Prospective Study of Short Stature and Newly Diagnosed Asthma in Women

The authors tested the hypothesis that short stature predicts adult-onset asthma independent of obesity among women in the Nurses' Health Study. Height, weight, and physician-diagnosed asthma were assessed with validated questionnaire items. Proportional hazard models adjusted separately for weight and body mass index. The rate of newly diagnosed asthma was 1.55 times greater in the shortest versus the tallest quintile after adjustment for weight (95% CI, 1.26–1.91). After adjustment for body mass index, the rate ratio was 1.16 (95% CI, 0.94–1.42). Short stature predicted adult-onset asthma in a large cohort of women, but this association was not independent of obesity.     

Smoking and Asthma in Men and Women with Normal Weight,Overweight, and Obesity

Background. There is a complex interrelationship among smoking, body weight, and asthma. It needs to be clarified whether smoking is related to an increased risk of asthma after taking into account for relative body weight. Objective. To examine the association between cigarette smoking and the prevalence of asthma in Canadian men and women with normal weight, overweight, and obesity. Methods. The analysis was based on data from 112,830 Canadians aged 18 years or more who participated in a national survey in 2007–2008. A questionnaire covered the information on prevalent asthma, smoking status, height, weight, and other factors. Logistic regression analysis was used to determine the association between smoking and the prevalence of asthma stratified by sex and body mass index (BMI). Results. The crude prevalence of asthma was 6.6% for men and 9.3% for women. After adjustment for covariates, the odds ratios (ORs) for current smoking associated with asthma was 1.20 [95% confidence interval (CI): 1.01–1.43] for men with normal weight, 0.98 (95% CI: 0.81, 1.18) for overweight men, and 1.02 (95% CI: 0.80–1.30) for obese men. For women, the corresponding adjusted ORs were 1.41 (95% CI: 1.23–1.62), 1.27 (95% CI: 1.05–1.54), and 1.28 (95% CI: 1.03–1.59), respectively. Conclusion. Current smoking was significantly associated with prevalent asthma in all women regardless of their relative body weight. In men, however, the association was only observed in those with under- or normal weight.     

Overweight, obesity, and incident asthma: a meta-analysis of prospective epidemiologic studies

RATIONALE: Although obesity has been implicated as an asthma risk factor, there is heterogeneity in the published literature regarding its role in asthma incidence, particularly in men. OBJECTIVES: To quantify the relationship between categories of body mass index (BMI) and incident asthma in adults and to evaluate the impact of sex on this relationship. METHODS: Online bibliographic databases were searched for prospective studies evaluating BMI and incident asthma in adults. Independent observers extracted data regarding annualized asthma incidence from studies meeting predetermined criteria, within defined categories of normal weight (BMI < 25), overweight (BMI, 25-29.9), and obesity (BMI >or= 30). Data were analyzed by inverse-variance-weighted, random-effects meta-analysis. Stratified analysis between BMI categories and within sex was performed. RESULTS: Seven studies (n=333,102 subjects) met inclusion criteria. Compared with normal weight, overweight and obesity (BMI >or= 25) conferred increased odds of incident asthma, with an odds ratio (OR) of 1.51 (95% confidence interval [CI], 1.27-1.80). A dose-response effect of elevated BMI on asthma incidence was observed; the OR for incident asthma for normal-weight versus overweight subjects was 1.38 (95% CI, 1.17-1.62) and was further elevated for normal weight versus obesity (OR, 1.92; 95% CI, 1.43-2.59; p<0.0001 for the trend). A similar increase in the OR of incident asthma due to overweight and obesity was observed in men (OR, 1.46; 95% CI, 1.05-2.02) and women (OR, 1.68; 95% CI, 1.45-1.94; p=0.232 for the comparison). CONCLUSIONS: Overweight and obesity are associated with a dose-dependent increase in the odds of incident asthma in men and women, suggesting asthma incidence could be reduced by interventions targeting overweight and obesity.     

