Lower levels of plasma 25-hydroxyvitamin D among young adults at diagnosis of autoimmune type 1 diabetes compared with control subjects: results from the nationwide Diabetes Incidence Study in Sweden (DISS)

AIMS/HYPOTHESIS

Low plasma vitamin D concentrations may promote the development of type 1 diabetes. To test this hypothesis, we measured plasma 25-hydroxyvitamin D (25OHD) in young adults with type 1 diabetes.

METHODS

The nationwide Diabetes Incidence Study in Sweden (DISS) covers 15- to 34-year-old people with newly diagnosed diabetes. Blood samples at diagnosis were collected during the 2-year period 1987/1988. Patients with islet antibodies (islet cell antibodies, GAD antibodies or tyrosine phosphatase-like protein antibodies) were defined as having autoimmune type 1 diabetes. Plasma 25OHD was measured in samples taken from 459 patients at the time of diagnosis, and in 138 of these subjects 8 years later. The results were compared with age- and sex-matched control subjects (n=208).

RESULTS

At diagnosis, plasma 25OHD levels were significantly lower in patients with type 1 diabetes than in control subjects (82.5+/-1.3 vs 96.7+/-2.0 nmol/l; p<0.0001). Eight years later, plasma 25OHD had decreased in patients (81.5+/-2.6 nmol/l; p=0.04). Plasma 25OHD levels were significantly lower in diabetic men than in diabetic women at diagnosis (77.9+/-1.4 vs 90.1+/-2.4 nmol/l; p<0.0001) and at follow-up (77.1+/-2.8 nmol/l vs 87.2+/-4.5 nmol/l; p=0.048).

CONCLUSIONS/INTERPRETATION

The plasma 25OHD level was lower at diagnosis of autoimmune type 1 diabetes than in control subjects, and may have a role in the development of type 1 diabetes. Plasma 25OHD levels were lower in men than in women with type 1 diabetes. This difference may be relevant to the high incidence of type 1 diabetes among young adult men.

HLA-DQB1 genotypes, islet antibodies and beta cell function in the classification of recent-onset diabetes among young adults in the nationwide Diabetes Incidence Study in Sweden

AIMS/HYPOTHESIS

The World Health Organization considers an aetiological classification of diabetes to be essential. The aim of this study was to evaluate whether HLA-DQB1 genotypes facilitate the classification of diabetes as compared with assessment of islet antibodies by investigating young adult diabetic patients.

SUBJECTS AND METHODS

Blood samples were available at diagnosis for 1,872 (90%) of the 2,077 young adult patients (aged 15-34 years old) over a 5-year period in the nationwide Diabetes Incidence Study in Sweden. Islet antibodies were measured at diagnosis in 1,869 patients, fasting plasma C-peptide (fpC-peptide) after diagnosis in 1,522, while HLA-DQB1 genotypes were determined in 1,743.

RESULTS

Islet antibodies were found in 83% of patients clinically considered to have type 1 diabetes, 23% with type 2 diabetes and 45% with unclassifiable diabetes. After diagnosis, median fpC-peptide concentrations were markedly lower in patients with islet antibodies than in those without (0.24 vs 0.69 nmol/l, p<0.0001). Irrespective of clinical classification, patients with islet antibodies showed increased frequencies of at least one of the risk-associated HLA-DQB1 genotypes compared with patients without. Antibody-negative patients with risk-associated HLA-DQB1 genotypes had significantly lower median fpC-peptide concentrations than those without risk-associated genotypes (0.51 vs 0.74 nmol/l, p=0.0003).

CONCLUSIONS/INTERPRETATION

Assessment of islet antibodies is necessary for the aetiological classification of diabetic patients. HLA-DQB1 genotyping does not improve the classification in patients with islet antibodies. However, in patients without islet antibodies, HLA-DQB1 genotyping together with C-peptide measurement may be of value in differentiating between idiopathic type 1 diabetes and type 2 diabetes.

Survival from invasive breast cancer among interval cases in the mammography screening programmes of northern Sweden

The aim of this study was to estimate breast cancer survival according to detection mode for 5120 women with invasive breast cancer, in particular for those detected in the screening intervals. We found a significant survival difference in favour of women with cancer detected in the screening intervals (n=729) compared with those uninvited (n=1879) during the 13-year follow-up. Detection mode was proven to modify the prognostic effect of stage. Women with stage I interval cancer had shorter survival and those with stage II had longer survival than expected. It is suggested that interval cancers might consist of two subgroups with different behaviour: one of fast-growing tumours presenting as stage I cases and another of slow-growing tumours presenting as stage II+ cases. A hypothesis related to this observation is discussed.

Excess mortality in incident cases of diabetes mellitus aged 15 to 34 years at diagnosis: a population-based study (DISS) in Sweden

AIMS/HYPOTHESIS

The objective of the study was to analyse the mortality, survival and cause of death patterns in incident cases of diabetes in the 15-34-year age group that were reported to the nationwide prospective Diabetes Incidence Study in Sweden (DISS).

MATERIALS AND METHODS

During the study period 1983-1999, 6,771 incident cases were reported. Identification of deaths was made by linking the records to the nationwide Cause of Death Register.

RESULTS

With an average follow-up of 8.5 years, resulting in 59,231 person-years, 159 deaths were identified. Diabetes was reported as the underlying cause of death in 51 patients (32%), and as a contributing cause of death in another 42 patients (26%). The standardised mortality ratio (SMR) was significantly elevated (RR=2.4; 95% CI: 2.0-2.8). The SMR was higher for patients classified by the reporting physician as having type 2 diabetes at diagnosis than for those classified as type 1 diabetic (2.9 and 1.8, respectively). Survival analysis showed significant differences in survival curves between males and females (p=0.0003) as well as between cases with different types of diabetes (p=0.005). This pattern was also reflected in the Cox regression model showing significantly increased hazard for males vs females (p=0.0002), and for type 2 vs type 1 (p=0.015) when controlling for age.

CONCLUSIONS/INTERPRETATION

This study shows a two-fold excess mortality in patients with type 1 diabetes and a three-fold excess mortality in patients with type 2 diabetes. Thus, despite advances in treatment, diabetes still carries an increased mortality in young adults, even in a country with a good economic and educational patient status and easy access to health care.

Vehicle exhaust exposure in an incident case-control study of adult asthma

The objective of this case-control study was to evaluate whether traffic-related air pollution exposure at home increases the risk of asthma in adults and to compare two commonly used exposure variables and differences between urban and rural living. Incident cases of asthma and matched controls of subjects aged 20-60 yrs were recruited in Luleå, Sweden. In total 203 cases and 203 controls were enrolled in the study. Exposure was estimated by traffic flow and measured levels of outdoor nitrogen dioxide (NO2) in the surrounding environment of each home, respectively. The relationship between measured levels of NO2 and traffic flow was studied using linear regression. The results indicated a nonsignificant tendency between living in a home close to a high traffic flow and an increased risk of asthma. The association between asthma and measured NO2 was weak and not significant, but the skin-prick test result acted as an effect modifier with a borderline significant association among positives. The correlation between traffic flow and outdoor NO2 was low. The results suggest that living close to high traffic flows might increase the asthma incidence in adults, while the tendency for nitrogen dioxide was only seen among atopics. Traffic flow and nitrogen dioxide had a lower than expected correlation.

Effectiveness of referral system for antenatal and intra-partum problems in Gutu district, Zimbabwe

We conducted a population-based cohort study to determine the prevalence of antenatal and intra-partum referrals, compliance with advice and perinatal outcomes in referred pregnant women in Gutu district, Zimbabwe. The cohort was composed of 10,572 women who received antenatal care in 23 rural health centres (RHC) in Gutu district between January 1995 and June 1998. Pregnancy records of women with antenatal or intra-partum referral were analysed for indication, compliance and perinatal outcomes. Using women who had no antenatal referral or those who complied as referents, the association of referral with perinatal outcome was expressed as relative risk (RR) with 95% confidence intervals (CI). A total of 30% of women (3,094/10,572) had an antenatal referral. Among women attending RHC in labour, 13% (694/5,338) were referred intra-partum. Nulliparous and women younger than 20 years were more likely to be referred. Nurse - midwives' compliance with referral recommendations was low as 59% women with historical risk factors and 52% with raised blood pressure (>140/90 mmHg) were not referred. Women complied with referral advice except when indication was high parity. Women with antenatal referral were more likely to have hospital delivery, 70% vs 18% (p < 0.001). A total of 13% (993/7,478) of women referred themselves for hospital delivery. The risk of perinatal death was elevated among intra-partum referrals (RR 3.4; 95% CI 1.7 - 6.8), self-referrals (RR 2.6; 95% CI 1.5 - 4.5) and also among women with historical risk factors who were not referred (RR 4.8; 95% CI 2.5 - 9.2). We concluded that although there was a functional referral system in Gutu district its efficiency was reduced by failure of health personnel to comply with referral recommendations. Women took appropriate action for most referral indications.

