['The goal was to link hypertension and the metabolic syndrome in adulthood directly to blood pressures measured decades earlier for the same individuals as children and to establish criterion values for blood pressure that predict hypertension and the metabolic syndrome later in life.', 'We analyzed serial data for 240 men and 253 women in the Fels Longitudinal Study. We derived age- and gender-specific childhood blood pressures that predict hypertension and the metabolic syndrome in adulthood, and we validated these criterion values in a larger sample.', 'Blood pressure diverged between adults with and without the metabolic syndrome beginning at age 5 for boys and age 8 for girls. The odds ratios for developing hypertension at > or = 30 years of age ranged from 1.1 for 14- to 18-year-old boys to 3.8 for 5- to 7-year-old boys and from 2.7 for 8- to 13-year-old girls to 4.5 for 5- to 7-year-old girls, if their blood pressure exceeded criterion values at a single examination in childhood. The corresponding odds ratios for the metabolic syndrome, with or without hypertension, ranged from 1.2 for 14- to 18-year-old boys to 2.6 for 8- to 13-year-old boys and from 1.5 for 14- to 18-year-old girls to 3.1 for 5- to 7-year-old girls. The relative risk of adult hypertension ranged from 1.5 to 3.8 for boys and from 1.5 to 4.7 for girls, and that of the metabolic syndrome ranged from 1.1 to 1.8 for boys and from 1.2 to 5.6 for girls. These relative risks varied directly with the number of examinations at which systolic blood pressure exceeded criterion values.'] Does systolic blood pressure in childhood predict hypertension and metabolic syndrome later in life?