Blood pressure in relation to relative weight at birth through childhood and youth in obese and non-obese adult men.

OBJECTIVE

To determine the influence on blood pressure of relative weight from birth through adulthood in non-obese and juvenile obese men.

DESIGN

Case-cohort study of obesity in Danish men, identified at age (mean+/-s.d.) 19.8+/-1.6 y at draft board examination, who participated in at least one of two follow-up studies in adulthood (age 36.8+/-6.7 and 47.9+/-6.8 y at first and second follow-up, respectively). Birth weight and weight and height from the age of 7-13 y were collected from school health records.

SUBJECTS

Three hundred and twenty-seven non-obese men (controls) selected as 0.5% of the draft board population and 285 obese men with body mass index (BMI)> or =31 kg/m(2) at draft board examination.

MAIN OUTCOME MEASURES

Systolic and diastolic blood pressure measured twice in adulthood adjusted for current age.

RESULTS

Birth weight was inversely related to systolic blood pressure at first and second follow-up, but only significantly so when adjusted for current BMI (regression coefficients in mmHg per unit Z-score (95% confidence interval (CI))-1.2 (-2.3, -0.1) and -1.6 (-3.1, 0.0)). Change in Z-score from birth weight to BMI at the age of 7 y was significantly positively related to systolic blood pressure, but the relationship weakened by adjustment for current BMI (0.8 (0.1, 1.6) and 0.6 (-0.4, 1.6), respectively). If both birth weight and change until 7 y were included in the same model, their effects were both positive and significant, but they weakened and became not significant when adjusted for current BMI. BMI since the age of 7 y had no significant effect on blood pressure beyond that of current BMI.

CONCLUSION

In a wide range of adult BMI in men, the birth weight was inversely related to systolic blood pressure, even when controlled for BMI since the age of 7 y. However, the effect may reflect the weight change between birth and 7 y of age. After that age BMI had no additional effect on blood pressure beyond the effect of current BMI.