Fewer Steps Per Day Send Disease Markers Up
Insulin levels hike very fast when daily physical activity declines, Danish study found.
TUESDAY, March 18, 2008 (HealthDay News) -- Forget about regular, scheduled exercise for a minute. If you just drop your average daily activity level -- by taking elevators instead of stairs, by parking your car in the closest space, or by never walking to do errands -- you increase your risk of diabetes, heart disease and premature death, according to new Danish research.
And, those changes begin in as little as 14 days after you start to reduce your activity level, the researchers say.
The team found that when healthy men cut their daily activity, their insulin levels spiked dramatically, as did levels of blood factors such as C-peptide and triglycerides -- suggesting an increased risk of diabetes and heart disease.
"It is amazing that only two weeks of reduced stepping can induce numerous metabolic abnormalities," said the one of the study's authors, Dr. Rikke Krogh-Madsen, from the Centre of Inflammation and Metabolism in Copenhagen. "It is of special interest that impaired metabolism occurred without a total weight gain," she added.
"The message here is that a lot of significant changes can occur without a huge change in weight, so if your only barometer of success and health is weight, you're missing out," said exercise physiologist Polly deMille, from the Hospital for Special Surgery in New York City.
Results of the study were published as a letter in the March 19 issue of the Journal of the American Medical Association.
The study included 18 young, healthy men with no family history of diabetes. None of the men smoked, and none participated in a regular exercise program for more than two hours each week.
The study volunteers were divided into two groups. The first group included eight men with an average age of 27 and an average BMI of 22.9, which is well within the normal range (obesity starts at a BMI of 30).
Prior to the study start, the men wore pedometers and averaged 6,203 steps each day. To reduce the amount of steps, the researchers asked the volunteers to take cars on short trips instead of walking or bicycling, and to take elevators instead of stairs. During the study period, the men reduced their daily steps to an average of 1,394 daily steps. After two weeks of reduced daily activity, the amount of insulin circulating in the blood increased by about 60 percent, suggesting that the body was no longer efficiently processing glucose (energy) from food and needed to increase insulin production to metabolize the sugar in food.
The second group included 10 men with an average age of 23.8 years and a BMI of 22.1. At the start of the study, their average daily number of steps were 10,501. After two weeks, they had reduced their average daily steps to 1,344 -- an almost 90 percent reduction in daily activity. In this group, insulin levels also rose by nearly 60 percent after two weeks of inactivity.
In this group, the researchers also measured additional effects and found levels of heart disease risk factors had also increased with reduced activity. For example, triglyceride levels increased and the lack of physical activity was associated with a 7 percent increase in abdominal fat, even though there was no overall weight gain, according to Krogh-Madsen.
"Reduced daily activity can induce metabolic changes, which can be associated with the progression of chronic disorders and premature mortality," the researcher said.
The good news here, deMille added, is that the flip side is also true.
With just a couple of weeks of increased physical activity, you can start to reduce your risk of diabetes and heart disease, even if you don't notice a big difference on the bathroom scale.
"Just get some movement in. Even if it's not what you think you should be doing, every lit bit helps in terms of keeping metabolism healthy," she said. DeMille recommended getting a pedometer to see how many steps you're already taking in a day, and then working toward adding to that each day.
"Ten thousand steps a day is recommended as a goal, but if you could get up to 5,000 a day, that's a big gain in terms of becoming a more active, healthy person. If you can do more, that's great, but every little bit counts," deMille said.
For tips on beginning an exercise program, visit the American Academy of Orthopaedic Surgeons.