Obesity and abdominal fatness associated with undernutrition early in life in a survey in Rio de Janeiro

BACKGROUND: Undernutrition early in life has been associated with chronic diseases and obesity among adults. Our study tested the hypothesis by examining the association between low stature, a marker of early poor nutrition, with obesity and abdominal fatness among adults. METHODS: A population-based survey was conducted in 1996, among 2040 households, with a non-response rate of 11.2%. Weight, height, waist and hip circumference, and skinfolds were measured at home. RESULTS: Age-adjusted prevalence of body mass index (BMI) greater than 25 kg/m2 was 32% more frequent among adult men, and 60% more frequent among adult women, comparing the first to the fourth quintile of height. A J-shaped curve describes the association between weight and the sum of skinfolds with stature after adjusting for confounding by age, energy intake, physical activity, smoking, age at menarche, and race. The adjusted odds ratio of obesity (BMI>30 kg/m2) for short stature, compared to normal stature, was 1.57 with a 95% confidence interval (CI) = 0.90-2.71 among men and 1.84 with a 95% CI=1.10-3.06 among women. Short stature was associated with the risk of abdominal fatness only among women, with an odds ratio=1.77; 95% CI=1.10-2.83. CONCLUSIONS: Increased risk of obesity and abdominal fatness among women of short stature, a marker for undernutrition early in life, was not explained by racial and socio-economic conditions, energy intake or age at menarche.     

The association between obesity and screening mammography accuracy

BACKGROUND: Obesity is increasing among American women, especially as they age. The influence of obesity on the accuracy of screening mammography has not been studied extensively. METHODS: We analyzed 100 622 screening mammography examinations performed on members of a nonprofit health plan. The relationship between body mass index (weight in kilograms divided by the square of height in meters) and measures of screening accuracy was assessed. Body mass index was categorized as underweight or normal weight (<25), overweight (25-29), obesity class I (30-34), and obesity classes II to III (> or =35). RESULTS: Compared with underweight or normal weight women, overweight and obese women were more likely to be recalled for additional tests after adjusting for important covariates, including age and breast density (overweight odds ratio [OR], 1.17; 95% confidence interval [CI], 1.11-1.23); obesity class I OR, 1.27; 95% CI, 1.19-1.35; obesity classes II-III OR, 1.31; 95% CI, 1.22-1.41). As body mass index increased, women were more likely to have lower specificity (overweight OR, 0.86; 95% CI, 0.81-0.90; obesity class I OR, 0.79; 95% CI, 0.74-0.84; and obesity classes II-III OR, 0.77; 95% CI, 0.71-0.82). No statistically significant differences were noted in sensitivity. Adjusted receiver operating characteristic analysis showed statistically significant improvement in the area under the curve (AUC) for underweight or normal weight women (AUC = 0.941) vs overweight women (AUC = 0.916, P =.02) and underweight or normal weight women vs obesity classes II and III women (AUC = 0.904, P =.02). CONCLUSIONS: Obese women had more than a 20% increased risk of having false-positive mammography results compared with underweight and normal weight women, although sensitivity was unchanged. Achieving a normal weight may improve screening mammography performance.     

Body mass index and asthma among Mexican adults: the effect of using self-reported vs measured weight and height

Several recent studies have demonstrated a positive association between obesity and asthma among women but not men. The present study examines the effect of misclassification of body mass index (BMI) in the association between obesity and asthma by gender. This cross-sectional analysis included a total sample of 961 Mexican adults. Use of measured BMI revealed that obesity (BMI >30 kg/m(2)) was a risk factor for asthma diagnosis in both men (OR, 2.5; 95% CI, 1.1-5.9) and women (OR, 2.3; 95% CI, 1.5-3.8). In contrast, use of self-reported BMI showed that only women (OR, 1.7; 95% CI, 1.1-2.7) and not men (OR, 1.3; 95% CI, 0.6-2.9) were at increased risk of asthma diagnosis. Use of self-reported BMI substantially underestimated the prevalence of obesity; this bias was not related to asthma per se but was mainly due to obesity. Therefore, misclassification of BMI obscured the relationship between obesity and asthma to a greater extent among men than among women since obesity prevalence in the general population was higher among men. Measurement bias merits greater attention in future research on obesity and asthma.     

