(RxWiki News) About eight in 10 people with type 2 diabetes are overweight or obese. While weight is related to the condition, putting on pounds over a few years may not signal increased risk.
A new study found that most people who were diagnosed with diabetes were “stably overweight,” meaning they maintained the same amount of excess weight for years prior to being diagnosed with diabetes.
The researchers stressed weight loss as a way to reduce diabetes risk among most individuals.
"Maintain a healthy weight to reduce the risk of diabetes."
Dorte Vistisen, PhD, Kristine Færch, PhD, from the Steno Diabetes Center in Gentofte, Denmark, and colleagues reviewed data on 6,705 diabetes-free individuals who were followed for 18 years to find out how body weight changed in people in the years before they were diagnosed with diabetes. The subjects were all British white men and women.
With type 2 diabetes, the body's cells are not responding appropriately to insulin, a hormone produced by beta cells in the pancreas. Insulin helps blood sugar (glucose) to be transported into the cells to be used as energy. When someone is overweight or obese, increased fat can make it more difficult for the body to correctly use insulin.
Every five years, participants in this study were tested for diabetes. Over the course of the follow-up, healthcare providers identified 645 people who had developed the condition.
The biggest group, with 606 people, was considered “stably overweight.” Their body mass index (BMI) changed very little from the start of the study. This group had an average weight gain of 2.3 BMI units during 18 years of follow-up. From five years prior to diagnosis onward, participants in this group had minor decline of beta cell function and insulin sensitivity (or how sensitive the body is to insulin).
Only 15 participants progressively gained weight in the years leading up to their diagnosis. They had an average gain of 8.6 BMI units prior to diagnosis. A few years prior to diagnosis, as these patients gained weight, they also experienced a linear rise in blood pressure and an increase in insulin resistance.
The 26 remaining subjects were labeled as persistently obese. They were obese throughout the entire investigation, and some were obese for 18 years prior to their diagnosis. As the patients in this group approached diagnosis, they experienced beta cell compensation (increasing the production of insulin) followed by loss of beta cell function. Their insulin sensitivity remained relatively stable.
"There are 26 million Americans with diabetes, according to the American Diabetes Association," said Dr. Barry Sears, President of the non-profit Inflammation Research Foundation in Marblehead, MA and creator of The Zone Diet. "They also estimate that approximately 79 million Americans have pre-diabetes (metabolic syndrome) that is characterized by insulin resistance. More than 70 percent of the American adults (approximately 160 million) are overweight or obese, which is about the same percentage of the diabetics who are overweight or obese."
According to Dr. Sears, "The reason why every obese or overweight American is not diabetic or pre-diabetic is due to their levels of inflammation and to which organs it is spread. For the overweight and obese individuals who are not diabetic or pre-diabetic, their inflammation is constrained to their fat cells. For those who are pre-diabetic, the inflammation has spread like a cancer from the fat cells to the liver and the muscles. From those organs, it can further spread to pancreas creating diabetes. Ominously, it can spread from pancreas to the brain, increasing the likelihood of Alzheimer's."
Dr. Sears continued, "What fuels this metastatic spread of inflammation is a pro-inflammatory diet. What causes the inflammation to recede is an anti-inflammatory diet rich in omega-3 fatty acids and polyphenols (the chemicals that give fruits and vegetables their color). Drugs only treat the symptoms of diabetes, not the underlying cause, which is a pro-inflammatory diet. This is why diabetes continues to be an epidemic disease."
Overweight and obesity for this study were defined by World Health Organization (WHO) standards. BMI is the ratio of a person's weight to height. A BMI measure greater than or equal to 25 is considered overweight. A BMI greater than or equal to 30 is obesity.
Overweight and obesity are the fifth leading risk for deaths around the world, according to the WHO. At least 2.8 million adults die each year as a result of being overweight or obese.
"Strategies focusing on small weight reductions for the entire population may be more beneficial than predominantly focusing on weight loss for high-risk individuals," the authors of this study concluded.
The study was published February 11 in PLoS Medicine.
Funding was provided by UK Medical Research Council, UK Economic and Social Research Council, British Heart Foundation, UK Health and Safety Executive, UK Department of Health, US National Heart, Lung and Blood Institute, US National Institute on Aging, US Agency for Health Care Policy Research and John D and Catherine T MacArthur Foundation.