Increased risk of diabetes among relatives of female insulin-treated patients diagnosed at 15-34 years of age

AIMS

This study aimed to determine the risk of developing diabetes among relatives of patients diagnosed between 15 and 34 years of age who were treated with insulin. Our second aim was to determine whether there was a difference in risk of diabetes between relatives of male and female patients.

METHODS

A questionnaire was sent to patients in the Diabetes Incidence Study in Sweden registry diagnosed between 1983 and 1993 to determine the presence of first-degree relatives with diabetes.

RESULTS

In 3087 index patients treated with insulin, 17.8% (95% confidence interval 16.5, 19.2) had a first-degree relative (excluding offspring) treated with insulin, the frequency being higher in female (19.8%) than in male (16.5%, P = 0.018) patients. A total of 10.7% had a parent treated with insulin. The prevalence of insulin-treated diabetes was higher among parents of female (12.5%) than of male (9.5%), insulin-treated index patients (P = 0.0068). A similar difference was observed using life table analysis (P = 0.0025), which also showed that the risk by 63 years of age was 7.6% for parents of female and 4.9% for parents of male insulin-treated index patients. In insulin-treated index patients, 8.4% had a sibling with insulin-treated diabetes.

CONCLUSIONS

We conclude that the risk for relatives of women with insulin-treated diabetes was higher than for relatives of insulin-treated male patients. We suggest that greater genetic susceptibility is required for females compared with males in the 15-34 age group in order to develop diabetes and hence females might carry more diabetes genes since more of their relatives also develop diabetes.

Hormone replacement therapy, body mass index and asthma in perimenopausal women: a cross sectional survey

BACKGROUND

Hormone replacement therapy (HRT) and obesity both appear to increase the risk of asthma. A study was undertaken to investigate the association of HRT with asthma and hay fever in a population of perimenopausal women, focusing on a possible interaction with body mass index (BMI).

METHODS

A postal questionnaire was sent to population based samples in Denmark, Estonia, Iceland, Norway, and Sweden in 1999-2001, and 8588 women aged 25-54 years responded (77%). Pregnant women, women using oral contraceptives, and women <46 years were excluded. Analyses included 2206 women aged 46-54 years of which 884 were menopausal and 540 used HRT. Stratified analyses by BMI in tertiles were performed.

RESULTS

HRT was associated with an increased risk for asthma (OR 1.57 (95% CI 1.07 to 2.30)), wheeze (OR 1.60 (95% CI 1.22 to 2.10)), and hay fever (OR 1.48 (95% CI 1.15 to 1.90)). The associations with asthma and wheeze were significantly stronger among women with BMI in the lower tertile (asthma OR 2.41 (95% CI 1.21 to 4.77); wheeze OR 2.04 (95% CI 1.23 to 3.36)) than in heavier women (asthma: p(interaction) = 0.030; wheeze: p(interaction) = 0.042). Increasing BMI was associated with more asthma (OR 1.08 (95% CI 1.05 to 1.12) per kg/m2). This effect was only found in women not taking HRT (OR 1.10 (95% CI 1.05 to 1.14) per kg/m2); no such association was detected in HRT users (OR 1.00 (95% CI 0.92 to 1.08) per kg/m2) (p(interaction) = 0.046). Menopause was not significantly associated with asthma, wheeze, or hay fever.

CONCLUSIONS

In perimenopausal women there is an interaction between HRT and BMI in the effects on asthma. Lean women who were HRT users had as high a risk for asthma as overweight women not taking HRT. It is suggested that HRT and overweight increase the risk of asthma through partly common pathways.

Association of asthma and hay fever with irregular menstruation

BACKGROUND

There is some evidence that asthmatic women are more likely to have abnormal sex hormone levels. A study was undertaken to determine whether asthma and allergy were associated with irregular menstruation in a general population, and the potential role of asthma medication for this association.

METHODS

A total of 8588 women (response rate 77%) participated in an 8 year follow up postal questionnaire study of participants of the ECRHS stage I in Denmark, Estonia, Iceland, Norway, and Sweden. Only non-pregnant women not taking exogenous sex hormones were included in the analyses (n = 6137).

RESULTS

Irregular menstruation was associated with asthma (OR 1.54 (95% CI 1.11 to 2.13)), asthma symptoms (OR 1.47 (95% CI 1.16 to 1.86)), hay fever (OR 1.29 (95% CI 1.05 to 1.57)), and asthma preceded by hay fever (OR 1.95 (95% CI 1.30 to 2.96)) among women aged 26-42 years. This was also observed in women not taking asthma medication (asthma symptoms: OR 1.44 (95% CI 1.09 to 1.91); hay fever: OR 1.27 (95% CI 1.03 to 1.58); wheeze preceded by hay fever: OR 1.76 (95% CI 1.18 to 2.64)). Irregular menstruation was associated with new onset asthma in younger women (OR 1.58 (95% CI 1.03 to 2.42)) but not in women aged 42-54 years (OR 0.62 (95% CI 0.32 to 1.18)). The results were consistent across centres.

CONCLUSIONS

Younger women with asthma and allergy were more likely to have irregular menstruation. This could not be attributed to current use of asthma medication. The association could possibly be explained by common underlying metabolic or developmental factors. The authors hypothesise that insulin resistance may play a role in asthma and allergy.

Birthweight and risk of type 1 diabetes in children and young adults: a population-based register study

AIMS/HYPOTHESIS

We investigated the association between type 1 diabetes and birthweight by age at disease onset.

METHODS

This population-based case-referent study used data from two nationwide case registers that are linked to the Swedish Medical Birth Registry and cover incident cases of type 1 diabetes in the 0- to 14-year (since 1 July 1977) and 15- to 34-year age groups (since 1 January 1983). Of the cases linked to the Medical Birth Registry, a total of 9,283 cases with onset before 15 years of age was recorded before 1 January 2003, and 1,610 cases were recorded with onset before 30 years of age and born after 1973 (together 95% of eligible cases). Multiple births and babies of diabetic mothers were excluded. Sex-specific birthweight by gestational week is expressed as multiples of the standard deviation (SDS) and adjusted for year of birth, maternal age and parity.

RESULTS

Cases with onset before 10 years of age (n = 5,792) showed a significant linear trend in odds ratio (OR) by SDS of adjusted birthweight (OR by SDS: 0.062; 95% CI: 0.037-0.086; p < 0.0001), while cases with onset at the age of 10-29 years showed no significant trend (OR by SDS: 0.004; 95% CI: -0.007 to 0.0014; p = 0.22).

CONCLUSIONS/INTERPRETATION

The association between type 1 diabetes risk and birthweight seems to be limited to cases with disease onset in younger years.

Antioxidant activity of steryl ferulate extracts from rye and wheat bran

Antioxidant activity of steryl ferulates from other sources than rice have not yet been studied much, despite the fact that rice steryl ferulates (gamma-oryzanol) have been shown to possess good antioxidant activity. In this study, steryl ferulate extracts from wheat or rye bran were studied for their capability to inhibit hydroperoxide formation in bulk methyl linoleate and methyl linoleate emulsion. Further, their activity to scavenge DPPH radicals was analyzed. The activities were compared to synthetic steryl ferulates, rice steryl ferulates, ferulic acid, and alpha-tocopherol. Nonrice cereal extracts of steryl ferulates exhibited good antioxidant activity, especially in the bulk lipid system. The radical scavenging activity was similar to that of nonesterified ferulic acid, indicating that the ferulic acid moiety is responsible for the antioxidant properties. This study illustrates a new aspect to the health-promoting properties of rye and wheat.

Comparison of early performance indicators for screening projects within the European Breast Cancer Network: 1989–2000

In 1989 the European Breast Cancer Network (EBCN) was established by the first pilot projects for breast cancer screening, co-funded by the Europe Against Cancer programme. We report early performance indicators for these EBCN projects while taking into account their organizational setting. Out of 17 projects in the network, 10 projects from six European countries contributed aggregated data on number of invitations, screening examinations, and breast cancers detected over the period 1989-2000. Results were summarized separately for projects in centralized versus decentralized health care environments. The European Guidelines for quality assurance in mammography screening provided reference values for the performance indicators. The most prominent finding in this study was the higher participation rate in centralized versus decentralized projects (average participation in 1998: 74 versus 33%; P<0.001), whereas the invitation system and screening policy in these projects were similar. Detection rates and characteristics of cancers detected at initial and subsequent screening examinations showed no significant differences between centralized and decentralized projects. Even though early performance indicators for centralized versus decentralized projects were similar, the impact of breast screening on mortality from this disease at the population level will differ since the decentralized projects reach only part of the target population.