The association between obesity and asthma is stronger in nonallergic than allergic adults

STUDY OBJECTIVE: To determine the modifying effects of sex and allergy history on the association between body mass index (BMI) and asthma prevalence. DESIGN: Cross-sectional study of 86,144 Canadians who were 20 to 64 years of age in 2000-2001. SETTING: A national survey. Measurements and analysis: Self-reported asthma, allergy history, height, and weight. Logistic regression analysis was used to detect effect modification and to adjust for covariates. Population weight and design effects associated with complex survey design were taken into consideration. RESULTS: The adjusted odds ratios (ORs) for obesity associated with asthma was 1.85 (95% confidence interval [CI], 1.65 to 2.07) for women and 1.21 (95% CI, 1.05 to 1.40) for men. One unit of increased BMI was associated with an approximate 6% increase in asthma risk in women, and 3% in men. A stronger association between obesity and asthma was observed in nonallergic women than in allergic women, with the adjusted ORs being 2.53 (95% CI, 2.11 to 3.04) and 1.57 (95% CI, 1.36 to 1.82), respectively. For men, the corresponding ORs were 1.30 (95% CI, 1.05 to 1.62) and 1.18 (95% CI, 0.98 to 1.53), respectively. CONCLUSIONS: Obesity is likely to have a larger effect on nonallergic asthma. The greater prevalence of nonallergic asthma in women may explain the stronger obesity-asthma association seen in women compared with men and children who have a greater prevalence of allergic asthma.     

Asthma development with obesity exposure: observations from the cohort of the National Health and Nutrition Evaluation Survey Epidemiologic Follow-up Study (NHEFS).

Results of cross-sectional studies suggest an association between body mass index and asthma. However, it is not clear whether the occurrence of asthma precedes increased body mass index or vice versa. From 1971 to 1975, the First National Health and Nutrition Examination Survey collected height and weight data and information about doctor-diagnosed asthma from 14,407 subjects aged 25-74. In 1982 through 1985, information was again obtained on doctor-diagnosed asthma with a follow-up rate of 84.8%. We took this opportunity to examine the relationship between body mass index (BMI) and asthma in this cohort. Subjects with subnormal BMI and subjects admitting current or history of doctor-diagnosed asthma were excluded from the cohort. Mean follow-up was 10 years (range 6.7-13 years). Analyses were adjusted for race and gender. Logistic regression analysis was conducted with asthma as the dependent variable and BMI modeled as a categorical independent variable (BMI groups). At baseline and at follow-up, increasing BMI was associated with increased prevalence of asthma. During the observation interval, however, no increased incidence of asthma associated with increasing BMI was noted. In comparison with normal BMI, the relative risk (RR) for development of doctor-diagnosed asthma in elevated BMI was 1.0 (95% confidence interval 0.9-1.2), for markedly elevated BMI was 1.0 (0.8-1.3), and for severely elevated BMI was 1.1 (0.8-1.5). Race did not affect this relationship. African Americans had an increased risk of asthma, but the risk was unassociated with increasing BMI. Gender did not affect this relationship. The disease burden of asthma appeared in normal weight and slightly overweight women rather than obese and markedly obese women. These results suggest that asthma development may be a point on the trajectory of chronic obesity disease or asthma appears with obesity as a concurrent disorder.     

Current Wheezing, Puberty, and Obesity Among Mexican Adolescent Females and Young Women

Background. Studies suggest an association between obesity and asthma. This may be modified by the physiological changes of puberty. We aim to explore the relation between overweight and current asthma among Mexican adolescent females and young women and evaluate how puberty may modify this association. Methods. Adolescent females (n = 6944) and young women aged 11-24 years provided data. Current asthma was defined as wheezing in the last 12 months and obesity by body mass index (BMI). Puberty was defined by age at menarche. The association of obesity and current wheezing was evaluated by using logistic regression adjusting for confounders. The impact of puberty was studied by using stratified analysis by age at menarche. Results. The prevalence of current wheezing was 16.2% (95% CI 15-17). Compared with girls of normal weight (BMI 15 to ≥ 85 percentile), obese girls (BMI ≥ 95 percentile) had an increased risk of current wheezing of 19% (OR = 1.19; 95% CI 0.97-1.46). After stratifying by age at menarche, we observed that this increased risk was only present in girls with menarche at 11 years old or younger (1.31%; 95% CI 1.01-1.73). Conclusions. The association between obesity and asthma seems to be greater among girls with early puberty, suggesting the role of female hormones.     

