Trends in death rates among U.S. adults with and without diabetes between 1997 and 2006: findings from the National Health Interview Survey

OBJECTIVE

To determine whether all-cause and cardiovascular disease (CVD) death rates declined between 1997 and 2006, a period of continued advances in treatment approaches and risk factor control, among U.S. adults with and without diabetes.

RESEARCH DESIGN AND METHODS

We compared 3-year death rates of four consecutive nationally representative samples (1997–1998, 1999–2000, 2001–2002, and 2003–2004) of U.S. adults aged 18 years and older using data from the National Health Interview Surveys linked to National Death Index.

RESULTS

Among diabetic adults, the CVD death rate declined by 40% (95% CI 23–54) and all-cause mortality declined by 23% (10–35) between the earliest and latest samples. There was no difference in the rates of decline in mortality between diabetic men and women. The excess CVD mortality rate associated with diabetes (i.e., compared with nondiabetic adults) decreased by 60% (from 5.8 to 2.3 CVD deaths per 1,000) while the excess all-cause mortality rate declined by 44% (from 10.8 to 6.1 deaths per 1,000).

CONCLUSIONS

Death rates among both U.S. men and women with diabetes declined substantially between 1997 and 2006, reducing the absolute difference between adults with and without diabetes. These encouraging findings, however, suggest that diabetes prevalence is likely to rise in the future if diabetes incidence is not curtailed.Diabetes has been associated with an average 10 years of life lost for individuals diagnosed during middle age (1). Fortunately, numerous evidence-based interventions exist, ranging from glycemic and cardiovascular disease (CVD) risk factor control to early screening for diabetes complications (2). These have been paralleled by population-wide improvements in glycemic control, CVD risk factors, and rates of several diabetes complications (3–5). Despite these improvements, it remains unclear whether longevity has increased uniformly among diabetic populations. Studies in specific diabetic cohorts in Framingham, Minnesota, and North Dakota suggest mortality declined during the 1990s (6–8). Analyses of consecutive cohorts of the U.S. population from the 1970s through the 1990s, however, found that all-cause and CVD death rates declined among diabetic men but not diabetic women (9,10). However, no national studies have examined mortality trends among the U.S. diabetic population since the 1990s, and the intervening years have been a period of continued advances in treatment approaches and risk factor levels. Newly available mortality follow-up data linked to the National Health Interview Survey (NHIS) provide a unique opportunity to determine whether CVD and all-cause mortality has improved among the U.S. population during recent decades as well as whether the excess mortality associated with diabetes has declined (11,12).