Childhood and infant exposure to famine in the Biafran war is associated with hypertension in later life: the Abia NCDS study by Ogah, OS, Oguntade, AS, Chukwuonye, II, Onyeonoro, UU, Madukwe, OO, Asinobi, A, Ogah, F, Orimolade, OA, Babatunde, AO, Okeke, MF, Attah, OP, Ebengho, IG, Sliwa, K, Stewart, S