RANDOMIZED CLINICAL-TRIAL OF LIFE-STYLE INTERVENTIONS IN PIMA-INDIANS- A PILOT-STUDY

A pilot trial was conducted to test adherence to specific lifestyle in terventions among Pima Indians of Arizona, and to compare them for cha nges in risk factors for diabetes mellitus, Ninety-five obese, normogl ycaemic men and women, aged 25-54 years, were randomized to treatments named 'Pima Action' (Action) and 'Pima Pride' (Pride), which were tes ted Sea; 12 months. Action involved structured activity and nutrition interventions, and Pride included unstructured activities emphasizing Pima history and culture, Adherence to interventions, changes in self- reported activity and diet, and changes in weight, glucose concentrati ons, and other risk factors were assessed regularly. Thirty-five eligi ble subjects who had declined randomization were also followed as an ' observational' group and 22 members of this group were examined once a t a median of 25 months for changes in weight and glucose concentratio n. After 12 months of intervention, members of both intervention group s reported increased levels of physical activity (median: Action 7.3 h month(-1), Pride 6.3 h month(-1), p < 0.001 for each), and Pride memb ers reported decreased starch intake (28 g, p = 0.008). Body mass inde x, systolic and diastolic blood pressures, weight, 2-h glucose and 2-h insulin had all increased in Action members (p < 0.003 for each), and waist circumference had decreased in Pride members (p = 0.05). Action members gained more weight than Pride members (2.5 kg vs 0.8 kg, p = 0.06), and had a greater increase in 2-h glucose than Pride members (1 .33 mM vs 0.03 mM, p = 0.007). Members of the observational group gain ed an average of 1.9 kg year(-1) in weight and had an increase of 0.36 mM year(-1) in 2-h glucose. Sustaining adherence in behavioural inter ventions over a long term was challenging. Pimas may find a less direc t, less structured, and more participative intervention more acceptabl e than a direct and highly structured approach, (C) 1998 John Wiley & Sons, Ltd.