Prenatal Exposure to Maternal Cigarette Smoke and Offspring Risk of Excess Weight Is Independent of Both Birth Weight and Catch-Up Growth

Prenatal exposure to maternal cigarette smoke (PEMCS) is one of the most common insults to the developing fetus and has consistently emerged as an important risk factor for excess weight in the offspring. However, no consensus exists on the mechanism of action or duration of impact. This study seeks to further examine the role of PEMCS on overweight status of children up to age 10. Mother and child pairs (n=1183) were analysed from the Québec Longitudinal Study of Child Development (QLSCD) (1998–2010). Multivariable logistic regression models were used to control for confounders and assess mediation. PEMCS was associated with overweight status at age 10 (OR: 1.70; 95% CI: 1.20–2.43) after adjustment for early life exposures and childhood behaviours. This relationship remained robust after adjustment for birth weight and catch-up growth. Other significant predictors included APGAR score, mother’s immigrant and weight status, family type and child energy intake. The elevated risk of excess weight among the offspring of smoking mothers was not accounted for by other known determinants, and PEMCS appears to play a role independent of birth weight and catch-up growth. Our research suggests that young mothers may be an important audience for targeting preventive strategies.

Burden of illness of patients with allergic asthma versus non-allergic asthma

OBJECTIVE

Allergic and non-allergic asthma share similar symptoms, but differ in that allergic asthma is triggered by inhaled allergens. This study compared healthcare resource utilization (HCRU) and costs between these groups using US employer-based claims data.

METHODS

Health insurance claims from Truven Marketscan database (2002Q1-2010Q2) were analyzed. Included patients had ≥2 asthma diagnoses and ≥1 year of eligibility prior to and following the date of first asthma diagnosis. Patients with ≥1 diagnosis for allergic asthma and ≥1 diagnosis for other allergic conditions formed the allergic asthma cohort whereas patients without any of these diagnoses formed the non-allergic asthma cohort. Allergic and non-allergic asthma patients were matched 1:1. HCRU and costs during the study period were compared between cohorts using incidence rate ratios (IRR) and bootstrap methods.

RESULTS

Sixty four thousand four hundred and seventy three allergic and non-allergic asthma patients were matched (mean age = 30; 57.1% female; mean CCI = 0.2), with 7.1% and 0.36% having received an allergy test during the baseline period, respectively. During the study period, allergic asthma patients had significantly more asthma-related pharmacy dispensings (IRR[95% CI] = 2.25[2.22-2.28], p < 0.001) and asthma-related outpatient visits (IRR[95% CI] = 2.29[2.27-2.32], p < 0.001). Allergic asthma patients incurred 39% greater per-patient-per-year all-cause costs (allergic: $4008; non-allergic: $2889, p < 0.001) and 79% greater asthma-related costs (allergic: $1063; non-allergic: $592, p < 0.001) than non-allergic asthma patients.

CONCLUSIONS

These results indicate, even in a relatively healthy population, allergic asthma is associated with greater HCRU and costs. Guideline-recommended IgE allergy tests should be employed in distinguishing the two forms of asthma, to optimize patient management and reduce costs.

Real-World Corticosteroid Utilization Patterns in Patients with Metastatic Castration-Resistant Prostate Cancer in 2 Large US Administrative Claims Databases

BACKGROUND

Prostate cancer is the most common noncutaneous malignancy in men in the United States. Patients with metastatic castration-resistant prostate cancer (mCRPC) may be treated with secondary hormonal therapy or with chemotherapy, and potentially with concomitant corticosteroids. Corticosteroids can help manage the side effects of chemotherapy and secondary hormonal therapy and ameliorate prostate cancer-related symptoms, although corticosteroids are also associated with adverse effects. With an increasing number of available treatment options for mCRPC, evaluating the real-world concomitant use of corticosteroids in this patient population is important.

OBJECTIVE

To evaluate the utilization patterns of corticosteroids for the treatment of patients with mCRPC based on real-world data from 2 large claim databases.

METHODS

This retrospective analysis included medical and pharmacy claims from 2 large publicly available healthcare claims databases covering more than 31 million individuals to identify treatment patterns in adult patients with mCRPC. A total of 2593 patients with mCRPC were identified in data set 1 and 626 patients in data set 2 between 2005 and 2011. The appropriate treatment for castration-resistant prostate cancer (CRPC) was defined as chemotherapy, an antiandrogen, an adrenal androgen blocker, or estrogen. The index date was the date of the first CRPC treatment or the first metastasis diagnosis, whichever occurred later. The observation period spanned from the index date to the end of health insurance eligibility. Study end points included population characteristics, the distribution of mCRPC therapies, and corticosteroid utilization patterns.

