Reproductive and menstrual factors and colorectal cancer incidence in the Women's Health Initiative Observational Study.

BACKGROUND: Reproductive and menstrual factors have been evaluated as surrogates for long-term hormonal exposures in several prospective studies of colorectal cancer, yet findings have been conflicting. METHODS: The relation of reproductive and menstrual factors (self-reported via a reproductive history questionnaire) with incident colorectal cancer was investigated among women enrolled in the Women's Health Initiative Observational Study (WHI-OS), a longitudinal cohort of 93 676 postmenopausal women (aged 50-79 years at enrolment) in which 1149 incident cases of colorectal cancer occurred over a median follow-up of 11.9 years. Multivariable Cox proportional hazards models that included established colorectal cancer risk factors were constructed to examine the association of colorectal cancer incidence with reproductive and menstrual factors. RESULTS: Having had two children (vs nulliparous: hazard ratio (HR)=0.80, 95% confidence interval (CI): 0.64-0.99) was inversely associated with colorectal cancer risk. Compared with never users, ever use of oral contraceptives was associated with lower colorectal cancer risk (HR=0.74, 95% CI: 0.63-0.86); however, no relationship was observed for duration of oral contraceptives use (4 years vs 1 year: HR=0.94, 95% CI: 0.67-1.32). None of the remaining reproductive and menstrual factors was associated with colorectal cancer incidence. CONCLUSIONS: Parity and prior use of oral contraceptives were associated with lower colorectal cancer risk in this cohort of postmenopausal women.

The adipokine profile of metabolically benign obese and at-risk normal weight postmenopausal women: the Women's Health Initiative Observational Study.

OBJECTIVE: Nearly, a third of obese individuals, termed metabolically benign obese, have a low burden of adiposity-related cardiometabolic abnormalities, whereas a substantial proportion of normal-weight individuals possess risk factors. METHODS: In cross-sectional analyses of 699 normal weight and 1,294 overweight/obese postmenopausal women enrolled in a nested case-control stroke study ancillary to the Women's Health Initiative Observational Study, we compared levels of adiponectin, leptin, and resistin among metabolically benign normal weight, at-risk normal weight, metabolically benign obese, and at-risk obese women using components of the ATP III definition of the metabolic syndrome (metabolically benign: ≤1 of the four components; at-risk phenotype: ≥2 components or diabetes). RESULTS: Overall, 382/699 normal-weight women (54.6%) and 328/1,194 overweight/obese women (27.5%) were metabolically benign. Among normal-weight women, at-risk women had higher leptin and lower adiponectin levels compared to metabolically benign women; multivariate-adjusted odds ratios were significant for having leptin (OR: 2.51; 95% CI: 1.28-5.01) and resistin (1.46; 1.03-2.07) in the top tertile and adiponectin in the bottom tertile (2.64; 1.81-3.84). Compared to metabolically benign overweight/obese women, at-risk obese women had higher odds of having leptin in the top tertile (1.62; 1.24-2.12) and adiponectin in the bottom tertile (2.78; 2.04-3.77). CONCLUSIONS: Overall, metabolically benign overweight/obese women had an intermediate adipokine profile (between at-risk obese and metabolically benign normal-weight women), whereas at-risk normal-weight women had a less favorable profile compared to metabolically benign normal-weight women. As adiponectin was the only adipokine independent of BMI, it may be most likely to have a role in the etiological pathway of these phenotypes.

Prevalence and persistence of sleep disordered breathing symptoms in young children: a 6-year population-based cohort study.

STUDY OBJECTIVES: To describe the prevalence, persistence, and characteristics associated with sleep disordered breathing (SDB) symptoms in a population-based cohort followed from 6 months to 6.75 years. DESIGN: Avon Longitudinal Study of Parents and Children (ALSPAC). SETTING: England, 1991-1999. PARTICIPANTS: 12,447 children in ALSPAC with parental report of apnea, snoring, or mouth-breathing frequency on any one of 7 questionnaires. MEASUREMENTS: Symptom prevalence rates-assessed as "Always" and "Habitually"-are reported at 0.5, 1.5, 2.5, 3.5, 4.75, 5.75, and 6.75 years of age. The proportion of children in whom symptoms develop, persist or abate between observation points is reported. Exploratory multivariate analyses identified SDB risk factors at 1.5, 4.75, and 6.75 years. RESULTS: The prevalence of apnea ("Always") is 1%-2% at all ages assessed. In contrast, snoring "Always" ranges from 3.6% to 7.7%, and snoring "Habitually" ranges from 9.6% to 21.2%, with a notable increase from 1.5- 2.5 years. At 6 years old, 25% are habitual mouth-breathers. The "Always" and "Habitual" incidence of each symptom between time points is 1%-5% and 5%-10%, respectively. In multivariate analyses of combined symptoms, socioeconomic factors have stronger, more persistent effects upon increased SDB risk than gestational age, gender, or race (aside from 1.5 years); adenoidectomy decreases risk by 40%-50%. CONCLUSIONS: This is the first natural history study of the primary symptoms of SDB across a key 6-year period in the development of SDB symptoms. Snoring rates are higher and spike earlier than previously reported. Symptoms are dynamic, suggesting the need for early and continued vigilance in early childhood.