Clustering of cases of type 1 diabetes in high socioeconomic communes in Santiago de Chile: spatio-temporal and geographical analysis

Trends in the Incidence of Type 1 Diabetes in European Children and Adolescents from 1994 to 2022: A Systematic Review and Meta-Analysis

Aim

To assess the incidence trends in type 1 diabetes among children and adolescents across Europe during the period from 1994 to 2022 using a systematic methodology.

Materials and Methods

Cross-sectional or follow-up studies reporting population-based incidence rates (IRs) of European children and adolescents diagnosed aged <15 years with type 1 diabetes were included. The Mantel‒Haenszel or DerSimonian and Laird random-effects method was used to compute the pooled IR estimates and their 95% confidence intervals (CIs). Subgroup analyses were conducted by study year, biological sex, age group (0-4, 5-9, and 10-14 years), country, and European regions.

Results

A total of 75 studies (219,331 children and adolescents aged 0-14 years) with data from 32 countries were included. Generally, a high overall rate of increase in type 1 diabetes incidence has been shown in most European countries from 1994 to 2022 in both sexes, with an overall increase from 10.85 (95% CI, 9.62-12.07) per 100,000 person-years from 1994 to 2003 to 20.96 (95% CI, 19.26-22.66) per 100,000 person-years from 2013 to 2022.

Conclusions

There are substantial between-country differences in the current levels and trends of IR in type 1 diabetes in European children and adolescents. Our data suggest a worrying upward trend in most European countries.

Parental socio-economic position and the risk of type 1 diabetes in children and young adults in Denmark: A nation-wide register-based study

AIM

Diabetes mellitus type 1 is one of the most common serious chronic diseases in childhood and the incidence is increasing. Insight into risk factors may inform our etiologic understanding of the disease and subsequent prevention. Any socio-economic gradient in disease risk indicates a potential for prevention, since this points towards socially patterned environmental risk factors. The aim of this study was to investigate the association between measures of parental socio-economic position and the onset of type 1 diabetes in offspring based on individual data in the entire Danish population.

METHODS

In a study population of all children born in Denmark between 1 January 1987 and 31 December 2010, we examined the association between parental socio-economic position and the risk of type 1 diabetes up to the age of 25 years. The risk of type 1 diabetes was estimated according to maternal education, paternal education and household income using Cox proportional hazards regression, with adjustments for the a priori selected confounding variables: year of birth, maternal age at birth and parental type 1 diabetes.

RESULTS

In the study population of 1,433,584 children, a total of 4610 developed type 1 diabetes. We found no clear pattern in type 1 diabetes risk according to parental educational attainment or parental household income.

CONCLUSIONS

In this large population covering study of the risk of type 1 diabetes according to individual-level parental socio-economic position, we found no strong indication of a socially patterned disease risk.

Type 1 Diabetes incidence among youth in Utah: A geographical analysis

Type 1 Diabetes (T1D) poses an increasing threat to public health, as incidence rates continue to rise globally. However, the etiology of T1D is still poorly understood, especially from the perspective of geography. The objective of this research is to examine the incidence of T1D among youth and to identify high-risk clusters and their association with socio-demographic and geographic variables. The study area was the entire state of Utah and included youth with T1D from birth to 19 years of age from 1998 to 2015 (n = 4161). Spatial clustering was measured both globally and locally using the Moran's I statistic and spatial scan statistic. Ordinary least squares (OLS) regression was used to measure the association of high-risk clusters with certain risk factors at the Census Block Group (CBG) level. The mean age at diagnosis was 9.3 years old. The mean incidence rate was 25.67 per 100,000 person-years (95% CI, 24.57-26.75). The incidence rate increased by 14%, from 23.94 per100,000 person-years in 1998 to 27.98 per 100,000 person-years in 2015, with an annual increase of 0.80%. The results of the spatial scan statistic found 42 high-risk clusters throughout the state. OLS regression analysis found a significant association with median household income, population density, and latitude. This study provides evidence that incidence rates of T1D are increasing annually in the state of Utah and that significant geographic high-risk clusters are associated with socio-demographic and geographic factors.

