Anxiety symptoms and associated functional impairment in children with CHD in a neurodevelopmental follow-up clinic.

OBJECTIVES: To examine the prevalence of anxiety symptoms and associated functional impairment to adaptive skills among elementary-aged children with CHD and to determine the need for anxiety screening in this high-risk population. STUDY DESIGN: In a single-centre retrospective, cohort design, caregivers reported anxiety symptoms using Conner's scales and functional impairment to adaptive skills using the Adaptive Behavior Assessment System. A total of 194 children were stratified across two cohorts: early elementary (ages 3-6 years) and late elementary (ages 6-14 years). Descriptive statistics summarised the frequency of anxiety symptoms and functional impairment. Spearman's correlations compared anxiety symptoms to functional impairment of adaptive functioning. Univariable logistic regressions examined demographic and clinical characteristics associated with anxiety symptoms. RESULTS: The majority of patients presented with anxiety, early elementary (63%), and late elementary cohorts (78%). Functional impairment was moderately correlated with anxiety symptoms in the early elementary cohort (rs = -.42, 95% CI [-0.58, -0.21], p = <.001). Greater anxiety symptoms were associated with lower cardiac complexity at primary age of surgery in the late elementary cohort (OR = 12.15, p = 0.019). Lesser anxiety symptoms were associated with having private insurance (OR = 0.25, p = 0.014). CONCLUSION: This study demonstrates anxiety symptoms are common and associated with functional impairment to adaptive functioning in younger children with CHD. No clear clinical predictors exist for anxiety symptoms or functional impairment; therefore, screening for anxiety symptoms may need to be added to standard clinical assessment of all children with CHD participating in neurodevelopmental follow-up.

Diagnostic Accuracy of Tests for Polyuria in Lithium-Treated Patients.

In lithium-treated patients, polyuria increases the risk of dehydration and lithium toxicity. If detected early, it is reversible. Despite its prevalence and associated morbidity in clinical practice, it remains underrecognized and therefore undertreated. The 24-hour urine collection is limited by its convenience and practicality. This study explores the diagnostic accuracy of alternative tests such as questionnaires on subjective polyuria, polydipsia, nocturia (dichotomous and ordinal responses), early morning urine sample osmolality (EMUO), and fluid intake record (FIR). This is a cross-sectional study of 179 lithium-treated patients attending a general adult and an old age psychiatry service. Participants completed the tests after completing an accurate 24-hour urine collection. The diagnostic accuracy of the individual tests was explored using the appropriate statistical techniques. Seventy-nine participants completed all of the tests. Polydipsia severity, EMUO, and FIR significantly differentiated the participants with polyuria (area under the receiver operating characteristic curve of 0.646, 0.760, and 0.846, respectively). Of the tests investigated, the FIR made the largest significant change in the probability that a patient experiences polyuria (<2000 mL/24 hours; interval likelihood ratio, 0.18 and >3500 mL/24 hours; interval likelihood ratio, 14). Symptomatic questioning, EMUO, and an FIR could be used in clinical practice to inform the prescriber of the probability that a lithium-treated patient is experiencing polyuria.

Risk factors for polyuria in a cross-section of community psychiatric lithium-treated patients.

OBJECTIVES: Polyuria increases the risk of dehydration and lithium toxicity in lithium-treated patients. Risk factors have been inconsistently described and the variance of this adverse effect remains poorly understood. This study aimed to establish independent risk factors for polyuria in a community, secondary-level lithium-treated sample of patients. METHODS: This was a cross-sectional study of the lithium-treated patients attending a general adult and an old age psychiatry service. Participants completed a 24-hour urine collection. Urine volume and the presence of polyuria were the outcomes of interest. The relationship between outcome and the participant's demographic and clinical characteristics was explored with univariable and multivariable analysis. RESULTS: A total of 122 participants were included in the analysis, with 38% being diagnosed with polyuria. Female gender and increased body weight independently predicted the presence of polyuria (standardized regression coefficient 1.01 and 0.94, respectively; p = 0.002 and p = 0.003, respectively). Female gender and increased body weight, lithium dose, and duration of lithium treatment independently predicted higher 24-hour urine volumes (standardized regression coefficients 0.693, p < 0.0005; 0.791, p < 0.0005; 0.276, p = 0.043; 0.181, p = 0.034, respectively). Of three different weight metrics, lean body weight was the most predictive. CONCLUSIONS: Female gender and increased body weight explain part of the variance of this adverse effect. Both risk factors offer fresh insights into the pathophysiology of this potentially reversible and dangerous adverse effect of lithium treatment. Future research should focus on understanding the differences between the genders and between different body compositions in terms of lithium pharmacokinetics and pharmacodynamics.

