**5. What the changing epidemiology implies for future research**

The number of investigations concerning the epidemiology of type 1 diabetes is extensive. However, the published results are controversial or even contradictory. There is consensus about fundamental aspects, such as the increasing incidence and prevalence of type 1 diabe‐ tes. Thereby, it becomes clear that type 1 diabetes will become more and more of a burden. Although most investigations and publications have been of high methodological quality, they lack exact explanations of the described phenomena, and understanding the mecha‐ nisms and triggers of type 1 diabetes remains a mystery.

Future research should lead to improved methods of estimating the epidemiology of type 1 diabetes. Like this, more valid and thereby comparable data on type 1 diabetes epidemiolo‐ gy and risk factors have to be gained, but also more data on the epidemiology of type 1 dia‐ betes over the whole lifespan are definitely needed (Knip 2012). Furthermore, future research may lead to a better understanding of the underlying pathogenesis of type 1 diabe‐ tes by complementing the results of descriptive epidemiology with those of 'aetiological' ep‐ idemiology (Knip 2012) including the assessment of suspected environmental triggers and risk factors as well as genetic background of the assessed individuals. Conclusively, future research on type 1 diabetes cannot exclusively be performed with population-based ap‐ proaches. Individualized approaches, e.g. metabolic profiling in both the pre-autoimmune period and the preclinical period (Oresic, Simell et al. 2008), may provide clues to environ‐ mental triggers, such as infections or dietary changes, which likely cause disturbances in the intestinal microbiota and the immune system and contribute to the onset of type 1 diabetes. Thereby, children/adolescents at a high risk may be identified and possibilities for preven‐ tion of type 1 diabetes may be detected.

**4.2. The age-related differences of type 1 diabetes mellitus prevalence**

Table 4) that were based on the Australian National Diabetes Register.

2011).

14 Type 1 Diabetes

Regarding age dependents phenomena of type 1 diabetes incidence (see section 3.4) it be‐ comes conclusive that 1) the prevalence of type 1 diabetes shows no sex-related differences and increases with age due to accumulation of individuals suffering from the disease and 2) the age-dependent increment of prevalence is not just linear but more likely exponential due to an age-dependent increment of type 1 diabetes incidence. These assumptions have been confirmed for example by the findings of the Australian Institute of Health and Welfare (see

**Age (years) Persons Prevalence**

0 to 4 405 28.8 (26.0 to 31.6)

5 to 9 1,731 128.0 (122.0 to 134.1)

10 to 14 3,597 256.3 (247.9 to 264.7)

total 5,733 137.8 (134.2 to 141.4)

**Table 4.** The estimated prevalence (per 100,000 inhabitants of the respective age group with 95% confidence interval) of type 1 diabetes among Australian children aged 0-14 years (Australian Institute of Health and Welfare

The number of investigations concerning the epidemiology of type 1 diabetes is extensive. However, the published results are controversial or even contradictory. There is consensus about fundamental aspects, such as the increasing incidence and prevalence of type 1 diabe‐ tes. Thereby, it becomes clear that type 1 diabetes will become more and more of a burden. Although most investigations and publications have been of high methodological quality, they lack exact explanations of the described phenomena, and understanding the mecha‐

Future research should lead to improved methods of estimating the epidemiology of type 1 diabetes. Like this, more valid and thereby comparable data on type 1 diabetes epidemiolo‐ gy and risk factors have to be gained, but also more data on the epidemiology of type 1 dia‐ betes over the whole lifespan are definitely needed (Knip 2012). Furthermore, future research may lead to a better understanding of the underlying pathogenesis of type 1 diabe‐ tes by complementing the results of descriptive epidemiology with those of 'aetiological' ep‐ idemiology (Knip 2012) including the assessment of suspected environmental triggers and risk factors as well as genetic background of the assessed individuals. Conclusively, future research on type 1 diabetes cannot exclusively be performed with population-based ap‐ proaches. Individualized approaches, e.g. metabolic profiling in both the pre-autoimmune

**5. What the changing epidemiology implies for future research**

nisms and triggers of type 1 diabetes remains a mystery.

In part promising therapeutic approaches to type 1 diabetes as immunotherapy, stem cell-, β-cell- or islet of Langerhans-transplantation have to be assessed in future studies to find causal therapeutic strategies (Chatenoud, Warncke et al. 2012; Li, Gu et al. 2012; McCall, James Shapiro et al. 2012). Additionally, further research is needed in the field of chronic type 1 diabetes and the detection and treatment of its complications. The role of genetics in susceptibility to nephropathy, retinopathy and other diabetic complications still largely re‐ mains to be explored (Borchers, Uibo et al. 2010).
