Aerobic fitness and the diurnal rhythm of blood pressure in adolescents

We examined the effects of aerobic fitness and race on the diurnal rhythm of blood pressure of 17S healthy adolescents who performed a cycle ergometer maximal exercise test while oxygen consumption was measured. A median split of maximum oxygen consumption for boys and girls separately classified them as either “more-fit” or “less-flt” subjects. Ambulatory blood pressure recordings were also performed, and the data were analyzed for means while subjects were awake and asleep. Less-fit black boys had higher systolic pressures than more-fit black boys while awake (124 vs. 115 mm Hg; <0.009) and asleep (117 vs. 109; p<0.001). Less-flt black boys also had higher systolic pressures than less-flt white boys while awake (114; p <0.002) and asleep (105; p< 0.001), and they had higher systolic pressures than more-fit white boys while asleep (105; p<0.01). Less-fit black girls had higher systolic pressures than more-fit black girls while awake (116 vs. 109; p<0.004) and asleep (109 vs. 100;p<0.001). Less-fit black girls also had higher diastolic pressures than more-fit black girls while awake (71 vs. 66; p<0.002) and asleep (66 vs. 61; p< 0.001). In addition, less-fit black girls had higher systolic pressures than more-fit white girls while asleep (104; p<0.05), higher diastolic pressures than more-fit white girls while awake (68; p<0.05) and asleep (60; p<0.006), and higher diastolic pressures than less-flt white giris while asleep (61; p <0.001). These findings indicate that fitness influences ambulatory blood pressure profiles, particularly in black adolescents.