Association of genetic and sulcal traits with executive function in congenital heart disease.

OBJECTIVE: Persons with congenital heart disease (CHD) are at increased risk of neurodevelopmental disabilities, including impairments to executive function. Sulcal pattern features correlate with executive function in adolescents with single-ventricle heart disease and tetralogy of Fallot. However, the interaction of sulcal pattern features with genetic and participant factors in predicting executive dysfunction is unknown. METHODS: We studied sulcal pattern features, participant factors, and genetic risk for executive function impairment in a cohort with multiple CHD types using stepwise linear regression and machine learning. RESULTS: Genetic factors, including predicted damaging de novo or rare inherited variants in neurodevelopmental disabilities risk genes, apolipoprotein E genotype, and principal components of sulcal pattern features were associated with executive function measures after adjusting for age at testing, sex, mother's education, and biventricular versus single-ventricle CHD in a linear regression model. Using regression trees and bootstrap validation, younger participant age and larger alterations in sulcal pattern features were consistently identified as important predictors of decreased cognitive flexibility with left hemisphere graph topology often selected as the most important predictor. Inclusion of both sulcal pattern and genetic factors improved model fit compared to either alone. INTERPRETATION: We conclude that sulcal measures remain important predictors of cognitive flexibility, and the model predicting executive outcomes is improved by inclusion of potential genetic sources of neurodevelopmental risk. If confirmed, measures of sulcal patterning may serve as early imaging biomarkers to identify those at heightened risk for future neurodevelopmental disabilities.

Association of Potentially Damaging De Novo Gene Variants With Neurologic Outcomes in Congenital Heart Disease.

Importance: Neurodevelopmental disabilities are commonly associated with congenital heart disease (CHD), but medical and sociodemographic factors explain only one-third of the variance in outcomes. Objective: To examine whether potentially damaging de novo variants (dDNVs) in genes not previously linked to neurodevelopmental disability are associated with neurologic outcomes in CHD and, post hoc, whether some dDNVs or rare putative loss-of-function variants (pLOFs) in specific gene categories are associated with outcomes. Design, Setting, and Participants: This cross-sectional study was conducted from September 2017 to June 2020 in 8 US centers. Inclusion criteria were CHD, age 8 years or older, and available exome sequencing data. Individuals with pathogenic gene variants in known CHD- or neurodevelopment-related genes were excluded. Cases and controls were frequency-matched for CHD class, age group, and sex. Exposures: Heterozygous for (cases) or lacking (controls) dDNVs in genes not previously associated with neurodevelopmental disability. Participants were separately stratified as heterozygous or not heterozygous for dDNVs and/or pLOFs in 4 gene categories: chromatin modifying, constrained, high level of brain expression, and neurodevelopmental risk. Main Outcomes and Measures: Main outcomes were neurodevelopmental assessments of academic achievement, intelligence, fine motor skills, executive function, attention, memory, social cognition, language, adaptive functioning, and anxiety and depression, as well as 7 structural, diffusion, and functional brain magnetic resonance imaging metrics. Results: The study cohort included 221 participants in the post hoc analysis and 219 in the case-control analysis (109 cases [49.8%] and 110 controls [50.2%]). Of those 219 participants (median age, 15.0 years [IQR, 10.0-21.2 years]), 120 (54.8%) were male. Cases and controls had similar primary outcomes (reading composite, spelling, and math computation on the Wide Range Achievement Test, Fourth Edition) and secondary outcomes. dDNVs and/or pLOFs in chromatin-modifying genes were associated with lower mean (SD) verbal comprehension index scores (91.4 [20.4] vs 103.4 [17.8]; P = .01), Social Responsiveness Scale, Second Edition, scores (57.3 [17.2] vs 49.4 [11.2]; P = .03), and Wechsler Adult Intelligence Scale, Fourth Edition, working memory scores (73.8 [16.4] vs 97.2 [15.7]; P = .03), as well as higher likelihood of autism spectrum disorder (28.6% vs 5.2%; P = .01). dDNVs and/or pLOFs in constrained genes were associated with lower mean (SD) scores on the Wide Range Assessment of Memory and Learning, Second Edition (immediate story memory: 9.7 [3.7] vs 10.7 [3.0]; P = .03; immediate picture memory: 7.8 [3.1] vs 9.0 [2.9]; P = .008). Adults with dDNVs and/or pLOFs in genes with a high level of brain expression had greater Conners adult attention-deficit hyperactivity disorder rating scale scores (mean [SD], 55.5 [15.4] vs 46.6 [12.3]; P = .007). Conclusions and Relevance: The study findings suggest neurodevelopmental outcomes are not associated with dDNVs as a group but may be worse in individuals with dDNVs and/or pLOFs in some gene sets, such as chromatin-modifying genes. Future studies should confirm the importance of specific gene variants to brain function and structure.

