Factors associated with dyspnea in adult patients with sickle cell disease

Chest. 2005 Nov;128(5):3336-44. doi: 10.1378/chest.128.5.3336.


Objective: The aim of this prospective study was to determine the cardiorespiratory factors associated with dyspnea in patients with sickle cell SS-hemoglobin disease, with a specific interest in lung vascular involvement.

Measurements: Forty-nine patients (29 women and 20 men; mean [+/- SD] age: women, 29 +/- 6 years; men, 31 +/- 11 years) underwent direct evaluations (Borg scale evaluation during a 6-min walk test) and indirect evaluations (modified Medical Research Council [MRC]score) of their dyspnea, pulmonary function tests (PFTs) [spirometry, volumes, diffusing capacity of the lung for carbon monoxide (Dlco), diffusing capacity of the alveolar-capillary membrane, and pulmonary capillary blood volume measurements], echocardiography, and biological evaluation.

Results: Thirty-four patients complained of significant breathlessness (MRC score, > 1). Indirect and direct evaluations of dyspnea were correlated. PFT results depicted a very mild restrictive pattern (mean total pulmonary capacity, 86 +/- 11% predicted) and an impairment of Dlco (mean Dlco corrected for the degree of anemia, 69 +/- 13% predicted). The statistical analysis demonstrated that dyspnea and exercise performance were closely linked to indexes of Dlco but not with any echocardiographic or biological measure including anemia. Nevertheless, only approximately 25% of the variability was explained by these associations. Despite having a similar history of vasoocclusive crisis events, women had more severe anemia, dyspnea, decreases in Dlco (corrected for the degree of anemia), and a higher capillary blood volume (corrected for alveolar volume) than men.

Conclusion: Lung vascular disease contributes to dyspnea and the exercise limitation of patients with sickle cell disease. A sequential assessment of Dlco would therefore constitute one of the objective functional end points for follow-up studies of these patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anemia, Sickle Cell / epidemiology*
  • Anemia, Sickle Cell / physiopathology
  • Breath Tests
  • Dyspnea / epidemiology*
  • Dyspnea / physiopathology
  • Female
  • Humans
  • Lung Diseases / epidemiology*
  • Lung Diseases / physiopathology
  • Male
  • Nitric Oxide / metabolism
  • Prospective Studies
  • Pulmonary Alveoli / metabolism
  • