CARDIOVASCULAR RISK-FACTORS IN A MELANESIAN POPULATION APPARENTLY FREE FROM STROKE AND ISCHEMIC-HEART-DISEASE - THE KITAVA-STUDY

Objectives. To compare cardiovascular risk factor levels between non-westernized Melanesians, apparently free from stroke and ischaemic heart disease [1], and healthy Swedish populations, and to analyse, among adult Melanesians, relations with age, sex and smoking status. Design. Cross-sectional survey. Subjects. (i) Traditional horticulturalists in Kitava, Trobriand Islands, Papua New Guinea, uninfluenced by western diet. This study tested 151 males and 69 females aged 14-87 years with 76% and 80% smokers over 20 years. (ii) Healthy Swedish reference populations. Main outcome measures. Sitting systolic and diastolic blood pressure, weight, height, body mass index, circumferences of waist, pelvis and mid upper arm, triceps skinfold thickness, fasting serum total cholesterol, triglycerides, high-density lipoprotein cholesterol, estimated low-density lipoprotein cholesterol, apolipoprotein B, apolipoprotein A1 and apolipoprotein (a). Results. Compared to Sweden, diastolic blood pressure, body mass index and triceps skinfold thickness were substantially lower in Kitava, where all subjects greater than or equal to 40 years were below Swedish medians. Among males greater than or equal to 20 and females greater than or equal to 60 years systolic blood pressure was lower in Kitavans. Fasting serum total cholesterol, low-density lipoprotein cholesterol and apolipoprotein B were 10-30% lower in Kitavan males greater than or equal to 40 and females greater than or equal to 60 years. Triglycerides were higher in Kitavans aged 20-39. High-density lipoprotein cholesterol did not differ while apolipoprotein Al was lower in Kitavans. Apolipoprotein (a) tended to be lower in Kitavans, but the differences were small. Conclusions. Of the analysed variables, leanness and low diastolic blood pressure seem to offer the best explanations for the apparent absence of stroke and ischaemic heart disease in Kitava. The lower serum cholesterol may provide some additional benefit. Differences in dietary habits may explain the findings.