Testosterone-to-estradiol ratio and lung function in a prospective study of Puerto Rican youth

Persistent cat ownership and asthma in a longitudinal study of Puerto Rican youth

BACKGROUND

Epidemiologic studies have reported conflicting findings for cat or dog exposure and childhood asthma. No study has evaluated whether persistent pet exposure from early life to school age is associated with asthma or allergic sensitization in youth.

OBJECTIVE

To evaluate whether persistent ownership of a cat or a dog throughout childhood is associated with asthma in Puerto Rican youth, a group disproportionately affected with asthma.

METHODS

Prospective study of 384 youth who completed a baseline visit at ages 6 to 14 years and a second visit at ages 9 to 20 years. Persistent cat or dog ownership was defined as ownership of a cat or a dog in early life (during pregnancy or the first year of life) at either study visit (at school age). An allergen-specific IgE result was considered positive if more than or equal to 0.35 IU/mL. Logistic regression was used for the multivariable analysis of asthma and allergic sensitization.

RESULTS

In an analysis adjusting for household income, family history of atopy, persistent overweight or obesity, a persistent unhealthy diet, the time interval between study visits, and other covariates, persistent cat ownership was significantly associated with 68% reduced odds of asthma (95% CI for odds ratio = 0.11-0.92) but not with any allergic sensitization or sensitization to cat allergen. In contrast, persistent dog ownership was not significantly associated with asthma or allergic sensitization.

CONCLUSION

Among school-aged Puerto Rican youth followed for an average of 5 years, persistent cat ownership from early life to school age was inversely associated with asthma.

Effects of testosterone and sex hormone binding globulin on lung function in males and females: a multivariable Mendelian Randomisation study

BACKGROUND

Observational studies suggest that total testosterone (TT) and sex hormone-binding globulin (SHBG) may have beneficial effects on lung function, but these findings might be spurious due to confounding and reverse causation. We addressed these limitations by using multivariable Mendelian randomisation (MVMR) to investigate the independent causal effects of TT and SHBG on lung function.

METHODS

We first identified genetic instruments by performing genome-wide association analyses of TT and SHBG in the large UK Biobank, separately in males and females. We then assessed the independent effects of TT and SHBG on forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC using one-sample MVMR. We addressed pleiotropy, which could bias MVMR, using several methods that account for it. We performed subgroup MVMR analyses by obesity, physical activity and menopausal status, and assessed associations between TT and SHBG with lung function decline. Finally, we compared the MVMR results with those of observational analyses in the UK Biobank.

FINDINGS

In the MVMR analyses, there was evidence of pleiotropy, but results were consistent when accounting for it. We found a strong beneficial effect of TT on FVC and FEV1 in both males and females, but a moderate detrimental effect of SHBG on FEV1 and FEV1/FVC in males only. Subgroup analyses suggested stronger effects of TT among obese and older males. The observational analyses, in line with previous studies, agreed with MRMV for TT, but not for SHBG.

INTERPRETATION

These findings suggest that testosterone improves lung function in males and females, while SHBG has an opposite independent effect in males.

Decreased levels of sex hormones in females with solitary pulmonary nodules were risk factors for malignancy

OBJECTIVE

The purpose of this research was to detect the relationship between the levels of sex hormones in females with solitary pulmonary nodules (SPNs) and their potential malignancies.

METHODS

A total of 187 consecutive patients with pathologically confirmed SPNs by chest CT were enrolled in our study. They were divided into two groups based on the pathologic findings of SPNs after surgery: benign and malignant SPNs. Progesterone (P), estradiol (E2), and testosterone (T) levels in the two groups were measured. Meanwhile, we used binary logistic regression analysis to analyze the risk factors for SPNs.

RESULTS

Of these 187 patients, 73 had benign SPNs, while 114 had malignant SPNs. We found that the levels of progesterone (P), estradiol (E2), and testosterone (T) were decreased significantly in patients with malignant SPNs compared to patients with benign SPNs (all P < 0.05). Multivariate logistic regression analysis revealed that second-hand smoke, burr sign, lobulation sign, pleural traction sign, vascular convergence sign, vacuole sign, and ≥ 1 cm nodules were independent risk factors for malignant pulmonary nodules in females.

CONCLUSIONS

Decreased levels of sex hormones in females were associated with malignant pulmonary nodules, suggesting that they can contribute to the diagnosis of lung cancer.

