Increasing prevalence of juvenile onset Type 1 (insulin-dependent) diabetes mellitus in Sardinia: the military service approach

Abstract

In order to obtain new and more detailed information about temporal trends and geographic distribution of Type 1 (insulin-dependent) diabetes mellitus in Sardinia, we screened a series of birth cohorts (1936-1973) of all male army conscripts aged 18-19 years, filed in the Sardinian Conscript Register where Type 1 diabetes is a cause of rejection. A total of 678 diabetic subjects, born and permanently residing in Sardinia, was identified. The point prevalence (x 1000) at the age of 20 years in the birth cohorts ranged from values close to zero for the first ten cohorts (1936-1945) up to a maximum of 3.08 (95% confidence limits 2.28-4.08) for the 1966 cohort and continued high thereafter although an apparent decrease was observed from the early 1970s birth cohorts. Type 1 diabetes was distributed throughout the four provinces of Sardinia with no particularly significant heterogeneity; however, in accordance with the geographical distribution of diabetes cases of the Eurodiab Ace survey (1989-1990), the highest prevalence of the disease was observed in the Cagliari and Oristano provinces, followed by Nuoro and Sassari. These data suggest a gradually increasing trend of male Type 1 diabetes prevalence in Sardinia with a 29-fold increase between the late 1930s and the late 1960s birth cohorts. This seems to confirm the high incidence of Type 1 diabetes in the 0-14 and 0-29 year age groups recently reported among Sardinians during the Eurodiab Ace collaborative multicentre study.

The Verona diabetes study: a population-based survey on known diabetes mellitus prevalence and 5-year all-cause mortality

“…Prevalence of IDDM in Verona on 31 December 1986 was 0.069 %, similar to that found in north-west Italy [3], but lower than that found in Sardinia [19]. Interestingly, in spite of the remarkable difference in the absolute prevalence of IDDM, in both Verona and Sardinia the highest prevalence of this type of diabetes was found in males born in the late 1960s and early 1970s, reflecting a trend observed in other areas [20].…”

The Sardinian IDDM Study: 1. Epidemiology and geographical distribution of IDDM in Sardinia during 1989 to 1994

“…Previous studies [3,7] of IDDM as observed at the military examination of 18-year-old male conscripts born in Sardinia during the period 1936±1973 showed a marked overall increasing time trend of IDDM risk (sharp increase from the early 1960 s) that cannot be explained in terms of variation in genetic susceptibility to IDDM of Sardinians, which are a genetically distinct and stable population.…”

Type 1 Diabetes Among Sardinian Children Is Increasing

“…[3][4][5][6][7][8][9][10][11][12][13][14][15].1]). The temporal trend seems to have two peaks: in 1993 and in 1998.…”

“…Type 1 diabetes incidence has been rising over the last decade by an yearly average of 3.0% worldwide (7) and 3.2% in Europe (8) with a higher rate of increase among children Ͻ5 years of age. Earlier data have demonstrated a marked increase in the point prevalence of type 1 diabetes also in Sardinia during the past decades among young men aged 18 years (9). However, that study was not able to investigate the incidence in recent years, nor the risk among women or among different agegroups.…”