AGE RELATIONS OF CARDIOVASCULAR RISK-FACTORS IN A TRADITIONAL MELANESIAN SOCIETY - THE KITAVA STUDY

This study examined cross-sectional age relations of blood pressure, a nthropometric indexes, serum lipids, and hemostatic variables in 203 s ubsistence horticulturists aged 20-86 y in Kitava, Trobriand Islands, Papua New Guinea. The population is characterized by extreme leanness (despite food abundance), low blood pressure, low plasma plasminogen a ctivator inhibitor 1 activity, and rarity of cardiovascular disease. T ubers, fruit, fish, and coconut are dietary staples whereas dairy prod ucts, refined fat and sugar, cereals, and alcohol are absent and salt intake is low. Although diastolic blood pressure was not associated wi th age in Kitavans, systolic blood pressure increased linearly after 5 0 y of age in both sexes. Body mass index decreased with age in both s exes. Serum total cholesterol, triacylglycerol, low-density-lipoprotei n cholesterol, and apolipoprotein B increased in males between 20 and 50 y of age, whereas high-density-lipoprotein cholesterol and apolipop rotein A-I decreased. There were no significant differences in these i ndexes with age in the few females studied. A slight linear age-relate d increase of lipoprotein(a) was present in males. Plasma fibrinogen, factor VII clotting activity, factor Vm clotting activity, and von Wil lebrand factor antigen increased with age in both sexes but plasminoge n activator inhibitor 1 activity did not. The modest or absent relatio ns between the indexes measured and age are apparently important expla nations of the virtual nonexistence of stroke and ischemic heart disea se in Kitava.