Disentangling socioeconomic inequalities of type 2 diabetes mellitus in Chile: A population-based analysis

Introduction

Chile experiences a growing prevalence of DM2 in its adult population over time. The country has prioritised the diagnosis and treatment of DM2 through a universal health care package, largely focused on the clinical dimensions of the disease. We analysed the significance of socioeconomic variables in the prevalence of DM2, as well as its related dimensions of presence of complications (diabetic foot and ophthalmologic complications), attendance to health checks and acquisition of recommended lifestyle changes due to this condition.

Methods

Secondary analysis of the national health survey (ENS) 2016–2017 (n = 6,233 respondents). Crude and income-adjusted odds of reporting DM2 was estimated, as well as the relationship between complications due to diabetes and a number of clinical and sociodemographic variables using weighted log-linear multiple regression models.

Results

We found a clear social gradient of the prevalence of DM2 by household income quintiles and educational level in the adult population. Income quintile and educational level gradients remained significantly associated with the presence of complications and attendance to health checks. We found no significant association, however; between income quintile and reported lifestyle change. The association between complications due to DM2 and socioeconomic variables, particularly income, remained relevant even after adjusting for all sociodemographic variables.

Conclusion

This is the first study to analyse the association between DM2 and socioeconomic variables in Chile, useful for monitoring and policy planning. Income was strongly associated with DM2 prevalence and with related clinical variables (complications and attendance to health checks). Age, health care provision and educational level were also relevant factors, but lost significance in the fully adjusted model.

Development of a small panel of SNPs to infer ancestry in Chileans that distinguishes Aymara and Mapuche components

Background

Current South American populations trace their origins mainly to three continental ancestries, i.e. European, Amerindian and African. Individual variation in relative proportions of each of these ancestries may be confounded with socio-economic factors due to population stratification. Therefore, ancestry is a potential confounder variable that should be considered in epidemiologic studies and in public health plans. However, there are few studies that have assessed the ancestry of the current admixed Chilean population. This is partly due to the high cost of genome-scale technologies commonly used to estimate ancestry. In this study we have designed a small panel of SNPs to accurately assess ancestry in the largest sampling to date of the Chilean mestizo population (n = 3349) from eight cities. Our panel is also able to distinguish between the two main Amerindian components of Chileans: Aymara from the north and Mapuche from the south.

Results

A panel of 150 ancestry-informative markers (AIMs) of SNP type was selected to maximize ancestry informativeness and genome coverage. Of these, 147 were successfully genotyped by KASPar assays in 2843 samples, with an average missing rate of 0.012, and a 0.95 concordance with microarray data. The ancestries estimated with the panel of AIMs had relative high correlations (0.88 for European, 0.91 for Amerindian, 0.70 for Aymara, and 0.68 for Mapuche components) with those obtained with AXIOM LAT1 array. The country’s average ancestry was 0.53 ± 0.14 European, 0.04 ± 0.04 African, and 0.42 ± 0.14 Amerindian, disaggregated into 0.18 ± 0.15 Aymara and 0.25 ± 0.13 Mapuche. However, Mapuche ancestry was highest in the south (40.03%) and Aymara in the north (35.61%) as expected from the historical location of these ethnic groups. We make our results available through an online app and demonstrate how it can be used to adjust for ancestry when testing association between incidence of a disease and nongenetic risk factors.

Conclusions

We have conducted the most extensive sampling, across many different cities, of current Chilean population. Ancestry varied significantly by latitude and human development. The panel of AIMs is available to the community for estimating ancestry at low cost in Chileans and other populations with similar ancestry.

Geographical variation in the incidence of type 1 diabetes in the Nordic countries: A study within NordicDiabKids

BACKGROUND

The incidence of type 1 diabetes (T1D) is high in the Nordic countries with geographic differences between as well as within countries.

