The Tokelau Island migrant study: prevalence of various conditions before migration.

The Tokelau Island Migrant Study has shown no important differences between those who subsequently left their home islands to migrate to New Zealand and those who remained, in key anthropometric and biochemical variables already reported. This comparison is now extended to various common diseases and conditions, and again no major difference emerges. The Tokelauans are compared with other Polynesians and shown to have less diabetes, hypertension, effort pain, chronic bronchitis and varicose veins than New Zealand Maoris, while resembling some Cook Island groups. Changes in prevalences of some conditions following migration are postulated.