Epidemiological studies on type 1 diabetes mellitus (DM1) have been developed in almost all the Spanish geography, but no registry currently provides national incidence and prevalence figures. This study aims to estimate the incidence of DM1 in children under 15 years of age in Spain based on the available studies, and to know the prevalence of diabetes in children under 15 years of age based from the data collected in the Primary Care Clinical Database (BDCAP).
Material and methodsBibliographic review of publications and communications that provided data up to December 2020. Estimation of the average incidence in Spain, based on data from each autonomous community. Estimation of the prevalence of DM1 in children under 15 years of age according to BDCAP.
ResultsThe reported incidences varied from 7.9 cases/100,000 population per year (c/105ppy) in the Balearic Islands to 30.48 c/105ppy in Gran Canaria. Diagnosis in diabetic ketoacidosis (DKA) is found in approximately one third of cases (21-43.7%). The average incidence of DM1 in children under 15 years of age in Spain would be 20.54 c/105ppy, with about 1,398 new cases per year. BDCAP records 12,346 cases of diabetes in children under 15 years of age, with a prevalence of 1.96 cases/1,000 population.
ConclusionsThere are studies of DM1 incidence in almost all Spanish communities. The incidence of DM1 in children under 15 years of age in Spain is very high according to the WHO classification (> 20 c/105ppy). The proportion of cases diagnosed with CAD is high, suggesting that programs to improve the early diagnosis of DM1 are still needed.
Se han desarrollado estudios epidemiológicos sobre diabetes mellitus tipo 1 (DM1) en casi toda la geografía española, pero no existe un registro que proporcione las cifras de incidencia y prevalencia a nivel nacional. Este estudio pretende estimar la incidencia de DM1 en menores de 15 años en España en base a los estudios disponibles, así como la prevalencia de diabetes en menores de 15 años a partir de los datos recogidos en la Base de Datos Clínicos de Atención Primaria (BDCAP).
Material y métodosRevisión bibliográfica de las publicaciones y comunicaciones que aportasen datos hasta diciembre de 2020. Estimación de la incidencia media en España, a partir de los datos de cada comunidad autónoma. Estimación de la prevalencia de diabetes en menores de 15 años según BDCAP.
ResultadosLas incidencias comunicadas varían desde 7,9 casos/100.000 habitantes-año (c/105h-a) de Baleares hasta 30,48 c/105h-a en Gran Canaria. El diagnóstico en cetoacidosis diabética (CAD) se encuentra en aproximadamente un tercio de los casos (21-43,7%). La incidencia media de DM1 en menores de 15 años en España sería de 20,54 c/105h-a, con unos 1.398 nuevos casos anuales. BDCAP registra 12.346 casos de diabetes en menores de 15 años, con una prevalencia de 1,96 casos/1.000 habitantes.
ConclusionesExisten estudios de incidencia de DM1 en casi todas las comunidades españolas. La incidencia de DM1 en menores de 15 años en España es muy alta según la clasificación dela OMS (> 20 c/105h-a). La proporción de casos diagnosticados con CAD es elevada, siendo necesarios programas para mejorar el diagnóstico temprano de la DM1.
Type 1 diabetes mellitus (T1DM) is one of the most common chronic diseases worldwide. Due to the complexity of its management and its chronic nature, it demands a high use of health care resources. Furthermore, it often begins in childhood, meaning that the consumption of these resources continues for decades. Epidemiological studies in T1DM allow us to analyze the distribution of the disease in a geographic area and a specific time or period, as well as temporal variations in its incidence. The data obtained can help plan health care resources dedicated to T1DM, and to study how possible etiological factors impact the incidence rate of this disease.
Standardized diabetes incidence registries began to be developed in the 1970s, allowing for comparisons between different geographical areas and confirming a great variability in the worldwide distribution of the disease. The European project EURODIAB1 and the global DIAMOND2 project by the World Health Organization (WHO) were the first registries with standardized methodology. The DIAMOND study calculates standardized incidence rates by direct adjustment using a standard population with an equal number of children for each age group (0–4 years, 5–9 years, and 10−14 years) and sex, calculating 95% confidence intervals based on the Poisson distribution. This study classifies geographical areas based on T1DM incidence: very low incidence rate: <1 case/100,000 inhabitants-year (c/10⁵ inhab-yr); low incidence rate: 1–4.99 c/10⁵ inhab-yr; intermediate incidence rate: 5–9.99 c/10⁵ inhab-yr; high incidence rate: 10–19.99 c/10⁵inhab-yr; very high incidence rate: ≥20 c/10⁵ inhab-yr.
In Spain, epidemiological studies on T1DM began with Serrano-Ríos in the Autonomous Community of Madrid, during the 1985–1988 period.3 The Diabetes Mellitus Registry of Catalonia started its journey between 1987 and 1990.4 Since then, various regional and local studies with heterogeneous methodologies have been published and communicated, providing data on the incidence of T1DM in various areas of the country.
In 2014, a paper was published that attempted to summarize the data collected in different studies conducted in Spanish autonomous communities, offering an estimate of the mean incidence in Spain of T1DM set at 17.69 c/10⁵inhab-yr.5
In recent years, new studies6–28 have provided more recent data from some autonomous communities, using standardized methodology. Some regional registries have remained active,7,16,23–25 providing updated incidence data, as well as, in some cases, an estimation of the progression of T1DM incidence rate over time.7,24
Currently, the IT systems and databases used in our health care systems (computerized primary care medical records, minimum basic data set [MBDS], electronic health record models) can facilitate the performance of these types of studies in Spain. Furthermore, at the national level, the Primary Care Clinical Database (BDCAP) constitutes a valuable source of information for determining the prevalence of certain diseases in Spain, including diabetes.29 The use of large databases will likely improve epidemiological studies of T1DM in Spain in the coming years.
The present work aims to update the epidemiological data of T1DM in pediatric age in Spain, based on publications and communications made about regional studies, giving relevance to those of higher quality and recency, as well as to analyze the data provided by the BDCAP database regarding diabetes in children younger than 15 years.
Material and methodsFor the present study, we conducted a search for publications and communications regarding the epidemiology of T1DM in Spain and its different autonomous communities, expanding the search conducted in the study published in 2013. Sources used: 1) search for publications on the internet (via Pubmed and Google Scholar); 2) review of abstract books from communications presented at the national congresses of the Spanish Society of Pediatric Endocrinology (SEEP) from 2001 through 2023 and at the national congresses of the Spanish Diabetes Society from 2002 through 2023; 3) review of bibliographic citations referred to in the articles found; 4) search for registries, publications, and databases from regional public health services, obtained through a simple Google search. Publications and communication abstracts including data on the epidemiology of T1DM in individuals younger than 15 years were selected. Only studies providing data up to December 31st, 2020, were selected for analysis. For the estimation of the mean incidence rate in Spain, references providing the most complete and updated data for each autonomous community were used, selecting the most recent study periods in the case of long-duration studies. For the calculation of the mean incidence in Spain, population data corresponding to the national census as of July 1st, 2020 (mid-period census) were used, applying the estimated average incidence for each autonomous community based on available studies to the proportion of the population corresponding to that autonomous community within the national population aged 0−14 years. For the estimation of new annual cases, the incidence rate found for each autonomous community was applied to its population aged 0−14 years, using the Poisson distribution to determine the 95% confidence interval (95%CI). In the case of autonomous communities or cities without available data, the national mean incidence rate was applied to estimate the No. of new annual cases. For the estimation of the prevalence of diabetes in children younger than 15 years in Spain, available data from the BDCAP database in 2020 were used, using the diagnostic codes for diabetes mellitus (T89 and T90).
ResultsA summary of the selected T1DM incidence studies in children younger than 15 years for each autonomous community is presented below. The 95%CI is indicated only when available from the source used.
