Aims: To examine ethnic variations in serum lipid levels and to determine whether lipids are related to lifestyle variables in a New Zealand multicultural workforce.
Methods: Fasting blood samples were collected from 5671 employed people for determination of serum total and HDL cholesterol, triglycerides, and LDL cholesterol. Individual exposures over the previous three months to smoking, alcohol, leisure time physical activity were recorded, and weight and height were measured to calculate body mass index (BMI).
Results: Maori and Pacific Islanders had lower age-adjusted total and LDL cholesterol levels than Europeans, and these differences were increased by controlling for BMI. In contrast, age-adjusted mean (SE) HDL cholesterol levels were also lower in Maori (men = 1.17 (0.02); women = 1.38 (0.03) mmol/L) and Pacific Islanders (men = 1.17 (0.01); women = 1.30 (0.02) mmol/L) compared with Europeans (men = 1.20 (0.01); women = 1.47 (0.01) mmol/L), but when BMI, smoking and other variables were controlled, levels were significantly higher in Maori and Pacific Islanders. With serum triglycerides, the pattern was not consistent in Maori and Pacific Islanders. Age-adjusted mean levels in Maori (men = 2.25 (0.07) mmol/L; women = 1.53(0.07) mmol/L) were significantly higher (p < 0.05) than in Pacific Islanders (men = 1.82 (0.06); women = 1.34(0.05) mmol/L) of the same sex. After controlling for BMI and other variables, triglyceride levels were also significantly lower in Pacific Islanders than in Europeans and Asians. BMI and smoking were positively associated with total and LDL cholesterol and triglycerides, and negatively with HDL cholesterol, after controlling for alcohol and physical activity.
Conclusion: Lifestyle risk factors, particularly BMI and smoking, are strongly related to serum levels of all major lipids. Ethnic variations in coronary heart disease mortality rates in New Zealand are more consistent with ethnic variations in triglycerides than with variations in the other serum lipids.