| Summary: | Background: As survival in the common autosomal recessive condition Cystic Fibrosis (CF) improves, there is focus on extra-pulmonary complications. Patients with CF have increased augmentation index (AIx) at rest which is greatest in those with diabetes (CFRD). We evaluated haemodynamic response to exercise, at an intensity similar to daily life.
Methods: We studied 36 (25 male) adults (n=11, CFRD) with stable CF, mean (range) age 28.9 (16–47) yrs and 25 age/gender/BMI matched controls. Central haemodynamic parameters; BP, AIx, augmented pressure (AP) and wasted LV pressure energy (▵EW) were determined by tonometry (SphygmoCor) at rest and 8minutes into a 10minute period of cycle ergometry at 60% age-predicted maximal HR. Serum IL-6 was measured.
Results: At rest, AIx was greater in both CFRD and non-CFRD patients than controls. During exercise, CFRD patients had greater MAP, AP, and ▵EW (p<0.05 for all) and a trend for greater AIx, whilst in non-CFRD patients were not different to controls (Table: at 8minutes exercise). Log10IL-6 was increased in patients (p<0.005) and related to exercise ▵EW (r=0.27, p<0.05).
Controls
Non-CFRD
CFRD
MAP (mmHg)
100 (8)
102 (11)
109 (11)*
AP (mmHg)
−2.2 (4.7)
−0.4 (4.6)
2.2 (4.2)*
▵EW (dynes.s/cm2)
−576 (1400)
−22.9 (1360)
665 (1164)*
AIx (%)
−5.7 (11.2)
−2.0 (10.9)
3.5 (10.3)
Mean (SD).
*P<0.05 from controls (ANOVA).
Conclusions: Patients with CFRD have increased central systolic loading during exercise. These changes have implications for myocardial work and oxygen demand. In contrast, the haemodynamic response in non-CFRD patients does not appear to be maladapted.
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