Exposure to violence and asthma in Puerto Rican youth with high Th2 immunity

BACKGROUND

Little is known about the determinants of asthma among youth with high T helper 2 (Th2) immunity. We hypothesized that exposure to violence (ETV) and violence-related distress are associated with asthma in children and adolescents with high Th2 immunity.

METHODS

We analyzed data from Puerto Ricans with high Th2 immunity aged 9-20 years in the Puerto Rico Genetics of Asthma and Lifestyle (PR-GOAL) and the Epigenetic Variation of Childhood Asthma in Puerto Ricans (EVA-PR) studies, and in a prospective study (PROPRA). High Th2-immunity was defined as ≥1 positive allergen-specific IgE and/or a total IgE ≥ 100 IU/mL and/or an eosinophil count ≥ 150 cells/μL. Asthma was defined as physician-diagnosed asthma and current wheeze. ETV and violence-related distress were assessed with the validated ETV Scale and Checklist of Children's Distress Symptoms (CCDS) questionnaires, respectively.

RESULTS

In multivariable analyses, each 1-point increment in ETV score was significantly associated with 1.13-1.17 times increased odds of asthma in PR-GOAL and in EVA-PR (both at p ≤ 0.01), and each 1-point increment in CCDS score was significantly associated with 1.53-1.54 increased odds of asthma in PR-GOAL and in EVA-PR (both at p ≤ 0.03). Further, a persistently high ETV score was significantly associated with asthma in PROPRA (odds ratio [OR] = 2.83, 95% confidence interval [CI] = 1.10-7.29). Similar results were obtained in a sensitivity analysis using an eosinophil count ≥ 300 cells/μL instead of ≥150 cells/μL to define high Th2 immunity.

CONCLUSIONS

ETV during childhood is associated with increased risk of persistent or new-onset asthma in youth with high Th2 immunity.

Low parental numeracy and severe asthma exacerbations in a prospective study of Puerto Rican youth

BACKGROUND

Numeracy is the mathematical knowledge required to understand and act on instructions from health care providers. Whether persistently low parental numeracy is linked to childhood asthma exacerbations is unknown.

OBJECTIVE

To evaluate whether low parental numeracy at 2 time points is associated with asthma exacerbations and worse lung function in Puerto Rican youth.

METHODS

Prospective study of 225 youth with asthma in San Juan (PR) who participated in 2 visits approximately 5.3 years apart, with the first at ages 6 to 14 years and the second at ages 9 to 20 years. Parental numeracy was assessed with a modified version of the Asthma Numeracy Questionnaire (score range = 0-3 points), and persistently low parental numeracy was defined as a score less than or equal to 1 point at both visits. Asthma exacerbation outcomes included more than or equal to 1 emergency department (ED) visit, more than or equal to 1 hospitalization, and more than or equal to 1 severe exacerbation (≥1 ED visit or ≥1 hospitalization) for asthma in the year before the second visit. Spirometry was conducted using an EasyOne spirometer (NDD Medical Technologies, Andover, Massachusetts).

RESULTS

In an analysis adjusting for age, sex, parental education, use of inhaled corticosteroids, and the time between study visits, persistently low parental numeracy was associated with more than or equal to 1 ED visit for asthma (odds ratio [ORs], 2.17; 95% confidence interval [CI], 1.10-4.26), more than or equal to 1 hospitalization for asthma (OR, 3.92; 95% CI, 1.42-10.84), and more than or equal to 1 severe asthma exacerbation (OR, 1.99; 95% CI, 1.01-3.87) in the year before the follow-up visit. Persistently low parental numeracy was not significantly associated with change in lung function measures.

CONCLUSION

Persistently low parental numeracy is associated with asthma exacerbation outcomes in Puerto Rican youth.

Association of age with computed tomography airway tree morphology in male and female never smokers without lung disease history

BACKGROUND

Sex and aging may affect the airway tree structure in patients with airway diseases and even healthy subjects. Using chest computed tomography (CT), this study sought to determine whether age is associated with airway morphological features differently in healthy males and females.

METHODS

This retrospective cross-sectional study consecutively incorporated lung cancer screening CT data of asymptomatic never smokers (n = 431) without lung disease history. Luminal areas were measured at the trachea, main bronchi, bronchus intermedius, segmental and subsegmental bronchus, and the ratio of their geometric mean to total lung volume (airway-to-lung size ratio, ALR) was determined. Airway fractal dimension (AFD) and total airway count (TAC) were calculated for the segmented airway tree resolved on CT.

