The association between salt intake and adult systolic blood pressure is modified by birth weight

• Published in: The American journal of clinical nutrition 2011-02, Vol.93 (2), p.422-426
• Main Authors: Perälä, Mia-Maria, Moltchanova, Elena, Kaartinen, Niina E, Männistö, Satu, Kajantie, Eero, Osmond, Clive, Barker, David JP, Valsta, Liisa M, Eriksson, Johan G
• Format: Article
• Language: English
• Subjects: adults; Biological and medical sciences; Birth Weight; Blood pressure; Blood Pressure - drug effects; body weight; Cohort Studies; diastolic blood pressure; Diet; Diet Surveys; Feeding. Feeding behavior; Female; food intake; Fundamental and applied biological sciences. Psychology; height; Human growth; human nutrition; Humans; Hypertension - etiology; low birth weight; Male; Middle Aged; Multivariate Analysis; nutrient intake; Nutrition; Regression analysis; Salt; sodium chloride; Sodium Chloride, Dietary - adverse effects; Surveys and Questionnaires; systolic blood pressure; Vertebrates: anatomy and physiology, studies on body, several organs or systems
• ISSN: 0002-9165; 1938-3207
• DOI: 10.3945/ajcn.2010.30022

Background: Epidemiologic evidence suggests that prenatal growth influences adult blood pressure. Nutritional factors, including salt intake, also influence blood pressure. However, it is unknown whether prenatal growth modifies the association between salt intake and blood pressure in later life. Objective: Our aim was to examine whether the relation between salt intake and adult blood pressure is modified by birth weight. Design: We studied 1512 participants of the Helsinki Birth Cohort Study who were born between 1934 and 1944. Information on birth weight was abstracted from birth records, and preterm births were excluded. During a clinical study, at the mean age of 62 y, blood pressure, weight, and height were measured. Diet was assessed with a validated food-frequency questionnaire. The relation between salt intake and blood pressure was tested by a piecewise multivariate regression analysis with the best fitting breakpoints to birth weight and salt intake. Results: An inverse association was observed between birth weight and systolic blood pressure (SBP) (P = 0.02). No significant association between salt intake and SBP was observed in the whole study population. Of those whose birth weight was ≤3050 g, a 1-g higher daily salt intake was associated with a 2.48-mm Hg (95% CI: 0.40, 4.52 mm Hg) higher SBP (P = 0.017) until the saturation point of 10 g. Of those whose birth weight exceeded 3050 g, SBP was not significantly associated with salt intake. For diastolic blood pressure, no significant relations were observed. Conclusion: Adult individuals with low birth weight may be particularly sensitive to the blood pressure–raising effect of salt.