RESULTS

The study population came from the 2 data sets and included 3219 men who were treated for mCRPC. Bone and lymph nodes were the predominant metastatic sites. Bicalutamide was the most common secondary hormonal therapy, and docetaxel was the most common chemotherapy used for these patients. Overall, 73.4% of the patients in data set 1 received concomitant corticosteroids, as did 71.6% of patients in population 2 during the entire period from the index date to the end of eligibility date. In addition, 62.8% and 60.4% of patients, respectively, received concomitant corticosteroids during the secondary hormonal therapy period, and 93.8% and 95.1% of patients, respectively, received concomitant corticosteroids during the chemotherapy period. Similar patterns of corticosteroid use were observed across geographic areas of the United States.

CONCLUSION

This study shows consistently similar utilization patterns of corticosteroids in patients with mCRPC in 2 large national databases. Using real-world data to inform concomitant corticosteroid use in the treatment of patients with mCRPC may assist healthcare providers with treatment selection and with sequencing decision. Future research is warranted to investigate evolving treatment options for patients with mCRPC.

Association between consistent omalizumab treatment and asthma control

BACKGROUND

Omalizumab is indicated for patients with moderate-to-severe allergic asthma with inadequately controlled symptoms.

OBJECTIVE

We evaluated the association between consistent omalizumab treatment and asthma control.

METHODS

Health insurance claims from the MarketScan database (2002Q1-2011Q2) were analyzed. Asthmatic patients with ≥12 months of continuous insurance coverage after the first omalizumab claim (index date) after 6 months of continuous omalizumab use were included. A 12-month landmark period was used to assess treatment consistency, defined as uninterrupted treatment without a gap of ≥28 days in omalizumab use. The effect of consistent omalizumab treatment on asthma control between months 13 and 24 was evaluated. Multivariate time-varying Cox regressions were also conducted to assess the adjusted effect of treatment interruption on asthma control from month 1 to month 24.

RESULTS

A total of 3044 patients (mean age, 48.5 years; female, 62%) formed the study population. Patients consistent with omalizumab treatment at 12 months (39% of patients) were less likely to have an uncontrolled asthma event during months 13 to 24 with only 49% of patients experiencing one event compared with 54% in the non consistent subgroup (P = .02). In addition, consistent omalizumab treatment at 12 months was associated with a 51% reduction in the mean number of asthma-related emergency department (ED) visits per patient and a 28% reduction in asthma-related hospitalizations. Multivariate analyses corroborated these findings (hazard ratio for consistent vs non-consistent: risk of short-acting β2-agonists prescription, oral corticosteroids prescription, ED visit, or hospitalization, 0.76; 95% CI, 0.69-0.83]).

CONCLUSION

This analysis showed that consistent omalizumab treatment was associated with significant reductions in ED visits and hospitalizations.

Cardiovascular adaptations of pregnancy in T and B cell-deficient mice

The pathophysiology of gestational hypertensive disorders is incompletely defined. T lymphocytes are implicated. Both T and natural killer (NK) cells express RAS and, in implantation sites, NK cells are highly enriched. We hypothesized that T cells and/or NK cells contribute to circulatory control during pregnancy. Using radiotelemetry of arterial pressure, heart rate, and activity, mice without T and B cells (genotypes BALB/c-Rag2(-/-) and NOD.scid) were examined at baseline and across pregnancy. These strains differ in NK cell competency, with Rag2(-/-) being normal and NOD.scid impaired. Circulatory features differed between these inbred strains. Rag2(-/-); had blood pressure responses to pregnancy that did not differ from congenic normal mice. NOD.scid had higher midgestational blood pressure compared with normoglycemic NOD mice (3-5 mm Hg greater than NOD; P < 0.004). In comparison to controls, both T and B strains had much higher heart rates after first trimester that did not remit until parturition (>30 bpm greater than control; P < 0.0001). NOD.scid had additional anomalies, including 90% depletion of circulating NK cells and elevated (57%) proliferation of uterine NK cells within implantation sites. These data demonstrate immune control of midgestational heart rate and suggest NK cells contribute to midpregnancy regulation of mean arterial pressure.