RESULTS

The lumen areas of the trachea, main bronchi, segmental and subsegmental airways, AFD and TAC visible on CT were smaller in females (n = 220) than in males (n = 211) after adjusting for age, height, and body mass index, while ALR or count of the 1st to 5th generation airways did not differ. Furthermore, in males but not in females, older age was associated with larger lumen sizes of the main bronchi, segmental and subsegmental airways, and ALR. In contrast, neither male nor female had any associations between age and AFD or TAC on CT.

CONCLUSION

Older age was associated with larger lumen size of the relatively central airways and ALR exclusively in males. Aging may have a more profound effect on airway lumen tree caliber in males than in females.

The Influence of Sex Hormones and X Chromosome in Immune Responses

Males and females differ in their susceptibility to develop autoimmunity and allergy but also in their capacity to cope with infections and cancers. Cellular targets and molecular pathways underlying sexual dimorphism in immunity have started to emerge and appeared multifactorial. It became increasingly clear that sex-linked biological factors have important impact on the development, tissue maintenance and effector function acquisition of distinct immune cell populations, thereby regulating multiple layers of innate or adaptive immunity through distinct mechanisms. This review discusses the recent development in our understanding of the cell-intrinsic actions of biological factors linked to sex, sex hormones and sex chromosome complement, on immune cells, which may account for the sex differences in susceptibility to autoimmune diseases and allergies, and the sex-biased responses in natural immunity and cancer.

Obesity-related asthma in children and adolescents

There is substantial epidemiological and experimental evidence of an obesity-related asthma phenotype. Compared to children of healthy weight, children with obesity are at higher risk of asthma. Children with obesity who have asthma have greater severity and poorer control of their asthma symptoms, more frequent asthma exacerbations, and overall lower asthma-related quality of life than children with asthma who have a healthy weight. In this Review, we examine some of the latest evidence on the characteristics of this phenotype and its main underlying mechanisms, including genetics and genomics, changes in airway mechanics and lung function, sex hormone differences, alterations in immune responses, systemic and airway inflammation, metabolic dysregulation, and modifications in the microbiome. We also review current recommendations for the treatment of these children, including in the management of their asthma, and current evidence for weight loss interventions. We then discuss initial evidence for potential novel therapeutic approaches, such as dietary modifications and supplements, antidiabetic medications, and statins. Finally, we identify knowledge gaps and future directions to improve our understanding of asthma in children with obesity, and to improve outcomes in these susceptible children. We highlight important needs, such as designing paediatric-specific studies, implementing large multicentric trials with standardised interventions and outcomes, and including racial and ethnic groups along with other under-represented populations that are particularly affected by obesity and asthma.

Asthma interactions between obesity and other risk factors

OBJECTIVE

To review and critically discuss published evidence on interactions between obesity and selected risk factors on asthma in children and adults, and to discuss potential future directions in this field.

DATA SOURCES

National Library of Medicine (via PubMed) STUDY SELECTION: A literature search was conducted for human studies on obesity and selected interactions (with sex, race and ethnicity, socioeconomic status, indoor and outdoor pollutants, depression, anxiety, and diet) on asthma. Studies that were published in English and contained a full text were considered for inclusion in this review.

RESULTS

Current evidence supports interactions between obesity and outdoor and indoor air pollutants (including second-hand smoke [SHS]) on enhancing asthma risk, although there are sparse data on the specific pollutants underlying such interactions. Limited evidence also suggests that obesity may modify the effects of depression or anxiety on asthma, whereas little is known about potential interactions between obesity and sex-hormone levels or dietary patterns.

CONCLUSION

Well-designed observational prospective studies (eg, for pollutants and sex hormones) and randomized clinical trials (eg, for the treatment of depression) should help establish the impact of modifying coexisting exposures to reduce the harmful effects of obesity on asthma. Such studies should be designed to have a sample size that is large enough to allow adequate testing of interactions between obesity and risk factors that are identified a priori and thus, well characterized, using objective measures and biomarkers (eg, urinary or serum cotinine for SHS, epigenetic marks of specific environmental exposures).

Diet, Asthma, and Severe Asthma Exacerbations in a Prospective Study of Puerto Rican Youth

BACKGROUND

Poor diet quality may contribute to the disproportionate asthma burden in Puerto Rican youth.

OBJECTIVE

To examine whether an unhealthy diet at one or two study visits conducted over about 5 years was associated with asthma, severe asthma exacerbations, and worse lung function in Puerto Rican youth.