AndalusiaIn 2000, the Andalusian Pediatric Diabetes Working Group (GADI) launched the T1DM registry for children under 14 years in Andalusia. In the absence of other published data, the Comprehensive Diabetes Plan of Andalusia reported in 2014 a T1DM incidence rate in children younger than 15 years of 23.63 c/10⁵inhab-yr, with a prevalence of 1.85 per 1000. In that year, 32.31% of cases were diagnosed as diabetic ketoacidosis (DKA).6
AragonThe T1DM registry for children younger than 15 years in Aragon has been active since 1991, with over 30 years of data collected to date. The report published with data collected up to 2020 indicates an incidence for the 2016–2020 period of 22.8 c/10⁵inhab-yr. The estimated age-adjusted prevalence rate is 1.3 per 1000. Throughout the 1991–2020 period, 37% of DKA at onset was found, with no significant variations throughout the study period.7
AsturiasAsturias currently maintains an active T1DM registry for individuals younger than 40 years of age, initiated in 2002. Its results for the 2011–2020 period were recently published, finding an estimated incidence of 19.65 c/10⁵inhab-yr (95%CI, 17.17–22.39 c/10⁵inhab-yr) in the 0−15 year age group.8 The proportion of DKA at diagnosis in this age group was 39.91%.9
Balearic IslandsThe only epidemiological study reference for the Balearic Islands is from a study conducted in Mallorca in 2013, communicated at the national SEEP congress in 2015, finding a mean annual incidence rate of 7.9 c/10⁵inhab-yr in the 2010–2012 period.10
Canary Islands
The most recent data for the Canary Islands are those published for Gran Canaria in the 2006–2018 period, with an adjusted annual mean incidence rate of 30.48 c/10⁵inhab-yr (95%CI, 27.74–33.42 c/10⁵inhab-yr).11 No studies for the complete autonomous community have been found.
CantabriaA doctoral thesis published in 2016 collected new T1DM diagnoses from the autonomous community of Cantabria in the 1995–2014 period12 finding a mean annual incidence rate of 14.1 c/10⁵inhab-yr, with a slight, non-significant increase from 2006 onwards. A more recent study shows an increase in incidence in the autonomous community from 2010 through 2019, with an estimated incidence rate of 23.03 c/10⁵inhab-yr for the 2018–2019 period, with a proportion of DKA at diagnosis of 38.6% throughout the study period.13
Castile-La ManchaThe first study covering the entire region of Castilla-La Mancha was published in 2012 by the Pediatric Diabetes Epidemiology Group of Castilla-La Mancha. They later communicated the results for the 2010–2015 period, with an incidence of 20.23 c/10⁵inhab-yr and an estimated prevalence of 1.21 cases/1000 inhabitants younger than 15 years.14
Castile and LeónIn 2006, the only epidemiological study conducted in the entire community of Castile and León was published, including new T1DM cases diagnosed in the 2003–2004 period in children younger than 15 years in this community. The estimated average incidence rate was 22.22 c/10⁵inhab-yr (95%CI, 14.57–29.81 c/10⁵inhab-yr), and the prevalence was 1.18 cases/1000 inhabitants younger than 15 years.15
CataloniaThe Catalan T1DM registry collects new T1DM cases diagnosed in Catalonia in patients younger than 30 years since 1987, and it is the reference for Spain in the EURODIAB and DIAMOND projects.4
Although data published in previous years showed a lower incidence rate, current figures published by Institut Català de la Salut show a T1DM incidence rate in children younger than 15 years of 20.6 c/10⁵inhab-yr in 2020. Taking the mean incidence rate for the 2016–2020 period as a reference, this would be 19.02 c/10⁵inhab-yr.
Valencian CommunityThe study published in 2022 is the first to collect data for the entire autonomous community, for the 2013–2017 period, finding a mean incidence rate of 19.1 c/10⁵inhab-yr (95%CI, 17.5–20.7 c/10⁵inhab-yr) and a prevalence at the end of the study period estimated at 1.82 cases/1000 persons younger than 15 years.17 The proportion of cases diagnosed as DKA was 33%.
ExtremaduraA study conducted in the 1996–2011 period is the most recent published in Extremadura, with data for the entire community.18 It reported an adjusted incidence rate of T1DM in children younger than 15 years of 22.67 c/10⁵inhab-yr (95%CI, 13.47–31.87 c/10⁵inhab-yr). 21% of cases were diagnosed with DKA.