Body mass index and physical activity in relation to asthma and atopic diseases in young adults

BACKGROUND: Obesity has been shown to increase the risk of asthma and wheezing. Conditioning exercise might decrease the asthma risk, and that could partly explain the association. The relation between obesity and allergic diseases is quite conflicting. METHODS: The association between body mass index (BMI) and physician-diagnosed asthma, allergic rhinitis or conjunctivitis, atopic dermatitis, and self-reported wheezing was investigated in a questionnaire study among 10,667 Finnish first-year university students aged 18-25 years. Logistic regression was used to evaluate possible confounding by parental education, passive smoking at age 0-2, childhood residential environment, current and past smoking and leisure time physical activity index. RESULTS: In men, there was a greater risk of asthma, but not wheezing with increasing BMI. Compared to those with BMI below 20, OR for male asthma was 1.98 (95% CI 1.11-3.52) in BMI category 20.0-22.4, 1.90 (95% CI 1.05-3.41) in BMI 22.5-24.9, and 3.5 (95% CI 1.63-7.64) in BMI > or = 27.5. Among women, the risks of asthma and wheezing were about two-fold among the overweight-obese subjects. Moderate leisure time physical activity was associated with lower risk of asthma in men (OR 0.62, 95% CI 0.62 (0.42-0.92), but not among women. The risk of allergic rhinoconjunctivitis and atopic dermatitis increased quite linearly with BMI among women but not men. CONCLUSIONS: Low leisure time physical activity seems not to explain the greater risk of asthma among obese men and women. The quite linear association between BMI and both allergic rhinoconjunctivitis and wheezing among women suggests the independent effect of body fat on atopic diseases.     

Asthma Development with Obesity Exposure: Observations from the Cohort of the National Health and Nutrition Evaluation Survey Epidemiologic Follow-up Study (NHEFS)

Results of cross-sectional studies suggest an association between body mass index and asthma. However, it is not clear whether the occurrence of asthma precedes increased body mass index or vice versa. From 1971 to 1975, the First National Health and Nutrition Examination Survey collected height and weight data and information about doctor-diagnosed asthma from 14,407 subjects aged 25–74. In 1982 through 1985, information was again obtained on doctor-diagnosed asthma with a follow-up rate of 84.8%. We took this opportunity to examine the relationship between body mass index (BMI) and asthma in this cohort. Subjects with subnormal BMI and subjects admitting current or history of doctor-diagnosed asthma were excluded from the cohort. Mean follow-up was 10 years (range 6.7–13 years). Analyses were adjusted for race and gender. Logistic regression analysis was conducted with asthma as the dependent variable and BMI modeled as a categorical independent variable (BMI groups). At baseline and at follow-up, increasing BMI was associated with increased prevalence of asthma. During the observation interval, however, no increased incidence of asthma associated with increasing BMI was noted. In comparison with normal BMI, the relative risk (RR) for development of doctor-diagnosed asthma in elevated BMI was 1.0 (95% confidence interval 0.9–1.2), for markedly elevated BMI was 1.0 (0.8–1.3), and for severely elevated BMI was 1.1 (0.8–1.5). Race did not affect this relationship. African Americans had an increased risk of asthma, but the risk was unassociated with increasing BMI. Gender did not affect this relationship. The disease burden of asthma appeared in normal weight and slightly overweight women rather than obese and markedly obese women. These results suggest that asthma development may be a point on the trajectory of chronic obesity disease or asthma appears with obesity as a concurrent disorder.     

Relationships between self-reported asthma and pulmonary function and various measures of obesity

Objective: We explore the association with self-reported asthma and pulmonary function based on spirometry measurements using different measures to determine obesity because body mass index (BMI) is limited in not differentiating fat and muscle mass. Methods: A multi-year cross-sectional study using Korean National Health and Nutrition Examination Survey data was conducted between July 2008 and May 2011. A total of 9409 subjects were included in the final analysis. Results: Obesity was associated with self-reported asthma and pulmonary function limitations mainly in adult women aged between 40 and 65 years and elderly men aged 65 or older. The association was stronger when the measurement of obesity was based on body fat percentage or waist-to-height ratio (WHtR), compared to BMI. There was a higher self-reported asthma risk among obese women according to the WHtR [odds ratio (OR) = 1.817, 95% CI: (1.208, 2.735)]. There was an increased risk of pulmonary function limitation with abdominal obesity [OR 1.418, 95% CI (1.020, 1.972)], weight-to-height ratio [OR 1.467, 95% CI (1.058, 2.034)], and obesity with regard to body fat percentage [OR 1.753, 95% CI (1.251, 2.457)] in adult women. In elderly men, obesity based on body fat percentage was associated with an increased risk of pulmonary function limitation [OR 1.93, 95% CI (1.098, 3.388)]. Conclusions: Measures other than BMI should be examined when investigating the effect of obesity on self-reported asthma and pulmonary function limitation.     

