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Insulin resistance and angiographical characteristics of coronary atherosclerosis
1Department of Internal Medicine, Fukuoka University School of Medicine, Japan.
Insights
Insulin resistance (IR) is linked to more severe coronary heart disease (CHD). This study found IR correlates with coronary atherosclerosis severity, not lesion distribution, increasing CHD risk.
Area of Science:
- Cardiology
- Endocrinology
- Metabolic Syndrome
Background:
- Insulin resistance (IR) is a common comorbidity in patients diagnosed with coronary heart disease (CHD).
- The correlation between IR and the specific angiographic features of coronary atherosclerosis requires further elucidation.
Purpose of the Study:
- To investigate the relationship between insulin resistance and the angiographical characteristics of coronary atherosclerosis in patients with coronary artery lesions.
- To determine if IR influences the severity and/or distribution of coronary artery disease.
Main Methods:
- Sixty-six patients with coronary artery lesions underwent assessment of insulin resistance using a 75-g oral glucose tolerance test and the Homeostasis Model Assessment (HOMA) for IR.
- Coronary atherosclerosis severity was quantified using Gensini's score (GS) and the number of significantly stenosed vessels.
- Patients were stratified into tertiles based on GS for comparative analysis.
Main Results:
- Patients with higher Gensini's scores exhibited significantly elevated fasting plasma insulin, insulin response, and HOMA IR values.
- The insulin/glucose ratio was significantly higher in groups with moderate to severe coronary atherosclerosis.
- No significant differences in glucose tolerance, serum lipids, lipoproteins, fibrinogen, uric acid, or blood pressure were observed across groups.
- Logistic regression revealed significant positive associations between GS, number of diseased arteries, and markers of IR (fasting insulin, insulin response, insulin/glucose ratio, HOMA IR).
Conclusions:
- Insulin resistance is significantly associated with the severity of coronary heart disease, as indicated by both Gensini's score and the number of diseased coronary arteries.
- IR appears to contribute to the overall severity of coronary atherosclerosis rather than the specific distribution of lesions.
- Elevated insulin resistance increases the risk of coronary heart disease, irrespective of the lesion location.
Abstract:
Insulin resistance (IR) is frequently observed in patients with coronary heart disease (CHD). The relationship between IR and the angiographical characteristics of coronary atherosclerosis were investigated in 66 patients with coronary artery lesions. Insulin resistance was assessed by a 75-g oral glucose tolerance test and homeostasis model assessment (HOMA). The angiographical characteristics of coronary atherosclerosis (i.e., the severity of CHD) were defined by both Gensini's score (GS) (a higher degree of coronary artery stenosis or a proximal lesion was assigned a higher score than a distal lesion) and the number of significantly stenosed vessels. When GS was examined as a categorical variable classified by tertile values (Group A, n = 22: 1< or =GS< or =14; Group B, n = 22: 15< or =GS< or =32; and Group C, n = 22: 33< or =GS), patients with a high GS (Group C) had significantly (p<0.05) higher values of fasting plasma insulin, insulin response, and HOMA IR than patients with a low GS (Group A) (12.6+/-1.2 microU/ml vs. 6.9+/-1.2 microU/ml, 122.2+/-11.9 microU ml(-1) h(-1) vs. 72.9+/-12.9 microU ml(-1) h(-1), and 2.9+/-0.3 vs. 1.5+/-0.3, respectively). The values in Group B patients (9.4+/-1.2,microU/mI, 108.5+/-12.5 microU ml(-1) h(-1), and 2.1+/-0.3, respectively) were intermediate between those in Groups A and C. The area of insulin/area of glucose ratio was significantly (p<0.05) higher in Groups B and C than in Group A (0.54+/-0.06 microU/mg, 0.54+/-0.06 microU/mg, and 0.32+/-0.06 microU/mg, respectively). However, no significant differences were observed in variables of glucose tolerance, serum lipid, lipoproteins, fibrinogen, uric acid, and blood pressure among the 3 groups. Significant (p<0.05) positive associations were found between GS, the number of diseased coronary arteries, and fasting immunoreactive insulin, insulin response, the area of insulin/area of glucose ratio and HOMA IR by logistic regression analysis. After adjusting for the number of diseased coronary arteries, the association between GS and IR was not significant, suggesting that IR contributed to the severity of coronary atherosclerosis but not to the distribution of lesions. In conclusion, IR was associated with the severity of CHD as measured by both Gensini's score and the number of diseased coronary arteries, and increased the risk of CHD regardless of the location of the lesions.