Mediation Effect of Physical Activity on Obesity in Black Women.

BACKGROUND AND OBJECTIVE: Sociodemographic and lifestyle factors, physical activity, diet, and nutrients are important in the understanding of obesity. The possibly direct or indirect nature of the associations among these factors and the eventual link to obesity is not well understood. In this study, we assess the indirect association between socio-demographic factors and obesity. DESIGN: A case-control study involving African American women conducted at Howard University Cancer Center. PARTICIPANTS AND METHODS: One hundred ninety eight participants gave information on anthropometric measurements, intake of dietary supplements and nutrients, socio-demographic factors (age, marital status, income and education) and physical activity. Path analysis was utilized to assess associations between socio-demographic factors and obesity through physical activity, dietary supplements and nutrients, smoking or alcohol consumption. MAIN RESULTS: The mean age of the participants was (55 ± 12 years), with 50% being obese (BMI ≥ 30 kg/m2). Obesity level decreased by approximately 7% for every one level increase in education via its prior effect on vigorous physical activity. Age had a significant positive indirect effect on obesity through vigorous physical activity - with obesity levels increasing by approximately 6% for every one year increase in age via its prior effect on vigorous physical activity. CONCLUSIONS: Vigorous physical activity mediates the association between education and age on obesity.

PM2.5 as a marker of exposure to tobacco smoke and other sources of particulate matter in Cairo, Egypt.

SETTING: Cairo and Giza governorates of Egypt. BACKGROUND: Particulate matter under 2.5 µm in diameter (PM2.5) arises from diverse sources, including tobacco smoke from cigarettes and waterpipes, and is recognized as a cause of acute and chronic morbidity and mortality. OBJECTIVE: To measure PM2.5 in workplaces with different intensities of smoking and varying levels of smoking restrictions. DESIGN: We conducted an air sampling study to measure PM2.5 levels in a convenience sample of indoor and outdoor venues in 2005-2006. RESULTS: Using a calibrated SidePak instrument, 3295 individual measurements were collected at 96 venues. Compared to indoor venues where tobacco smoking was banned (PM2.5 levels 72-81 µg/m(3)), places offering waterpipes to patrons of cafes (478 µg/m(3)) and Ramadan tents (612 µg/m(3)) had much higher concentrations, as did venues such as public buildings with poor enforcement of smoking restrictions (range 171-704 µg/m(3)). Both the number of waterpipe smokers and the number of cigarette smokers observed at each venue contributed significantly to the overall burden of PM2.5. CONCLUSION: Such data will support smoke-free policies and programs aimed specifically at reducing environmental tobacco exposure and improving air quality in general, and will provide a baseline for monitoring the impact of tobacco control policies.

Cardiorespiratory Fitness and Metabolic Syndrome in Postmenopausal African-American Women.

We examined the association of cardiorespiratory fitness with metabolic syndrome in overweight/obese postmenopausal African-American women. Pooled baseline data on 170 African-American women from 2 exercise trials were examined. Metabolic syndrome was defined as at least 3 of the following: abdominal obesity, glucose intolerance, hypertension, low high-density lipoprotein cholesterol (HDL-C), and high triglycerides. Cardiorespiratory fitness (VO2peak) was determined using the Bruce treadmill protocol and categorized as: Very Low (VLCRF<18 mL·kg(-1) min(-1)), Low (LCRF=18.0-220-22-22.0 mL·kg(-1) min(-1)), and Moderate (MCRF>22.0 mL·kg(-1) min(-1)). Associations of metabolic syndrome with cardiorespiratory fitness were analyzed using one-way ANOVA and linear regression. VO2peak was significantly lower in the VLCRF compared to the MCRF group. Lower cardiorespiratory fitness was associated with higher prevalence of metabolic syndrome, abdominal obesity, hypertriglyceridemia, and low HDL among overweight/obese postmenopausal African-American women. In fully adjusted models, higher waist circumference and triglycerides were associated with lower VO2peak levels (P<0.01) and higher HDL-C was associated with higher VO2peak levels (P=0.03). Overweight/obese postmenopausal African-American women with very low cardiorespiratory fitness are more likely to have metabolic syndrome, higher body mass index, and unhealthier levels of certain metabolic syndrome components than women with moderate cardiorespiratory fitness.

Frequent loss of the BLID gene in early-onset breast cancer.

The BH3-like motif-containing inducer of cell death (BLID) is an intronless gene localized on 11q24.1. Loss of that region has frequently been reported in early-onset breast cancer and is significantly associated with poor prognosis and reduced survival. Downregulation of BLID is associated with younger age, triple-negative phenotype, and reduced disease-free and overall survival of breast cancer patients. In this study, we investigated allelic loss of BLID in breast tumor specimens from 78 women with invasive breast cancer using 2 dinucleotide polymorphic markers closely linked to the BLID gene (no intragenic marker for BLID is available). Seventy-three cases were informative. Overall, loss of heterozygosity (LOH) at the BLID locus was detected in 32% of the informative cases (23/73). However, in patients 40 years old and younger, LOH was detected in 50% of the cases (9/18). Patients aged 40 years and younger were significantly more likely to experience LOH than those aged 41-55 years (p = 0.04). Specifically, the odds of BLID loss for patients aged 40 years and younger were 3.7 times the odds of loss for patients aged 41-55 years (95% CI, 1.1-13). Our findings suggest a tumor suppressor role of the BLID gene in early-onset breast cancer.