GaliciaA study of the entire autonomous community, conducted from 2001 through 2010, found a mean annual incidence rate of 17.2 c/10⁵inhab-yr.19 28.44% of patients presented with DKA at onset. Since then, only local studies have been reported: one from the Santiago de Compostela area, with an incidence of 22.2 c/10⁵inhab-yr in the 2000–2018 period,20 and another from the Pontevedra area for the 1999–2018 period, with an incidence of 16 c/10⁵inhab-yr, and a proportion of DKA at diagnosis of 28%.21
La RiojaThe only study found for the Community of La Rioja did not provide any results regarding incidence rates.22
MadridData for the 1997–2016 period from the Madrid Community Diabetes Mellitus Registry were published in 2021.23 The initial period (1997–2013) showed an incidence rate of 13.7 c/10⁵inhab-yr. In the 2014–2016 period, case finding through the MBDS system (minimum basic data set at hospital discharge) was implemented, finding an incidence rate of 20 c/10⁵inhab-yr (95%CI, 18.4–21.6 c/10⁵inhab-yr). The authors attribute this difference to underestimation in the previous period.
NavarreThe Population-based Type 1 Diabetes Registry of Navarre collects and publishes data from 2009 to the present, and includes all patients diagnosed with T1DM without age limit. The most recent publication, carried out in 2023, reports an incidence rate of 20.6 c/10⁵inhab-yr (95%CI, 16.5–25.5 c/10⁵inhab-yr) in children younger than 15 years during the 2009–2020 period.24 In 35.6% of cases, DKA was present at diagnosis.
Basque CountryOnly references to epidemiological studies of T1DM conducted in each of its provinces separately have been found.
In the province of Biscay, studies have been conducted since 1990. In the period analyzed in the present study, the most recent communication from this working group reported an average annual incidence for the 2002–2013 period of 12.2 c/10⁵inhab-yr in children younger than 15 years ofr, with an exhaustiveness of 99.1%.25
The study reported for the province of Gipuzkoa for the 2006–2020 period found a mean incidence rate of 13.3 cases/100,000 inhabitants-year, with a growing trend in incidence rate from 2010 onwards.26 The prevalence in 2020 is 0.75 cases/1000 inhabitants. In 43.7% of cases, the diagnosis was in the form of DKA.
Data for the province of Álava are published for the 2000–2018 period.27 The incidence rate was 11.02 c/10⁵inhab-yr, with 34.49% DKA at diagnosis.
Based on the available studies in each of the three provinces applied to population data for 0−14 years, the mean incidence rate for the autonomous community would be 12.37 c/10⁵inhab-yr.
Region of MurciaIn 2020, a retrospective study from Hospital Virgen de la Arrixaca with patients younger than 15 years of age diagnosed with T1DM from January 2016 through January 2021 found an incidence rate of 24.8 c/10⁵inhab-yr and 30.3 c/10⁵inhab-yr28 throughout the period. A total of 35.5% of patients presented with DKA at onset.
Estimation of diabetes incidence in children younger than 15 in SpainUsing the previously described methodology, the mean annual incidence rate of T1DM in children younger than 15 years of age in Spain would be 20.54 c/10⁵inhab-yr, and the estimated number of new annual cases would be 1,398.
Table 1 shows the data analyzed for each autonomous community, along with an estimation of the number of new annual cases with the 95%CI estimated using the Poisson distribution.
Expected number of new T1DM cases in children younger than 15 years of age by autonomous community, estimated from reported incidence figures in reviewed studies.
