Diabetes incidence dropped but mortality rose after 2010
The population-based longitudinal study used four Danish medical databases and included 415,553 patients treated for type 2 diabetes for the first time from 1995-2018 and 2,060,279 matched comparators not treated for diabetes.
From 1995 until the 2012 introduction of A1c as a diagnostic option, the annual standardized incidence rates of type 2 diabetes more than doubled, from 193 per 100,000 population to 396 per 100,000 population, at a rate of 4.1% per year.
But from 2011 to 2018, the annual standardized incidence rate declined by 36%, to 253 per 100,000 population, a 5.7% annualized decrease.
The increase prior to 2011 occurred in both men and women and in all age groups, while the subsequent decline was seen primarily in the older age groups. The all-cause mortality risk within the first year after diabetes diagnosis was higher than subsequent 1-year mortality risks and not different between men and women.
From the periods 1995-1997 to 2010-2012, the adjusted mortality rate among those with type 2 diabetes decreased by 44%, from 72 deaths per 1000 person-years to 40 deaths per 1000 person-years (adjusted mortality rate ratio, 0.55). After that low level in 2010-2012, mortality increased by 27% to 48 per 1000 person-years (adjusted mortality rate ratio 0.69, compared with 1995-1997).
The reversed mortality trend after 2010-2012 was caused almost entirely by the increase in the first year after diabetes diagnosis, Dr. Knudsen and colleagues noted.
According to Dr. Kirkman, “A1c is strongly predictive of complications and mortality. That plus its ease of use and the fact that more people may be screened mean it’s still a good option. But for any of these tests, people who are slightly below the cut-point should not be considered normal or low risk.”
Indeed, Dr. Knudsen and colleagues said, “these findings may have implications for clinical practice and suggest that a more multifactorial view of metabolic risk is needed.”
Dr. Knudsen and Dr. Kirkman have reported no relevant financial relationships.
A version of this article first appeared on Medscape.com.