January 04, 2008 By: Diana Barnes-Brown for Diabetes1
Research conducted in France last year has demonstrated that wide fluctuations in blood sugar levels can cause as much damage as prolonged periods of hyperglycemia (high blood sugar) in diabetics.
| Learn the Symptoms |
Signs of Hyperglycemia:
Frequent, pronounced hunger
Frequent, excessive thirst
Frequent urination
Blurred vision
Fatigue
Weight loss, even if eating normally
Poor wound healing
Dry mouth
Dry or itchy skin
Impotence in men
Recurrent fungal and bacterial infections
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Signs of Hypoglycemia:
Hunger
Feeling wobbly, nervous or shaky
Perspiration, including night sweats
Dizziness or light-headedness
Sleepiness
Confusion
Difficulty speaking
Anxiety
Weakness
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In healthy people, food is broken down into glucose, a simple sugar, by the process of digestion. The food then enters the blood stream where insulin that is secreted by cells in the pancreas helps the sugar to enter cells. This sugar provides cells with the energy they need to function. In diabetics, either the pancreatic cells responsible for creating insulin do not work as they should, or the body becomes resistant to insulin. As a result, blood sugar levels increase, causing hyperglycemia, unless they are controlled by insulin injections. Alternately, when too much insulin is administered or when the amount of food eaten or exercise done causes more sugar than usual to be burned off, blood sugar becomes too low, and hypoglycemia occurs.
Because of the need to keep blood sugar at safe levels and avoid either big dips or spikes, diabetes is often seen as a lifelong balancing act for patients and their caregivers. The findings from France suggest that this balancing act may require even more attention than previously thought.
The research, conducted by Louis Monnier, MD, and his research team at the University of Montpelier and published in the Journal of the American Medical Association (JAMA), found that fluctuations in blood sugar can trigger oxidative stress, a medical term which describes changes in metabolism that can cause cell damage and death, and trigger a host of diabetes complications. While medical researchers were aware that hyperglycemia could cause oxidative stress, this was the first time that repeated highs and lows were found to be similarly damaging.
Previously, it was believed that chronic hyperglycemia was the main cause of blood vessel damage in diabetics, so the preferred method for monitoring these levels was to measure average blood glucose over a period of several months. However, such tests can show an average that looks healthy, but is based on wild swings between low and high blood sugar levels.
Accurate, continuous glucose monitors are now available, and they allow researchers to measure glucose fluctuation by recording glucose levels continuously over several days. This enables researchers to monitor not only averages but also peaks and valleys and their effects.
The researchers at Montpelier studied a group of 21 participants with diabetes over a three-day period, and found that those with greater glucose fluctuation also had higher levels of a biomarker released as a result of oxidative stress. Furthermore, the relationship between wide fluctuations and oxidative stress was more direct and predictable than that between hyperglycemia and oxidative stress.
In conclusion, the researchers noted that the research must be expanded upon before causal links can be established. They did note that “because activation of oxidative stress is one of the main mechanisms that leads to diabetic complications, the present data open the field to conduct interventional studies aimed at treating glycemic disorders not only by reducing . . . mean hyperglycemia but also by flattening acute glucose fluctuations.”