Birth size, adult body composition and muscle strength in later life

OBJECTIVE: Low birth weight has been linked to lower lean body mass and abdominal obesity later in life, whereas high birth weight has been suggested to predict later obesity as indicated by high body mass index (BMI). We examined how birth weight was related to adult body size, body composition and grip strength. DESIGN/SUBJECTS: Cross-sectional study on 928 men and 1075 women born in 1934-1944, with measurements at birth recorded. MEASUREMENTS: Height, weight, waist and hip circumference and isometric grip strength were measured. Lean and fat body mass were estimated by bioelectrical impedance with an eight-polar tactile electrode system. RESULTS: A 1 kg increase in birth weight corresponded in men to a 4.1 kg (95% CI: 3.1, 5.1) and in women to a 2.9 kg (2.1, 3.6) increase in adult lean mass. This association remained significant after adjustment for age, adult body size, physical activity, smoking status, social class and maternal size. Grip strength was positively related to birth weight through its association with lean mass. The positive association of birth weight with adult BMI was explained by its association with lean mass. Low birth weight was related to higher body fat percentage only after adjustment for adult BMI. Abdominal obesity was not predicted by low birth weight. CONCLUSIONS: Low birth weight is associated with lower lean mass in adult life and thus contributes to the risk of relative sarcopenia and the related functional inability at the other end of the lifespan. At a given level of adult BMI, low birth weight predicts higher body fat percentage.     

Body mass index and the risk of asthma in adults

Asthma and obesity are both chronic conditions and their prevalences have risen in affluent societies. A positive association between asthma and being overweight or obese has been reported in children and women, but associations in men are less clearly described. The objective of this study was to explore the association between body mass index (BMI) and asthma in men and women of diverse ethnic and socioeconomic background living in New York State, USA. In this study, we analyzed cross-sectional data on 5524 subjects aged 18 years and older who were interviewed by telephone in the 1996 and 1997 New York State Behavioral Risk Factor Surveillance System. Asthma (doctor-diagnosed), and weight and height were self-reported. BMI (kg/m2) was used as a measure of adiposity. Weighted logistic regression analysis, with stratification by gender and age, was used to examine the relationship between asthma prevalence and BMI, adjusting for race/ethnicity, education, health insurance, time since last physical examination, physical activity and smoking status. The results showed that the prevalence of asthma was 4.6% (CI: 3.6-5.5%) among men and 8.1% (CI: 7.1-9.1%) among women. In women, the prevalence of asthma was significantly increased in those with a BMI 25 kg/m2 or higher (BMI 25-27.5: OR = 1.76, 95% CI: 1.06-2.94; BMI 27.5-29.9: OR = 2.45, 95% CI: 1.41-4.25; BMI > or = 30: OR = 2.67, 95% CI: 1.66-4.29) when compared to the reference category (BMI: 22-24.9 kg/m2). In men, the prevalence of asthma was increased in the lowest weight category, BMI < 22 kg/m2 (OR = 3.05, 95% CI: 1.37-6.78) and in the highest category, BMI > or = 30 kg/m2 (OR = 2.92, 95% CI: 1.39-6.14). This U-shaped association persisted when restricting the analysis to men who had never smoked and was more pronounced for those between 18 and 49 years of age. In conclusion, this cross-sectional study showed that men and women differ significantly in the association between BMI and asthma prevalence only with respect to the lowest weight category. While women had a monotonic association, men showed a U-shaped relationship, indicating that both extremes of weight are associated with a higher prevalence of asthma.     

Current Wheezing,Puberty, and Obesity Among Mexican Adolescent Females and Young Women

Background. Studies suggest an association between obesity and asthma. This may be modified by the physiological changes of puberty. We aim to explore the relation between overweight and current asthma among Mexican adolescent females and young women and evaluate how puberty may modify this association. Methods. Adolescent females (n = 6944) and young women aged 11–24 years provided data. Current asthma was defined as wheezing in the last 12 months and obesity by body mass index (BMI). Puberty was defined by age at menarche. The association of obesity and current wheezing was evaluated by using logistic regression adjusting for confounders. The impact of puberty was studied by using stratified analysis by age at menarche. Results. The prevalence of current wheezing was 16.2% (95% CI 15–17). Compared with girls of normal weight (BMI 15 to ≥ 85 percentile), obese girls (BMI ≥ 95 percentile) had an increased risk of current wheezing of 19% (OR = 1.19; 95% CI 0.97–1.46). After stratifying by age at menarche, we observed that this increased risk was only present in girls with menarche at 11 years old or younger (1.31%; 95% CI 1.01–1.73). Conclusions. The association between obesity and asthma seems to be greater among girls with early puberty, suggesting the role of female hormones.     

