Type 1 Diabetes Among Sardinian Children Is Increasing

Abstract

OBJECTIVE -The Sardinian type 1 diabetes register represented the basis to determine the most recent trends and the age distribution of type 1 diabetes incidence among Sardinians Ͻ15 years of age during 1989 . Part of the data (1989 has been already published by the EURODIAB Group with a lower completeness of ascertainment (87%). The geographical distribution of type 1 diabetes risk was also investigated. RESEARCH DESIGN AND METHODS -The new cases of type 1 diabetes in children aged 0 -14 years in Sardinia were prospectively registered from 1989 to 1999 according to the EURODIAB ACE criteria. The completeness of ascertainment calculated applying the capturerecapture method was 91%. Standardized incidence rates and 95% CI were calculated assuming the Poisson distribution. Trend of type 1 diabetes incidence was analyzed using the Poisson regression model. Maps of the geographical distribution of type 1 diabetes risk for the whole time period and separately for 1989 -1994 and 1995-1999 were produced applying a Bayesian method.RESULTS -A total of 1,214 type 1 diabetic patients were registered yielding to an overall age-and sex-standardized incidence rate of 38.8/100,000 (95% CI 36.7-41.1). There was a male excess with an overall male-to-female ratio of 1.4 (1.3-1.8). The increase of incidence during the 11 years analyzed was statistically significant (P ϭ 0.002) with a yearly increasing rate of 2.8% (1.0 -4.7). No evidence of an effect of age and sex on this trend has been found. The geographical distribution of type 1 diabetes relative risk (RR) showed that the highest risk areas are located in the southern and central-eastern part of the island and the lowest risk in the northeastern part, even if most of these differences were not statistically significant. This geographical distribution seemed to remain mainly the same between 1989 -1994 and 1995-1999. CONCLUSIONS -The homogeneity of diabetes risk and the increase of incidence over the age-groups in the Sardinian population stress the role of an environmental factor uniformly distributed among the genetically high-risk Sardinians.

Oral glucose tolerance test in Italian overweight/obese children and adolescents results in a very high prevalence of impaired fasting glycaemia, but not of diabetes

“…Within the overweight/obese group, subjects with IGR were also significantly different from NGT subjects, resulting more insulin-resistant and dyslipidemic. Given the high prevalence of autoimmune diabetes in Sardinia [13], we controlled for the presence of GAD and IA2 antibodies in our IGR subjects. The results showed that 2 of the 3 children already with diabetes were affected by autoimmune type 1 diabetes, showing that this condition may also be associated with an overweight/obese phenotype.…”

“…Given the high prevalence of autoimmune type 1 diabetes in Sardinia [13], we evaluated the presence of circulating autoantibodies in the 58 children with IGR. GADA were detectable in 2 of the 3 children affected by diabetes mellitus who had high titres (5.48 and 37.71 U/mL) of circulating GADA associated to high titres (7.53 and 9.28 U/mL) of IA2 autoantibodies, thus confirming a diagnosis of type 1 diabetes.…”

“…To our knowledge, these are the only large studies in European children, and further studies are warranted to define the real impact of hyperglycaemia in obese children and adolescents. Moreover, data are missing on the prevalence of T2D in paediatric populations from areas at high risk for type 1 diabetes such as Sardinia and Finland [13,14]. At this time, Sardinian children and adolescents are experiencing the same increase in obesity as other European populations [15].…”

Risk assessment does not explain high prevalence of gestational diabetes mellitus in a large group of Sardinian women

“…30.60, 35.88) of Type 1 diabetes, which is the second highest in the world after Finland [19][20][21][22], and a high prevalence of other autoimmune diseases Type 1 diabetes related, such as Multiple Sclerosis, Celiac Disease, Autoimmune Thyroid Disease and others [23][24][25][26]. For these reasons, Sardinia represents an ideal observatory for investigating genetic and immunological factors.…”

Increased prevalence of proliferative retinopathy in patients with type 1 diabetes who are deficient in glucose-6-phosphate dehydrogenase

“…Sardinia has one of the highest incidences of type 1 diabetes in the world [6], second only to Finland, and a very high prevalence of G6PD deficiency (present in 12-15% of the male population compared with 0.48% in continental Italy) [2]. In Sardinia, all variants of G6PD deficiency are due to the same mutation, which results in only 5-10% residual activity of the enzyme [7] and G6PD deficiency does not show an association with diabetes [8].…”