Plasma 25-hydroxyvitamin D and risk of breast cancer in the Nurses' Health Study II

Introduction Experimental evidence indicates vitamin D may play an important role in breast cancer etiology but epidemiologic evidence to date is inconsistent. Vitamin D comes from dietary intake and sun exposure and plasma levels of 25-hydroxyvitamin D (25(OH)D) are considered the best measure of vitamin D status. Methods We conducted a prospective nested case-control study within the Nurses\u27 Health Study II (NHSII). Plasma samples collected in 1996 to 1999 were assayed for 25(OH)D in 613 cases, diagnosed after blood collection and before 1 June 2007, and in 1,218 matched controls. Multivariate relative risks (RR) and 95% confidence intervals (CI) were calculated by conditional logistic regression, adjusting for several breast cancer risk factors. Results No significant association was observed between plasma 25(OH)D levels and breast cancer risk (top vs. bottom quartile multivariate RR = 1.20, 95% CI (0.88 to 1.63), P-value, test for trend = 0.32). Results were similar when season-specific quartile cut points were used. Results did not change when restricted to women who were premenopausal at blood collection or premenopausal at diagnosis. Results were similar between estrogen receptor (ER)+/progesterone receptor (PR)+ and ER-/PR- tumors (P-value, test for heterogeneity = 0.51). The association did not vary by age at blood collection or season of blood collection, but did vary when stratified by body mass index (P-value, test for heterogeneity = 0.01). Conclusions Circulating 25(OH)D levels were not significantly associated with breast cancer risk in this predominantly premenopausal population

Vitamins and Perinatal Outcomes Among HIV-Negative Women in Tanzania.

Prematurity and low birth weight are associated with high perinatal and infant mortality, especially in developing countries. Maternal micronutrient deficiencies may contribute to these adverse outcomes. In a double-blind trial in Dar es Salaam, Tanzania, we randomly assigned 8468 pregnant women (gestational age of fetus, 12 to 27 weeks) who were negative for human immunodeficiency virus infection to receive daily multivitamins (including multiples of the recommended dietary allowance) or placebo. All the women received prenatal supplemental iron and folic acid. The primary outcomes were low birth weight (<2500 g), prematurity, and fetal death. The incidence of low birth weight was 7.8% among the infants in the multivitamin group and 9.4% among those in the placebo group (relative risk, 0.82; 95% confidence interval [CI], 0.70 to 0.95; P=0.01). The mean difference in birth weight between the groups was modest (67 g, P<0.001). The rates of prematurity were 16.9% in the multivitamin group and 16.7% in the placebo group (relative risk, 1.01; 95% CI, 0.91 to 1.11; P=0.87), and the rates of fetal death were 4.3% and 5.0%, respectively (relative risk, 0.87; 95% CI, 0.72 to 1.05; P=0.15). Supplementation reduced both the risk of a birth size that was small for gestational age (<10th percentile; 10.7% in the multivitamin group vs. 13.6% in the placebo group; relative risk, 0.77; 95% CI, 0.68 to 0.87; P<0.001) and the risk of maternal anemia (hemoglobin level, <11 g per deciliter; relative risk, 0.88; 95% CI, 0.80 to 0.97; P=0.01), although the difference in the mean hemoglobin levels between the groups was small (0.2 g per deciliter, P<0.001). Multivitamin supplementation reduced the incidence of low birth weight and small-for-gestational-age births but had no significant effects on prematurity or fetal death. Multivitamins should be considered for all pregnant women in developing countries. (ClinicalTrials.gov number, NCT00197548 [ClinicalTrials.gov].)

Non-Communicable Diseases in Sub-Saharan Africa: The Case for Cohort Studies

Michelle Holmes and colleagues argue that there is an urgent need for longitudinal cohorts based in sub-Saharan Africa to address the growing burden of noncommunicable diseases in the region

Milk consumption and the prepubertal somatotropic axis

© 2007 Rich-Edwards et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Constraining the Milky Way potential with a 6-D phase-space map of the GD-1 stellar stream

The narrow GD-1 stream of stars, spanning 60 deg on the sky at a distance of ~10 kpc from the Sun and ~15 kpc from the Galactic center, is presumed to be debris from a tidally disrupted star cluster that traces out a test-particle orbit in the Milky Way halo. We combine SDSS photometry, USNO-B astrometry, and SDSS and Calar Alto spectroscopy to construct a complete, empirical 6-dimensional phase-space map of the stream. We find that an eccentric orbit in a flattened isothermal potential describes this phase-space map well. Even after marginalizing over the stream orbital parameters and the distance from the Sun to the Galactic center, the orbital fit to GD-1 places strong constraints on the circular velocity at the Sun's radius V_c=224 \pm 13 km/s and total potential flattening q_\Phi=0.87^{+0.07}_{-0.04}. When we drop any informative priors on V_c the GD-1 constraint becomes V_c=221 \pm 18 km/s. Our 6-D map of GD-1 therefore yields the best current constraint on V_c and the only strong constraint on q_\Phi at Galactocentric radii near R~15 kpc. Much, if not all, of the total potential flattening may be attributed to the mass in the stellar disk, so the GD-1 constraints on the flattening of the halo itself are weak: q_{\Phi,halo}>0.89 at 90% confidence. The greatest uncertainty in the 6-D map and the orbital analysis stems from the photometric distances, which will be obviated by Gaia.Comment: 16 pages, 18 figures; accepted to ApJ; full resolution version is available at http://www.ast.cam.ac.uk/~koposov/files/gd1_fullres.pd

