It is no license to gain weight, but a University of Pittsburgh Schools of the Health Sciences study does show that people, and particularly women, with Type 1 diabetes who have more fat have less heart disease.
Added weight indicates that the chronic disease is under better control with insulin therapy, thus reducing the degree of heart disease.
"Insulin in the right doses adds to weight," said Dr. Trevor Orchard, professor of epidemiology at the University of Pittsburgh Graduate School of Public Health and the study's principal investigator. "For that reason, it is important that people with Type 1 who put on weight with more insulin don't feel bad about it. It is a sign they are doing well."
People with Type 1 diabetes must inject or inhale insulin, the hormone produced in the pancreas that allows blood glucose to enter cells and be used as energy. People with uncontrolled Type 1 diabetes lose weight because their bodies cannot use blood glucose.
Dr. Orchard said the findings could be controversial if diabetics misinterpret them as a license to overeat.
He was scheduled to present the findings at the 67th annual meeting of the American Diabetes Association Scientific sessions Friday through tomorrow in Chicago.
The Pitt research team studied the link between an early sign of heart disease -- coronary artery calcification -- and body fat in 315 patients with Type 1 diabetes. The patients are involved in the Pittsburgh Epidemiology of Diabetes Complications Study, a prospective study of Type 1 diabetes that began in 1986. Baqiyyah Conway was lead author of the study abstract.
During the study, patients with a mean age of 42 who have had diabetes on average for 34 years, underwent a special CT scan to assess coronary artery calcification. They also were evaluated for fat underneath the skin and in the abdominal region, and for body mass index and waist circumference.
While researchers noted an association between fatness and coronary artery calcification, they also noted in two-thirds of the patients with calcification that the relationship was reversed: People with more fat had less severe calcification.
The association also varied by gender. Women with less fat under the skin had more evidence of calcification than those with more fat. Thinner men also had more evidence of calcification than men with a higher BMI.
Results stood even after researchers controlled for such risk factors as increased LDL, or bad cholesterol, triglycerides, high blood pressure, and lower levels of HDL, or good cholesterol.
Eliminating kidney disease, another common complication of diabetes, as a factor weakened the association between added weight and less calcification in men, but not in women.
Cardiovascular complications, including heart disease, are a leading cause of death for people with diabetes, who tend to suffer cardiovascular disease decades earlier than those without diabetes.
Dr. Orchard said the study should not encourage people with Type 1 diabetes to gain weight. But it does suggest that weight recommendations for Type 1 diabetes may differ from those for the general population.
"Gaining weight may reflect good or better treatment with insulin therapy, which may partly explain why participants who gained weight over time had lower mortality rates," he said.
Monday, June 25, 2007
By David Templeton, Pittsburgh Post-Gazette