Ratings of Physician Communication by Caregivers of Hospitalized Children With and Without Autism.

BACKGROUND AND OBJECTIVES: To investigate caregivers' perceptions of physician communication and hospital ratings for hospitalized children with and without autism and assess associations between perceived quality of physician communication and overall ratings of the hospital. METHODS: We studied survey data from caregivers of 543 patients with autism compared with a 2:1 matched control sample of 1086 patients with similar characteristics but without autism from a single children's hospital. We analyzed survey items related to physician communication and hospital ratings from the Consumer Assessment of Healthcare Physicians and Systems Child Hospital Survey. We constructed multivariable regression models to examine the relationship between caregiver-perceived physician communication and caregivers' overall ratings of the hospital. RESULTS: A similar proportion of caregivers of children with and without autism reported that doctors "always" listened carefully to them (71.4% vs 74.3%; adjusted prevalence ratio 0.96; 95% confidence interval 0.90-1.03) and "always" treated them with respect (80.0% vs 84.1%; adjusted prevalence ratio 0.95; 95% confidence interval 0.90-1.00). Caregivers of children with autism were less likely to "definitely" recommend the hospital (87.0% vs 92.3%; adjusted prevalence ratio 0.94; 95% confidence interval 0.91-0.98). All items related to caregiver-perceived physician communication were associated with the highest hospital rating and the highest recommendation of the hospital in both groups. CONCLUSIONS: When matched on the basis of medical and social factors, caregivers of children with and without autism reported similar frequencies of highest-quality physician communication. Improvement of physician communication with caregivers of medically and socially complex children with and without autism may improve caregivers' overall ratings of the hospital.

A Review: The Prospect of Inhaled Insulin Therapy via Vibrating Mesh Technology to Treat Diabetes.

Background: Inhaled insulin has proven to be viable and, in some aspects, a more effective alternative to subcutaneous insulin. Past and present insulin inhaler devices have not found clinical or commercial success. Insulin inhalers create a dry powder or soft mist insulin aerosol, which does not provide the required uniform particle size or aerosol volume for deep lung deposition. Methods: The primary focus of this review is to investigate the potential treatment of diabetes with a wet insulin aerosol. Vibrating mesh nebulisers allow the passive inhalation of a fine wet mist aerosol for the administration of drugs to the pulmonary system in higher volumes than other small-volume nebulisers. Results: At present, there is a significant focus on vibrating mesh nebulisers from the pharmaceutical and biomedical industries for the systemic administration of pharmaceuticals for non-traditional applications such as vaccines or the treatment of diabetes. Systemic drug administration using vibrating mesh nebulisers leads to faster-acting pharmaceuticals with a reduction in drug latency. Conclusions: Systemic conditions such as diabetes, require the innovative development of custom vibrating mesh devices to provide the desired flow rates and droplet size for effective inhaled insulin administration.

