RELATIONSHIP BETWEEN BLOOD-PRESSURE AT AGE 3-4 YEARS AND BIRTH CORPULENCE - A POPULATION-BASED STUDY

Background : To study the association between blood pressure of 3-4 ye ar-old children and birth corpulence estimated from birth ponderal ind ex (body weight/length(3)) a school based cross sectional survey was c onducted in the Rhone department. Methods: 1296 randomly selected chil dren were examined at the time of a school medical visit. Physicians a bstracted information on pregnancy and measurements at birth from the Child Health Handbook and from parents interview. Systolic and diastol ic blood pressure measurements were carried out by using an automated oscillometric device. Results : Multiple linear regression analyses re vealed an inverse association between systolic blood pressure and birt h ponderal index (converted into Z-score adapted to gestational age), this was obtained after adjustment for current length and for current body mass index (body weight/length(2) - converted into Z-score), for child emotion and for linked study factors. Such a model provided apt assessment of regression coefficient : - 0.67 mmHg/birth ponderal inde x Z-score unit (95 % confidence interval I - 1.24 to - 0.11). So, esti mation of systolic blood pressure difference between two 3-4 year-old children, one at - 2 SD birth ponderal index and another at + 2 SD, wa s obtained : 2.6 mmHg. No evidence of an association between diastolic : blood pressure and birth ponderal index was observed. Conclusion : I n this large population with a limited range of age, our results show that, at age 3-4 years, systolic blood pressure is higher with lower b irth ponderal index, suggesting that thinness at birth might be a risk factor of hypertension in adulthood.