| Autonomous Community | Population aged 0–14 years | % of Spanish population aged 0–14 across the various autonomous communities | Estimated incidence (per 100,000/year) in available studies | Expected annual new cases (95%CI) |
|---|---|---|---|---|
| Andalusia | 1,308,773 | 19.23% | 23.63 | 309 (275–344) |
| Aragon | 184,527 | 2.71% | 22.80 | 42 (29–55) |
| Asturias, Principality of | 103,557 | 1.52% | 19.65 | 20 (12–29) |
| Balearic Islands | 176,127 | 2.59% | 7.90 | 14 (7–21) |
| Canary Islands | 278,030 | 4.08% | 30.48 | 85 (67–103) |
| Cantabria | 74,928 | 1.10% | 23.03 | 17 (10–24) |
| Castile and León | 281,082 | 4.13% | 22.22 | 62 (47–78) |
| Castile-La Mancha | 303,443 | 4.46% | 20.23 | 61 (46–77) |
| Catalonia | 1,159,885 | 17.04% | 19.02 | 221 (191–250) |
| Valencian Community | 730,388 | 10.73% | 19.10 | 140 (116–163) |
| Extremadura | 141,791 | 2.08% | 22.67 | 32 (21–43) |
| Galicia | 314,404 | 4.62% | 17.20 | 54 (40–68) |
| Community of Madrid | 1,017,300 | 14.94% | 20.00 | 203 (176–231) |
| Region of Murcia | 253,012 | 3.72% | 24.80 | 63 (47–78) |
| Chartered Community of Navarre | 100,194 | 1.47% | 20.60 | 21 (12–30) |
| La Rioja | 43,048 | 0.63% | 20.54a | 9 (3–15) |
| Basque Country | 300,696 | 4.42% | 12.37 | 37 (25–49) |
| Ceuta | 16,469 | 0.24% | 20.54a | 3 (0–7) |
| Melilla | 19,708 | 0.29% | 20.54a | 4 (0–8) |
| National Total | 6,807,362 | 100% | 20.54 | 1398 (1325–1471) |
Fig. 1 shows an estimation of the T1DM incidence rates across the various autonomous communities ordered from lowest to highest incidence rate based on the reviewed studies.
Fig. 2 shows a map with the estimated T1DM incidence in children younger than 15 years in each Spanish autonomous community, based on the reviewed studies.
Table 2 shows the estimated incidence rate in each autonomous community in the study published in 2014, comparing it with the estimate in the present work, along with an assessment of the variation between both data and the classification of the incidence of each community according to the WHO.2
| Autonomous Community | Estimated incidence 20105 | Estimated incidence 2020 | Difference between 2nd and 1st | WHO2 T1DM incidence classification |
|---|---|---|---|---|
| Andalusia | 20.76 | 23.63 | Increase | Very high |
| Aragon | 17.05 | 22.80 | Increase | Very high |
| Asturias | 11.50 | 19.65 | Increase | High |
| Balearic Islands | No data | 7.90 | No prior data | Intermediate |
| Canary Islands | 23.20 | 30.48 | Increase | Very high |
| Cantabria | 16.40 | 23.03 | Increase | Very high |
| Castile-La Mancha | 27.60 | 20.23 | Decrease | Very high |
| Castile and León | 22.22 | 22.22 | Same reference | Very high |
| Catalonia | 13.35 | 19.02 | Increase | High |
| Valencian Community | 16.70 | 19.10 | Increase | High |
| Extremadura | 21.38 | 22.67 | Increase | Very high |
| Galicia | 17.20 | 17.20 | Same reference | High |
| La Rioja | No data | – | – | – |
| Community of Madrid | 15.90 | 20.00 | Increase | Very high |
| Chartered Community of Navarre | 16.48 | 20.60 | Increase | Very high |
| Basque Country | 11.60 | 12.37 | Similar | High |
| Region of Murcia | 25.41 | 24.80 | Similar | Very high |
| Spain Total | 17.69 | 20.54 | Increase | Very high |
The analysis of 2020 data on the diagnosis of diabetes mellitus in children shows a total of 12,346 children younger than 14 years affected by diabetes mellitus (9273 identified as insulin-dependent diabetes mellitus and 4546 identified as non-insulin-dependent diabetes mellitus), with a prevalence of 1.96 cases/1000 inhabitants.29Table 3 shows the data extracted from the BDCAP Statistical Analysis Portal.
Number of people aged 0–14 years diagnosed with diabetes and prevalence (per 1000 persons) in 2020 according to the BDCAP.29
| Diagnosis in BDCAP | Number of people with health problems (0–14 years) | People with health problems per thousand assigned (0–14 years) |
|---|---|---|
| T89: Insulin-dependent diabetes mellitus | 9273 | 1.47 |
| T90: Non–insulin-dependent diabetes mellitus | 4546 | 0.72 |
| Total | 12,346 | 1.96 |
Since the publication of the first review on the epidemiology of T1DM in children in Spain,5 almost all autonomous communities have provided new data. In the Valencian Community17 and Extremadura,18 regional studies have been carried out, which were not available in the previous stage. In the community of Castile and León, no new publications or communications have been found, and in the community of Galicia, only newly published local studies,20,21 are available. Only in the case of La Rioja22 and the autonomous cities of Ceuta and Melilla do we lack reported incidence data.