A prospective study of asthma incidence and its predictors: the RHINE study

The objective of this longitudinal study was to estimate the incidence rate of asthma, and to compare the incidence between subjects with or without baseline reporting of certain respiratory symptoms. A follow-up of the random population samples in the European Respiratory Health Survey (ECRHS) in Sweden, Norway, Denmark, Iceland and Estonia was conducted in 1999-2001, in a population aged 30-54 yrs at follow-up (n=14,731). Asthma was defined as reporting either asthma or physician-diagnosed asthma, and a reported year when asthma symptoms were first noticed. Incidence rates, incidence rate ratios and hazard ratios were calculated with 95% confidence intervals. The incidence rate of asthma was 2.2 cases per 1,000 person-yrs. The incidence was higher among females (2.9 cases.1,000 person-yrs(-1)) than among males (1.5 cases.1,000 person-yrs(-1)). When subjects with baseline reporting of wheezing were excluded, the incidence rate decreased to 1.7 cases.1,000 person-yrs(-1), with a further decrease to 1.5 cases.1,000 person-yrs(-1) after exclusion of subjects with wheezing, nocturnal dyspnoea, chest tightness and cough. There was a strong association between onset of asthma and wheezing at baseline. In this prospective, population-based study, the incidence rate of asthma in the whole population sample ranged 1.5-2.2.1,000 person-yrs(-1), with a higher incidence range among females. The incidence was dependent on the extent to which subjects with respiratory symptoms were excluded from follow-up. Hence, for comparability between studies, the exclusion criteria in the follow-up population must be stated.

Obesity increases the risk of incident asthma among adults

The annual incidence of asthma in adults in northern Sweden has been estimated at 2.3 per thousand population. Risk factors for incident asthma among adults were studied in a case-referent study based on incident cases of asthma during 1995-1999. The healthcare providers reported suspected cases of incident asthma. After clinical examination, 309 (65% female) of 473 reported subjects were included. Inclusion criteria were a history of incident asthma (onset <12 months) and verified bronchial variability. Referents were randomly selected and stratified by age, sex and area of residence. The significant risk factors were hay fever, a family history of asthma, ex-smoking status and elevated body mass index (25.0-29.9 and > or =30). The risk factor pattern was similar for females and males, and increased body mass index was a significant risk factor for both males and females, as well as for allergic and nonallergic subjects. In conclusion, in addition to hay fever, a family history of asthma, allergic sensitisation and ex-smoking status, increased body mass index was a significant risk factor for incident asthma independent of sex and allergic status.

Insomnia is more common among subjects living in damp buildings

BACKGROUND

Insomnia is a condition with a high prevalence and a great impact on quality of life. Little is known about the relation between and sleep disturbances and the home environment.

AIM

To analyse the association between insomnia and building dampness.

METHODS

In a cross-sectional, multicentre, population study, 16 190 subjects (mean age 40 years, 53% women) were studied from Reykjavik in Iceland, Bergen in Norway, Umeå, Uppsala, and Göteborg in Sweden, Aarhus in Denmark, and Tartu in Estonia. Symptoms related to insomnia were assessed by questionnaire.

RESULTS

Subjects living in houses with reported signs of building dampness (n = 2873) had a higher prevalence of insomnia (29.4 v 23.6%; crude odds ratio 1.35, 95% CI 1.23 to 1.48). The association between insomnia and different indicators of building dampness was strongest for floor dampness: "bubbles or discoloration on plastic floor covering or discoloration of parquet floor" (crude odds ratio 1.96, 95% CI 1.66 to 2.32). The associations remained significant after adjusting for possible confounders such as sex, age, smoking history, housing, body mass index, and respiratory diseases. There was no significant difference between the centres in the association between insomnia and building dampness.

CONCLUSION

Insomnia is more common in subjects living in damp buildings. This indicates that avoiding dampness in building constructions and improving ventilation in homes may possibly have a positive effect on the quality of sleep.

Relation of parity to pregnancy outcome in a rural community in Zimbabwe

This population-based cohort study was conducted to compare pregnancy complications and outcome among nulliparous, low (1-5) and high (> or = 6) parity women. Women who registered for antenatal care and gave birth in Guru District, Zimbabwe, between January 1995 and June 1998 were classified into groups by parity. The women were compared for baseline characteristics, utilisation of health facilities and occurrence of pregnancy complications such as hypertensive disorders of pregnancy, haemorrhage, pre-term delivery, operative delivery, low birth weight and perinatal death. In estimating risk, primiparous (parity = 1) women were used as referents. Pregnancy records for 10,569 women were analysed. Mean ages of nulliparous and high parity (> or = 6) women were 20.1 and 37.7 years respectively (p < 0.001). Prevalence of anaemia at booking (haemoglobin < or =10.5 g/dl) was reduced in nulliparous compared to multiparous women (11.7% vs 16.8%; p > or = 0.001). Nulliparous women were likely to book early (< or = 20 weeks) for antenatal care, have a higher number of visits (> or = 6) and fewer home births. Nulliparous women had higher risk for low birth weight (RR 1.70; 95% CI 1.36 - 2.13). Compared to low parity women, nulliparous and high parity women had an elevated risk of hypertensive complications RR 1.62 (95% CI 1.37-1.92) and RR 1.64 (95% CI 1.29 - 2.07) respectively. The risk of developing any pregnancy complications was highest in nulliparous women (RR 1.48; 95% 1.31- 1.67). In conclusion, nulliparous women had an increased risk of pregnancy complications. High parity women with no previous complicated pregnancy were at low risk of complications.

An altered immune response to Epstein-Barr virus in multiple sclerosis: a prospective study

OBJECTIVE

To investigate the association between human herpesviruses and multiple sclerosis (MS), as well as between measles virus and MS.

METHODS

The authors identified prospectively collected serum samples from 73 MS cases and retrospective sera from 161 MS cases in two population-based serum bank registers. Analyses of IgG antibody responses in cases and matched referents were performed for Epstein-Barr virus (EBV [EBNA-1 and VCA]), human herpesvirus 6 (HHV-6), herpes simplex virus (HSV), varicella zoster virus (VZV), and measles.

RESULTS

All cases showed signs of past EBV infection. High activity to EBNA-1 and HHV-6 significantly (borderline significance for HHV-6) increased the risk for MS in prospective sera. A discrepancy between activities to EBNA-1 and VCA was striking in MS samples collected less than 5 years before relapsing-remitting MS onset, where high activity to EBNA-1 significantly increased, and high VCA activity significantly decreased the risk for MS. There was no support for major causal roles for HSV, VZV, or measles.

CONCLUSION

Individuals who will develop MS exhibit an altered immune response against the EBV virus characterized by a high IgG activity to EBNA-1 in the absence of high activity to VCA, this being most pronounced in the 5-year period preceding MS onset.

Early breast cancer deaths in women aged 40–74 years diagnosed during the first 5 years of organised mammography service screening in north Sweden

The aim of this study was to analyse individual cases of lethal breast cancer and not to evaluate the screening programme. Women aged 40-74 years who were diagnosed with breast cancer in 1990-94 and died on or before 31 December 1998, during the gradual introduction of organised mammography service screening in north Sweden, were included in the study. Out of 342 breast cancer deaths, 280 (82%) were in symptomatic patients whose cancers were clinically detected. Most breast cancers that proved fatal were already in an advanced stage and/or of high histological grade at the time of detection. A shift towards a lower stage was seen among screen-detected and interval-detected fatal cases. In a few of the cases with fatal outcome, in patients primarily presenting with histological grade I tumours of various sizes or small screen-detected tumours less than 10mm in size, early diagnosis by mammography followed by state-of-the-art treatment did not seem to have been enough to prevent death.

Normal weight promotes remission and low number of islet antibodies prolong the duration of remission in Type 1 diabetes

AIM

To identify clinical, immunological and biochemical factors that predict remission, and its duration in a large cohort of young adults with Type 1 diabetes mellitus (DM).

