Prevalence of sleep apnea syndrome among Swedish men--an epidemiological study

The prevalence of the sleep apnea syndrome (SAS) among Swedish men 30-69 years old was estimated by a two-stage procedure. In the first stage, 4064 questionnaires were mailed to a random sample of a defined population in the municipality of Uppsala. The response rate was almost 80%; 15.6% of the responders were habitual snorers and 5.8% complained of daytime sleepiness. From these, a group of 166 men highly suspected of having SAS was selected. Eventually, 61 of these came for all-night polysomnographic studies, and 15 of these were found to have SAS. On this basis the lower limit of the prevalence of SAS was estimated to be as high as 1.3%. The majority of subjects with the syndrome were in the age group 50-59 years.     

Evidence for a discrete binding protein of plasminogen activator inhibitor in plasma

Gel-filtration experiments of mixtures of functionally active and inactive forms of plasminogen activator inhibitor (PAI) with human plasma or bovine serum albumin have provided evidence for the existence of a discrete binding protein of PAI in plasma. Most likely it is a glycoprotein with a molecular weight of approximately 150,000. The data suggest that it forms a very stable complex with functionally active forms of PAI, but not with the inactive or "latent" PAI. However, the PAI activity seems not to be significantly altered by the interaction with the binding protein. Assuming that a stoichiometric complex is formed, titration experiments suggest that a pool of normal human plasma contains about 40-50 mg of PAI-binding protein liter.     

Design and subjects of a Finnish epidemiological study on psychiatric disorders in childhood

In an epidemiological multi-centre study, parents filled in the Rutter Parent Questionnaire (RA2) and teachers filled in the Rutter Teacher Questionnaire (RB2) for almost 6000 children. The children filled in the Children's Depression Inventory (CDI). The subjects well represented the entire population of 8-9-year-old children in Finland. The material and design of the study as well as the basic demographic characteristics are presented.     

Four-year course of teacher-reported internalising, externalising and comorbid syndromes in preadolescent children

The aim of this study was to elucidate the nature of comorbidity between internalising and externalising syndromes and its meaning in the course of these syndromes from 8 to 12 years of age in a school setting. The children in the cohort (N = 1320) were born in 1981. They were first surveyed in second grade (N = 1284) and followed up in sixth grade (N = 906). Teachers were the informants, and the study was carried out by means of a questionnaire. Data from both points of time were available on 861 subjects. The Rutter Teacher Questionnaire (RB2) measured behavioural and emotional symptoms at Time 1, and the Teacher Report Form (TRF) at Time 2. Comorbidity was more prevalent in boys than girls. Childhood comorbidity predicted externalising syndrome and comorbidity, but not internalising syndrome in early adolescence. It changed the course of boys' internalising syndromes to an externalising direction over time. The data suggest a gender difference in the pattern of comorbidity. When comorbidity was partialled out, it was very rare for internalising and externalising syndromes to develop into contrasting syndromes over time. The recovery rate for childhood comorbidity was poor. Special attention should be paid to making schools recognise and help these children.     

Developments in the field of allergy in 2008 through the eyes of Clinical & Experimental Allergy

In 2008, many thousands of articles were published on the subject of allergic disease with over 200 reviews, editorials and original papers in Clinical & Experimental Allergy alone. These represent a considerable amount of data and even the most avid reader could only hope to assimilate a small fraction of this knowledge. There is therefore a pressing need for the key messages that emerge from a journal such as Clinical & Experimental Allergy to be summarized by experts in the field in a form that highlights the significance of the developments and sets them in the context of important findings in the field published in other journals. This also has the advantage of making connections between new data in conditions such as asthma, where articles often appear in different sections of the journal. As can be seen from this review, the body of work is diverse both in terms of the disease of interest and the discipline that has been used to investigate it. However, taken as a whole, we hope that the reader will gain a flavour of where the field is mature, where there remain controversies and where the cutting edge is leading.     

Bone mineral density in primary care patients related to serum calcium concentrations: a longitudinal cohort study from Sweden

Objective: Elevated calcium concentration is a commonly used measure in screening analyses for primary hyperparathyroidism (pHPT) and cancer. Low bone mineral density (BMD) and osteoporosis are common features of pHPT and strengthen the indication for parathyroidectomy. It is not known whether an elevated calcium concentration could be a marker of low BMD in suspected pHPT patients with a normal parathyroid hormone concentration.

Purpose: To study if low BMD and osteoporosis are more common after ten years in patients with elevated compared with normal calcium concentrations at baseline.

Design: Prospective case control study.

Setting: Primary care, southern Sweden.

Subjects: One hundred twenty-seven patients (28 men) with baseline elevated, and 254 patients (56 men) with baseline normal calcium concentrations, mean age 61 years, were recruited. After ten years, 77% of those still alive (74 with elevated and 154 with normal calcium concentrations at baseline) participated in a dual energy x-ray absorptiometry measurement for BMD assessment and analysis of calcium and parathyroid hormone concentrations.

Main outcome measures: Association between elevated and normal calcium concentration at base-line and BMD at follow-up. Correlation between calcium and parathyroid hormone concentrations and BMD at follow-up.

Results: A larger proportion of the patients with elevated baseline calcium concentrations who participated in the follow-up had osteoporosis (p value?=?0.036), compared with the patients with normal concentrations. In contrast, no correlation was found between calcium or parathyroid hormone concentrations and BMD at follow-up.

Conclusions: In this study, patients with elevated calcium concentrations at baseline had osteoporosis ten years later more often than controls (45% vs. 29%), which highlights the importance of examining these patients further using absorptiometry, even when their parathyroid hormone level is normal.

• Key Points

• Osteoporosis is common, difficult to detect and usually untreated. It is not known whether elevated calcium concentrations, irrespective of the PTH level, could be a marker of low bone mineral density.

• No correlation was found between calcium or parathyroid hormone concentrations and bone mineral density at follow-up.

• In this study, patients with elevated calcium concentrations at baseline had osteoporosis ten years later more often than controls (45% vs. 29%).

     

Seasonal trends in house dust mite allergen in children's beds over a 7-year period

BACKGROUND: House dust mite (HDM) allergy is closely linked to the expression of asthma and other allergic diseases. Understanding factors influencing variation in allergen may help in controlling allergic disease. The objective of this study was to investigate the effects of seasonal changes in climate, type of bed used in very early childhood and anti-mite interventions on HDM allergen concentration. METHODS: Participants were enrolled in a randomized-controlled trial of HDM avoidance. Der p 1 was measured in dust samples from children's beds on 13 occasions, from birth to age 5 years, between 1997 and 2004. Bed types were categorized as bassinette, cot or bed. The effects of study month, type of bed and intervention group on HDM allergen concentration were estimated by multiple linear regression. The relation between climatic variables and HDM allergen concentration was investigated using a polynomial distributed lag model. RESULTS: House dust mite allergen concentrations were initially low in cots and bassinettes in 1997/1998, peaked in bassinettes and beds between 1999 and 2001 and then slowly declined during the period 2002/2004. Seasonal fluctuations occurred with minima in summer and two- to threefold higher maxima during late autumn. Allergen peaks were correlated with relative humidity peaks 2 months previously. Seasonal changes in allergen were not affected by the HDM avoidance intervention. CONCLUSIONS: House dust mite allergen concentrations in Sydney beds fluctuate approximately two- to threefold on an annual cycle, partly determined by relative humidity, with peaks in late autumn and minima in summer. Fluctuations of this magnitude might be sufficient to influence asthma symptoms.