Overweight and obesity as risk factors for atrial fibrillation or flutter: the Danish Diet, Cancer, and Health Study

PURPOSE: We examined the association between the body mass index analyzed as a continuous variable and by categorization according to World Health Organization criteria (normal weight, overweight and obesity) and the risk of a hospital (inpatient as well as outpatient) diagnosis of atrial fibrillation or flutter. METHODS: Population-based prospective cohort study conducted from December 1993 to December 2001 among 47589 participants (22482 men and 25107 women) without preexisting cardiovascular or endocrine disease and with a mean age at baseline of 56 years (range 50-64 years) in the Danish Diet, Cancer, and Health Study. Subjects were followed up in the Danish National Registry of Patients and in the Danish Civil Registration System. RESULTS: During follow-up (mean, 5.7 years) atrial fibrillation or flutter developed in 553 subjects (372 men and 181 women). The adjusted hazard ratio for atrial fibrillation or flutter per unit of increase in the body mass index was 1.08 (95% confidence interval [CI]: 1.05 to 1.11) in men and 1.06 (95% CI: 1.03 to 1.09) in women. When using normal weight as a reference, the adjusted hazard ratio for atrial fibrillation or flutter by overweight was 1.75 (95% CI: 1.35 to 2.27) in men and 1.39 (95% CI: 0.99 to 1.94) in women. The adjusted hazard ratio by obesity was 2.35 (95% CI: 1.70 to 3.25) in men and 1.99 (95% CI: 1.31 to 3.02) in women. CONCLUSION: Overweight and obesity are associated with an increased risk of a diagnosis of atrial fibrillation or flutter.     

Sex differences in the relationship between amiodarone use and the need for permanent pacing in patients with atrial fibrillation

BACKGROUND: Amiodarone use was associated with an increased need for pacemaker insertion in a retrospective study of patients with atrial fibrillation (AF) and prior myocardial infarction. The aims of this study were to determine prospectively whether amiodarone increases the need for pacemakers in a general population of patients with AF and whether this effect is modified by sex. METHODS: The study included 1005 patients with new-onset AF who were enrolled in the Fibrillation Registry Assessing Costs, Therapies, Adverse events, and Lifestyle (FRACTAL). Multivariable Cox regression models, including time-dependent covariates accounting for medication exposure, were used to evaluate the risk of pacemaker insertion associated with amiodarone use. RESULTS: Amiodarone use was associated with an increased risk of pacemaker insertion (hazard ratio [HR], 2.01; 95% confidence interval [CI], 1.08-3.76) after adjustment for age, sex, atrial flutter, coronary artery disease, heart failure, and hypertension. The effect of amiodarone use was modified by sex, with a significant risk in women but not in men (HR, 4.69; 95% CI, 1.99-11.05 vs HR, 1.05; 95% CI, 0.42-2.58 [P = .02]). This interaction remained significant after adjustment for weight, body mass index, weight-adjusted amiodarone dose, and use of other antiarrhythmic or rate control drugs. CONCLUSION: The risk of bradyarrhythmia requiring pacemaker insertion associated with amiodarone use for AF is significantly greater in women than in men, independent of weight or body mass index.     