OBJECTIVE

To describe the geographical distribution of the incidence of T1D among children in four Nordic countries, an area where the population is considered genetically similar.

METHODS

Data on children 0 to 14 years of age and diagnosed with T1D 2006 to 2011 was collected from four Nordic national pediatric quality diabetes registries. Data included year of diagnosis (2006-2011), sex, and age at diagnosis. Figures for number of children at risk during 2006 to 2011-as well as total population, proportion with foreign background and size of populated areas of geographic regions-were collected from official statistics.

RESULTS

The total incidence during the study period for all four countries was 35.7/100 000 person years but differed between the countries (range 18.2-44.1; P < .001). The incidence difference between the countries was most obvious in the highest age group, 10 to 14 years of age, whereas there was no difference in the youngest age group 0 to 5 years of age. Iceland had similar incidence in the entire country, whereas the other countries had areas with different incidence. Densely populated areas, such as major cities, had the lowest incidence.

CONCLUSION

The incidence of T1D differed between the Nordic countries and also between the neighboring countries and generally decreased with population density. This indicates that environmental factors may contribute to the level of incidence of T1D.

Correlating the global increase in type 1 diabetes incidence across age groups with national economic prosperity: A systematic review

BACKGROUND

The global epidemiology of type 1 diabetes (T1D) is not yet well known, as no precise data are available from many countries. T1D is, however, characterized by an important variation in incidences among countries and a dramatic increase of these incidences during the last decades, predominantly in younger children. In the United States and Europe, the increase has been associated with the gross domestic product (GDP) per capita. In our previous systematic review, geographical variation of incidence was correlated with socio-economic factors.

AIM

To investigate variation in the incidence of T1D in age categories and search to what extent these variations correlated with the GDP per capita.

METHODS

A systematic review was performed to retrieve information about the global incidence of T1D among those younger than 14 years of age. The study was carried out according to the PRISMA recommendations. For the analysis, the incidence was organized in the periods: 1975-1999 and 2000-2017. We searched the incidence of T1D in the age-groups 0-4, 5-9 and 10-14. We compared the incidences in countries for which information was available for the two periods. We obtained the GDP from the World Bank. We analysed the relationship between the incidence of T1D with the GDP in countries reporting data at the national level.

RESULTS

We retrieved information for 84 out of 194 countries around the world. We found a wide geographic variation in the incidence of T1D and a worldwide increase during the two periods. The largest contribution to this increase was observed in the youngest group of children with T1D, with a relative increase of almost double when comparing the two periods (P value = 2.5 × e^-5). Twenty-six countries had information on the incidence of T1D at the national level for the two periods. There was a positive correlation between GDP and the incidence of T1D in both periods (Spearman correlation = 0.52 from 1975-1999 and Spearman correlation = 0.53 from 2000-2017).

CONCLUSION

The incidence increase was higher in the youngest group (0-4 years of age), and the highest incidences of T1D were found in wealthier countries.

Association of cholesterol and lifestyle markers with type 1 diabetes incidence rates at a population level

Background

We investigated the hypotheses that mean population body mass index (BMI), systolic blood pressure (SBP), fasting plasma glucose (FPG), total cholesterol (TC) and the prevalence of type 2 diabetes (T2DM) are correlated with type 1 diabetes (T1DM) incidence rates.

Methods

Population-based mean incidence rates for T1DM in children aged ≤14 years participating in the World Health Organization Diabetes Mondial (DiaMond) project were compared with population mean values for BMI, SBP, TC and FPG, as well as prevalence rates for T2DM as reported by The Global Burden of Metabolic Risk Factors Chronic Diseases Collaborating Group, using Spearman's rank correlation and multiple regression analysis.

Results

The mean incidence rate for T1DM in boys was significantly correlated with country mean BMI, SBP and TC in men and mean TC in women, and negatively correlated with the country incidence of T2DM in either gender. We also found significant correlations between mean incidence rates of T1DM in girls and mean BMI, SBP and TC in men and mean TC in women. In multiple regression analyses, mean TC emerged as the sole significant predictor for T1DM in both boys (P < 0.001, adjusted R2 = 0.393) and girls (P < 0.001, adjusted R2 = 0.372).

