**3. Age of onset**

326 Type 1 Diabetes – Complications, Pathogenesis, and Alternative Treatments

21,0/100000/year from 1977 to 1983 for children aged less than 19 year old. Another study for the same population found that the incidence of T1DM had increased from 22,7/100000 in 1984 to 26,0/100000 in 1993 and this increase of about 2% a year, though small, is statistically significant and the effect over 10 years is a large increase [16]. An important increase in incidence of T1DM was also observed in Saxony between the five year periods 1999-2003 and

Ιn our study we have ascertained the mean annual incidence on T1DM in the Greek Cypriot population during the period 1990 - 1999 in children younger than 15 years of age. During this period the incidence of T1DM was 10.76 /100000[18]. In order to identify an increase in the incidence of T1DM in our country, as occurred in the majority of the populations worldwide, we had performed an analysis of the newly diagnosed cases until the end of the year 2004. There was a statistically significant increase in the incidence during the period 2000-2004 with an estimated mean overall incidence 11.9/100000[19]. We had subsequently extended this work by adding the new cases of the five year period 2005 – 2009 in order to document this rising trend by comparing the incidence between the two decades (1990-1999 vs 2000-2009). We have observed a rising trend of the mean incidence from 10.76/100.000 at the first decade (1990-1999) of the study up to 14.4/100.000 at the second decade (2000-2009). According to Wilcoxon two-sample test this increasing trend of incidence during the 20 years analysed is statistically significant (p-value=0.0091). The mean incidence rate for each 5 year- period in accordance with the population data (population below the age of 15yr) is presented in figure 2. The overall mean incidence of T1DM, in the Greek Cypriot population was 12.46/100000 during the twenty-year period 1990-2009. This raised

2004-2008 with estimated rates 15.7/100000 and 19.2/100000 respectively [17].

incidence classifies Cyprus among the countries with high incidence of T1DM.

Fig. 2. Different annual incidence rates during five year periods.

T1DM formerly called as juvenile diabetes it is one of the most common chronic disease of youth as 80% of individuals with T1DM are younger than 20 year of age [20-21]. The age of manifestation of childhood onset T1DM has a bimodal allotment with one peak at 4 to 6 years of age and a second in early puberty (10 to 14 years of age) [22-23]. Recent studies report a higher rate of increase among children younger than 5 years than in children between 5 and 15 years of age [24-25]. This may be related to an earlier onset of clinical manifestation or to a true increase in the causative factors of the disease.

Although the clinical appearance occurs at all ages [21] one fourth of individuals with T1DM are diagnosed as adults [26]. Up to 10% of adults primarily supposed to have type 2 diabetes are found to have antibodies associated with T1D [27] and beta cell destruction in adults seems to take place at a much slower rate than in young T1D cases, often delaying the need for insulin therapy after diagnosis.
