Vitamin D status and recurrent preterm birth: a nested case-control study in high-risk women

OBJECTIVE

To determine whether vitamin D status is associated with recurrent preterm birth, and any interactions between vitamin D levels and fish consumption.

DESIGN

A nested case-control study, using data from a randomised trial of omega-3 fatty acid supplementation to prevent recurrent preterm birth.

SETTING

Fourteen academic health centres in the USA.

POPULATION

Women with prior spontaneous preterm birth.

METHODS

In 131 cases (preterm delivery at <35 weeks of gestation) and 134 term controls, we measured serum 25-hydroxyvitamin D [25(OH)D] concentrations by liquid chromatography-tandem mass spectrometry (LC-MS) from samples collected at baseline (16-22 weeks of gestation). Logistic regression models controlled for study centre, maternal age, race/ethnicity, number of prior preterm deliveries, smoking status, body mass index, and treatment.

MAIN OUTCOME MEASURES

Recurrent preterm birth at <37 and <32 weeks of gestation.

RESULTS

The median mid-gestation serum 25(OH)D concentration was 67 nmol/l, and 27% had concentrations of <50 nmol/l. Serum 25(OH)D concentration was not significantly associated with preterm birth (OR 1.33; 95% CI 0.48-3.70 for lowest versus highest quartiles). Likewise, comparing women with 25(OH)D concentrations of 50 nmol/l, or higher, with those with <50 nmol/l generated an odds ratio of 0.80 (95% CI 0.38-1.69). Contrary to our expectation, a negative correlation was observed between fish consumption and serum 25(OH)D concentration (-0.18, P < 0.01).

CONCLUSIONS

In a cohort of women with a prior preterm birth, vitamin D status at mid-pregnancy was not associated with recurrent preterm birth.

Defining vitamin D status by secondary hyperparathyroidism in the U.S. population

BACKGROUND

Vitamin D is associated with a variety of health outcomes, but the exact definition of vitamin D sufficiency remains controversial.

AIM

We sought to define skeletal-related vitamin D sufficiency by estimating maximum PTH suppression in the U.S. population.

METHODS

We performed a cross-sectional analysis of the National Health and Nutrition Examination Survey (NHANES), 2003-2006. We examined the association between serum 25-hydroxyvitamin D (25OHD) level and serum PTH level in 14,681 participants aged ≥6 yr. We also evaluated the 25OHD-PTH association using 2 thresholds of hyperparathyroidism: PTH≥45 pg/ml and ≥75 pg/ml.

RESULTS

The mean 25OHD level was 24 ng/ml and mean PTH was 42 pg/ml. PTH≥45 pg/ml was present in 35% of the population, while PTH≥75 pg/ml was present in 7%. The prevalence of 25OHD levels <40 ng/ml and <30 ng/ml was 95% and 77%, respectively. In both unadjusted and adjusted models, there was a strong inverse relationship between 25OHD and PTH. Compared to 25OHD≥40 ng/ml, the 25OHD-PTH association was 2.36 [95% confidence interval (CI), 2.08-2.67] times greater for 25OHD<5 ng/ml and 1.12 (95%CI, 1.07-1.17) times greater for 25OHD 30-39.9 ng/ml. Compared to 25OHD≥40 ng/ml, 25OHD levels of 20- 29.9 ng/ml [odds ratio (OR) 2.0 (95%CI, 1.4-2.8)] but not 30- 39.9 ng/ml [OR 1.1 (95%CI, 0.8-1.6)] were independently associated with PTH≥45 pg/ml.

CONCLUSIONS

Optimal vitamin D status, defined by estimated maximum PTH suppression, does not occur until at least 25OHD levels ≥40 ng/ml. Using these thresholds, most of the U.S. population needs more vitamin D. Large, prospective studies are needed to determine optimal vitamin D supplementation.

The role of body mass index in acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Low body mass index (BMI) is a strong prognostic marker in stable chronic obstructive pulmonary disease (COPD); however, little is known about its role in acute exacerbations of COPD.

OBJECTIVES

To determine the prevalence and determinants of low BMI in emergency department (ED) patients with acute exacerbations of COPD, and to examine whether low BMI was associated with more severe acute exacerbations, more intensive ED treatments and worse post-ED outcomes.

METHODS

A secondary analysis was performed using data from a prospective multicentre cohort study involving 29 ED in the USA and Canada. Using a standard protocol, ED patients with acute exacerbations of COPD were interviewed and their charts reviewed. BMI was calculated using self-reported weight and height. Main outcome measures included hospital admission, post-ED relapse and ongoing exacerbation.

