Islet cell surface antibodies are more common in patients and relatives in areas and during seasons with high incidence of insulin-dependent diabetes mellitus

Iodine deficiency during pregnancy: a national cross-sectional survey in Latvia

Objective

Low iodine intake during pregnancy may cause thyroid dysfunction, which results in inadequate fetal brain development. In the absence of a universal salt iodization programme, we conducted a nationwide survey of iodine deficiency in pregnant women in Latvia.

Design

A countrywide twenty-cluster survey, with at least twenty women per cluster. Participants completed a questionnaire on dietary habits concerning iodine intake (n 739). Thyroid function (thyroid-stimulating hormone, free thyroxine and thyroperoxidase antibodies) was measured (n 550). Urinary iodine was measured using the ammonium persulfate method (n 696).

Setting

The survey was performed in all regions of Latvia during the spring and autumn seasons in 2013.

Subjects

Pregnant women (n 829).

Results

The median creatinine (Cr)-standardized urinary iodine concentration (UIC) was 80·8 (interquartile range (IQR) 46·1–130·6) µg/g Cr or 69·4 (IQR 53·9–92·6) µg/l during pregnancy, and 81 % of pregnant women had UIC levels below the WHO recommended range of 150–250 µg/g Cr. The UIC was lowest during the first trimester of pregnancy, 56·0 (IQR 36·4–100·6) µg/g Cr, reaching higher concentrations of 87·5 (IQR 46·4–141·7) µg/g Cr and 86·9 (IQR 53·8–140·6) µg/g Cr in the second and third trimesters, respectively. Women taking supplements containing ≥150 µg iodine (6·8 % of respondents) had non-significantly higher UIC than did women without supplementation (96·2 v. 80·3 µg/g Cr, respectively, P=NS). Thyroperoxidase antibody concentration did not correlate significantly with UIC: Spearman’s ρ=−0·012, P=0·78.

Conclusions

The median UIC indicates iodine deficiency in pregnant women in Latvia. Iodine supplementation (150 µg daily) and regular UIC monitoring should be suggested to overcome iodine deficiency and to reach the recommended levels without inducing autoimmune processes.

Seasonal variation in the activity of systemic lupus erythematosus

OBJECTIVE

To determine whether there is any seasonal variation in the activity of systemic lupus erythematosus (SLE) overall and by individual organs.

METHODS

The study group comprised 2102 patients with SLE who were followed in a prospective longitudinal cohort study. In this cohort, 92.3% of the patients were women. The mean ± SD age of the patients was 47.9 ± 13.9 years, 56.3% were white, 37.1% were African American, and 3.1% were Asian. Global disease activity was recorded by the Safety of Estrogens in Lupus Erythematosus National Assessment - Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI) and the physician's global assessment. Activity of each organ was also recorded using SLEDAI terms and a visual analog scale (VAS; 0 to 3).

RESULTS

There was significant seasonal variation in photosensitive rash (p < 0.0001), which was more frequent in the spring and summer months (p < 0.0001). There was significantly more arthritis activity in spring and summer, as measured by both SELENA-SLEDAI (p = 0.0057) and the joint VAS (p = 0.0047). A decrease in renal activity was found in the summer months compared to the rest of the year (p = 0.0397). Serositis recorded by VAS had higher activity from August to October (p = 0.0392). Anti-dsDNA levels were significantly higher during October and November (p < 0.0001). There was significant seasonal variation in antiphospholipid antibody levels (p < 0.0001) and lupus anticoagulant (p = 0.0003). We found a significant variation in activity through the year in global disease activity as measured by SELENA-SLEDAI (p = 0.048).

CONCLUSION

In the Hopkins Lupus Cohort, skin and joint activity is increased during the spring and summer, but other organs have different patterns. These seasonal variations likely reflect environmental factors that influence disease activity, including ultraviolet light and infections.

