Aggiornamento sulla epidemiologia della sclerosi multipla nel nord Sardegna: un triste primato

Aim: To determine the current burden of MS in Sardinia, insular Italy, a region at high risk for the disease. Methods: Age- and gender-specific population-based prevalence and incidence were updated based on data from 40-year MS surveillance in the study area (provinces of Sassari and Olbia-Tempio, pop. 481,000 ca). Medical records and district health statistics (hospital discharge ICD9-CM and ticket exemption codes) were scrutinized for the study population. Estimates were based on MS according to Poser et al. criteria. Results: On prevalence day, December 31st 2008, 1265 individuals suffering from MS (345 men, 920 women) were living in the study area. Crude total prevalence was 260.3 per 100,000 (95%CIs: 256,3-264,3), 144,5 and 372,2 for men and women, respectively. The respective estimates adjusted for the 2008 Italian population were 247,6, 137,8, 353.2. Prevalence significantly increased from 1971 (13.6) to 2008. Mean age at death also increased from 40.6 (1971) to 58.7 (2008) years (no gender effect). Mean total incidence for the period 2000-4 was 10.5 per 100,000/year (95%CIs: 8.1, 12.4), 6.3 for men, 14.5 for women. In 1965-2008, mean age at clinical onset increased from 25.5 to 32.1 years with no gender effect; F:M ratio increased from 1.54 to 2.90 Conclusions: MS burden in Sardinia, insular Italy is to our knowledge the highest worldwide. MS in Sardinians shows a relevant incremental temporal trend of prevalence that can be explained by increasing survival but remarkably by increasing incidence especially in women. Because such variation has occurred within a relatively short period of time in this genetically stable population, a corrisponding change in the temporal distribution of an enviromental factor(s) and/or in the population’s lifestyle deserves further investigation.