METHODS

In Sweden, 362 patients (15-34 years), classified as Type 1 DM were included in a prospective, nation-wide population-based study. All patients were followed at local hospitals for examination of HbA(1c) and insulin dosage over a median period after diagnosis of 5 years. Duration of remission, defined as an insulin maintenance dose </= 0.3 U/kg/24 h and HbA(1c) within the normal range, was analysed in relation to characteristics at diagnosis.

RESULTS

Remissions were seen in 43% of the patients with a median duration of 8 months (range 1-73). Sixteen per cent had a remission with a duration > 12 months. Among patients with antibodies (ab(+)), bivariate analysis suggested that adult age, absence of low BMI, high plasma C-peptide concentrations, lack of ketonuria or ketoacidosis at diagnosis and low insulin dose at discharge from hospital were associated with a high possibility of achieving remission. Multiple regression showed that normal weight (BMI of 20-24.9 kg/m(2)) was the only factor that remained significant for the possibility of entering remission. In survival analysis among ab(+) remitters, a low number of islet antibodies, one or two instead of three or four, were associated with a long duration of remissions.

CONCLUSION

In islet antibody-positive Type 1 DM, normal body weight was the strongest factor for entering remission, whilst a low number of islet antibodies was of importance for the duration.

Clinical characteristics of multiple sclerosis in Västerbotten County in northern Sweden

BACKGROUND

Most clinical data for multiple sclerosis are hospital based-that is, derived from patients referred to clinics specialising in the disease.

OBJECTIVES

To present data derived from two population based multiple sclerosis populations, an incidence cohort and a prevalence population, from Västerbotten County, northern Sweden.

METHODS

The two populations were identified from multiple sources, and case ascertainment was assured through a personal clinical review, including interviews and examination of the patients.

RESULTS

Characteristics at onset for the different clinical subtypes of multiple sclerosis are presented, including the clinical spectrum of the first attack, the anatomical correlation between the first and second attacks, sex distribution, and disability distribution.

CONCLUSIONS

Based on the comparison of present and earlier natural history data, multiple sclerosis appears to be a slightly more benign disease than previously recognised.

Islet antibodies and remaining beta-cell function 8 years after diagnosis of diabetes in young adults: a prospective follow-up of the nationwide Diabetes Incidence Study in Sweden

OBJECTIVES

To establish the prevalence of remaining beta-cell function 8 years after diagnosis of diabetes in young adults and relate the findings to islet antibodies at diagnosis and 8 years later.

DESIGN

Population-based cohort study.

SETTING

Nationwide from all Departments of Medicine and Endocrinology in Sweden.

SUBJECTS

A total of 312 young (15-34 years old) adults diagnosed with diabetes during 1987-88.

MAIN OUTCOME MEASURE

Plasma connecting peptide (C-peptide) 8 years after diagnosis. Preserved beta-cell function was defined as measurable C-peptide levels. Three islet antibodies - cytoplasmic islet cell antibodies (ICA), glutamic acid decarboxylase antibodies and tyrosine phosphatase antibodies - were measured.

RESULTS

Amongst 269 islet antibody positives (ab+) at diagnosis, preserved beta-cell function was found in 16% (42/269) 8 years later and these patients had a higher body mass index (median 22.7 and 20.5 kg m-2, respectively; P = 0.0003), an increased frequency of one islet antibody (50 and 24%, respectively; P = 0.001), and a lower prevalence of ICA (55 and 6%, respectively; P = 0.007) at diagnosis compared with ab+ without remaining beta-cell function. Amongst the 241 patients without detectable beta-cell function at follow-up, 14 lacked islet antibodies, both at diagnosis and at follow-up.

CONCLUSIONS

Sixteen per cent of patients with autoimmune type 1 diabetes had remaining beta-cell function 8 years after diagnosis whereas 5.8% with beta-cell failure lacked islet autoimmunity, both at diagnosis and at follow-up.

A community based study of HIV in women in rural Gutu District, Zimbabwe 1992 to 1993

OBJECTIVE

To estimate the prevalence of HIV-1 infection and its relation to socio-economic and obstetric history factors.

DESIGN

A cross sectional study.

SETTING

12 randomly selected villages in rural Gutu District, Zimbabwe.

SUBJECTS

All women of fertile age (15 to 44 years) in the selected villages were invited to participate. In total 1,213 women were interviewed and examined. On average 75% and 81% of those eligible in 1992 and 1993 respectively participated (range for villages 57 to 87%).

MAIN OUTCOME MEASURES

HIV sero-positivity.

RESULTS

HIV prevalence was high, 21.9%. Single women below 20 years had the lowest prevalence (7.6%), while the highest (30.0%) was found in married women aged 20 to 29 years. Using a case-referent approach, women divorced, widowed or separated had twice as high a risk of being HIV positive as single women (Odds Ratio (OR) = 2.03; 95% confidence interval (CI) 1.40 to 2.93). There was a huge difference in the prevalence of HIV between villages, from 8.4 to 32.8%, thus the risk of having HIV in the two villages with the highest prevalence was more than five times higher (OR = 5.21 and 5.31 respectively) than in the village with the lowest. The multivariate logistic regression confirmed the findings of an increased risk for women aged 20 to 39 years as compared with women 15 to 19 years, and for women that were divorced, widowed or separated as compared with single. It also confirmed that the huge difference in the prevalence found between wards was statistically significant.

CONCLUSION

Women contract HIV early in marriage. Young men's risk behaviour needs to be addressed and women must be aware of their risks before marriage.

Increasing body mass index at diagnosis of diabetes in young adult people during 1983-1999 in the Diabetes Incidence Study in Sweden (DISS)

OBJECTIVE

To study trends in body mass index (BMI) at diagnosis of diabetes in all young Swedish adults in the age range of 15-34 years registered in a nation-based registry.

DESIGN

The BMI was assessed at diagnosis in diabetic patients 15-34 years of age at diagnosis, for a period of 17 years (1983-1999). Islet cell antibodies (ICA) were measured during three periods (1987-1988, 1992-1993 and 1998-1999).

SETTING

A nationwide study (Diabetes Incidence Study in Sweden).

SUBJECTS

A total of 4727 type 1 and 1083 type 2 diabetic patients.

MAIN OUTCOME MEASURES

Incidence-year specific BMI adjusted for age, gender and time of diagnosis (month).

RESULTS

Body mass index at diagnosis increased significantly both in type 1 (21.4 +/- 3.6 to 22.5 +/- 4.0; P < 0.0001) and in type 2 (27.4 +/- 6.8 to 32.0 +/- 6.0; P < 0.0001) diabetic patients, also when adjusted for age, gender and month of diagnosis. A similar significant increase in BMI was found in type 1 diabetic patients and in type 2 diabetic patients in the periods 1987-1988, 1992-1993 and 1998-1999; years when ICA were assessed and considered in the classification of diabetes. Despite this increase in BMI, there was no increase in the incidence of diabetes in young-adult people in Sweden.

CONCLUSION

Body mass index at diagnosis of diabetes in subjects 15-34 years of age has substantially increased during 1983-1999 in Sweden when adjusted for age, gender and month of diagnosis.

Service screening with mammography. Long-term effects on breast cancer mortality in the county of Gävleborg, Sweden

In the current study the long-term effects of a pilot service screening programme in the Swedish county of Gävleborg were studied. Women aged 40-64 years in 13 sub-areas were followed from start of screening between 1974 and 1979. Two control groups were used for comparison; the neighbouring counties and all of Sweden. A reference period prior to the study period was used to facilitate an adjustment for possible differences in baseline breast cancer mortality. Only deaths from breast cancer diagnosed after the first invitation to screening were analysed. Two outcome measures were used for breast cancer mortality; the underlying cause of death and excess mortality. Using the neighbouring counties as a control group, the relative risk, after 22 years of follow-up, of 10 years of screening was estimated at 0.84 (95% CI 0.71-1.00) using excess mortality. Due to lead time bias the relative risk was overestimated by 4%. Hence, a significant 20% reduction of breast cancer excess mortality was found.

Iron status and iron deficiency anaemia in adolescents in a Tanzanian suburban area

OBJECTIVES

To assess the extent and degree of anaemia in adolescents in a Tanzanian suburban area, to estimate the contribution of iron deficiency, using serum (S)-ferritin and soluble transferrin receptor (sTfR) as markers of iron deficiency.

MATERIALS

Consecutive primigravidae at booking for antenatal care (n = 76), primary school boys (n = 101) and postmenarchal girls (n = 130) age >or=12 years were investigated.

