Sedentary Behavior Linked With Increased Plasma Glucose

Recent findings demonstrate a deleterious relationship between sedentary behavior — as indicated by television viewing — and glycemic measures in adults without diagnosed diabetes. This relationship was independent of physical activity time and adiposity status. Dr. David W. Dunstan, of the International Diabetes Institute, Melbourne, Australia, and colleagues examined the association between television viewing and fasting plasma glucose (FPG) and 2-h post-challenge plasma glucose (2-h PG) levels in 3781 men and 4576 women in Australia. All of the subjects were diabetes-fee at baseline.

An interviewer-administered questionnaire was used to assess self-reported television viewing time in the previous week. Based on fasting glucose and insulin levels, the team calculated homeostasis model assessment (HOMA) of insulin sensitivity (HOMA-%S) and beta-cell function (HOMA-%B).

After adjustment for confounders and physical activity time, a positive association was observed between television viewing time and 2-h PG, log fasting insulin and log HOMA-%B in women. No relationship was observed with FPG. Time spent watching television was inversely associated with log HOMA-%S.

There were no significant associations observed with glycemic measures in men.

Dr. Dunstan stated that,  "The findings reinforce the case for a strong focus in diabetes and obesity research on sedentary behaviors, such as television viewing, in addition to the now well-established base of evidence on the importance of increasing physical activity."

"It is possible that other sedentary behaviors may have an additive effect on risk, in that TV viewing may be a marker for a broader pattern of sedentary lifestyle that includes a variety of other forms of sitting time," he suggested.

"In our study, TV time was more strongly associated with 2-h plasma glucose compared to fasting blood glucose," Dr. Dunstan added. "We speculate that this relationship could at least be partly explained by the acute and/or cumulative absence of muscle contraction through inactivity, a defining characteristic of sedentary pursuits."

"There is a strong case for considering the underlying sedentary or inactivity physiology as a distinct research problem, since a better understanding of the biological mechanisms of sedentary living could assist with the development of primary prevention strategies for many chronic diseases."

Diabetes Care 2007;30:516-522.

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FACT:

Industry survey: Diabetes ignorance high:  Nearly 80 percent of U.S. adults do not know the difference between type 1 and type 2 diabetes, and many think type 1 diabetes is curable, a survey found.  The survey, conducted by Harris Interactive for Medtronic, Inc., found 67 percent of people incorrectly believed a cure existed for type 1 diabetes. Type 1 diabetes develops when the body’s immune system destroys pancreatic beta cells, the only cells that make insulin, a hormone that regulates blood glucose. About 1 million Americans with type 1 diabetes — which often appears in children — depend on daily delivery of insulin from an insulin pump or injections to survive. Fifty-one percent of the survey respondents knew there were two types of diabetes. Type 2 diabetes is non-insulin-dependent diabetes. It appears mostly in older adults, but it’s on the rise in younger adults due to the exploding obesity rate in the United States.