Is birth weight associated with blood pressure among African children and adolescents? A systematic review.

There is substantial evidence of an inverse association between birth weight and later blood pressure (BP) in populations from high-income countries, but whether this applies in low-income countries, where causes of low birth weight are different, is not certain.

OBJECTIVE: We conducted a review of the evidence on the relationship between birth weight and BP among African children and adolescents. Medline, EMBASE, Global Health and Web of Science databases were searched for publications to October 2016. Papers reporting the relationship between birth weight and BP among African children and adolescents were assessed. Bibliographies were searched for further relevant publications. Selected papers were summarized following the preferred reporting items for systematic review and meta-analysis (PRISMA) guidelines. In total, 16 papers from 13 studies conducted in nine African countries (Nigeria, Republic of Seychelles, Gambia, Democratic Republic of Congo, Cameroon, South Africa, Algeria, Zimbabwe and Angola) were reviewed. Eight studies were cohorts, while five were cross-sectional. The relationship between birth weight and later BP varied with age of the participants. Studies in neonates showed a consistently positive association, while predominantly inverse associations were seen among children, and studies in adolescents were inconsistent. Based on the limited number of studies identified, the relationship between birth weight and later BP may vary with age in African children and adolescents. Not all studies adequately controlled for confounding, notably gender or age. Whether the inverse relationship between birth weight and BP in later life observed in Western settings is also seen in Africa remains unclear.