METHODS

Weight and height were measured; venous blood was drawn for haematological analyses, malaria screening, S-ferritin, sTfR, and C-reactive protein. Stool specimens were analysed for intestinal parasites.

RESULTS

Anaemia (Hb <105 g/l) was highly prevalent in adolescent primigravidae (75.5%). Adolescent girls were more anaemic (Hb <120 g/l) than boys (14.5 vs. 7.9%). Iron deficiency and hookworm infestation were predominant in both groups of adolescents, however, malaria contributed more to anaemia in the primigravidae. Nearly 40% of the anaemic primigravidae had indication of infection, and S-ferritin was less useful as a marker of iron deficiency in this group. sTfR identified iron deficiency in both pregnant and non-pregnant adolescents.

Evaluation of the new ADA and WHO criteria for classification of diabetes mellitus in young adult people (15-34 yrs) in the Diabetes Incidence Study in Sweden (DISS)

AIMS/HYPOTHESIS

We aimed to evaluate how an aetiology-based classification, as recommended in the ADA and WHO guidelines for classification of diabetes mellitus, matches clinical judgement in the Diabetes Incidence Study in Sweden (DISS), a study covering incident cases of diabetic patients aged 15 to 34 years.

METHODS

During a 1-year period (1998), blood samples were taken at diagnosis and 4 months (median) thereafter. Patients were classified according to clinical judgement by the reporting physicians and assessments of islet antibodies (ICA, GADA, and IA-2A) and plasma C-peptide.

RESULTS

In 1998, 422 patients were registered in DISS. Among the 313 patients participating in the follow-up, most with clinical Type 1 diabetes (185/218, 85%, 95% CI 79-89%) were islet antibody positive (ab+) at diagnosis. In addition, 14 out of 58 (24%, 14-37%) with clinical Type 2 diabetes and 21 out of 37 (57%, 40-73%) with unclassifiable diabetes were antibody positive at diagnosis. Further to this, 4 out of 33 (12%, 3-28%) were antibody negative with clinical Type 1 diabetes and 4 out of 44 (9%, 3-22%) with Type 2 had converted to antibody positive at follow-up. Among those who were constantly antibody negative, 10 out of 29 (34%, 18-54%) with clinical Type 1 and 1 out of 16 (6%, 0-30%) with unclassifiable diabetes had fasting plasma C-peptide concentrations below the normal range (<0.25 nmol/l) at follow-up.

CONCLUSION/INTERPRETATION

Most young adults with clinical Type 1 diabetes (199/218, 91%) had objective Type 1 (ab+ at diagnosis/follow-up and/or low fasting plasma C-peptide concentrations at follow-up), as did one third (18/58, 31%) with clinical Type 2 diabetes and more than half (22/37, 59%) with unclassifiable diabetes. About 10% of those who were antibody negative converted to antibody positive. Our study underlines that a classification considering aetiology is superior to clinical judgement.

Children born in the summer have increased risk for coeliac disease

STUDY OBJECTIVE

Coeliac disease, also called permanent gluten sensitive enteropathy, is being recognised as a widespread health problem. Defining the possible role of environmental factors in its aetiology might open doors to primary prevention. This study therefore analysed if the risk for coeliac disease varies with month of birth as a proxy for a seasonal pattern for possible causal environmental exposure(s).

DESIGN

A population based incidence register of coeliac disease in children below 15 years of age covering the period from 1973 to 1997. Incidence rates were calculated by month of birth, stratified for age at diagnosis. Poisson regression analyses were used to estimate the relative risk for coeliac disease for children below 2 years of age by season of birth, also taking into account gender and time period of diagnosis.

SETTING

Sweden.

PARTICIPANTS

All 2151 children in the study base with verified coeliac disease.

MAIN RESULTS

The risk for coeliac disease was significantly higher if born during the summer as compared with the winter (RR=1.4, 95% CI 1.2 to 1.7), but only in children below 2 years of age at diagnosis. This relative seasonal risk pattern prevailed during a 10 year epidemic of coeliac disease, although incidence rates varied threefold. The incidence was constantly higher among girls as compared with boys, but boys showed a more pronounced seasonal variation in risk than girls.

CONCLUSIONS

An increased coeliac disease risk in children born in the summer compared with the winter reflects causal environmental exposure(s) with a seasonal pattern. Infections might be the exposure of importance, either by means of a direct causal role and/or through interaction with other exposures, for example, gluten intake. However, non-infectious exposures should also be explored as possible contributing causal factors.

Incidence (1988-97) and prevalence (1997) of multiple sclerosis in Västerbotten County in northern Sweden

OBJECTIVE

To investigate the incidence and prevalence of multiple sclerosis in Västerbotten County in northern Sweden.

METHODS

Multiple sources were used in the case identification process. Follow up interviews with clinical examinations were undertaken and, when indicated, additional paraclinical investigations were done. In this way case ascertainment was assured and supplemental clinical data were collected. The incidence rate was based on symptom onset. Onset adjusted prevalence was applied.

RESULTS

The crude incidence rate of multiple sclerosis in 1988-97 in Västerbotten County was 5.2/10(5) (95% confidence interval, 4.4 to 6.2): 6.7/10(5) (6.0 to 8.3) in women and 3.7/10(5) (2.7 to 4.9) in men. The onset adjusted prevalence for 31 December 1997 was 154/10(5) (139 to 170): 202/10(5) (179 to 228) in women and 105/10(5) (89 to 125) in men. When compared with a previous estimate of prevalence, a yearly 2.6% increase in prevalence between 1990 and 1997 was found, mainly attributable to a higher incidence than mortality.

CONCLUSIONS

The present incidence rate and prevalence confirms earlier findings that Västerbotten is a high risk area for multiple sclerosis. The adjusted incidence was twice as high as the incidence from 1974-88 in the only previous Swedish population based study from Göteborg, but comparable with other recent Fennoscandian multiple sclerosis incidence rates.

Vaginal misoprostol for induction of labour: a more effective agent than prostaglandin F2 alpha gel and prostaglandin E2 pessary

OBJECTIVES

To compare labour outcome in women who had labour induced with PGF2 alpha gel, PGE2 vaginal pessary or misoprostol administered intravaginally or orally.

STUDY DESIGN

Unmasked randomised controlled trial.

SETTING

Department of Obstetrics and Gynaecology, University of Zimbabwe, Harare.

SUBJECTS

Women with a singleton foetus in cephalic presentation after 37 weeks gestation admitted for induction of labour who were randomised to prostaglandin F2 alpha gel (n = 76), prostaglandin E2 pessary (n = 75) and misoprostol administered either intra-vaginally (n = 128) or orally (n = 127).

MAIN OUTCOME MEASURES

Primary outcome was induction to delivery interval. Secondary outcomes included use of oxytocin during labour, mode of delivery, duration of labour, neonatal condition at delivery and maternal complications.

METHODS

Four hundred and six women admitted for induction of labour with a singleton foetus in cephalic presentation after 37 weeks gestation were enrolled. To estimate the risk with induction using other agents the odds ratio and 95% confidence interval was calculated using the group that received prostaglandin F2 alpha gel as referents.

RESULTS

The women were comparable for baseline characteristics. Compared to prostaglandin F2 alpha gel, the need for augmentation with oxytocin in labour was significantly reduced in women induced with prostaglandin E2 pessary (OR 0.46; 95%CI 0.23 to 0.93), vaginal misoprostol (OR 0.34; 95%CI 0.18 to 0.63) and oral misoprostol (OR 0.42; 95%CI 0.22 to 0.78). There was no difference in mode of delivery. There was a significantly reduced risk (OR 0.20; 95%CI 0.04 to 0.86) of Caesarean section (CS) for failure to progress in the vaginal misoprostol group. Labour induced with misoprostol and prostaglandin E2 pessary was significantly shorter than in prostaglandin F2 alpha gel. Vaginal misoprostol significantly shortened the induction to delivery interval. There were more admissions to the neonatal unit in the misoprostol groups.

CONCLUSION

Compared to prostaglandin F2 alpha gel, misoprostol and prostaglandin E2 pessary had reduced need for oxytocin and a shorter duration of labour. Effects of misoprostol on the foetus need further investigation before it is used as a routine agent for induction of labour.

