates for diabetes mellitus (DM), but these studies have been limited for the Korean population. The present study aimed to construct a forecasting model that includes risk factors for type 2 DM using individual- and national-level data for Korean adults to produce prevalence estimates for the year 2030.MethodsTime series data from the Korea National Health and Nutrition Examination Survey and national statistics from 2005 to 2013 were used. The study subjects were 13,908 male and 18,697 female adults aged 30 years or older who were free of liver cirrhosis. Stepwise logistic regression analysis was used to select significant factors associated with DM prevalence.ResultsThe results showed that survey year, age, sex, marital, educational, or occupational status, the presence of obesity or hypertension, smoking status, alcohol consumption, sleep duration, psychological distress or depression, and fertility rate significantly contributed to the 8-year trend in DM prevalence (P<0.05). Based on sex-specific forecasting models that included the above factors, DM prevalence for the year 2030 was predicted to be 29.2% (95% confidence interval [CI], 27.6% to 30.8%) in men and 19.7% (95% CI, 18.2% to 21.2%) in women.ConclusionThe present study projected a two-fold increase in the prevalence of DM in 2030 compared with that for the years 2013 and 2014 in Korean adults. Modifiable factors contributing to this increase in DM prevalence, such as obesity, smoking, and psychological factors, may require attention in order to reduce national and individual costs associated with DM

Association of fetal hormone levels with stem cell potential: Evidence of prenatal influence on cancer risk

Intrauterine and perinatal factors have been linked to risk of testicular cancer and breast cancer in the offspring. In particular, many studies have provided evidence that supports the hypothesis of an intrauterine component in the origin of breast cancer. Human studies to examine the underlying biological mechanisms, however, have been limited. In Chapter 1, we review the likely role of stem cells in hormone-mediated carcinogenic process, particularly as intermediate steps between in utero exposure to hormones and breast cancer. We summarize also studies related to the assumptions of the hypothesis concerning in utero exposure. In Chapter 2 and 3, we report a reproducibility study for hormone assay and a population-based study that measured stem cell potential to explore mechanisms mediating the relation between in utero exposure to pregnancy hormones and cancer risk in the offspring. In these studies, we utilized umbilical cord blood collected two collection sites. Cord blood donors were 99 women, 18 years or older, who delivered a singleton birth. We assayed plasma concentrations of estradiol, unconjugated estriol, testosterone, progesterone, prolactin, sex-hormone binding globulin, insulin-like growth factor-1 (IGF-1), and IGF binding protein-3 (IGFBP-3). We observed in a reproducibility study that assays of these plasma hormones and binding proteins are reliable. For stem cell potential, we measured concentrations of CD34+, CD34 +CD38− cells, CD34+c-kit +. We applied linear regression analysis and controlled for maternal and neonatal characteristics. Data from two sample collection sites were analyzed separately and collectively. Based on the pooled data further taking into account cord sample collection sites, we found that CD34+ increases with increasing E3 (23% per SD increase, p = 0.02) and IGF-1 (25% per SD increase, p = 0.04). A similar increase was observed for IGFBP-3 (p = 0.05). E3, T, SHBG, and progesterone were weakly associated with CD34+CD38 −. These findings indicate that levels of growth factors and steroid hormones are associated with stem cell potential in human umbilical cord blood and point to a potential mechanism that may mediate the relation between in utero exposure to hormones and cancer risk in the offspring