The study resembles a four-year follow-up on the influence of physical activity and fitness, blood pressure, BMI and stress on vascular health in primary schoolchildren. It examines the predictive value of retinal vessel diameters for the development of childhood hypertension.

The study aims to examine the usefulness of retinal vessel analysis in childhood cardiovascular prevention. It investigates the long-term influence of physical activity and fitness on retinal vessel diameters, blood pressure, BMI and psychosocial stress in children. The study aims to set new standards for an integrative primary prevention concept to initiate healthy ageing from childhood to adulthood.

Inclusion Criteria:

• All fifth-graders of public primary schools in Basel-Stadt with an informed consent signed by their parents are included.

Exclusion Criteria:

• Fifth-graders with motor-or other disabilities that do not allow participation will be excluded.

This study will be designed as a four-year follow-up of the 2014 Sportcheck. All first-graders of primary schools in the canton Basel-Stadt took part in measurements of height, body weight and physical fitness during physical education lesson. From the 1255 children, 540 (43%) were allowed by their parents to join additional measurements of blood pressure and retinal vessel diameters and filled in questionnaires. In the year 2018, all fifth-graders of Basel-Stadt will be invited to take part in the same measurements as in 2014. All children will again conduct physical fitness tests and measurements of height and body weight during physical education. All children with an informed consent will participate in the same medical tests that were performed four years previously.