The ADRB3 Trp64Arg variant and obesity in African-American breast cancer cases

OBJECTIVE: To determine if a missense change at codon 64 of ADRB3 (Trp64Arg), a candidate obesity gene, is associated with obesity and levels of subcutaneous or visceral fat in African-American breast cancer cases. Several observational studies have found that women, who are overweight or obese at the time of diagnosis, as well as those who gain weight after diagnosis, are at greater risk for breast cancer recurrence and death than non-overweight women. DESIGN: Prospective cohort of breast cancer cases. SUBJECTS: 219 African-American breast cancer patients participating in the Los Angeles component of the Health, Eating, Activity and Lifestyle Study. MEASURES: ADRB3 Trp64Arg genotype, measures of weight including body mass index (BMI), weight gain (weight 5 years before diagnosis compared with weight at 30 months after diagnosis), obesity (BMI> or =30 kg/m(2)), waist/hip circumference and visceral or subcutaneous fat were determined by magnetic resonance imaging. RESULTS: African-American women who were homozygous for the ADRB3 wild-type allele had significantly higher mean visceral fat levels than women who carried the variant (P=0.04), and were significantly more likely to be obese (odd ratios (OR)=2.1, 95% confidence interval (CI)=1.1-4.2). The association with obesity was most pronounced among women who were premenopausal (OR=4.8, 95% CI=1.3-18), who received chemotherapy for their breast cancer (OR=6.1, 95% CI=1.8-20), or who were not physically active (OR=3.9, 95% CI=1.5-9.7). CONCLUSION: The wild-type allele of the ADRB3 missense change was associated with measures of obesity in our sample of African-American women. The association was modified by menopausal status, history of chemotherapy and modest levels of physical activity. These results will need to be confirmed in an independent sample.     

Impact of obesity on perinatal outcomes among asthmatic women

BACKGROUND:

Only one study has investigated the combined effect of maternal asthma and obesity on perinatal outcomes; however, it did not consider small-for-gestational age and large-for-gestational age infants.

OBJECTIVES:

To examine the impact of obesity on perinatal outcomes among asthmatic women.

METHODS:

A cohort of 1386 pregnancies from asthmatic women was reconstructed using three of Quebec’s administrative databases and a questionnaire. Women were categorized using their prepregnancy body mass index. Underweight, overweight and obese women were compared with normal weight women. The primary outcome was the birth of a small-for-gestational-age infant, defined as a birth weight below the 10th percentile for gestational age and sex. Secondary outcomes were large-for-gestational-age infants (birth weight >90th percentile for gestational age) and preterm birth (<37 weeks’ gestation). Logistic regression models were used to obtain the ORs of having small-for-gestational-age infants, large-for-gestational-age infants and preterm birth as a function of body mass index.

RESULTS:

The proportions of underweight, normal weight, overweight and obese women were 10.8%, 53.3%, 19.7% and 16.2%, respectively. Obese asthmatic women were not found to be significantly more at risk for giving birth to small-for-gestational-age infants (OR 0.6 [95% CI 0.4 to 1.1]), large-for-gestational-age infants (OR 1.2 [95% CI 0.7 to 2.2]) or having a preterm delivery (OR 0.7 [95% CI 0.4 to 1.3]) than normal-weight asthmatic women.

CONCLUSIONS:

No significant negative interaction between maternal asthma and obesity on adverse perinatal outcomes was observed.     

Risk of venous thrombosis: obesity and its joint effect with oral contraceptive use and prothrombotic mutations

In the Multiple Environmental and Genetic Assessment of risk factors for venous thrombosis (MEGA study), body weight, height and body mass index (BMI) were evaluated as risk factors. Additionally, the joint effect of obesity together with oral contraceptive use and prothrombotic mutations on the risk of venous thrombosis were analysed. Three-thousand eight-hundred and thirty-four patients with a first venous thrombosis and 4683 control subjects were included, all non-pregnant and without active malignancies. Relative to those with a normal BMI (<25 kg/m(2)), overweight (BMI > or = 25 and BMI < 30 kg/m(2)) increased the risk of venous thrombosis 1.7-fold [odds ratio (OR)(adj(age and sex)) 1.70, 95% confidence interval (CI) 1.55-1.87] and obesity (BMI > or = 30 kg/m(2)) 2.4-fold (OR(adj) 2.44, 95% CI 2.15-2.78). An increase in body weight and body height also individually increased thrombotic risk. Obese women who used oral contraceptives had a 24-fold higher thrombotic risk (OR(adj) 23.78, 95% CI 13.35-42.34) than women with a normal BMI who did not use oral contraceptives. Relative to non-carriers of normal BMI, the joint effect of factor V Leiden and obesity led to a 7.9-fold increased risk (OR(adj) 7.86, 95% CI 4.70-13.15); for prothrombin 20210A this was a 6.6-fold increased risk (OR(adj) 6.58, 95% CI 2.31-18.69). Body height, weight and obesity increase the risk of venous thrombosis, especially obesity in women using oral contraceptives.