Abstract
Funding Acknowledgements
Type of funding sources: None.
Background
Although individuals of South Asian (S. Asian) origin represent 20% of the world population, they are under-represented in studies investigating the presence of coronary artery calcification (CAC).
Aim
We compared the prevalence of CAC in Caucasians and Asians who underwent electron beam computed tomography (EBCT). CAC score (CACS) was performed on an Imatron C300 Ultrafast EBCT scanner (GE Healthcare), using a standard method with calcium deposition scored according to Agatston method. Demographic information and the presence of risk factors were abstracted from referral letters and questionnaires completed by the patients prior to their test.
Results
CACS was assessed in 935 S. Asians (739 males and 196 females) and 13,501 Caucasians (10,232 males and 3269 females). Gender distribution between Caucasians and S. Asians was similar (p = 0.1); conversely, the Caucasians group was older to its S. Asians counterpart (52.8 ± 9.6 vs. 50.6 ± 10.3; p < 0.001); while on the other hand, S. Asians appeared to have a higher prevalence of diabetes mellitus (17.5% vs. 4.3%; p <0.0001). There was no difference in the prevalence of smoking between the 2 groups (15% vs. 12.1%; p = 0.06), of hypertension (31.3% vs. 25.3%; p =0.4), family history of CHD (22.8% vs. 16.1%; p = 0.3), and hyperlipidemia (24.5% vs. 17.3%; p = 0.3). The prevalence of CAC (CACS >0) was similar between Caucasians and S. Asians (50.9% vs. 50.8%; p = 0.9), although a statistically significant difference in the prevalence of CAC in South Asians >50 years was noted (p = 0.01). S. Asian males showed a higher mean CACS as compared to Caucasians (179.6 ± 545.1 vs. 144.1 ± 420.1; p = 0.03). In males <50 years, there was no statistically significantly difference in mean CACS between S. Asians and Caucasians (36.1 ± 277.8 vs. 23.8 ± 104.2; p = 0.06), but in males >50 years old the difference in mean CACS was significant (S. Asians, 339.1 ± 702.9 vs. Caucasians 232.3 ± 528.7; p < 0.0001). On the other hand, no difference was observed in the mean CACS between South Asian and Caucasian females (59.2 ± 224.9 vs. 56.6 ± 219.2; p = 0.86). S. Asian females <50 years and S. Asian females >50 years had similar mean CACS compared to Caucasians.
Conclusion
S. Asians seem more prone to extensive calcification. Age seems to play an important role as the prevalence of CAC was similar in S. Asians and Caucasians <50 years but there was a difference in prevalence of CAC after the age of 50, but this deference was statistically significant only in males. Our results support current evidence in showing that the pattern of CAC is influenced by ethnicity. If this reflects a difference in traditional risk factors or has genetic origin it has to be clarified.