Impaired fasting glucose is associated with increased severity of subclinical coronary artery disease compared to patients with diabetes and normal fasting glucose: evaluation by coronary computed tomographic angiography

Abstract

Objective: This study was designed to evaluate the severity of subclinical atherosclerosis in patients with asymptomatic impaired fasting glucose (IFG) compared to those with diabetes mellitus (DM) and normal fasting glucose (NFG), as measured by coronary computed tomographic angiography (CCTA).

Design: Subjects were divided into three groups: NFG (<100 mg/dL), IFG (100-125 mg/dL) and DM. Coronary artery calcium on non-contrast CT and plaque analysis on CCTA were performed.

Setting: University hospital, single centre.

Participants: 216 asymptomatic participants prospectively underwent CCTA for the evaluation of coronary artery disease (CAD).

Primary and secondary outcome measures: Atherosclerotic plaque burden in IFG compared to NFG patients.

Results: 2664 segments were analysed in 120 NFG, 44 IFG and 52 DM participants. The mean calcium scores were 178±395, 259±510 and 414±836 for NFG, IFG and DM, respectively (p=0·037). The mean plaque burdens in the NFG, IFG and DM groups were 0.31±0.45, 0.50±0.69 and 0.68±0.69, respectively (p=0·0007). A greater proportion of patients with DM (19/52, 36.5%) and IFG (13/44, 29.5%) had obstructive CAD compared to those with NFG (16/120, 13.3%) (p=0.0015). The number of segments with severe disease was significantly higher in the DM (60/637, 9.4%) and IFG (42/539, 7.8%) groups compared to that in the NFG group (34/1488, 2.3%) (p=0.0001).

Conclusions: (1) IFG and DM have significantly higher, but comparable, calcium scores, plaque burden and obstructive CAD compared to NFG in asymptomatic individuals. (2) Pending corroboration by other reports, more intensive efforts may be devoted to the evaluation and treatment of patients with IFG.

Figure 1

Plaque burden score in 216 patients separated according to their glycaemic status, with SEM shown in bars. Plaque burden was computed by scoring each assessable coronary segment as 0 for normal, 1 for mild plaque, 2 for moderate plaque and 3 for severe plaque and dividing by the number of assessable segments. *p=0.04, **p<0.0001, ‡p=0.23.

Figure 2

Percentage of patients studied with CACS >400 and obstructive CAD (at least one coronary artery segment with >60% stenosis) separated based on their glycaemic status. *p=0.46 and 0.02 for CACS> 400 and obstructive CAD, respectively; **p=0.01 and 0.0009 for CACS >400 and obstructive CAD, respectively; ‡p=0.24 and 0.52 and for CACS >400 and obstructive CAD, respectively. CACS, coronary artery calcium score; CAD, coronary artery disease.