Strategies for prevention of adult hypertension and cardiovascular risk behaviour in childhood. An Australian perspective.

This paper addresses approaches to evaluating the importance of different childhood behaviours on subsequent risk of high blood pressure and related cardiovascular risk factors and outlines results of a randomised controlled trial of nutrition and exercise interventions in schoolchildren. Clustering of cardiovascular risk factors was studied in relation to diet, blood pressure, fitness, fatness and blood cholesterol in a representative sample of 555 Perth schoolchildren aged 15 years. Twenty-one percent of males and females had high risk profiles associated with dietary excesses, particularly in fat, cholesterol and sodium intake, and deficiencies of minerals, vitamins and dietary fibre. Socio-economic status was inversely associated with cardiovascular risk and undernutrition in girls. Thus 21% of the school children shared unhealthy lifestyles putting them at substantial risk of subsequent cardiovascular disease. A randomised controlled trial designed to reduce cardiovascular risk was conducted in 1147 children 10-12 years old, assigned to one of six groups for a year. The groups were fitness, fitness and school nutrition, school nutrition, school and home nutrition, home nutrition or controls. On cluster analysis 30% of the children were at higher risk at baseline in terms of blood pressure, blood cholesterol levels, fitness and body fat. With the fitness programmes fitness increased in both high and low risk girls but only in high risk cluster boys. Systolic pressure fell more in the high risk boys in the fitness group than in low risk boys, while diastolic pressure fell in girls regardless of initial risk. Triceps skinfold thickness fell more in higher than lower risk girls in the school and home nutrition group, and more in high risk boys in the home nutrition group. Higher risk girls showed a greater reduction in fat intake and increase in dietary fibre with home nutrition programmes. We concluded that higher risk children do show greater responses to lifestyle intervention programmes in general, with the greatest effects seen with home nutrition or fitness programmes. The results indicate the need for different approaches to prevention of hypertension and cardiovascular risk in higher and lower risk children and for boys and girls.