RESULTS

395 patients were enrolled. Their median age was 69 years (interquartile range 62-76); 52% were women. Thirteen per cent (95% CI 10% to 16%) were underweight, 37% normal weight, 27% overweight and 23% were obese. Current smoking was independently associated with underweight (OR 5.4, 95% CI 1.1 to 25.2). In the propensity-matched cohort, there were no significant differences in severity of exacerbation, treatments received in the ED, or short-term clinical outcomes, according to BMI.

CONCLUSIONS

Low BMI is not uncommon in patients with acute exacerbations of COPD, and current smoking is associated with low BMI in these patients. Unlike its role in stable COPD, BMI appears to have little impact on exacerbation severity, treatments received in the ED, and short-term clinical outcomes in acute exacerbations of COPD.

Comparison of Canadian versus United States emergency department visits for chronic obstructive pulmonary disease exacerbation

INTRODUCTION

Despite the frequency of emergency department (ED) visits for chronic obstructive pulmonary disease (COPD) exacerbation, little is known about practice variation in EDs.

OBJECTIVES

To examine the differences between Canadian and United States (US) COPD patients, and the ED management they receive.

METHODS

A prospective multicentre cohort study was conducted involving 29 EDs in the US and Canada. Using a standard protocol, consecutive ED patients with COPD exacerbations were interviewed, their charts reviewed and a two-week telephone follow-up completed. Comparisons between Canadian and US patients, as well as their treatment and outcomes, were made. Predictors of antibiotic use were determined by multivariate logistic regression.

RESULTS

Of 584 patients who had physician-diagnosed COPD, 397 (68%) were enrolled. Of these, 63 patients (16%) were from Canada. Canadians were older (73 years versus 69 years; P=0.002), more often white (97% versus 65%; P<0.001), less educated (P=0.003) and more commonly insured (P<0.001) than the US patients. US patients more commonly used the ED for their usual COPD medications (17% versus 3%; P=0.005). Although Canadian patients had fewer pack-years of smoking (45 pack-years versus 53 pack-years; P=0.001), current COPD medications and comorbidities were similar. At ED presentation, Canadian patients were more often hypoxic and symptomatic. ED treatment with inhaled beta-agonists (approximately 90%) and systemic corticosteroids (approximately 65%) were similar; Canadians received more antibiotics (46% versus 25%; P<0.001) and other treatments (29% versus 11%; P=0.002). Admission rates were similar in both countries (approximately 65%), although Canadian patients remained in the ED longer than the US patients (10 h versus 5 h, respectively; P<0.001).

CONCLUSIONS

Overall, patients with acute COPD in Canada and the US appear to have similar history, ED treatment and outcomes; however, Canadian patients are older and receive more aggressive treatment in the ED. In both countries, the prolonged length of stay and high admission rate contribute to the ED overcrowding crisis facing EDs.

Weight loss and asthma: a systematic review

Epidemiological studies first demonstrated the association between obesity and asthma and they have begun to provide additional evidence to support causality: a dose-effect relationship, consistency across studies (especially among women) and the correct temporal order (ie, obesity before asthma). To date, relatively few studies have addressed reversibility, an important but less frequently demonstrated epidemiological criterion of causality. Reversibility suggests that if excessive weight is a risk factor for asthma, then reducing body weight should decrease the prevalence of asthma, or at least decrease asthma related symptoms or health care utilisation. We performed a systematic review on weight loss and asthma, based on searches between January 1966 and January 2007 of both PubMed and the Cochrane Clinical Trial Database. Of the 15 relevant studies, asthma was the primary outcome in only five. Only one study was conducted in children. Regardless of the type of intervention (surgical vs medical), all 15 studies noted an improvement in at least one asthma outcome after weight loss. The improvement was noted across studies that differed in sample age, gender or country of origin. The heterogeneity of the interventions and outcomes precluded quantitative synthesis. We briefly review the role of specific factors (eg, gastro-oesophageal reflux) in the weight loss-asthma association, and potential directions for future research.

Vitamin D levels and early mortality among incident hemodialysis patients

Vitamin D deficiency is associated with cardiovascular disease, the most common cause of mortality in hemodialysis patients. To investigate the relation between blood levels of 25-hydroxyvitamin D (25D) and 1,25-dihydroxyvitamin D (1,25D) with hemodialysis outcomes, we measured baseline vitamin D levels in a cross-sectional analysis of 825 consecutive patients from within a prospective cohort of incident US hemodialysis patients. Of these patients, 78% were considered vitamin D deficient with 18% considered severely deficient. Calcium, phosphorus, and parathyroid hormone levels correlated poorly with 25D and 1,25D concentrations. To test the association between baseline vitamin D levels and 90-day mortality, we selected the next 175 consecutive participants who died within 90 days and compared them to the 750 patients who survived in a nested case-control analysis. While low vitamin D levels were associated with increased mortality, significant interaction was noted between vitamin D levels, subsequent active vitamin D therapy, and survival. Compared to patients with the highest 25D or 1,25D levels who received therapy, untreated deficient patients were at significantly increased risk for early mortality. Our study shows that among incident hemodialysis patients, vitamin D deficiency is common, correlates poorly with other components of mineral metabolism and is associated with increased early mortality.