Usefulness of risk scoring at booking for antenatal care in predicting adverse pregnancy outcome in a rural African setting

Antenatal care (ANC) attempts to screen and provide surveillance and treatment to individuals according to the level of need. We assessed the value of antenatal risk allocation made at the first visit in identifying women who will experience pregnancy complications in a rural area in Zimbabwe. As part of an ANC trial women were allocated into low- and high-risk categories based on medical, demographic and obstetric history. All highrisk women were recommended hospital delivery. This evaluation is based on 5223 women who received traditional care from nurse-midwives in 12 rural health centres, of whom 2890 (55%) were classified as high risk by the traditional risk markers, including 1618 nulliparous women. Complications occurred in 924 (17.7%) women 577 (62.4%) of whom had risk markers identified at booking. Twenty per cent (577/2890) of women classified as high risk developed complications. There was a high recurrence of complications, such as hypertensive disorders, operative delivery and preterm delivery. Nulliparity was a risk for low birth weight, operative delivery and hypertensive disorders, whereas grandmultiparity (> or =6) was a risk for hypertension in pregnancy. Young age (< or =16 years) was)a risk factor for low birth weight and perinatal death. Age above 35 years was not an independent risk factor. The traditional risk allocation system, with a likelihood ratio of 1.16, was not effective in identifying women at risk of pregnancy complications and resulted in too large a risk group for referral.

Anaemia in women of reproductive age in Dar-es-Salaam, Tanzania

BACKGROUND

Anaemia is among the greatest health problems in reproductive age women in developing countries.

OBJECTIVES

To estimate the prevalence of anaemia among non-pregnant parous women, and to investigate the main underlying cause for the anaemia.

SETTING

A sub-urban Maternal and Child Health Clinic (MCH) in Dar es Salaam.

DESIGN

Cross-sectional.

METHODS

Consecutive parous non-pregnant women who had brought their children for vaccination and/or had come for family planning to Mbagala MCH clinic were invited to participate in the study. Obstetric and social history was recorded, and their height and weight were checked. Haemoglobin was measured using HemoCue hemoglobinometer. Anaemic women were further investigated to determine the cause of anaemia by haematological and biochemical tests.

RESULTS

Five hundred and four parous non-pregnant women were screened, 49% were anaemic (Hb <12 g/dl) and 1.6% severely anaemic (Hb <7 g/dl). Anaemia was not related to socio-demographic and obstetric history characteristics, but decreased significantly with increasing Body Mass Index (BMI) (p=0.042). The prevalence of anaemia was significantly lower in women using hormonal contraceptives, compared to non-users (36% vs 54%) (p=0.04). Eighty-seven percent of the anaemic women were iron deficient and 8.7% had elevated serum C-reactive protein indicating undiagnosed infections.

CONCLUSION

Nutritional deficiencies in women have to be corrected before and between pregnancies and all contacts women have with the health system should be utilised for anaemia control interventions, in addition to long-term community approaches. To improve maternal health calls for a broader agenda and a change of approach in the MCH-clinics.

The incidence of Type I diabetes has not increased but shifted to a younger age at diagnosis in the 0-34 years group in Sweden 1983-1998

AIMS/HYPOTHESIS

To analyse the incidence of Type I (insulin-dependent) diabetes mellitus in the 0-34 years age group in Sweden 1983-1998.

METHODS

Incidence and cumulative incidence per 100 000 and Poisson regression analysis of age-period effects was carried out using 11 751 cases from two nation-wide prospective registers.

RESULTS

Incidence (95%-CI) was 21.4 (20.8-21.9) in men and 17.1 (16.6-17.5) in women between 0 and 34 years of age. In boys aged 0-14 and girls aged 0-12 years the incidence increased over time, but it tended to decrease at older age groups, especially in men. Average cumulative incidence at 35 years was 748 in men and 598 in women. Cumulative incidence in men was rather stable during four 4-year periods (736, 732, 762, 756), while in women it varied more (592, 542, 617, 631). In males aged 0-34 years, the incidence did not vary between the 4-year periods ( p=0.63), but time changes among the 3-year age groups differed ( p<0.001). In females the incidence between the periods varied ( p<0.001), being lower in 1987-1990 compared to 1983-1986, but time changes in the age groups did not differ ( p=0.08). For both sexes median age at diagnosis was higher in 1983-1986 than in 1995-1998 ( p<0.001) (15.0 and 12.5 years in males; 11.9 and 10.4 in females, respectively).

CONCLUSION/INTERPRETATION

During a 16-year period the incidence of Type I diabetes did not increase in the 0-34 years age group in Sweden, while median age at diagnosis decreased. A shift to younger age at diagnosis seems to explain the increasing incidence of childhood Type I diabetes.

Service screening with mammography of women aged 50-69 years in Sweden: effects on mortality from breast cancer

OBJECTIVES

To estimate the effect of the population based service screening programme in Sweden on mortality from breast cancer among women aged 50-69. SETTING; In 1986, population based service screening with mammography started in Sweden, and by 1997 screening had been introduced in all counties. Half of the counties invite women from 40 years of age whereas women 50 and older are invited in the other counties. The upper age limit was either 69 or 74. Women in the age group 50-69 years are thus invited to screening in all counties.

METHODS

The counties which started with mammographic screening in 1986-87 constituted the study group and were compared with the counties which started in 1993 or later. In 1987 the mean number of women aged 50-69 was 161,986 and 98,608 in the study and control groups, respectively. Refined excess mortality (smoothed with the Lowess method) from breast cancer and refined cause specific mortality from breast cancer were used as effect measures. To adjust for geographical differences in mortality from breast cancer a reference period was used. Allowance was made for two potential biases: (a) inclusion bias implying the inclusion of cases diagnosed before invitation to screening in the first screening round, and (b) lead time bias.

RESULTS

After a mean follow up time of 10.6 years since the start of screening and a mean individual follow up time of 8.4 years, a non-significant reduction in refined excess mortality for breast cancer was estimated as relative risk (RR) 0.84 (95% confidence interval (95% CI) 0.67 to 1.05). After adjustment for inclusion and lead time biases the RR was 0.80 (20% reduction). Only 27% of the deaths from breast cancer in the total mortality for women aged 50-79 at death consisted of women aged 50-69 at diagnosis who were diagnosed after the start of screening. This figure has important implications for judgement of the impact of screening on age specific national breast cancer mortalities.

CONCLUSIONS

A non-significant reduction in mortality from breast cancer was found in counties performing service screening with mammography in Sweden. Adjustment for possible biases changed the result towards a larger effect of screening. The results do not contradict the effects found in the Swedish randomised mammography trials.

Labor induction with vaginal misoprostol and extra-amniotic prostaglandin F2alpha gel

OBJECTIVE

To compare the effectiveness of vaginally administered misoprostol with extra-amniotic prostaglandin F2alpha (PGF2alpha) gel for induction of labor.

METHOD

A randomized controlled trial, with women allocated to receive either misoprostol 50 microg intra-vaginally or extra-amniotic PGF2alpha gel 5 mg, was conducted in Harare Maternity Hospital. A total of 152 women were admitted for induction of labor with a term singleton, pregnancy and cephalic presentation were recruited. The main outcome was duration of induction.

RESULTS

There were no differences in the characteristics of women in the two groups at recruitment. In the misoprostol group there was a significantly reduced need for augmentation of labor with oxytocin (OR=0.36; 95% C.I. 0.17-0.73) and delivery by cesarean section for failure to progress (OR=0.11; 95% C.I. 0.00-0.88). The risk for duration of induction to vaginal delivery exceeding 12, 18 or 24 h was reduced by 18%, 38% and 68%, respectively, but only the risk for duration >24 h was significantly reduced (OR=0.32; 95%C.I. 0.11-0.91). The mean duration of induction was shorter in the misoprostol group, 15.2 vs. 23.6 h (P=0.02). There were no differences in fetal outcome.

CONCLUSION

Misoprostol 50 microg was associated with less use of oxytocin in labor, a shorter induction to delivery interval and fewer cesarean sections for failure to progress when compared with extra-amniotic PGF2alpha gel.

Sociodemographic predictors of self-rated health in patients with diabetes of short duration

AIMS

To examine the impact of gender and socioeconomic factors on health-related quality of life (HRQoL) one year and eight years after diabetes diagnosis.

METHODS

Two national incidence cohorts who contracted diabetes between the ages of 15 and 34 years (n=554) and matched control groups from the general population of Sweden (n=1,029) were surveyed. Data on HRQoL, diabetes treatment, marital status, education, social class, and employment were collected via a questionnaire mailed to the younger cohort (aged 16-35) one year after diagnosis and to the older cohort (aged 23-42) eight years after diagnosis. Response rates were 73% among people with diabetes and 68% among the controls. Multivariable linear regression models were used to analyse the impact of gender and socioeconomic factors on HRQoL in the diabetic and control groups. The dependent variable was the "general health perceptions" score of the SWED-QUAL instrument, which corresponds to the "global self-rated health" concept.

