Australian Aboriginal People and Torres Strait Islanders Have an Atherogenic Lipid Profile That is Characterised by Low HDL-cholesterol Level and Small LDL Particles

Aim: To characterise lipid profiles for Australian Aboriginal people and Torres Strait Islanders.

Methods: Community-based, cross-sectional surveys in 1995-1997 including: 407 female and 322 male Australian Aboriginal people and 207 female and 186 male Torres Strait Islanders over 15 years old. A comparator of 78 female (44 with diabetes) and 148 male (73 with diabetes) non-indigenous participants recruited to clinical epidemiological studies was used. Lipids were determined by standard assays and LDL diameter by gradient gel electrophoresis.

Results: Diabetes prevalence was 14.8% and 22.6% among Aboriginal people and Torres Strait Islanders, respectively. LDL size (mean [95% CI (confidence interval)]) was smaller (P<0.05) in non-diabetic Aboriginal (26.02 [25.96-26.07] nm) and Torres Strait Islander women (26.01 [25.92-26.09] nm) than in non-diabetic non-indigenous women (26.29 [26.13-26.44] nm). LDL size correlated (P<0.0005) inversely with triglyceride, WHR, and fasting insulin and positively with HDL-cholesterol. HDL-cholesterol (mean [95% CI] mmol/L) was lower (P<0.0005) in indigenous Australians than in non-indigenous subjects, independent of age, sex, diabetes, WHR, insulin, triglyceride, and LDL size: Aboriginal (non-diabetic women, 0.86 [0.84-0.88]; diabetic women, 0.76 [0.72-0.80]; non-diabetic men, 0.79 [0.76-0.81]; diabetic men, 0.76 [0.71-0.82]); Torres Strait Islander (non-diabetic women, 1.00 [0.95-1.04]; diabetic women, 0.89 [0.83-0.96]; non-diabetic men, 1.00 [0.95-1.04]; diabetic men, 0.87 [0.79-0.96]); non-indigenous (non-diabetic women, 1.49 [1.33-1.67]; diabetic women, 1.12 [1.03-1.21]; non-diabetic men, 1.18 [1.11-1.25]; diabetic men, 1.05 [0.98-1.12]).

Conclusions: Indigenous Australians have a dyslipidaemia which includes small LDL and very low HDL-cholesterol levels. The dyslipidaemia was equally severe in both genders. Strategies aimed at increasing HDL-cholesterol and LDL size may reduce high CVD risk for indigenous populations.