Conclusion

Population mean total cholesterol is a significant predictor for country incidence of type 1 diabetes in both boys and girls. This association may fuel the rising incidence rates of type 1 diabetes reported in many countries.

[Does geographic context matter in diabetes-related mortality? Spatial and time trends in Argentina, 1990-2012]

The aim of this study was to identify spatial-temporal clusters of high and low diabetes-related mortality from 1990 to 2012 in Argentina. This was a spatial-temporal retrospective ecological study in the population older than 34 years living in Argentina, according to sex, from 1990 to 2012. The spatial units of analysis consisted of the country's departments (subdivisions of the provinces) plus the Autonomous City of Buenos Aires. Spatial-temporal exploration technique was used to detect clusters with high and low mortality. Areas with high mortality from diabetes mellitus were found in the Central-West of the country, and areas with low mortality were found in the coastal region of the province of Buenos Aires and Patagonia. Clusters with high mortality occupied a period from 1995 to 2008; clusters with low mortality shifted towards the years 2002 to 2012. The recent drop in mortality from diabetes was not geographically homogeneous, but displayed a marked decrease in the eastern area of the Province of Buenos Aires and the Autonomous City of Buenos Aires.

Incidence and Mortality Rates and Clinical Characteristics of Type 1 Diabetes among Children and Young Adults in Cochabamba, Bolivia

OBJECTIVES

To determine incidence, mortality, and clinical status of youth with diabetes at the Centro Vivir con Diabetes, Cochabamba, Bolivia, with support from International Diabetes Federation Life for a Child Program.

METHODS

Incidence/mortality data analysis of all cases (<25 year (y)) diagnosed January 2005-February 2017 and cross-sectional data (December 2015).

RESULTS

Over 12.2 years, 144 cases with type 1 diabetes (T1D) were diagnosed; 43.1% were male. Diagnosis age was 0.3-22.2 y; peak was 11-12 y. 11.1% were <5 y; 29.2%, 5-<10 y; 43.1%, 10-<15 y; 13.2%, 15-<20 y; and 3.5%, 20-<25 y. The youngest is being investigated for monogenic diabetes. Measured incidence in Cercado Province (Cochabamba Department) was 2.2/100,000 children < 15 y/y, with ≈80% ascertainment, giving total incidence of 2.7/100,000 children < 15 y/y. Two had died. Crude mortality rate was 2.3/1000 patient years. Clinical data on 141 cases <35 y: mean/median HbA1c was 8.5/8.2% (69/62 mmol/mol), levels higher in adolescents. Three were on renal replacement therapy; four others had substantial renal impairment. Elevated BMI, triglycerides, and cholesterol were common: 19.1%, 18.3%, and 39.1%, respectively.

CONCLUSIONS

Bolivia has low T1D incidence. Reasonable glycemic control is being achieved despite limited resources; however, some have serious complications and adverse cardiovascular risk factor profiles. Further attention is needed for complications.

Geographical distribution of alcohol-attributable mortality in Chile: a Bayesian spatial analysis

OBJECTIVE

To describe the distribution of alcohol-attributable mortality (AAM) at the local level (345 municipalities) in Chile, including fully and partially attributable causes in 2009.

METHODS

AAM was estimated for the population 15years of age and older using per capita alcohol consumption combined with survey estimates. The effect of alcohol on each cause of death was extracted from the published scientific literature. We used Bayesian hierarchical models to smooth the Standardized Mortality Ratio for each municipality for six groups of causes related to alcohol consumption (total, neuro-psychiatric, cardiovascular, cancer, injuries and other causes).

RESULTS

The percentage of municipalities with high risk for any group of causes in each region ranges from 0% to 87.0%. Municipalities with high risk were concentrated in south-central and southern Chile for all groups of causes related to alcohol.