Currently, most studies use a standardized methodology (capture-recapture method, similar case definition, age limit, and adjustment of rates to the WHO population), and we continue to find heterogeneity in terms of duration and geographical scope (absence of regional studies in some cases). However, there continues to be a marked disparity among the analyzed studies: they have variable durations, represent different study periods, and their quality is not homogeneous, as in some cases the data come from a relatively short period,15,17 while in others, data are collected through epidemiological registries.7,8,16,23–25
In any case, this study has tried to identify the most complete publication available for each autonomous community. Furthermore, the most recent works have been selected, and in the case of broad study periods where incidence may have varied throughout time, data from the most recent period within the publication (eg, most recent quinquennium) have been selected if available. For the autonomous community of Galicia, the data from the 2011 publication19 have been maintained, as the more recently published data are only from local studies. We are aware that probably more recent data exist for communities such as Andalusia (whose T1DM registry remains active through GADI) and Galicia, but no published studies or communications on them have been found.
The highest incidence rates have were reported in the Canary Islands (30.48 c/10⁵inhab-yr in Gran Canaria),11 Murcia (24.8 c/10⁵inhab-yr),28 and Andalusia (23.63 c/10⁵inhab-yr),6 and the lowest in the Balearic Islands (7.9 c/10⁵inhab-yr)10 and the Basque Country (12.37 c/10⁵inhab-yr),25–27 maintaining a certain south-north gradient previously described,5 as well as a striking difference between the 2 island communities. The high incidence of T1DM in the Canary Islands has been attempted to be associated with the high incidence rate found in recent years in North African countries.30
Although in some communities the incidence figures appear to remain stable (Basque Country, Region of Murcia), most autonomous communities have shown higher incidence figures in recent studies vs those found in the 2014 study.5 In some cases, such as the Community of Madrid, the authors refer to a possible improvement in reporting systems as the cause of this increase, by incorporating new data sources, such as the MBDS system.23 However, other communities with long-standing registries (Aragon, Catalonia, Navarre)5,16,24 find higher incidence figures in recent years, despite a consistent methodology throughout the study period. In this regard, the Navarre study refers to a progressive increase and subsequent stabilization.24 It is possible that the higher national incidence found in our study is due to a combination of these factors (better data collection in some cases, a real increase in others).
Since 2020, when our analysis concludes, many international studies have shown data suggesting a possible increase in the incidence of diabetes, including T1DM in children, following the COVID-19 pandemic.31 Some of them have shown a subsequent stabilization of these figures. A recently published study from the province of Biscay, not included in the analysis as it provides data after 2020, shows this increase in a province where incidence had historically remained stable.32 The Aragon registry also shows an increase in incidence from the pandemic onwards, with a decrease in 2023.33 Likewise, in Gran Canaria, a non-significant increase of 25.7% in incidence (with a peak of 48.1 c/10⁵inhab-yr)34 was observed in the 2020–2021 period. Data published in the coming years will likely shed more light on this possible increase in incidence.
Using a methodology similar to that used in the 2014 publication5 and taking into account the limitations due to the heterogeneity of the reviewed studies, we made an estimation of the global incidence of T1DM in children younger than 15 years in Spain. The mean annual incidence obtained by this method for the Spanish population is 20.54 c/10⁵inhab-yr. Considering these figures, we could say that Spain is a country with a very high incidence rate of T1DM according to the WHO classification.2
When comparing this incidence rate with that of other countries in our vicinity, we can observe that it is higher than that estimated in other Southern European countries, such as Portugal, France, and Italy, and closer to that published in Central European countries, such as Germany, Czech Republic, Austria, or Hungary.35
In the present study, we aimed to provide an estimate of the expected new annual cases, both globally and for each autonomous community based on its published incidence rate. The 2014 publication estimated the expected annual number of cases at 1235 in 2010.5 The increase in the estimated incidence (from 17.69 to 20.54 c/10⁵inhab-yr) has meant that, despite the 0−14 year population in Spain having decreased since 2010, the figure for expected cases has increased to nearly 1400 new annual cases. In any case, the lack of updated data from some communities (Andalusia, Castile and León, and Galicia) suggests that the average incidence in Spain may possibly be slightly higher than we have estimated.
