Correlates of preclinical cardiovascular disease in Indigenous and Non-Indigenous Australians: a case control study.
BACKGROUND
The high frequency of premature death from cardiovascular disease in indigenous Australians is often attributed to the high prevalence of risk factors, especially type II diabetes mellitus (DM). We evaluated the relationship of ethnicity to atherosclerotic burden, as evidenced by carotid intima-media thickness (IMT), independent of risk factor status.


METHODS
We studied 227 subjects (147 men; 50 +/- 13 y): 119 indigenous subjects with (IDM, n = 54), and without DM (InDM, n = 65), 108 Caucasian subjects with (CDM, n = 52), and without DM (CnDM, n = 56). IMT was measured according to standard methods and compared with clinical data and cardiovascular risk factors.


RESULTS
In subjects both with and without DM, IMT was significantly greater in indigenous subjects. There were no significant differences in gender, body mass index (BMI), systolic blood pressure (SBP), or diastolic blood pressure (DBP) between any of the groups, and subjects with DM showed no difference in plasma HbA1c. Cardiovascular risk factors were significantly more prevalent in indigenous subjects. Nonetheless, ethnicity (beta = -0.34; p < 0.0001), age (beta = 0.48; p < 0.0001), and smoking (beta = 0.13; p < 0.007) were independent predictors of IMT in multiple linear regression models.


CONCLUSIONS
Ethnicity appears to be an independent correlate of preclinical cardiovascular disease, even after correction for the high prevalence of cardiovascular risk factors in indigenous Australians. Standard approaches to control currently known risk factors are vital to reduce the burden of cardiovascular disease, but in themselves may be insufficient to fully address the high prevalence in this population.
Haluska
Brian A
BA
School of Medicine, University of Queensland, Brisbane, Australia. b.haluska@uq.edu.au
Chan
Lionel
L
Jeffriess
Leanne
L
Shaw
A Andrew
AA
Shaw
Joanne
J
Marwick
Thomas H
TH
D001315:Australia; D002318:Cardiovascular Diseases / Q000150:complications / Q000000981:diagnostic imaging / Q000208:ethnology*; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging; D016022:Case-Control Studies; D003920:Diabetes Mellitus / Q000208:ethnology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000208:ethnology; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D017539:Tunica Intima / Q000000981:diagnostic imaging; D017540:Tunica Media / Q000000981:diagnostic imaging; D014463:Ultrasonography