CONCLUSIONS

AAM risk shows marked geographic concentrations, mainly in south-central and southern regions of Chile. This combination of methods for small-area estimates of AAM is a powerful tool to identify high risk regions and associated factors, and may be used to inform local policies and programs.

Spatial vulnerability of fine particulate matter relative to the prevalence of diabetes in the United States

Recent research supports a link between diabetes and fine particulate matter (≤ 2.5μg in diameter; PM2.5) in both laboratory and epidemiology studies. However, research investigating the potential relationship of the spatial vulnerability of diabetes to concomitant PM2.5 levels is still sparse, and the level of diabetes geographic disparities attributed to PM2.5 levels has yet to be evaluated. We conducted a Bayesian structured additive regression modeling approach to determine whether long-term exposure to PM2.5 is spatially associated with diabetes prevalence after adjusting for the socioeconomic status of county residents. This study utilizes the following data sources from 2004 to 2010: the Behavioral Risk Factor Surveillance System, the American Community Survey, and the Environmental Protection Agency. We also conducted spatial comparisons with low, median-low, median-high, and high levels of PM2.5 concentrations. When PM2.5 concentrations increased 1 μg/m(3), the increase in the relative risk percentage for diabetes ranged from -5.47% (95% credible interval = -6.14, -4.77) to 2.34% (95% CI = 2.01, 2.70), where 1323 of 3109 counties (42.55%) displayed diabetes vulnerability with significantly positive relative risk percentages. These vulnerable counties are more likely located in the Southeast, Central, and South Regions of the U.S. A similar spatial vulnerability pattern for concentrations of low PM2.5 levels was also present in these same three regions. A clear cluster of vulnerable counties at median-high PM2.5 level was found in Michigan. This study identifies the spatial vulnerability of diabetes prevalence associated with PM2.5, and thereby provides the evidence needed to prompt and establish enhanced surveillance that can monitor diabetes vulnerability in areas with low PM2.5 pollution.

Spatial and temporal variation in type 1 diabetes incidence in Western Australia from 1991 to 2010: increased risk at higher latitudes and over time

This study analysed spatial and temporal variation in childhood incidence of type 1 diabetes mellitus (T1DM) among Western Australia׳s 36 Health Districts from 1991 to 2010. There was a strong latitudinal gradient of 3.5% (95% CI, 0.2-7.2) increased risk of T1DM per degree south of the Equator, as averaged across the range 15-35° south. This pattern is consistent with the hypothesis of vitamin D deficiency at higher latitudes. In addition there was a 2.4% (95% CI, 1.3-3.6) average increase in T1DM incidence per year. These effects could not be explained by population density, socioeconomic status, remoteness or ethnicity.

Diabetes in the young - a global view and worldwide estimates of numbers of children with type 1 diabetes

This paper describes the methodology, results and limitations of the 2013 International Diabetes Federation (IDF) Atlas (6th edition) estimates of the worldwide numbers of prevalent cases of type 1 diabetes in children (<15 years). The majority of relevant information in the published literature is in the form of incidence rates derived from registers of newly diagnosed cases. Studies were graded on quality criteria and, if no information was available in the published literature, extrapolation was used to assign a country the rate from an adjacent country with similar characteristics. Prevalence rates were then derived from these incidence rates and applied to United Nations 2012 Revision population estimates for 2013 for each country to obtain estimates of the number of prevalent cases. Data availability was highest for the countries in Europe (76%) and lowest for the countries in sub-Saharan Africa (8%). The prevalence estimates indicate that there are almost 500,000 children aged under 15 years with type 1 diabetes worldwide, the largest numbers being in Europe (129,000) and North America (108,700). Countries with the highest estimated numbers of new cases annually were the United States (13,000), India (10,900) and Brazil (5000). Compared with the prevalence estimates made in previous editions of the IDF Diabetes Atlas, the numbers have increased in most of the IDF Regions, often reflecting the incidence rate increases that have been well-documented in many countries. Monogenic diabetes is increasingly being recognised among those with clinical features of type 1 or type 2 diabetes as genetic studies become available, but population-based data on incidence and prevalence show wide variation due to lack of standardisation in the studies. Similarly, studies on type 2 diabetes in childhood suggest increased incidence and prevalence in many countries, especially in Indigenous peoples and ethnic minorities, but detailed population-based studies remain limited.