METHODS

This was a prospective study of 406 Puerto Rican youth aged 6 to 14 years at a baseline visit and 9 to 20 years at a follow-up visit. As in prior work, diet was assessed using a dietary score ranging from -2 to +2. The exposure of interest was an unhealthy diet, defined as a nonpositive dietary score (0 to -2) at one or both visits. Outcomes of interest were asthma (defined as physician-diagnosed asthma and one of more episode of wheeze in the year before the second visit), one or more severe asthma exacerbation in the year before the second visit, and change in percent predicted lung function measures (FEV₁, FVC, and FEV₁/FVC) between the first and second visits.

RESULTS

In a multivariable analysis, an unhealthy diet at both visits was associated with increased odds of asthma (adjusted odds ratio = 3.38; 95% confidence interval, 1.74-6.57) and severe asthma exacerbations (adjusted odds ratio = 2.65; 95% confidence interval, 1.16-6.03), but not with change in lung function.

CONCLUSIONS

An unhealthy diet at both visits was associated with increased odds of asthma and severe asthma exacerbations, compared with a healthy diet at both visits. Our findings support health policies promoting a healthy diet in Puerto Rican youth, a population at high risk for asthma.

Sex differences in body composition affect total airway resistance during puberty

BACKGROUND

During puberty, changes in body composition due to sex hormones are associated with lung mechanics. However, little is known about the mediation effect of sex differences in body composition during puberty with total airway resistance.

METHODS

We prospectively recruited 620 children (10-12 years old) from the general population and conducted a cross-sectional study. This study assessed pubertal status according to the five Tanner stages using a questionnaire, line drawings, and each subject's blood sex hormone profile. Both the impulse oscillation system for total lung mechanics and multifrequency bioelectrical impedance for body composition analyses were conducted. The effects of puberty on body composition and subsequent total lung resistance were evaluated using mediation analysis.

RESULTS

Among the 503 children enrolled, there were 261 males (51.9%) and 242 females (48.1%). In males, higher testosterone levels corresponded with reduced total lung resistance (β = -0.13, 95% CI = -0.21 to -0.05, p < 0.001), and the proportion of the mediating effect through the muscle-fat ratio was 19% (95% CI = 4 to 59, p = 0.02). In contrast, in females, pubertal status reduced total lung resistance (β = -0.27, 95% CI = -0.58 to -0.05, p = 0.04), however, the proportion of the mediating effect through the body mass index was -51% (95% CI = -244 to -4%, p = 0.04).

CONCLUSION

The muscle-fat ratio in adolescent males had a synergistic effect with testosterone on improving total airway resistance, whereas improvements in lung resistance by pubertal status were partially masked by body mass index in adolescent females. In conclusion, body composition changes during puberty between males and females have differing effects on total airway resistance.

Violence-related distress and lung function in two longitudinal studies of youth

Increasing violence-related distress over time was associated with worse lung function and worse asthma-related quality of life in youth with asthma despite treatment with low-dose inhaled corticosteroids.Exposure to violence has been associated with lower lung function in cross-sectional studies. We examined whether increasing violence-related distress over time is associated with worse lung function and worse asthma control or quality of life in a secondary analysis of a 48-week randomized clinical trial in 98 youth with asthma (ages 9-16 years) treated with low-dose inhaled corticosteroids (the Vitamin D Kids Asthma Study [VDKA]). We then replicated our findings for lung function in a prospective study of 232 Puerto Rican youth followed for an average of 5·4 years. Violence-related distress was assessed using the Checklist of Children's Distress Symptoms (CCDS) scale. Our outcomes of interest were percent predicted (%pred) lung function measures and (in VDKA only) asthma control (assessed using the Asthma Control Test) and asthma-related quality of life (assessed using the Pediatric Asthma Quality of Life questionnaire). In a multivariable analysis in VDKA, each 1-point increment in the CCDS score was associated with decrements of 3.27% in %predFEV₁ (95% confidence interval [CI]=-6.44% to -0.22%, p=0.04) and a 2.65% decrement in percent predicted FVC (95% CI=-4.86% to -0.45%, p=0.02), and 0.30 points in the overall PAQLQ score (95% CI=-0.50 to -0.10, p<0.01). Similar findings for FEV₁ and FVC were obtained in the prospective study of Puerto Rican youth. Our findings suggest that violence-related distress may worsen lung function and quality of life in youth with asthma (even those treated with low-dose inhaled corticosteroids) and further support policies to reduce exposure to violence among children in the U.S. and Puerto Rico.