Body mass index standard deviation score and obesity in children with type 1 diabetes in the Nordic countries. HbA1c and other predictors of increasing BMISDS.

BACKGROUND: Intensified insulin therapy may increase body weight and cause obesity. This study compared body mass index standard deviation score (BMISDS) and obesity rate in children with type 1 diabetes (T1D) in Denmark, Iceland, Norway and Sweden, and uncovered predictors for increasing BMISDS. METHODS: Data registered in the Nordic national childhood diabetes databases during the period 2008-2012 on children below 15 years with T1D for more than 3 months were compiled, including information on gender, age, diabetes duration, hemoglobin A1c (HbA1c ), insulin dose, severe hypoglycemia (SH), treatment modality, height and weight. The Swedish reference chart for BMI was used for calculating BMISDS. RESULTS: Totally, 11 025 children (48% females) (30 994 registrations) were included. Medians by the last recorded examination were: age, 13.5 years; diabetes duration, 4.3 years; HbA1c , 7.9% (63 mmol/mol); insulin dose, 0.8 IU/kg/d and BMISDS, 0.70. Obesity rate was 18.5%. Adjusted mean BMISDS (BMISDS adj) was inversely related to HbA1c and directly to diabetes duration. Higher BMISDS adj was found in those with an insulin dose above 0.6 IU/kg/d, and in girls above 10 years. Pump users had higher BMISDS adj than pen users, and patients with registered SH had higher BMISDS adj than patients without SH (both P < .001). CONCLUSION: Obesity rate in children with T1D in the Nordic countries is high, however, with country differences. Low HbA1c , long diabetes duration, higher insulin dose, pump treatment and experiencing a SH predicted higher BMISDS. Diabetes caregivers should balance the risk of obesity and the benefit of a very low HbA1c.

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.

Time trend of childhood type 1 diabetes incidence in Lithuania and Sweden, 1983-2000.

AIM: To compare the time trend of childhood type 1 diabetes over an 18-y period in Lithuania and Sweden--countries with different incidence levels and different socio-economic conditions. METHODS: Percent average incidence change per year between 1983 and 2000, based on 8031 Swedish and 1100 Lithuanian cases in the age group 0-14 y, was calculated using Poisson regression. RESULTS: Average age- and sex-standardized incidence/100 000/y was 28.9 (95% CI: 28.2-29.5) in Sweden and 7.5 (95% CI: 7.1-8.0) in Lithuania. Between 1983 and 2000, the average increase per year was 2.2% in Sweden (95% CI: 1.7-2.6) and 2.3% in Lithuania (95% CI: 1.1-3.5), but the latter trend depended on an increase during the last few years of the period, and only for girls. In Sweden, incidence increased significantly in all age groups, but more so in the younger groups (3.0%, 2.2% and 1.7% per year in 0-4, 5-9 and 10-14-y age groups, respectively), while in Lithuania a significant increase was found only in the 10-14-y age group (3.0%). In Sweden, a trend towards a younger age at diagnosis was indicated for both boys and girls when comparing 1983-1991 and 1992-2000, whereas in Lithuania, the changes in age distribution over time were small, with an opposite tendency for boys. CONCLUSION: Incidence variability over time differed considerably in the two countries in the region of the Baltic Sea, suggesting a complex effect of environmental risk factors, some of which may be associated with wealth and socio-economic conditions.

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.

Infections and risk of Type I (insulin-dependent) diabetes mellitus in Lithuanian children.

AIMS/HYPOTHESIS: The role of infections in the aetiology of Type I diabetes is controversial. Certain enteroviral infections might be involved in triggering the beta-cell destruction but insufficient exposure to early infections might increase the risk. We studied how the number of infections experienced during several periods from birth to onset influence diabetes risk. METHODS: The study group came from the five largest Lithuanian cities: 124 patients, selected from the 0-14 years-of-age childhood diabetes register and 372 population-based control subjects matched with them for age group and sex. Information about infections and duration of breastfeeding was collected from health care booklets, other data from a mailed questionnaire, returned by 94.4% of patients and 72.6 % of control subjects. RESULTS: One or more infections experienced during the first half year of life tended to reduce diabetes risk. Crude odds ratios (95% confidence intervals) in the 0-14, 0-4 and 5-14 years-of-age groups were 0.66 (0.42-1.04), 1.06 (0.48-2.36) and 0.52 (0.30-0.90) respectively. Adjustment for the duration of breastfeeding, number of people in the household, duration of mother's education and birth order of the index child made little difference. Odds ratios (95 % confidence intervals) in the 0-14, 0-4 and 5-14 years-of-age groups were 0.60 (0.37-0.98), 0.94 (0.40-2.20) and 0.47 (0.26-0.87), respectively. The number of infections recorded during the last pre-onset year or from birth to onset did not influence diabetes risk. CONCLUSION/INTERPRETATION: Exposure to infections early in life could decrease diabetes risk, particularly for children diagnosed after the age of 4 years.