Bayesian analysis of the geographical variation of type 1 diabetes mellitus in under 15 yr olds in northeast Spain, 1991-2009

OBJECTIVE

High variability has been observed in type 1 diabetes mellitus (DM1) incidence rates (IRs) in childhood. The aim of this study was to characterize DM1 in Aragón and to identify variations in the geographical pattern by gender.

METHODS

A descriptive and ecological study was conducted to determine geographical variations in the DM1 incidence for the period 1991-2009. The source of information was the registry of DM1. To determine data completeness, a capture-recapture analysis was performed. Cases were georeferenced according to the Basic Healthcare Area (BHA) of residence. IRs for both genders, age group, 5 yr of diagnosis, and 95% confidence intervals (95% CIs) were calculated. Geographical pattern was studied applying Bayesian statistical model. The standardized incidence ratios (SIRs), smoothed SIR, and the posteriori risk probability (PRP) were represented cartographically for BHA stratified by gender.

RESULTS

The completeness was 93.5%. The global IR was 19.2 cases/10(5) person-years (95% CI: 17.6-20.8), boys 21.4 (95% CI: 19.0-23.8) and girls 16.8 (95% CI: 14.7-19.1). The age-specific rates were significantly lower in the 0-4 year age group with respect to the groups of 5-9 and 10-14 years. For boys, areas with a statistically significant excess of risk were found in the north [smoothed SIR: 118-167.9 and PRP of what the smoothed SIR would be greater than 100 (PRP) above 0.8] and below average risk in the south (smoothed SIR: 65.9-79.1 and PRP less than 0.2).

CONCLUSIONS

DM1 IR presented a north-south geographical pattern in boys. This pattern was not observed in girls or when both genders were considered together. Later studies should include gender as an essential variable.

Which factors predict glycemic control in children diagnosed with type 1 diabetes before 6.5 years of age?

Predictors of long-term glycemic control and growth patterns in children diagnosed with type 1 diabetes (T1D) before 6.5 years of age were evaluated. One hundred seventy-three children (84 boys) with a mean diabetes duration of 4.9 ± 2.8 years participated in this observational study. Medical charts were reviewed for background, disease- and treatment-related parameters, and growth parameters. Study endpoints were HbA1c value, rates of severe hypoglycemia and diabetic ketoacidosis events, and growth patterns. Mean HbA1c for the total duration of diabetes (HbA1c-TDD) was 7.9 ± 0.8%. Comparison of the study variables between patients with HbA1c-TDD <7.5% (n = 53) or ≥7.5% yielded a significantly shorter duration of diabetes (P = 0.01) and lower rate of diabetic ketoacidosis (P = 0.02) in those with HbA1C-TDD <7.5%, without differences between these groups in age at diabetes onset, insulin regimens, daily glucose measurements, and rate of severe hypoglycemia. Factors significantly predicting achievement of the mean target HbA1c-TDD <7.5% were lower HbA1c at 0.5 years and 1 year after diabetes diagnosis (P = 0.002 and P < 0.001, respectively). Patients followed for at least 5 years (n = 48) showed a significant decrease in height-SDS (P < 0.001) and a significant increase in weight-SDS (P = 0.004) from diabetes diagnosis to the last follow-up visit, without a significant change in weight-SDS from 0.5 years after diagnosis to the last follow-up visit. Our results suggest that in patients with T1D diagnosed during the preschool-age, mean HbA1c level in the first year is a strong predictor of achieving target HbA1c level in the subsequent years, regardless the type of insulin regimen. This "metabolic tracking" emphasizes the importance of achieving early optimal control even in younger children.