NEW ORLEANS — The rate of obesity appears to be increasing more quickly among young adults with type 1 diabetes compared with national prevalence data, results from a 5-year, single-center study showed.
At the same time, obesity significantly increased the likelihood of having elevated systolic and diastolic blood pressures and LDL cholesterol levels, and reduced HDL cholesterol levels, after adjusting for demographic factors, Samuel L. Ellis, Pharm.D., reported at the annual scientific sessions of the American Diabetes Association. “We need to continue this research and look at the impact of obesity on progression and complications,” he said.
While obesity is closely related to metabolic syndrome and type 2 diabetes in older adults, little is known about the prevalence and associated clinical effects of obesity in patients with type 1 diabetes. “There are limited data outside of the clinical trial population such as those in the Diabetes Control and Complications Trial,” said Dr. Ellis of the department of clinical pharmacy at the University of Colorado Denver School of Pharmacy, Aurora.
He and his associates evaluated the electronic medical records of all patients with type 1 diabetes aged 18–50 years who received care at the Barbara Davis Center for Childhood Diabetes in Aurora during 2000–2005. Patients were excluded if they were pregnant during the study period or if they had type 2 diabetes.
The number of patients seen per year ranged from 1,141 in 2000 to 1,573 in 2005. The mean age of patients at baseline was 23 years and their mean hemoglobin A1c level was 8.5%.
Patients were followed for the primary outcome of progression to obesity, defined as a body mass index of 30 kg/m
Secondary outcomes studied included the effects of obesity on blood pressure, lipids, and HbA1c levels.
Dr. Ellis reported that the number of patients with a body mass index of 30 kg/m
Patients in the overweight and obese groups had significantly greater LDL levels during the study period compared with patients who had a BMI of less than 25 kg/m
In addition, patients in the overweight and obese groups had significantly reduced HDL concentrations at all time periods compared with those in the healthy BMI group. “We also noticed that those individuals who were obese had significantly lower HDLs in 2003, 2004, and 2005,” Dr. Ellis said.
A similar pattern was seen from a systolic BP standpoint. Patients in the healthy BMI group had fairly normal systolic blood pressures, “but patients in the obese group had elevated systolic blood pressures throughout the time period,” he said. “There were significant differences between the obese and the healthy BMI groups as well as between the obese and overweight groups.”
At the same time, diastolic blood pressures in the obese group were 5–10 mm Hg higher than those in the healthy BMI group, and 2–4 mm Hg higher than those in the overweight group.
Mean HbA1c values throughout the study period were significantly lower in the obese group compared with patients in the healthy BMI group (8.41% vs. 8.06%, respectively). This finding may be the result of aggressive insulin therapy to lower HbA1c, which in turn results in weight gain, Dr. Ellis said in an interview. “But usually we don't see this degree of weight change with a decrease in HbA1c,” he said.
Dr. Ellis said that the study's observational, single-center design makes it difficult “to create an external validity that we can take outside of the state of Colorado.”
Dr. Ellis disclosed that he has served as a paid consultant for Merck.