Seasonal variation in the diagnosis of type 1 diabetes in south-east Sweden

With the aim to survey the seasonal pattern of diagnosis of type 1 diabetes we included all 1903 children <16 years of age and who had been diagnosed with type 1 diabetes between 1977 and 2001 in the south-east of Sweden. To investigate the seasonal pattern a mixture of two cosine functions was included in a logistic regression model. There was a clear seasonal variation over the years (p<0.001). Children in the oldest age group (11-15 years) showed the most obvious seasonal variation (p<0.001). Children with a short duration of symptoms had about the same seasonal variation as children with a long duration. Both children with and without an infection 3 months prior to diagnosis showed significant seasonal variation (p<0.001) although the seasonal pattern differed between the two groups (p<0.001). As the incidence of diabetes increased during the 25 years the study period was divided into periods of 5 years and it was only during the two last periods that significant seasonal variation occurred. There is a clear seasonal variation in diagnosis of type 1 diagnosis in children and the results suggest that children with a less aggressive disease process at diagnosis were most responsible for this variation. Children with and without prior infection showed a different seasonal pattern.

IA-2A positivity rate at manifestation of type 1 diabetes mellitus in Slovak children culminates in September

BACKGROUND

New cases of type 1 diabetes mellitus (DM1) in Slovak children accumulate in late summer, autumn and winter.

HYPOTHESES

Children manifesting the disease in these seasons have higher autoantibody positivity than those first diagnosed in spring or summer.

PATIENTS AND METHODS

One hundred and fifty Slovak children (and adolescents), aged 1-14 (15-17) years at the manifestation of DM1, born 1978-2000, with the disease manifested 1989-2001, were investigated at diagnosis by IA-2A, GADA and IAA autoantibody positivity, using standard radioimmunoassay procedures. The resulting risk score values (0-1) were related to calendar days of diagnosis. Their annual, semi-annual and quarterly periodicity was tested using Halberg's cosinor regression.

RESULTS

Only IA-2A positivity at the time of diagnosis showed significant seasonal cycling, with the acme around the autumn equinox and with the nadir in spring. There was no increase of this positivity in winter.

CONCLUSION

The maximum autoantibody levels were found for those manifesting the disease in late summer and early autumn--the only time of year in Slovakia when both the numbers of births of future diabetic children as well as those of manifestation of new cases are significantly above average.

Secular and seasonal cycling of IA2-ab autoantibody in Slovak diabetic children

The concept of seasonal and secular cycling of initial autoantibody plasma levels in children with diabetes mellitus 1 is not common, despite the known fluctuations in one of the triggering factors, i.e., various enteroviral infections. The aim of this study was therefore to assess the trends and cycles in the time series of IA2-autoantibody (ab) blood plasma levels measured in each patient at the moment of diagnosis of the disease, before the first injection of insulin. In a retrospective study, the IA2-ab data, with each item related to a calendar day, were analyzed from 83 male and 108 female patients aged up to 14 years, with the date of disease menifestation between January 1993 and December 1999. The data source was the Slovak National Register of Childhood Diabetes. The plasma levels of the autoantibody against pancreatic tyrosine phosphatase (IA2-ab) were measured by radioimmunoassay. The chronogram of the daily observed values, modified by moving averages, from three successive data items per patient, was processed by Halberg's cosinor method to test the presence of seven-year sinusoids and one-year rhythms. One seven-year sinusoid, peaking in February 1998 (boys) and in October 1996 (girls), and a seasonal rhythm culminating in May/June each year were significant. There are some similarities to the cycling of other variables such as the incidence of diabetes, the birth of future diabetics, Coxsackie virus epidemics and pancreatic glutamic acid decarboxylase (GAD 65) autoantibody. Moreover, some cosmo-geophysical periods also seem to be cycling in a parallel manner. The novelty of this contribution is that it examines the seasonal cycling of the autoantibody, connected with the pathogenesis of diabetes and directed against IA2-ab.