A study of the relationship between albuminuria, proteinuria and urinary reagent strips.

BACKGROUND: The aims of this study were to examine the relationship between proteinuria and albuminuria and to assess the equivalence between the albumin to creatinine ratio (ACR) and the protein to creatinine ratio (PCR) at the cut-offs recommended by the National Institute for Health and Clinical Excellence (NICE) guidance on chronic kidney disease. The sensitivity and specificity of the reagent strips used in our laboratory for the detection of clinical proteinuria was also assessed. METHODS: Urine samples (n = 117) were screened for protein using the Bayer Multistix 10SG and read manually. Urinary total protein and creatinine was measured on the Roche P Modular by the benzethonium chloride and kinetic Jaffe methods, respectively. Urinary albumin was measured by immunoturbidimetry on the Roche Cobas Mira. RESULTS: The relationship between urinary protein and albumin loss was non-linear (P < 0.05). As urinary protein loss increased the percentage of albumin to total protein increased. At the NICE guidance recommended cut-offs for clinical proteinuria (ACR > or =30 mg/mmol and PCR > or =50 mg/mmol) there was one discordant result between ACR and PCR (ACR <30 mg/mmol and PCR >50 mg/mmol). The Bayer Multistix 10SG had a sensitivity and specificity of 97% and 62%, respectively, for the detection of clinical proteinuria compared with ACR. CONCLUSIONS: The proportion of urinary total protein attributable to albumin changes with concentration. There was only one discordant result between ACR and PCR: therefore either ratio may be used for the identification of clinical proteinuria. As a screening test for proteinuria, the Bayer Multistix 10SG had an acceptable sensitivity but poor specificity.

Parenting and social functioning of children with and without cerebral palsy.

OBJECTIVE: To examine the associations between parenting dimensions and the social functioning of children with and without cerebral palsy (CP). The primary hypothesis was that controlling for cognitive ability, specific parenting dimensions would be associated with higher social functioning, including larger social networks, higher-quality friendships, and healthier social adjustment in children with and without CP. PARTICIPANTS: Forty-one children with cerebral palsy and 60 typically developing (TD) children, ages 6 to 12. MEASURES: Parenting Dimensions Inventory; Social Network Inventory for Children, Friendship Quality Questionnaire, Personality Inventory for Children-Second Edition, WISC-III Vocabulary. RESULTS: Bivariate associations revealed that cognitive ability was associated with social functioning in both groups. In the group with CP, controlling for cognitive ability, parenting dimensions were not associated with social functioning, in contrast with findings in the TD sample. CONCLUSIONS: Findings suggest different parenting influences on the social development of children with and without CP. Theoretical and methodologic implications are discussed.

The biologic variability of B-type natriuretic peptide and N-terminal pro-B-type natriuretic peptide in stable heart failure patients.

BACKGROUND: There are conflicting data on the usefulness of B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) in the optimization of therapy for heart failure (HF). Discordant results may be explained by the intra-individual variability of these peptides. This study evaluates the intraindividual variability of BNP and NT-proBNP and the impact of the covariates of age, sex, and renal function. METHODS AND RESULTS: Stable HF patients attending our unit were included. Blood samples were drawn 1 hour apart on 2 occasions 1 week apart. Forty-five patients were enrolled (69.6 +/- 12.1 years, 64% male, 84% systolic HF). Within-hour and within-week intraindividual variability were: 6.9% and 21.1% for NT-proBNP; 14.6% and 28.4% for BNP (P < .01 for within-hour comparison of BNP and NT-proBNP). Reference change values over 1 week for NT-proBNP and BNP were 49.2% and 66.2%, respectively. There were no significant relationships identified between variability and age, gender, or glomerular filtration rate. CONCLUSION: There is considerable intraindividual variability in these peptides in stable HF patients. Changes of approximately 50% and 66% for NT-proBNP and BNP from week to week are needed to indicate an altered clinical status and caution should be exercised in interpreting serial changes in these peptide levels when monitoring patient responses to treatment or clinical status.

Challenging Case of Parotitis: A Comprehensive Approach.