Headache in United States emergency departments: demographics, work-up and frequency of pathological diagnoses

Headache is a common complaint in the emergency department (ED). In order to examine headache work-ups and diagnoses across the USA, we queried a representative sample of adult ED visits (the National Hospital Ambulatory Medical Care Survey) for the years 1992-2001. Headache accounted for 2.1 million ED visits per year (2.2% of visits). Of the 14% of patients who underwent neuroimaging, 5.5% received a pathological diagnosis. Of the 2% of patients who underwent lumbar puncture, 11% received a pathological diagnosis. On multivariable analysis, a decreased rate of imaging was noted for patients without private insurance [odds ratio (OR) 0.61, confidence interval (CI) 0.44, 0.86] and for those presenting off-hours (OR 0.55, CI 0.39, 0.77). Patients over 50 were more likely to receive a pathological diagnosis (OR 3.3, CI 1.2, 9.3). In conclusion, clinicians should ensure that appropriate work-ups are performed regardless of presentation time or insurance status, and be vigilant in the evaluation of older patients.

Boys with high body masses have an increased risk of developing asthma: findings from the National Longitudinal Survey of Youth (NLSY)

OBJECTIVE

To determine the relation between body mass index and the development of asthma in children.

DESIGN

Prospective study of 4393 asthma-free children followed for up to 14 years.

SETTING

Children of participants in the National Longitudinal Survey of Youth.

METHODS

Analysis was limited to children who were followed from birth and were asthma-free during the first 24 months of life. The outcome was the development of asthma during follow-up (incident asthma). Body mass index (BMI) was our main predictor of interest. Survival analyses, using time to development of asthma as the main endpoint, were stratified by sex and controlled for race/ethnicity, poverty status, and prenatal maternal smoking.

RESULTS

Asthma developed in 218 (5.0 %) children during the follow-up period. The relation between BMI and incident asthma varied by sex. A BMI > or =85th percentile at age 2-3 years was a risk factor for subsequent asthma development in boys (hazard ratio (HR) 1.6 95% confidence interval (CI) 1.1, 2.4) but not girls (HR 0.8, 95% CI 0.5, 1.4). Similarly, boys with BMIs always > or =85th percentile were at increased risk for subsequent asthma development (HR 2.4, 95% CI 1.4, 4.4) but not girls (HR 1.5, 95% CI 0.7, 2.9).

CONCLUSION

Boys with high body masses may be at an increased risk for developing asthma.

Tiotropium for stable chronic obstructive pulmonary disease: A meta-analysis

BACKGROUND

A systematic review was undertaken to evaluate the efficacy of tiotropium, a long acting anticholinergic drug, on clinical events, symptom scales, pulmonary function, and adverse events in stable chronic obstructive pulmonary disease (COPD).

METHODS

A systematic search was made of the Cochrane trials database, MEDLINE, EMBASE, CINAHL, and a hand search of 20 respiratory journals. Missing data were obtained from authors and the manufacturer. Randomised controlled trials of > or =12 weeks' duration comparing tiotropium with placebo, ipratropium bromide, or long acting beta2 agonists (LABA) were reviewed. Studies were pooled to yield odds ratios (OR) or weighted mean differences with 95% confidence intervals (CI).

RESULTS

Nine trials (8002 patients) met the inclusion criteria. Tiotropium reduced the odds of a COPD exacerbation (OR 0.73; 95% CI 0.66 to 0.81) and related hospitalisation (OR 0.68; 95% CI 0.54 to 0.84) but not pulmonary (OR 0.50; 95% CI 0.19 to 1.29) or all-cause (OR 0.96; 95% CI 0.63 to 1.47) mortality compared with placebo and ipratropium. Reductions in exacerbations and hospitalisations compared with LABA were not statistically significant. Similar patterns were evident for quality of life and symptom scales. Tiotropium yielded greater increases in forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) from baseline to 6-12 months than did placebo, ipratropium, and LABA. Decline in FEV1 over 1 year was 30 ml (95% CI 7 to 53) slower with tiotropium than with placebo and ipratropium (data were not available for LABA). Reports of dry mouth and urinary tract infections were increased with tiotropium.