Uterine NK cells, spiral artery modification and the regulation of blood pressure during mouse pregnancy

Reproductive success in mammals involves coordinated changes in the immune and cardiovascular as well as in the neuroendocrine and reproductive systems. This review addresses studies that identify potential links for NK cells and T cells with the local and systemic cardiovascular adaptations of pregnancy. The studies reviewed have utilized immunohistochemisty and in vivo analyses of vascular parameters by ultrasound, chronic monitoring of hemodynamics via radiotelemetric recording and intravital microscopy. At the uterine level, functional subsets of uterine natural killer cells were identified. These included subsets expressing molecules important for vasoregulation, in addition to those previously identified for angiogenesis. Spiral arteries showed conducted responses that could account for conceptus control of vasoactivity and mouse gestational blood pressure 5-phase pattern. Vascular immunology is an emerging transdisciplinary field, critical for both reproductive immunology and cardiovascular disease.

Respiratory rhythms generated in the lamprey rhombencephalon

Brainstem networks generating the respiratory rhythm in lampreys are still not fully characterized. In this study, we described the patterns of respiratory activities and we identified the general location of underlying neural networks. In a semi-intact preparation including the brain and gills, rhythmic discharges were recorded bilaterally with surface electrodes placed over the vagal motoneurons. The main respiratory output driving rhythmic gill movements consisted of short bursts (40.9+/-15.6 ms) of discharge occurring at a frequency of 1.0+/-0.3 Hz. This fast pattern was interrupted by long bursts (506.3+/-174.6 ms) recurring with an average period of 37.4+/-24.9 s. After isolating the brainstem by cutting all cranial nerves, the frequency of the short respiratory bursts did not change significantly, but the slow pattern was less frequent. Local injections of a glutamate agonist (AMPA) and antagonists (6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) or D,L-amino-5-phosphonopentanoic acid (AP5)) were made over different brainstem regions to influence respiratory output. The results were similar in the semi-intact and isolated-brainstem preparations. Unilateral injection of AP5 or CNQX over a rostral rhombencephalic region, lateral to the rostral pole of the trigeminal motor nucleus, decreased the frequency of the fast respiratory rhythm bilaterally or stopped it altogether. Injection of AMPA at the same site increased the rate of the fast respiratory rhythm and decreased the frequency of the slow pattern. The activity recorded in this area was synchronous with that recorded over the vagal motoneurons. After a complete transverse lesion of the brainstem caudal to the trigeminal motor nucleus, the fast rhythm was confined to the rostral area, while only the slow activity persisted in the vagal motoneurons. Our results support the hypothesis that normal breathing depends on the activity of neurons located in the rostral rhombencephalon in lampreys, whereas the caudal rhombencephalon generates the slow pattern.

Modulation of respiratory activity by locomotion in lampreys

In vertebrates, locomotion is associated with changes in respiratory activity, but the neural mechanisms by which this occurs remain unknown. We began examining this in lampreys using a semi-intact preparation of young adult Petromyzon marinus, in which respiratory and locomotor behaviors can be recorded simultaneously with the activity of the underlying neural control systems. Spontaneous fictive respiration was recorded with suction electrodes positioned over the glossopharyngeal or the rostral vagal motor nucleus. In this preparation, locomotor activity, characterized by symmetrical tail movements (electromyogram recordings), was evoked by mechanical stimulation of the skin. During locomotion, the mean respiratory frequency and the mean area of the motor bursts were significantly increased (81.6+/-28.6% and 62.8+/-25.4%, respectively; P<0.05). The frequency returned to normal 92+/-51 s after the end of locomotion. There were fluctuations in the instantaneous respiratory and locomotor frequencies that were rhythmical but antiphasic for the two rhythmic activities. The changes in respiratory activity were also examined during bouts of locomotion occurring spontaneously, and it was found that a modification in respiratory activity preceded the onset of spontaneous locomotion by 3.5+/-2.6 s. This suggests that the early respiratory changes are anticipatory and are not caused by feedback generated by locomotion. The increase in respiratory frequency during locomotion induced by sensory stimulation persisted after removal of the mesencephalon. When both the mesencephalon and spinal cord were removed, resulting in the isolation of the rhombencephalon, changes in the respiratory activity were also present following skin stimulations that would have normally induced locomotion. Altogether, the results suggest that respiratory changes are programmed to adjust ventilation prior to motor activity, and that a central rhombencephalic mechanism is involved.