The diagnosis and management of parotitis can be challenging. Patients often present with pain and edema in the neck, jaw, head, and ear due to congestion of the gland. Parotitis is typically caused by an infection within the parotid gland and surrounding lymph nodes, and the infection can spread to nearby cervical fascial planes and cause major complications if not managed successfully. Specific guidelines for the outpatient management of parotitis are limited, and outpatient treatment failures are common, requiring inpatient therapy with multiple broad-spectrum antibiotics. In the current case, a comprehensive patient-centered approach was used to treat a woman whose overlapping clinical conditions, lifestyle, and work factors led to an infection of the parotid gland.

Evaluation of the albumin cobalt binding (ACB) assay for measurement of ischaemia-modified albumin (IMA) on the Beckman Coulter LX-20.

BACKGROUND: In the presence of ischaemia, albumin undergoes changes resulting in the formation of ischaemia-modified albumin (IMA). Increased serum concentrations of IMA have been found in patients with myocardial ischaemia. The purpose of this study was threefold: to evaluate the albumin cobalt binding (ACB) assay for measurement of IMA on the Beckman Coulter LX-20; to establish a reference range for IMA; and to investigate the relationship between IMA and total albumin concentrations. METHODS: The ACB assay was evaluated under the following headings: imprecision, accuracy and reliability. A reference range was established on a population of 81 healthy subjects. RESULTS: The within-batch coefficient of variation (CV) at IMA concentrations of 88, 99 and 120 KU/L were 1.4, 2.0 and 2.5%, respectively. The between-batch CVs at 74, 84 and 123 KU/L were 3.4, 3.3 and 3.0%, respectively. Comparison with the Cobas Mira Plus showed a mean negative bias of 7 KU/L. The 97.5th percentile established on our reference population was 110 KU/L. A significant inverse relationship was found between total serum albumin and IMA concentrations (r = -0.66, P < 0.0001). Correcting the IMA concentrations for total albumin in our reference population, using a formula devised in this study, yielded a range similar to that of uncorrected IMA. CONCLUSIONS: The ACB assay was found to have acceptable precision and performed very satisfactorily on the Beckman Coulter LX-20. A correction to measured IMA concentrations, to take into account total albumin concentrations, may need to be applied for the proper interpretation of IMA results.

Differential production of adrenal steroids by purified cells of the human adrenal cortex is relative rather than absolute.

OBJECTIVES: The adrenal cortex produces aldosterone, cortisol and androgens in response to ACTH and angiotensin II. To define the differential response of morphologically distinct cells of the adrenal cortex, we examined the phenotypical and functional characteristics of human adrenocortical cells. RESULTS: Tumour growth factor-beta receptor-1 (TGFbeta-R1) and CYP-11 were found to be expressed predominantly in the zona fasciculata, whereas human leukocyte antigen (HLA-DR) and CYP-17 were localised to the zona reticularis. The angiotensin II receptor, AT-1, was found to be predominantly expressed in the zona glomerulosa. Adrenocortical cells, separated by density, yielded two distinct fractions which displayed differential growth patterns. Lipid-rich cells of fraction I expressed TGFbeta-R1 and produced significantly more cortisol relative to androstenedione than unseparated or fraction II cells, whereas lipid-poor cells of fraction II expressed HLA-DR and produced more androstenedione relative to cortisol in the presence of ACTH. Aldosterone production by fraction II was significantly greater than fraction I or unseparated cells. TGFbeta-R1-positive fasciculata-type cells separated into fraction I and HLA-DR-positive cells consistent with reticularis cells separated into fraction II. Aldosterone-producing cells indicative of glomerulosa cells separated into fraction II. CONCLUSIONS: Our findings are consistent with the concept that all adrenocortical cells are capable of producing a range of steroids, but the relative production of cortisol, androgen and aldosterone differs.

The association of foot arch posture and prior history of shoulder or elbow surgery in elite-level baseball pitchers.

