EXERCISE TOLERANCE AND BLOOD-PRESSURE RESPONSE TO EXERCISE TESTING INCHILDREN AND ADOLESCENTS AFTER RENAL-TRANSPLANTATION

The aim of the study was to assess exercise tolerance and blood pressu re (BP) response to treadmill exercise in children after renal transpl antation. Forty-five children were selected (29 males and 16 females) whose mean age was 14.3 +/- 4.2 years. All children had Hb greater tha n or equal to 10 g/dl and creatinine clearance greater than or equal t o 40 ml/min/1.73 m(2). They were at least 6 months posttransplantation and were on triple immunosuppressive therapy. Twenty-seven were also on various antihypertensive medications. Each underwent clinical exami nation and measurement of BP, both at rest and during exercise testing on treadmill. The test was stopped on muscular fatigue or exhaustion. The patients were divided into two groups: those off (A) or on (B) an tihypertensive therapy. When compared to a population of healthy child ren the patients had reduced exercise tolerance (10.1 +/- 2.1 vs 15.1 +/- 1.7 min, p < 0.001) (67 +/- 16%), increased heart rate (174 +/- 19 vs 161 +/- 19 beats/min, p < 0.001) (109 +/- 15%), and increased maxi mum systolic BP (150 +/- 26 vs 134 +/- 13 mmHg, p < 0.001) (113 +/- 19 %) at comparable workloads. Within the two patient groups, significant differences were observed during exercise testing for maximum heart r ate, which was lower in group B (p = 0.03), and maximum systolic BP, w hich was higher in group A (p = 0.04). Our study confirms that childre n and adolescents on immunosuppressive therapy after renal transplanta tion have a hypertensive response during exercise, probably related to medication-induced peripheral vascular tone.