The study was the first to investigate the association over time between glycosylated hemoglobin – a long-term measure of blood sugar – and the risk of cognitive difficulties, and the first to investigate that association in people without diabetes. It appears in the Volume 10, Number 4 issue of the Journal of Nutrition, Health, and Aging.
“We already know there’s a connection between diabetes and cognitive problems,” says lead author Kristine Yaffe, MD, a staff physician at the San Francisco VA Medical Center and a professor of psychiatry, neurology, and epidemiology at the University of California, San Francisco. “We were interested in what this measurement would tell us about a group of women with and without diabetes who were followed for four years. Nobody has really looked at that before.”
The glycosylated hemoglobin test measures the percentage of hemoglobin – the oxygen-bearing protein in red blood cells – that is bound to glucose. Unlike the standard diabetic blood sugar test, which measures blood sugar at the moment of testing, glycosylated hemoglobin is considered an accurate measure of blood sugar levels over the course of two to four months preceding the test. A result of seven percent or less indicates good long-term blood sugar control.
The researchers studied 1,983 post-menopausal women with a mean age of 67 years. Their baseline glycosylated hemoglobin levels were tested at the beginning of the study, and they were assessed for dementia every year for four years. At the end of the study, each one percent increase in glycosylated hemoglobin at baseline was associated with a 40 percent increased risk of developing MCI or dementia four years later.
Women with a glycosylated hemoglobin of seven percent or higher at baseline were four times more likely to develop MCI or dementia than women who tested at less than seven percent.
When the 53 women in the study known to have diabetes at baseline were excluded from the results, there was still a statistically significant association between elevated glycosylated hemoglobin and the risk of MCI or dementia.
The authors conclude, “This finding supports the hypothesis that abnormal glycemic control is linked to an increased risk of developing cognitive impairment and dementia in elderly women.”
The authors note that there are a number of possible reasons why chronically high blood sugar may cause cognitive impairment, ranging from the overall effects of diabetic complications to direct and indirect brain damage caused by high blood sugar to a possible association between the enzyme that degrades insulin and the development of Alzheimer’s disease.
“Type 2 diabetes is a very common and growing problem,” notes Yaffe. “The point is that now you can identify people who are at risk for MCI or dementia and monitor them closely with glycosylated hemoglobin. I think we need to take these people who are at risk and see whether we can target them for trials or interventions for better blood glucose control.”
Co-authors of the study were Terri Blackwell, MS, of California Pacific Medical Center; Rachel Whitmer, PhD, of Kaiser Permanente Division of Research; Katherine Kreuger, MD, of Eli Lilly and Company; and Elizabeth Barrett-Connor, MD, of UC San Diego.
The research was supported by grants from the National Institutes of Health, the Mount Zion/UCSF Fund for Women’s Health, and the Paul Beeson Faculty Scholars in Aging. The parent trial, of which the current study was a part, was funded by Eli Lilly and Company.
SFVAMC has the largest medical research program in the national VA system, with more than 200 research scientists, all of whom are faculty members at UCSF.
UCSF is a leading university that consistently defines health care worldwide by conducting advanced biomedical research, educating graduate students in the life sciences, and providing complex patient care.
Steve Tokar | EurekAlert!
Europe’s Demographic Future. Where the Regions Are Heading after a Decade of Crises
10.08.2017 | Berlin-Institut für Bevölkerung und Entwicklung
Scientists reveal source of human heartbeat in 3-D
07.08.2017 | University of Manchester
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
17.08.2017 | Physics and Astronomy
17.08.2017 | Earth Sciences
17.08.2017 | Physics and Astronomy