PORTLAND, Ore. - Jan. 31, 2006 - A researcher from Kaiser Permanente's Center for Health Research in Portland has found that modest weight gain in normal-weight people greatly increases the risk of diabetes and heart disease. The study results appear in the February issue of the International Journal of Epidemiology.

Teresa Hillier, MD, MS, worked in France with government scientists at the Institute National de la Santé et de la Recherche Médicale (INSERM) to follow 3,770 French men and women for six years. Dr. Hillier and her French colleagues found that each kilogram (2.2. pounds) of weight gain increased the risk of a condition known as metabolic syndrome by 22 percent. Metabolic syndrome includes abdominal obesity, high triglycerides, low HDL cholesterol, elevated blood pressure, and insulin resistance. People with the syndrome, including an estimated 50 million Americans, greatly increase their risk of developing type 2 diabetes and coronary heart disease. After six years, 3 percent of participants who maintained a stable weight developed the metabolic syndrome, while 21 percent who gained nine kilograms or more (19.8 pounds or more) developed the syndrome.

"This is the first study to track the effects of weight change as it takes place on the metabolic syndrome in a normal-weight population," says Dr. Hillier, who is lead author of the article. "This study gives us a way to understand how we might alter the course of our worldwide epidemic of obesity and type 2 diabetes by evaluating how they begin in a normal-weight population.

"Three of our findings are especially important from a public health perspective," Dr. Hillier says. "The first is that the more pounds normal-weight people gain, the more their risk increases for developing the metabolic syndrome. The second is that insulin levels had the greatest proportional increase among all metabolic syndrome parameters across all weight-change groups, nearly doubling for both men and women. This is important new information because it shows that even mild weight gain is associated with insulin resistance. Finally, we also found that many people whose weight remained stable or who lost modest amounts of weight did not develop the metabolic syndrome or, if they had the syndrome at baseline, reverted to normal."

The participants in this study were adults aged 30 to 64 at baseline and were recruited between 1994 and 1996 from 10 government health examination centers in western-central France. Men and women were recruited equally among five-year age groups. Participants had their weight, height, waist circumference, blood pressure, and the following fasting measurements taken at both baseline and the six year follow-up: glucose, insulin, triglycerides, and HDL cholesterol. After six years, there was an average worsening in both men and women in all the measures - weight, BMI, waist girth, glucose, insulin, HDL cholesterol, and blood pressure - except for HDL cholesterol in women.

"These findings provide valuable information for both public health and clinical practice," Dr. Hillier says. "They show that even modest weight gain in normal-weight people is an important indicator for the metabolic syndrome and thus for diabetes and heart disease risk. They also tell us that we need to pay particular attention to even modest increases in waist circumference and insulin levels."

For France, which has had the lowest prevalence of obesity among nine Northern European countries and among the lowest of Westernized countries in the world, these results raise some important social and cultural questions, says Dr. Hillier.

"The so-called French paradox - the belief that there is something in the French lifestyle, red wine perhaps, that protects them against obesity, heart disease, and diabetes - may be a myth or it may be a truism that is passing into history. As more and more French men and women adopt a lifestyle that is increasingly American - fast foods, processed foods, more soda pop and caloric intake, little or no exercise - they may be entering the front end of the obesity and diabetes epidemics that began in America nearly 20 years ago."

This study was funded by a Trans-Atlantic Fellowship awarded to Dr. Hillier by the American Diabetes Association-European Association for the Study of Diabetes (ADA-EASD). Dr. Hillier spent a year (2004-2005) in Paris at INSERM working on this study and other projects.

Kaiser Permanente's Center for Health Research, founded in 1964, is a non-profit research institution whose mission is advancing knowledge to improve health.

Jim Gersbach - 503-813-4820 or
Terry Fitzpatrick - 503-335-6602