Is the incidence of diabetes increasing in all age-groups in The Netherlands?: Results of the second study in the Dutch Sentinel Practice Network

OBJECTIVE - To assess possible changes in the incidence oi diabetes in all age-groups in The Netherlands during a 10-year period (1980-1983/1990-1992). RESEARCH DESIGN AND METHODS - since 1970, a network of sentinel stations (the Dutch Sentinel Practice Network) consisting of similar to 1% of the Dutch population has been in operation to gain insight into the morbidity patterns of the Dutch population as recorded by general practitioners. One of the items recorded from 1990 to 1992 was the incidence of diabetes. The first study with a similar design that registered the incidence of diabetes was conducted from 1980 to 1983. RESULTS - The overall incidence of diabetes increased significantly by 12.1% in the period between the two studies. This overall increase can largely be attributed to a statistically significant increase in the age-group 45-64 years (30.5%). Although not statistically significant, the 36% increase of diabetes in the age-group 0-19 years is in accordance with the increase of type I diabetes based on the first and second nationwide retrospective studies covering the total Dutch population. CONCLUSIONS - There is a marked increase in the incidence of diabetes in the age-group 45-64 years. This selective increase is probably not due to a real rise caused by changes in exposure to risk factors but to an earlier recognition of symptoms and signs of diabetes followed by blood glucose measurements and/or to more intensive case finding in general practice.