RESULTS

A model including all the sociodemographic variables explained 6% of the variance in self-rated health one year after diabetes diagnosis and 13% of the variance eight years after diagnosis. In the control groups, the level of explanation was 2-3%. Female gender was an independent predictor of poor self-rated health in the older diabetic cohort, but not in the younger cohort.

CONCLUSIONS

Gender and socioeconomic factors were more closely associated with self-rated health eight years after diabetes diagnosis than one year after diagnosis, indicating early sociodemographic stratification in the health of the diabetic populations studied.

An incident case-control study of first unprovoked afebrile seizures in children: a population-based study of pre- and perinatal risk factors

PURPOSE

The aim of this prospective incident community-based study was to assess the influence of pre- and perinatal risk factors in children in whom an unprovoked afebrile epileptic seizure later developed.

METHODS

From November 1, 1985, until June 30, 1987, 75 children aged 0-15 years with a first unprovoked afebrile seizure were identified. After exclusion of cases with neonatal seizures (n = 14), two controls per case were selected from the same province in northern Sweden matched by age and sex. Files from maternity wards and pediatric clinics could be traced for 58 cases and 109 controls. These formed the study group.

RESULTS

In the univariate analysis, the risk for an unprovoked afebrile seizure was significantly elevated for birth order (OR = 9.3; CI, 2.2-39), vaginal bleeding (OR = 17; 95% CI, 3.5-85), onset of hypertension during pregnancy (OR = 4.8; CI, 1.3-17), cesarean section (OR = 18; 95% CI, 3.7-88), short or long gestational age (OR = 6.7; 95% CI, 2.0-22), and an Apgar score < or =6 at any time (OR = 3.8; 95% CI, 1.2-12). None of these six factors was present in 48.3% of the cases and 89% in the controls. A combination of two or more risk factors found to be significant in the univariate analysis showed a pronounced increased risk for seizures (OR = 19; 95% CI, 5.6-65). In the multivariate analysis, the following characteristics remained statistically significant: vaginal bleeding, gestational age, and Cesarean section. Furthermore, smoking also was identified as a risk factor in the multivariate analysis (OR = 3.4; 95% CI, 1.1-10).

CONCLUSIONS

Both pre- and perinatal factors may be associated with later development of epileptic seizures in children. However, in many of the cases, no such factors were identified.

Combinations of beta cell specific autoantibodies at diagnosis of diabetes in young adults reflects different courses of beta cell damage

To explore the natural course of beta cell function in recent onset diabetes, a subgroup (n=157) of all incident cases (n=879) 15-34 years old, 1992-1993 in Sweden, and with positivity for at least one autoantibody of islet cell antibodies (ICA), glutamic acid decarboxylase antibodies (GADA) or tyrosine phosphatase antibodies (IA-2A) were followed prospectively for the first four years with annual analysis of C-peptide. The aim was to relate the course of beta cell function, measured as C-peptide, in early diabetes with the presence of different islet autoantibodies at diagnosis. We found that patients positive for ICA alone (n=11) had significantly higher C-peptide levels both at diagnosis and during the first three years compared with the other patients (n=146; p=0.022, p<0.001, p=0.004 and p=0.0022). Patients positive for GADA alone or in combination with other antibodies (n=125) had significantly lower C-peptide during the first three years after diagnosis compared with the other patients (n=32, p<0.001, p=0.0011 and p=0.0136). Patients with two or three autoantibodies had C-peptide levels similar to levels found in patients positive only for GADA. However, after four years, there were no significant differences between any of the groups of different autoantibody combinations. At diagnosis, 55% (86/157) of the patients had C-peptide levels above the lower normal range of 0.25 nmol/l, but the frequency of patients with beta cell function above this level decreased after two years to 41% (65/157; p=0.035) and after four years to 22% (35/157; p=0.0041). It is concluded that young adult diabetic patients positive only for ICA at diagnosis have a better preserved beta cell function with higher levels of C-peptide during the first three years compared with patients positive for GADA alone or in combinations with other autoantibodies.

Family characteristics and life events before the onset of autoimmune type 1 diabetes in young adults: a nationwide study

OBJECTIVE

To elucidate whether family characteristics and stressful life events were associated with onset of autoimmune type 1 diabetes in young adults.

RESEARCH DESIGN AND METHODS

This investigation was based on a nationwide study (Diabetes Incidence Study in Sweden) of newly diagnosed patients aged 15-34 years. Patients clinically classified as type 1 diabetic with antibodies to islet cells and/or to GAD65 were compared with age- and sex-matched control subjects via questionnaire. The questionnaire covered diabetes heredity, social environment, educational level, and life events experienced during the 12 months before diagnosis.

RESULTS

The rate of response was 82% for the diabetic patients and 65% for the control subjects. Questionnaires from 349 diabetic patients and 979 control subjects were considered. Diabetes in relatives was more frequent in the patients (odds ratio [OR]2.6) who were born in Sweden and whose mothers were of Swedish origin. No major stress factors were detected in the diabetic patients; however, in comparison with the control subjects, the diabetic patients had experienced fewer conflicts with their parents and had less often broken contacts with friends.

CONCLUSIONS

Young adults with recent-onset type 1 diabetes were more exposed to heredity for diabetes, but no major prediabetic stress factors were detected. Our study does not directly support the concept that psychosocial stressful life events are involved in the development of autoimmune type 1 diabetes in young adults.

Intrauterine infection may be a major cause of stillbirth in Sweden

AIM OF THE STUDY

To investigate intrauterine infection as a cause for unexplained stillbirth.

METHODS

Chorioamnionitis was studied in a material of stillbirths (117 subjects from the years 1985-1994) from a region in the south Sweden. Control material (126 alive and healthy newborns and with healthy mothers) was gathered from the same region.

RESULTS

Chorioamnionitis was a common diagnosis both with stillbirths and 'healthy' deliveries (82 and 68%, respectively). Extension of the inflammation to decidua basalis was seven times more common among stillbirths than among controls (odds ratio 7.2, confidence interval 2.8-21.9). The most common bacteria found at cultures were Escherichia coli, Coagulase negative staphylococcus, Enterococcus faecalis and group B Streptococcus. The risk for stillbirth was doubled if both inflammation and bacteria were present (odds ratio 2.3, confidence interval 0.92-5.8). Meconium discharge was more common among stillbirths than controls (odds ratio=4.7, confidence interval 1.7-14). There were no differences in any respect regarding macerated and non-macerated stillbirths. Our findings are similar to the results from studies in developing countries except for the higher incidence of stillbirths in such countries.

CONCLUSIONS

Thus, a large part of otherwise unexplained stillbirths might be due to ascending infections.

Prevalence of multiple sclerosis in Västerbotten County in northern Sweden

OBJECTIVE

To estimate the prevalence and clinical characteristics of multiple sclerosis (MS) in Västerbotten County in northern Sweden.

METHODS

Individuals with MS were identified from several sources. A follow-up interview and/or examination was performed in 94% of cases still living in the area during 1997-99. Onset adjusted prevalence and a definition of onset symptoms were applied.

RESULTS

A total of 313 cases were identified, resulting in an onset adjusted crude prevalence of MS for January 1990 of 125/105 (95% confidence interval (CI): 112-140). Female predominance was evident (163/105 (95% CI: 142-187) vs 86/105 (95% CI: 71-104)). Diagnostic coding registers were the most important source for identification of cases.

CONCLUSIONS

The crude prevalence of MS in Västerbotten was higher than previous reports from other major areas in Scandinavia. The adjusted prevalence was significantly higher when compared with a previous study from Göteborg, south-western Sweden. The methodology used in this study gives a high degree of case ascertainment and increases the comparability of multiple sclerosis epidemiological studies.

Increased mortality in diabetes during the first 10 years of the disease. A population-based study (DISS) in Swedish adults 15-34 years old at diagnosis

OBJECTIVES

To study, prospectively, in young adult patients, the mortality during the first years after the diagnosis of diabetes.

DESIGN

The Diabetes Incidence Study in Sweden (DISS) aims to register all incident cases aged 15-34 years. During a 10-year period all deaths were identified by record linkage to the national Cause of Death Registry.

SUBJECTS

During the period, 4097 new cases were registered and classified as type 1 diabetes (73%), type 2 (16%), secondary (2%) and unclassified (9%). The median follow-up was 5 years (21 001 person-years).

MAIN OUTCOME MEASURES

Calculation of the standardized mortality ratio (SMR) and 95% confidence interval (CI). Evaluation of all deceased by scrutiny of clinical records, death certificates and autopsy protocols.