CONCLUSIONS

Tiotropium reduced COPD exacerbations and related hospitalisations, improved quality of life and symptoms, and may have slowed the decline in FEV1. Long term trials are warranted to evaluate the effects of tiotropium on decline in FEV1 and to clarify its role compared with LABA.

Association between leptin and asthma in adults

BACKGROUND

Leptin, a pro-inflammatory cytokine produced by adipose tissue, has previously been shown to be associated with asthma in children. We hypothesised that high serum leptin concentrations would also be associated with asthma in adults.

METHODS

The Third National Health and Nutrition Examination Survey is a cross sectional study that included fasting serum leptin concentrations and self-report of doctor diagnosed asthma. Data were analysed using multivariable logistic regression analysis.

RESULTS

Of 5876 participants, those with current asthma had a higher mean unadjusted leptin concentration than those who had never had asthma (geometric mean (SE) 9.2 (0.6) microg/l v 7.6 (0.2) microg/l; p = 0.02). After adjustment for triceps skinfold thickness and other covariates, the association between leptin and asthma appeared stronger in women than in men, and in premenopausal women than in postmenopausal women. Body mass index (BMI) was also associated with current asthma in women, but this association was not significantly affected by adjustment for leptin concentrations.

CONCLUSIONS

The results of this large population based study support the hypothesis that leptin is associated with asthma in women. In addition, while BMI also is related to asthma in women, this study does not support the suggestion that leptin contributes significantly to this association.

Relation between phase of the menstrual cycle and asthma presentations in the emergency department

BACKGROUND

The phase of the menstrual cycle is thought to influence the course of asthma in women. One recent study reported a large increase in exacerbations during the perimenstrual phase, while another found a preovulatory increase. A study was undertaken to determine the relation between phase of the menstrual cycle and acute asthma in patients presenting to the emergency department (ED).

METHODS

All women aged 18-54 years presenting with a diagnosis of acute asthma exacerbation were considered for enrollment in the study. Women who were pregnant, postmenopausal, following hysterectomy, with a >28 day menstrual cycle or incomplete reproductive history were excluded. The 792 eligible women were classified by menstrual phase based on both date of symptom onset and date of ED visit.

RESULTS

When classified by date of symptom onset, 28% were preovulatory (days 5 to 11), 25% were periovulatory (days 12 to 18), 21% were postovulatory (days 19 to 25), and 27% were perimenstrual (days 26 to 4; p = 0.03). When classified by date of ED visit, 28% were preovulatory, 22% were periovulatory, 22% were postovulatory, and 27% were perimenstrual (p = 0.004). Using either approach, there were no significant differences in demographic factors or in asthma severity of women in the various menstrual phase groups.

CONCLUSION

Acute asthma exacerbations do not markedly increase during the perimenstrual phase. The results support the suggestion that both preovulatory and perimenstrual phases are actual triggers of asthma exacerbation in some women, or that these two phases serve as "co-factors" that worsen other recognised triggers of acute asthma.

Results of 132 hepatectomies for living donor liver transplantation: report of one death

AIMS

Liver transplant is the primary therapy for patients with end-stage liver disease. Its high success rates have lead to a broadening of the indications for liver transplantation, resulting in an increasing shortage of donors. Living donor liver transplantation has become an option to overcome waiting list mortality. We describe our experience with hepatectomy for living donor liver transplantation and report a case of death.

METHODS

Patients (n = 132) underwent hepatectomy for living donor liver transplantation from June 2000 through June 2004. A 4-phase preoperative evaluation was performed on all patients, whose ages ranged from 13 to 54 years (mean = 29.7 +/- 8.1 years). Of the 132 patients, 76 patients (57.5%) underwent left lateral segmentectomy, 33 patients (25%) underwent left lobectomy, and 23 patients (16%) underwent right hepatectomy. In 2 other patients (1.5%), a monosegment (segment II) was obtained after left lateral segmentectomy.

RESULTS

Twenty patients (15%) experienced a complication, the most common being incisional hernia, pneumonia, and biliary fistulae. On the seventh postoperative day, 1 patient developed a fatal cerebral hemorrhage while recovering from mild liver dysfunction.

CONCLUSIONS

Although living donor liver transplantation is generally safe, serious and fatal complications may occur.

