Disproportionately high incidence of diabetes-related end-stage renal disease in the Canary Islands. An analysis based on estimated population at risk.

ABSTRACT

BACKGROUND: An exceptionally high incidence of diabetes-related end-stage renal disease (DM-ESRD) has been reported in the Canary Islands. This phenomenon was attributed to an increased prevalence of diabetes in this community. We compared the incidence of DM-ESRD in the Canary Islands with the rest of Spain among the estimated number of individuals at risk (people with diabetes in the population). METHODS: The population-at-risk was calculated using census population figures and estimates of self-reported diabetes prevalence from the Spanish National Health Survey in the years 2003 and 2006. The incidence of DM-ESRD for the same years was obtained through Spanish regional registries. The independent effect of age, community of residence and calendar year was estimated with a Poisson regression model. Age-standardized acceptance rate ratios were calculated for each community. RESULTS: Overall DM-ESRD incidence in the Canary Islands population-at-risk was 1209.9 per million population (pmp) in 2003 and 1477.3 pmp in 2006. Rates for the remaining Spanish regions ranged from 177.3-984.9 pmp. The incidence was higher in the Canary Islands across all age groups, but was most striking for patients > or =75 years. Diabetes prevalence in the general population was greater in the two youngest age strata and diminished from 75 years on in the Canary Islands, in comparison with other areas of Spain. Using a cluster of three communities with the lowest incidence as a reference, the relative risk of DM-ESRD in the Canary Islands population-at-risk was 3.88 [95% confidence interval (CI) 3.07-4.89]. Age-standardized acceptance ratios (95% CI) in the Canary Islands were 2.21 (1.85-2.61) in 2003 and 2.73 (2.34-3.17) in 2006. CONCLUSIONS: Individuals with diabetes in the Canary Islands present a disproportionately high incidence of ESRD. Diabetic Canary inhabitants are exposed to the disease for a longer time and therefore, may be more vulnerable to the development of chronic diabetes complications, including ESRD.