No abstract

We designed this study to explore to what extent the excess risk of cardiovascular events in diabetic individuals is attributable to hypertension. We retrospectively analyzed prospectively collected data from the Framingham Original and Offspring cohorts. Of the 1145 Framingham subjects newly diagnosed with diabetes who did not have a prior history of cardiovascular events, 663 (58%) had hypertension at the time diabetes was diagnosed. During 4154 person-years of follow-up, 125 died and 204 suffered a cardiovascular event. Framingham participants with hypertension at the time of diabetes diagnosis exhibited higher rates of all cause mortality (32 versus 20 per 1000 person years, p<0.001) and cardiovascular events (52 versus 31 per 1000 person years, p<0.001) compared with normotensive subjects with diabetes. After adjustment for demographic and clinical covariates, hypertension was associated with a 72% increase in the risk of all cause death and a 57% increase in the risk of any cardiovascular event in individuals with diabetes. The population attributable risk from hypertension in individuals with diabetes was 30% for all-cause death and 25% for any cardiovascular event (increasing to 44% and 41% respectively if the 110 normotensive subjects who developed hypertension during follow-up were excluded from the analysis). In comparison, after adjustment for concurrent hypertension, the population attributable risk from diabetes in Framingham subjects was 7% for all cause mortality and 9% for any CVD event. While diabetes is associated with increased risks of death and cardiovascular events in Framingham subjects, much of this excess risk is attributable to coexistent hypertension.

ObjectiveThe objective of this study was to compare international trends in pre-eclampsia rates and in overall pregnancy hypertension rates (including gestational hypertension, pre-eclampsia and eclampsia).DesignPopulation data (from birth and/or hospital records) on all women giving birth were available from Australia (two states), Canada (Alberta), Denmark, Norway, Scotland, Sweden and the USA (Massachusetts) for a minimum of 6 years from 1997 to 2007. All countries used the 10th revision of the International Classification of Diseases, except Massachusetts which used the 9th revision. There were no major changes to the diagnostic criteria or methods of data collection in any country during the study period. Population characteristics as well as rates of pregnancy hypertension and pre-eclampsia were compared.ResultsAbsolute rates varied across the populations as follows: pregnancy hypertension (3.6% to 9.1%), pre-eclampsia (1.4% to 4.0%) and early-onset pre-eclampsia (0.3% to 0.7%). Pregnancy hypertension and/or pre-eclampsia rates declined over time in most populations. This was unexpected given that factors associated with pregnancy hypertension such as pre-pregnancy obesity and maternal age are generally increasing. However, there was also a downward shift in gestational age with fewer pregnancies reaching 40 weeks.ConclusionThe rate of pregnancy hypertension and pre-eclampsia decreased in northern Europe and Australia from 1997 to 2007, but increased in Massachusetts. The use of a different International Classification of Diseases coding version in Massachusetts may contribute to the difference in trend. Elective delivery prior to the due date is the most likely explanation for the decrease observed in Europe and Australia. Also, the use of interventions that reduce the risk of pregnancy hypertension and/or progression to pre-eclampsia (low-dose aspirin, calcium supplementation and early delivery for mild hypertension) may have contributed to the decline.

No abstract