A Swedish study has found that even less than a 1% reduction in A1c’s lowered the mortality rate among type 2 patients by 50 percent compared to patients whose A1c’s remained stable or increased. (Mortality was defined as the likelihood of dying from any cause within the next five years.)
The five-year study by the University of Gothenburg tracked 12,359 older type 2s (average age 62 years) with poor control and high body mass indexes, but no cardiovascular problems. Their average baseline A1c was 7.8%.
Researchers divided the patients into two groups: one whose average A1c’s had decreased by at least 0.1% over a five-year period, and one whose average A1c’s had increased by at least 0.1% over the same period.
Taking into account the patients’ conditions at the start of the study, researchers then tracked treatments they received over the five-year study and their effects on A1c’s. At the study’s conclusion, they found that patients whose A1c levels had decreased were 50 percent less likely to develop cardiovascular problems than patients whose A1c’s had gone up.
A1c’s in the “improved control” group had dropped from the baseline of 7.8% to 7.0%. In the meantime, the “poorly controlled” group’s average A1c had increased by 0.7% to 8.4%.
In terms of mortality, 15 percent of the poorly controlled/no improvement group had died by the end of the study compared to 10 percent of the improved control group-a 50 percent difference in mortality rate.
Although mortality rates were lower among the better controlled type 2s, lower A1c percentages did not entirely remove the risk of cardiovascular problems. While 20 percent of the poor-control group developed coronary heart disease over the study’s course, 12 percent of the improved control group also developed the disease. Cardiovascular problems developed in 30 percnet of the poor-control group and 17 percent of the improved-control group.
Overall, the study indicates that lowering A1c’s among older people can be directly linked to a lessened chance of developing cardiovascular problems or having as high a risk of dying from a health-related cause as people with poorer control.
(The improved-control group’s average A1c of 7.0% coincides with the American Diabetes Association’s recommendation of 7.0% as an appropriate target A1c for older people.)
The Swedish study was presented in September at the 2012 meeting of the European Association for the Study of Diabetes.