The association between duration of breastfeeding and childhood asthma outcomes.

BACKGROUND: Postnatal exposures, including breastfeeding, may influence asthma development. OBJECTIVE: To investigate the association between breastfeeding duration and child asthma. METHODS: We studied 2021 mother-child dyads in the ECHO PATHWAYS consortium of prospective pregnancy cohorts (GAPPS, CANDLE, TIDES). Women reported the duration of any and exclusive breastfeeding and child asthma outcomes during follow-up at child age 4 to 6 years. Outcomes included current wheeze (previous 12 months), ever asthma, current asthma (having ≥2 of current wheeze, ever asthma, medication use in past 12-24 months), and strict current asthma (ever asthma with either or both current wheeze and medication use in past 12-24 months). We used multivariable logistic regression to assess associations (odds ratios and 95% confidence intervals) between breastfeeding and asthma outcomes adjusting for potential confounders. We assessed effect modification by mode of delivery, infant sex, and maternal asthma. RESULTS: Among women, 33%, 13%, 9%, and 45% reported 0 to less than 2, 2 to 4, 5 to 6, and more than 6 months of any breastfeeding, respectively. The duration of any breastfeeding had a protective linear trend with ever asthma but no other outcomes. There was a duration-dependent protective association of exclusive breastfeeding and child asthma outcomes (eg, current asthma adjusted odds ratio [95% confidence interval], 0.64 [0.41-1.02], 0.61 [0.38-0.98], and 0.52 (0.31-0.87) for 2to 4 months, 5 to 6 months, and more than 6 months, respectively, compared with <2 months). For exclusive breastfeeding, protective associations were stronger in dyads with children born by vaginal vs cesarean delivery although interactions did not reach statistical significance (Pinteractions 0.12-0.40). CONCLUSION: Longer duration of exclusive breastfeeding had a protective association with child asthma.

Relative validation of fruit and vegetable intake and fat intake among overweight and obese African-American women.

OBJECTIVE: To compare commonly used dietary screeners for fat intake and fruit and vegetable intake with 24 h dietary recalls among low-income, overweight and obese African-American women. DESIGN: Three telephone interviews were completed; measures included two 24 h dietary recalls (a weekday and weekend day) using the Nutrition Data System for Research software, the Behavioral Risk Factor Surveillance System's (BRFSS) Fruit and Vegetable Consumption Module and the National Cancer Institute's (NCI) Percentage Energy from Fat Screener. SETTING: Participants were recruited from three federally qualified health centres in south-west Georgia, USA. SUBJECTS: Participants (n 260) were African-American women ranging in age from 35 to 65 years. About half were unemployed (49.6%) and 58.7% had a high-school education or less. Most were obese (88.5%), with 39.6% reporting a BMI ≥ 40.0 kg/m(2). RESULTS: Mean fruit and vegetable intake reported from the 24 h dietary recall was 2.66 servings/d compared with 2.79 servings/d with the BRFSS measure. The deattenuated Pearson correlation was 0.22, with notable variation by weight status, education level and age. Mean percentage of energy from fat was 35.5% as reported from the 24 h dietary recall, compared with 33.0% as measured by the NCI fat screener. The deattenuated Pearson correlation was 0.38, also with notable variation by weight status, education level and age. CONCLUSIONS: Validity of brief dietary intake measures may vary by demographic characteristics of the sample. Additional measurement work may be needed to accurately measure dietary intake in obese African-American women.

Comparison of energy expenditure estimates from 4 physical activity questionnaires with doubly labeled water estimates in postmenopausal women.

BACKGROUND: Physical activity energy expenditure (EE) is an important determinant of health, and epidemiologists have used various methods, such as physical activity and energy intake recalls and records, to estimate energy cost. However, most epidemiologic studies have not validated these methods against the doubly labeled water (DLW) technique for measuring EE. OBJECTIVE: The aim was to compare EE estimated by 4 physical activity questionnaires with that obtained with the DLW technique in free-living postmenopausal women. DESIGN: We measured EE in kcal/d using the DLW method, the Harvard Alumni questionnaire, the Five City Project questionnaire, the Cross-Cultural Activity Participation Study (CAPS) Four Week Activity Recall, and the CAPS Typical Week Activity Survey in 65 healthy postmenopausal women. RESULTS: Compared with DLW, the Harvard Alumni questionnaire, the Five City Project questionnaire, and the CAPS Four Week Activity Recall overestimated (P < 0.05) daily EE by 62%, 16%, and 11%, respectively, whereas the CAPS Typical Week Activity Recall underestimated (P < 0.05) EE by 31%. Both the Harvard Alumni and Five City Project questionnaires overestimated EE in obese and overweight women. CONCLUSIONS: When using 3 of the 4 questionnaire methods, postmenopausal women overestimated EEs. Of all women, obese women overestimated daily EE the most.

Usefulness of body mass index as a sufficient adiposity measurement for sex hormone concentration associations in postmenopausal women.