The association between betaine and choline intakes and the plasma concentrations of homocysteine in women

Elevated total homocysteine (tHcy), a risk factor for many chronic diseases, can be remethylated to methionine by folate. Alternatively, tHcy can be metabolized by other 1-carbon nutrients, ie, betaine and its precursor, choline

Gender-Related Differences in the Prevalence of Cardiovascular Disease Risk Factors and their Correlates in Urban Tanzania.

\ud Urban areas in Africa suffer a serious problem with dual burden of infectious diseases and emerging chronic diseases such as cardiovascular diseases (CVD) and diabetes which pose a serious threat to population health and health care resources. However in East Africa, there is limited literature in this research area. The objective of this study was to examine the prevalence of cardiovascular disease risk factors and their correlates among adults in Temeke, Dar es Salaam, Tanzania. Results of this study will help inform future research and potential preventive and therapeutic interventions against such chronic diseases. The study design was a cross sectional epidemiological study. A total of 209 participants aged between 44 and 66 years were included in the study. A structured questionnaire was used to evaluate socioeconomic and lifestyle characteristics. Blood samples were collected and analyzed to measure lipid profile and fasting glucose levels. Cardiovascular risk factors were defined using World Health Organization criteria. The age-adjusted prevalence of obesity (BMI > or = 30) was 13% and 35%, among men and women (p = 0.0003), respectively. The prevalence of abdominal obesity was 11% and 58% (p < 0.0001), and high WHR (men: >0.9, women: >0.85) was 51% and 73% (p = 0.002) for men and women respectively. Women had 4.3 times greater odds of obesity (95% CI: 1.9-10.1), 14.2-fold increased odds for abdominal adiposity (95% CI: 5.8-34.6), and 2.8 times greater odds of high waist-hip-ratio (95% CI: 1.4-5.7), compared to men. Women had more than three-fold greater odds of having metabolic syndrome (p = 0.001) compared to male counterparts, including abdominal obesity, low HDL-cholesterol, and high fasting blood glucose components. In contrast, female participants had 50% lower odds of having hypertension, compared to men (95%CI: 0.3-1.0). Among men, BMI and waist circumference were significantly correlated with blood pressure, triglycerides, total, LDL-, and HDL-cholesterol (BMI only), and fasting glucose; in contrast, only blood pressure was positively associated with BMI and waist circumference in women. The prevalence of CVD risk factors was high in this population, particularly among women. Health promotion, primary prevention, and health screening strategies are needed to reduce the burden of cardiovascular disease in Tanzania.\u

Effects of vitamin D, omega-3 and a simple strength exercise programme in cardiovascular disease prevention: The DO-HEALTH randomized controlled trial

Background: The effects of non-pharmaceutical interventions in the prevention of cardiovascular diseases (CVD) in older adults remains unclear. Therefore, the aim was to investigate the effect of 2000 IU/day of vitamin D$_3$, omega-3 fatty acids (1 g/day), and a simple home strength exercise program (SHEP) (3×/week) on lipid and CVD biomarkers plasma changes over 3 years, incident hypertension and major cardiovascular events (MACE). Methods: The risk of MACE (coronary heart event or intervention, heart failure, stroke) was an exploratory endpoint of DO-HEALTH, incident hypertension and change in biomarkers were secondary endpoints. DO-HEALTH is a completed multicentre, randomised, placebo-controlled, 2 × 2 × 2 factorial design trial enrolling 2157 Europeans aged ≥70 years. Results: Participants' median age was 74 [72, 77] years, 61.7% were women, 82.5% were at least moderately physically active, and 40.7% had 25(OH)D < 20 ng/mL at baseline. Compared to their controls, omega-3 increased HDL-cholesterol (difference in change over 3 years: 0.08 mmol/L, 95% CI 0.05-0.10), decreased triglycerides (-0.08 mmol/L, (95%CI -0.12 to -0.03), but increased total- (0.15 mmol/L, 95%CI 0.09; 0.2), LDL- (0.11 mmol/L, 0.06; 0.16), and non-HDL-cholesterol (0.07 mmol/L, 95%CI 0.02; 0.12). However, neither omega-3 (adjustedHR 1.00, 95%CI 0.64-1.56), nor vitamin D$_3$ (aHR 1.37, 95%CI 0.88-2.14), nor SHEP (aHR 1.18, 95%CI 0.76-1.84) reduced risk of MACE or incident hypertension compared to control. Conclusion: Among generally healthy, active, and largely vitamin D replete, older adults, treatment with omega-3, vitamin D$_3$, and/or SHEP had no benefit on MACE prevention. Only omega-3 supplementation changed lipid biomarkers, but with mixed effects. TRIAL REGISTRATION CLINICALTRIALS