Cardiac Anomalies Seen in Poorly Controlled Diabetes

Girls with poorly controlled type 2 diabetes are more likely to have structural and functional cardiac abnormalities than are their healthy peers or even girls with type 1 diabetes, according to a study in of Diabetes Care.

The study "highlights the potential high cardiovascular risk occurring in adolescent type 2 diabetes," even though the disease has been present for just a few years, Gillian A. Whalley, from The University of Auckland, New Zealand, and co-researchers conclude.

The findings are based on a study of 8 girls with type 2 diabetes and 11 with type 1 disease who were drawn from a hospital diabetes service. A nondiabetic comparison group, or "control group," included 9 lean and 11 overweight girls.

Although the groups were similar in age and height, girls with type 2 diabetes weighed more than the other girls. On average, type 2 diabetics weighed 107.2 kg compared with 80.6 kg in nondiabetic overweight controls, the group with the next highest weight.

Echocardiography revealed that the left ventricular dimensions and left ventricular mass were greater in the type 2 diabetics than in the other groups, a finding that remained after the subject's height was considered, the authors note.

Both diabetic groups showed impairments during the diastolic phase of heart contraction, but only the type 2 group had reduced function during the systolic phase, the report indicates.

Only 1 of the 8 girls with type 2 diabetes had no cardiac abnormalities. The prevalence of left ventricular dilation, elevated left ventricular mass, and left atrial dilation in this group were 63 percent, 75 percent, and 38 percent, respectively. By comparison, in the lean healthy and type 1 diabetic groups, abnormalities were almost non-existent, and even in the overweight control group, many girls had no cardiac abnormalities.

"This study is the first to demonstrate that important cardiac abnormalities occur early in adolescent-onset type 2 diabetes and highlights the potential for higher cardiovascular risk," the authors conclude. "If left unchecked, it is likely that these changes will lead to the development of clinically overt cardiovascular disease."