High prevalence of abnormal glucose metabolism in young adult patients with complex congenital heart disease

Abstract

Background: Abnormal glucose metabolism (AGM) adversely impacts morbidity and mortality in patients with chronic heart failure. No data on AGM in adult patients with congenital heart disease (ACHD) are available.

Methods: To assess the AGM in ACHD and compare the results with their clinical characteristics, we performed a 75-g oral glucose tolerance test to detect AGM, that is, insulin resistance, impaired glucose tolerance, and diabetes mellitus, in 205 consecutive ACHD (24 +/- 8 years), including 16 unrepaired patients, 67 Fontan patients, 122 postbiventricular (BV) patients, and 27 healthy controls (27 +/- 5 years).

Results: All ACHD groups had a high prevalence of AGM (unrepaired, 43.8%; Fontan, 43.3%; BV, 46.7%; control, 3.7%; P < .001). In the 2 postoperative groups, the Matsuda index was decreased (P < .0001), and greater waist circumference, liver dysfunction, higher plasma renin activity, and diuretic use were associated with AGM. Although male gender was associated with AGM (P < .01), baseline glucose and lipid metabolic variables did not correlate with the 75-g oral glucose tolerance test-induced hyperglycemia (area under the plasma glucose curve [AUC-PG]) in the Fontan patients but did correlate in the BV patients. The AUC-PG correlated inversely with exercise capacity (P < .05) in the 2 postoperative ACHD groups, and the AGM ACHD had a high incidence of future cardiac events (P < .05), especially the Fontan patients with diabetes mellitus (P < .01).

Conclusions: Complex ACHD have a high prevalence of AGM, and this newly recognized pathophysiology should be considered in managing long-term survivors of complex ACHD.