BACKGROUND: Both obesity and sex hormones are known risk factors for postmenopausal breast cancer. Although adiposity and sex hormones have been studied in the past, previous reports in postmenopausal women have not been conducted under carefully controlled dietary conditions. In this study, we investigated the usefulness of body mass index (BMI) as a sufficient adiposity measurement to assess associations with sex hormone levels. METHODS: This study was conducted as a cross-sectional analysis within the control segment (0 g alcohol group) of a randomized, crossover design, in which 51 postmenopausal women consumed 0 (control), 15 (one drink), and 30 (two drinks) g alcohol (ethanol)/d for 8 weeks each as part of a controlled diet. Dual-energy X-ray absorptiometry scans were administered to the women during the control (0 g alcohol) segment, and a blood sample was drawn at the end of that diet period for hormone analysis. RESULTS: In multivariate analysis (adjusted for age, race, family history of breast cancer, parity, and menarche <12 years), women who were overweight or obese had significantly higher serum concentrations of estradiol, bioavailable estradiol, estrone, and estrone sulfate and lower sex hormone-binding globulin than normal weight women (all P < 0.05). In models adjusted for BMI and the covariates above, none of the dual-energy X-ray absorptiometry adiposity measures added further information (all P > 0.10) for these five analytes beyond that of BMI alone. CONCLUSIONS: In this population of postmenopausal women, under carefully controlled dietary conditions, we confirmed previous findings that higher levels of adiposity were associated with higher concentrations of estrogens and lower sex hormone-binding globulin, and we found that the use of the epidemiology-friendly BMI seems sufficient to assess associations with these hormone levels.

Dietary patterns differ between urban and rural older, long-term survivors of breast, prostate, and colorectal cancer and are associated with body mass index.

BACKGROUND: Older adult cancer survivors are at greater risk of cancer recurrence and other comorbidities that can be prevented through improved diet and weight management. The tertiary prevention needs of rural-dwelling survivors can be even greater, yet little is known about rural and urban differences in lifestyle factors among this high-risk population. OBJECTIVES: To compare dietary patterns of urban and rural cancer survivors and to examine associations of dietary patterns with body mass index (BMI). DESIGN: A secondary analysis was performed of baseline data from the Reach Out to Enhance Wellness (RENEW) trial, a diet and exercise intervention among overweight, long-term (≥5 years), older survivors of colorectal, breast, and prostate cancer. Survivors in the present analysis (n=729) underwent two 45- to 60-minute telephone surveys, which included two 24-hour dietary recalls. Principal components analysis and multivariable general linear models were used to derive dietary patterns and to evaluate associations between dietary patterns and BMI, respectively. RESULTS: Principal components analysis identified three primary dietary patterns among rural dwellers (high sweets and starches, high reduced-fat dairy, cereal, nuts, and fruits, and mixed) and three among urban dwellers (high fruits and vegetables, high meat and refined grains, and high sugar-sweetened beverages). Among rural survivors, greater adherence to the high reduced-fat dairy, cereal, nuts, and fruits pattern was positively associated with lower BMI (P trend <0.05), whereas higher scores on the mixed pattern was associated with greater BMI (P trend <0.05). Greater adherence to the high fruits and vegetables pattern among urban survivors was inversely associated with BMI (P trend <0.05). CONCLUSIONS: Urban and rural differences in dietary intake behavior should be considered in designing public health interventions among the increasing population of older cancer survivors. In addition, targeting overall dietary patterns might be one approach to help reduce the burden of obesity among this population.

Relationship between serum leptin levels and alcohol consumption in a controlled feeding and alcohol ingestion study.

We examined serum leptin levels in a controlled feeding and alcohol ingestion study to elucidate potential mechanisms by which alcohol may affect cancer and immunologically related health risks. A total of 53 healthy, nonsmoking postmenopausal women completed a random-order, three-period crossover design study in which each woman received zero (0 g of alcohol), one (15 g of alcohol), or two (30 g alcohol) drinks per day. After accounting for differences in body mass index, women who consumed 15 or 30 g of alcohol per day had 7.3% (95% confidence interval [CI] = 3.0% to 15.1%) and 8.9% (95% CI = 1.6% to 16.7%) higher serum leptin levels, respectively (P(trend) =.018), than women who consumed 0 g of alcohol per day. Younger women (i.e., 49-54 years) demonstrated a statistically significantly larger association of alcohol consumption level with the increase in serum leptin levels than older women (i.e., 55-79 years) (24.4%, 95% CI = 9.3% to 42.0% versus 3.7%, 95% CI = -4.1% to 12.1% increase in serum leptin levels for 30 g of alcohol per day relative to 0 g of alcohol per day for the lowest age quartile compared with the three highest age quartiles combined; P =.022). These results indicate that moderate alcohol consumption (15-30 g of alcohol per day) increases serum leptin levels in postmenopausal women and may predispose moderate drinkers to the morbidities associated with chronic elevations of this hormone including cancer.