STUDY DESIGN: Case-control. OBJECTIVES: The specific aim of this study was to examine the association between abnormal foot arch postures and a history of shoulder or elbow surgery in baseball pitchers. BACKGROUND: Pitching a baseball generates forces throughout the musculoskeletal structures of the upper and lower limbs. Structures such as the longitudinal arch of the foot are adaptable to stresses over time. Repeated pitching-related stresses may contribute to acquiring abnormal foot arch postures. Inversely, congenitally abnormal foot arch posture may lead to altered stresses of the upper limb during pitching. METHODS: A convenience sample of 77 pitchers was recruited from a Division I university team and a professional baseball franchise. Subjects who had a history of shoulder or elbow surgery to the pitching arm were classified as cases. Subjects who met the criteria for classification of pes planus or pes cavus based on longitudinal arch angle were classified as having abnormal foot arch posture. Odds ratios were calculated to examine the association between abnormal foot arch posture and pitching-arm injury requiring surgery. RESULTS: Twenty-three subjects were classified as cases. The odds of being a case were 3.4 (95% confidence interval: 1.2, 9.6; P = .02) times greater for subjects with abnormal foot arch posture and 2.9 (95% confidence interval: 1.0, 8.1; P = .04) times greater for subjects with abnormal foot posture on the lunge leg. CONCLUSION: Abnormal foot arch posture and a surgical history in the pitching shoulder or elbow may be associated. Because the foot and its arches are adaptable and change over time, the pathomechanics of this association should be further explored.

Glenohumeral findings on magnetic resonance imaging correlate with innings pitched in asymptomatic pitchers.

BACKGROUND: In recent years, there has been a documented increase in the number of professional baseball players on the disabled list and the total number of days on the disabled list. Pitchers account for the largest number of disabled list reports. PURPOSE: To examine the relationship between magnetic resonance imaging (MRI) findings in asymptomatic professional pitchers and subsequent time on the disabled list (DL). STUDY DESIGN: Cohort study (Prognosis); Level of evidence, 2. METHODS: A total of 21 asymptomatic professional pitchers from a single Major League Baseball (MLB) organization underwent preseason MRIs of their dominant shoulder from 2001 to 2010. Asymptomatic was defined as no related DL stays in the 2 seasons before the MRI. These studies were reevaluated by a fellowship-trained musculoskeletal radiologist who was blinded to patient name, injury history, and baseball history. A second investigator who was blinded to the MRI results collected demographic data, total career number of innings pitched, and any subsequent DL reports for each subject. RESULTS: The mean age at the time of MRI was 29.04 years (range, 20-39 years). Eleven of 21 pitchers had a rotator cuff tear (RCT): 9 had an articular surface tear (AST), and 2 had a full-thickness rotator cuff tear (FTT). Ten had superior labral anterior posterior (SLAP) tears, and 13 had either anterior or posterior labral tears. There was a statistically significant relationship between the number of innings pitched and presence of an RCT (AST + FTT). The mean number of career innings pitched by those with an RCT was 1014 compared with a mean of 729 innings pitched in pitchers without an RCT (P < .01). In addition, the number of career innings pitched was moderately correlated with presence of RCT (r = 0.46) and presence of superior and anterior/posterior labral tears (r = 0.43). There were no statistically significant findings between any single preseason MRI finding and subsequent time on the DL. CONCLUSION: The MRI findings in asymptomatic MLB pitchers do not appear to be related to near future placement on the DL. However, there was a significant difference in numbers of innings pitched between pitchers who had an RCT and those who did not and a moderate correlation between innings pitched and the presence of RCT as well as the presence of labral lesions. This finding supports the notion that RCT and labral injury in pitchers may result from repetitive overhead motion with subsequent strain on the rotator cuff tendons and glenoid labrum. Asymptomatic shoulder lesions in professional baseball pitchers appear to be more frequent than previously thought.

The diagnosis and investigation of adrenal insufficiency in adults.

There is considerable variation in the methods used to diagnose and investigate adrenal insufficiency in clinical practice. These include a range of adrenocorticotropin (ACTH) stimulation and other dynamic testing protocols, serum cortisol cut-off values for diagnosis and tests used for differential diagnosis. With the introduction of modern cortisol and ACTH assays, the interpretation of tests used for diagnosis and differential diagnosis has become more complex and requires local validation. This review examines the basis of normal hypothalamic-pituitary-adrenal axis function and adrenal insufficiency states based upon an evidence base accumulated over the past four decades. The role of the laboratory in the differential diagnosis and interpretation based upon assay methodology is discussed. The accurate identification of patients who may benefit from corticosteroid replacement in special settings such as critical illness is challenging and will be explored.