Polymorphisms in the interleukin 17F gene (IL17F) and asthma

Interleukin17F (IL17F) is a regulatory cytokine for T-cell-mediated immune responses. The gene coding for IL17F (IL17F) is located on chromosome 6p, a genomic region linked to asthma and asthma-related phenotypes in multiple genome scans. IL17F is expressed in lung tissue, in bronchoalveolar lavage fluid from asthmatic subjects, and in activated CD4+ cells. We were thus interested in testing for association between single-nucleotide polymorphisms (SNPs) and haplotypes in IL17F and asthma. To characterize polymorphisms in IL17F, we sequenced this gene in a group of African Americans and a group of European Americans. A total of 50 SNPs (30 not previously reported in a public database (dbSNP build 118)) and two insertions/deletions were detected in IL17F; five of these polymorphisms were genotyped in participants of the Nurses' Health Study. We then tested for association between SNPs and haplotypes in IL17F and physician-diagnosed asthma in subjects with (cases) and without (control subjects) physician-diagnosed asthma. None of the SNPs or haplotypes tested in IL17F were associated with asthma. The polymorphisms identified in this study may be used in future studies of association between IL17F and phenotypes related to immune responses.

Inhaled tiotropium for stable chronic obstructive pulmonary disease

BACKGROUND

Tiotropium is a new anticholinergic therapy for chronic obstructive pulmonary disease (COPD) that differs from ipratropium by its functional relative selectivity for muscarinic receptor subtypes and which allows once-per-day dosing.

OBJECTIVES

To determine the efficacy of tiotropium on clinical endpoints such exacerbations and hospitalisations, symptom scales and pulmonary function compared to placebo and other bronchodilators used for stable COPD.

SEARCH STRATEGY

Randomised controlled trials (RCTs) were identified from the Cochrane Airways Review Group Specialised Register, a compilation of systematic searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and CINAHL, and hand searching of 20 respiratory journals. Bibliographies from included studies and reviews were searched. The date of the last search was October 2004.

SELECTION CRITERIA

Randomised clinical trials comparing tiotropium with placebo, ipratropium bromide, or long-acting ss2-agonists for greater than, or equal to, one month's duration.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data. Missing data were obtained from authors or the manufacturer of tiotropium. The data were analysed using the Cochrane Review Manager RevMan 4.2. Studies were pooled to yield weighted mean differences (WMD) or odds ratios (OR) and reported using 95% confidence intervals (CI).

MAIN RESULTS

From 69 identified references, nine RCTs (6,584 patients) met inclusion criteria. Tiotropium reduced the odds of a COPD exacerbation (OR 0.74; 95% CI 0.66 to 0.83) and related hospitalisations (OR 0.64; 95% CI 0.51 to 0.82) compared to placebo or ipratropium. When applied to an annual baseline risk of 45% for exacerbations and 10% for hospitalisation, the number of patients needed to treat with tiotropium for one year were 14 (95% CI 11 to 22) to prevent one exacerbation and 30 (95% CI 22 to 61) to prevent one hospitalisation compared to placebo and ipratropium. Reductions in these endpoints compared to long-acting ss2-agonists were not statistically significant. Similar patterns were evident for quality-of-life and symptom scales. Increases in FEV1 and FVC from baseline were significantly larger with tiotropium than with placebo, ipratropium and long-acting ss2-agonists over 6 to 12 months. The decline in trough FEV1 from steady state was 30 ml (95% CI 7 to 53 ml) less with tiotropium than with placebo or ipratropium over one year; no data on decline in FEV1 from steady state were available for long-acting ss2-agonists. Dry mouth was increased by tiotropium.

AUTHORS' CONCLUSIONS

Tiotropium reduced COPD exacerbations and related hospitalisations compared to placebo and ipratropium. It also improved health-related quality-of-life and symptom scores among patients with moderate and severe disease, and may have slowed decline in FEV1. Additional long-term studies are required to evaluate its effect on mortality and change in FEV1 to clarify its role in comparison to, or in combination with, long-acting ss2-agonists and to assess its effectiveness in mild and very severe COPD.

Corticosteroid therapy for acute asthma

Asthma is a chronic inflammatory disease, which is characterised by reversible airflow obstruction in response to a variety of stimuli. Exacerbations in response to airway irritants are part of the natural history of asthma, but often they also represent a failure in chronic treatment. Presentations to emergency departments and other acute care settings are common and frequently lead to hospitalisation and other complications. After treatment, however, most patients are discharged to the care of their primary care physician for further management. This review highlights the role of systemic and inhaled corticosteroids as mainstays of treatment in the acute and sub-acute phase of an exacerbation. These agents form the basis of most current clinical practice guidelines, yet their use is not universal. We will review the evidence for the use of these agents that arises from the Cochrane Collaboration of Systematic Reviews contained in the Cochrane Library.