http://www.cnr.it/ontology/cnr/individuo/prodotto/ID229163

Bayesian analysis of ecological data studying the association between Insulin-Dependent Diabetes Mellitus and malaria. (Contributo in volume (capitolo o saggio))

Type

Prodotto della ricerca (Classe)
Contributo in volume (capitolo o saggio) (Classe)

Label

Bayesian analysis of ecological data studying the association between Insulin-Dependent Diabetes Mellitus and malaria. (Contributo in volume (capitolo o saggio)) (literal)

Anno

1999-01-01T00:00:00+01:00 (literal)

Alternative label

Bernardinelli L, Pascutto C, Gilks W, Montomoli C, Komacek J, Gilks W, Solinas G, Fiorani O, Lisa A, Zei G, Songini M, Bottazzo GF (1999)
Bayesian analysis of ecological data studying the association between Insulin-Dependent Diabetes Mellitus and malaria.
John Wiley & Sons, Ltd., Chichester (Regno Unito), Chichester (Regno Unito) in Statistics for the Environment 4: Health & the Environment., 1999
(literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori

Bernardinelli L, Pascutto C, Gilks W, Montomoli C, Komacek J, Gilks W, Solinas G, Fiorani O, Lisa A, Zei G, Songini M, Bottazzo GF (literal)

Pagina inizio

29 (literal)

Pagina fine

47 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#titoloVolume

Statistics for the Environment 4: Health & the Environment. (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni

IGM-CNR; (literal)

Titolo

Bayesian analysis of ecological data studying the association between Insulin-Dependent Diabetes Mellitus and malaria. (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#isbn

0-471-97645-8 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#curatoriVolume

V. Barnett, A. Stein, K.F.Turkman (literal)

Abstract

Sardinians are known to be susceptible to autoimmune diseases: the risk for IDDM (Insulin-Dependent Diabetes Mellitus) and multiple sclerosis in Sardinia is much higher than that observed on the mainland and it is one of the highest in Europe. There is also a geographical variation of IDDM risk across Sardinian communes as estimated in 0-29-year-old individuals. This variation is partially explained by the geographical variation of long-term malaria endemicity. In particular, people living in areas where malaria prevalence was found to be high are at lower risk of IDDM than those living in areas with a low prevalence of malaria. This result emerges from the negative association between long-term malaria endemicity and IDDM incidence. The association is statistically significant also when accounting for altitude, a potential confounder, as shown by the estimated regression coefficient. Although its 95% credible interval is rather wide, suggesting uncertainty about the true strength of this relationship, the estimated regression coefficient is shifted towards scientifically significant values. A possible interpretation of this finding is that, since malaria has been endemic in the plains of Sardinia for centuries, places with a high prevalence of malaria in 1938 are those in which a stronger selection process took place, both providing resistance to malaria and preventing the onset of autoimmune conditions. A negative association between IDDM risk and malaria emerges also from the time profile of the IDDM year-specific prevalence as observed in military Conclusions 45 conscripts. There is a marked increasing risk over time in both low and high-malaria groups, but the profile in the low-malaria areas is significantly higher than in the high-malaria areas for the cohorts of conscripts born before the 1960s. In interpreting these results we should take into account that malaria was completely eradicated only in the 1950s through the Rockefeller campaign, but malaria morbidity had probably started decreasing a few decades before, as a result of local efforts to control the disease. Because of the short time-lag between the eradication of malaria and the time when the IDDM risk started to increase, the marked increase in IDDM risk cannot be explained purely in terms of changes in the genetic characteristics of the Sardinian population: environmental factors must also have played an important role. We might hypothesize a similar mechanism as that suggested to explain why there is an apparent protection from autoimmune diseases in West Africa, where malaria is endemic, in contrast to a higher incidence in Afro-American populations, who are mostly of West African descent. If endemic malaria stimulates the production of immunosuppressive substances like nitric oxide, it might have helped in keeping a low prevalence of IDDM in Sardinia before the Rockefeller campaign. After the eradication of malaria, the high susceptibility to autoimmune diseases of the Sardinians may have resulted in a rapid increase in the prevalence of IDDM. However, we should consider alternative explanations to those reported above. For example, the post-malaria eradication time coincided also with the post-war time. So it may be that changes in lifestyle affected the risk for IDDM. It is also possible that we have not taken into account important possible factors other than altitude. In any case, having found in two independent sets of data that the IDDM risk is lower in areas at high past-malaria endemicity makes us feel confident in the hypothesis that malaria must have played a role in determining the susceptibility to IDDM of the Sardinian population. (literal)

Editore