RESULTS

Fifty-eight patients died, corresponding to an SMR of 3.5 (CI=2.7-4.5), which increased from 1.5 at 15-19 years to 4.1 at 30-34 years. SMR was 2.7 in primary diabetes: 2.3 (1.6-3.3) in type 1 and 4.1 (2.6-6.7) in type 2. In secondary diabetes, alcohol-associated pancreatitis a common cause, SMR was 32 (CI=24-45). Evidence of alcohol or drug misuse, mental dysfunction or suicide was found in 40 of all 58 deceased cases. Less often, hypoglycaemia (n=7) or hyperglycaemia-ketoacidosis (n=11) was present at death. Unexplained 'dead in bed' was found once.

CONCLUSIONS

In the investigated population-based cohort the early mortality was about threefold increased. Hypoglycaemia and ketoacidosis per se played a relatively small role compared with a heavy impact from social and mental dysfunction, and from careless use of alcohol or drugs.

Service screening with mammography in Sweden--evaluation of effects of screening on breast cancer mortality in age group 40-49 years

The aim of the study was to develop a model for estimating the effect of the nation-wide service screening program with mammography on breast cancer mortality in Sweden. In 1997, the introduction of population-based service screening had been completed in all 26 counties. In approximately half of the counties suitable for evaluation, the lower age limit for invitation was 40 years (study population) and in the other half the age limit was 50 years (control population). The numbers of females aged 40 49 years for the two populations were 202,152 and 237,279, respectively (1988). The study and control populations were compared for the period 1986-1996 with regard to refined breast cancer mortality. To adjust for geographical differences, the period 1976 1986 was used as reference. With a mean follow-up time of 8 years, the estimated relative risk of breast cancer death in relation to invitation to service screening among women aged 40-49 years at breast cancer diagnosis was 0.91 (95% confidence interval 0.72-1.15). These findings were compatible with those presented in the previous overview of the Swedish randomized studies.

Prognostic factors for the course of beta cell function in autoimmune diabetes

This study presents a 2-yr follow-up of 281 patients, aged 15-34 yr, diagnosed with diabetes between 1992 and 1993. At diagnosis, 224 (80%) patients were positive for at least one of the following autoantibodies: islet cell antibodies (ICAs), glutamic acid decarboxylase antibodies (GADAs), or tyrosine phosphatase antibodies (IA-2As); the remaining 57 (20%) patients were negative for all three autoantibodies. At diagnosis, C-peptide levels were lower (0. 27; 0.16-0.40 nmol/L) in autoantibody-positive patients compared with autoantibody-negative patients (0.51; 0.28-0.78 nmol/L; P: < 0. 001). After 2 yr, C-peptide levels had decreased significantly in patients with autoimmune diabetes (0.20; 0.10-0.37 nmol/L; P: = 0. 0018), but not in autoantibody-negative patients. In patients with autoimmune diabetes, a low initial level of C-peptide (odds ratio, 2. 6; 95% confidence interval, 1.7-4.0) and a high level of GADAs (odds ratio, 2.5; 95% confidence interval, 1.1-5.7) were risk factors for a C-peptide level below the reference level of 0.25 nmol/L 2 yr after diagnosis. Body mass index had a significant effect in the multivariate analysis only when initial C-peptide was not considered. Factors such as age, gender, levels of ICA or IA-2A or insulin autoantibodies (analyzed in a subset of 180 patients) had no effect on the decrease in beta-cell function. It is concluded that the absence of pancreatic islet autoantibodies at diagnosis were highly predictive for a maintained beta-cell function during the 2 yr after diagnosis, whereas high levels of GADA indicated a course of decreased beta-cell function with low levels of C-peptide. In autoimmune diabetes, an initial low level of C-peptide was a strong risk factor for a decrease in beta-cell function and conversely high C-peptide levels were protective. Other factors such as age, gender, body mass index, levels of ICA, IA-2A or IAA had no prognostic importance.

Glutamic acid decarboxylase antibodies (GADA) is the most important factor for prediction of insulin therapy within 3 years in young adult diabetic patients not classified as Type 1 diabetes on clinical grounds

BACKGROUND

Differentiation between Type 1 and Type 2 diabetes in adults is difficult at diagnosis. In this study we tested the hypothesis that autoantibodies at diagnosis are predictive for insulin treatment within 3 years in patients initially not classified as Type 1 diabetes.

METHODS

In a nationwide population-based study, blood samples were obtained from 764 patients, all diagnosed with diabetes during a 2-year period. At diagnosis, 583 (76%) were classified as Type 1, 110 (14%) as Type 2 and 71 (9.3%) could not be classified.

RESULTS

Among patients not classified as Type 1 diabetes, 52 (47%) of Type 2 and 42 (59%) of unclassified patients were positive for islet cell antibodies (ICA), glutamic acid decarboxylase antibodies (GADA) or tyrosine phosphatase antibodies (IA-2A). These patients (n=94) had lower body mass index (BMI) (p<0.001) and lower C-peptide (p<0.001) compared to the autoantibody negative patients (n=87). Compared to clinically classified Type 1 diabetes patients positive for autoantibodies (n=477), they have higher BMI (p<0.001), higher C-peptide (p<0.001) and the same levels of ICA, GADA and IA-2A. After 3 years, 93% of autoantibody positive patients initially not classified as Type 1 were on insulin. When ICA, GADA, IA-2A, BMI and C-peptide were tested in a multiple logistic regression, only GADA was significant for insulin treatment within 3 years (OR=18.8; 95% CI 1.8-191) in patients treated with diet or oral drugs at diagnosis.

CONCLUSIONS

A correct classification is difficult in adult diabetic patients. The presence of pancreatic autoantibodies, especially GADA, at diagnosis of diabetes are highly predictive for insulin therapy within 3 years from diagnosis.

Mortality risk in an adult cohort with a newly diagnosed unprovoked epileptic seizure: a population-based study

PURPOSE

We sought to investigate mortality risk in an adult cohort with newly diagnosed unprovoked epileptic seizures.

METHODS

One hundred seven patients who were at least 17 years old and had newly diagnosed unprovoked epileptic seizures were prospectively identified during a period of 20 months between 1985 and 1987. Patients were followed until the date of death or the end of 1996. The standard mortality ratio (SMR) was analyzed in the whole cohort and in the portion of the cohort with recurrent seizures at inclusion. The influences on the SMR of time since diagnosis, sex, age at diagnosis, seizure cause, seizure type, and cause of death were also investigated.

RESULTS

The SMR was significantly increased (SMR, 2.5; 95% confidence interval [CI], 1. 2-3.2). This significantly increased risk was found during the first 2 years after diagnosis (year 1: SMR, 7.3; 95% CI, 4.4-12.1; year 2: SMR, 3.6; 95% CI, 1.6-8.1) and at years 9-11 (SMR, 5.4; 95% CI, 2. 7-11.2). The increased mortality risk was most pronounced when the seizures occurred before the age of 60 years. Mortality risk was elevated among patients with remote symptomatic epilepsy (SMR, 3.3; 95% CI, 2.4-4.5) but not idiopathic epilepsy.

CONCLUSIONS

There is increased mortality risk in an adult cohort with newly diagnosed unprovoked epileptic seizures. This increase is found in symptomatic patients, young patients, and during the first 2 years after the diagnosis.

Excess costs of medical care 1 and 8 years after diagnosis of diabetes: estimates from young and middle-aged incidence cohorts in Sweden

To analyze the excess costs of medical care during the first decade after diabetes diagnosis, we surveyed two national incidence cohorts who contracted diabetes at age of 15-34 years and matched control groups from the general population of Sweden. Ninety percent of the diabetic subjects were on insulin treatment. Data on healthcare utilization and use of glucose lowering drugs and medical devices were collected via a questionnaire mailed to a recent cohort 1 year after diagnosis and a previously registered cohort 8 years after diagnosis. Costing was based on average national costs of hospital inpatient and out-patient care, an original study of daycare costs, and sales prices of the National Corporation of Swedish Pharmacies. One year after diabetes diagnosis, the annual excess costs of care were US$4743 among men and US$4976 among women (1997 prices). Hospital inpatient care accounted for more than 50% of the excess costs. Eight years after diagnosis, the excess costs were US$2010 among men and US$2734 among women. The higher costs for women were mainly related to hospital out-patient care, but also to more intensive self-monitoring. We conclude that diabetes in young and middle-aged people is a major economic challenge even before significant complications may have developed.