The BDCAP database publishes data obtained through primary care health records from a representative sample of the Spanish population. The utility of this system for obtaining an epidemiological approximation of diabetes mellitus data in Spain was published in 2021.36 That study already noted a significant limitation of this system: in practice, primary care coding does not always adequately differentiate between types of diabetes mellitus (in fact, some patients have both diabetes codes, T89 and T90, coded). Therefore, the number of children identified as "non-insulin-dependent diabetes mellitus" is abnormally high, and therefore, this study has not discriminated between types of diabetes mellitus in pediatric age in this section. Therefore, a global prevalence of diabetes of 1.96 cases/1000 inhabitants in children younger than 15 years has been obtained. In any case, we know that in pediatric age, more than 90% of cases are T1DM, and therefore we believe that BDCAP can be a reliable indicator for understanding the evolution of the disease's prevalence in the coming years.
Some of the analyzed studies report the proportion of cases diagnosed with diabetic ketoacidosis (DKA), finding this in approximately one-third of new cases, ranging from 21% (Extremadura)18 to 43.7% (Gipuzkoa).26 Based on the estimated number of annual cases nationwide, this would mean about 500 new diagnoses in DKA situations in Spain each year.
Other more recent studies have reported an increase in the number of cases diagnosed with DKA in 2020, attributed to greater difficulty in accessing health care during the COVID-19 pandemic.37 This fact was also confirmed in Spain, in the publication by the SEEP diabetes working group.38 In any case, the proportion of cases diagnosed with DKA does not appear to decrease over the years, making it necessary to insist on the need for programs aimed at diagnosing diabetes by its initial symptoms.
To summarize the limitations of the present study, we must highlight that the studies found and analyzed continue to show marked heterogeneity, not so much in methodology as in the duration of the studied period, the timing of the study, and the existence or not of a population registry. Furthermore, some autonomous communities have not published new data in recent years, and this includes some with a significant pediatric population, such as Andalusia, Casteile and León, and Galicia. We must also highlight that in the case of the Balearic Islands, Canary Islands, Galicia, and the Basque Country, there are no publications covering the entire autonomous community, and in other cases (La Rioja, Ceuta, and Melilla), there is no published data. The heterogeneity of the reviewed studies makes it impossible to establish a degree of statistical significance for the higher estimated incidence we found compared to the 2014 publication, nor have we been able to assess a trend of temporal variation in incidence. On the other hand, regarding prevalence, the BDCAP database offers us global prevalence data for diabetes in children younger than 15 years, but it does not allow us to differentiate between T1DM and other types of diabetes. As strengths, we highlight that the extensive bibliographic search allowed us to obtain available published data for almost the entire national territory, including both relevant publications and others that, despite being of lower quality, were the only ones providing data in some cases. Furthermore, despite the noted limitations, we were able to make an approximate estimation of the incidence of T1DM and the prevalence of diabetes in children under 15 years in Spain in 2020, with a reliability that is probably superior to that of the 2014 publication, given the greater homogeneity in the methodology of the analyzed studies.
Improvements in case-finding systems, by incorporating electronic health record registries as data sources, represent an opportunity to improve existing incidence registries or establish new ones. Similarly, the recent creation of a National T1DM Incidence Registry by the Spanish Society of Endocrinology and Nutrition (SEEN), the Spanish Diabetes Society (SED), and the Spanish Society of Pediatric Endocrinology (SEEP) will be able to offer more precise data about T1DM in Spain in the coming years.
For decades, significant progress has been made in accurately predicting T1DM through autoantibody determination. Screening programs in other European countries have shown 90% reductions in DKA cases at onset.39 Furthermore, in 2022, the FDA approved the use of the first drug that could delay the clinical diagnosis of T1DM,40 and its approval by the EMA is expected soon. The potential use of this and other immune-modulating drugs could change the epidemiological landscape of T1DM in the near future. Having the data and estimates provided by our study will be critical for developing population screening strategies for T1DM in early stages of the disease development in Spain.
FundingNone declared.
None declared.