Cardiovascular risk markers in obstructive sleep apnoea syndrome and correlation with obesity.

BACKGROUND: High C-reactive protein (CRP) and homocysteine levels are risk factors for cardiovascular disease. Some, but not all, previous studies have reported increased levels of CRP and homocysteine in patients with obstructive sleep apnoea syndrome (OSAS). A study was undertaken to investigate the levels of these factors in carefully selected patients with OSAS and matched normal controls. METHODS: CRP and homocysteine levels were measured in 110 subjects following polysomnography (PSG). Non-OSAS patients (group 1) were compared with two patient groups (mild/moderate OSAS (group 2) and severe OSAS (group 3)) group-matched for body mass index (BMI), and a fourth group of patients with severe OSAS who were more obese (group 4). All were free of other disease and similar in age, smoking habits and cholesterol levels. 50 suitable patients were commenced on continuous positive airway pressure (CPAP) treatment after PSG and 49 were reassessed 6 weeks later. RESULTS: CRP levels were similar in groups 1, 2 and 3 (median (interquartile range (IQR)) 1.11 (0.76-2.11) mg/l vs 1.82 (1.20-3.71) mg/l vs 2.20 (1.16-3.59) mg/l; p=0.727, Kruskal-Wallis test), but were significantly higher in group 4 than in the other groups (5.36 (2.42-9.17) mg/l, p<0.05 by individual group comparisons). In multivariate analysis of all subjects, BMI was an independent predictor for CRP levels (beta=0.221; p=0.006) but apnoea-hypopnoea index and other measures of OSAS were not. There was no difference in homocysteine levels between all four groups (p=0.1). CPAP did not alter CRP (2.29 (1.32-4.10) vs 2.84 (1.13-5.40) mg/l; p=0.145) or homocysteine levels (8.49 (3.66) vs 9.90 (4.72) micromol/l; p=0.381). CONCLUSION: CRP and homocysteine levels are not associated with OSAS severity in men but CRP is independently associated with obesity.

Evaluation of three different specimen types (serum, plasma lithium heparin and serum gel separator) for analysis of certain analytes: clinical significance of differences in results and efficiency in use.

BACKGROUND: There is a lack of consensus regarding the most appropriate specimen type for analysis of many biochemistry analytes. The aim of this study was to compare renal and lipid analyte profiles and phenytoin values in plain serum (S), serum gel (G) and plasma (lithium heparin, P) tubes and to investigate the stability of these analytes after prolonged contact with cells or gel at room temperature (RT, 20 degrees C) and as aliquoted and stored at 4 degrees C. METHODS: Primary specimens were centrifuged once, maintained at RT and analysed within 2 h (T(0)) and after 24 h (T(24)) and 48 h (T(48)). For assessment of stability at 4 degrees C, two cell-free aliquots were separated from each of the primary tubes and stored at 4 degrees C and then analysed at T(24) and T(48). Differences in analyte concentrations between tubes at T(0) and following storage (at T(24) and T(48)) were evaluated for both statistical and clinical significance. RESULTS: At T(0) all analytes, except potassium, demonstrated equivalence between serum, gel and plasma tubes. Potassium and creatinine were more stable in gel tubes than in serum/plasma tubes. In contrast, phentytoin was stable in plain serum and plasma up to T(48) at RT, but showed a progressive and clinically significant decrease in concentration in gel tubes at T(24) and T(48) at RT. All analytes except CO(2) were stable up to T(48) when aliquoted and stored at 4 degrees C. CONCLUSIONS: We concluded that the serum gel tube has advantages over plain serum and plasma tubes for measurement of the analytes investigated in this study, with the exception of phenytoin. In practice, the gel tubes demonstrate enhanced analyte stability and reduce the need to aliquot specimens, with greater protection against possible contamination. Further investigation would be required to evaluate a broader range of analytes.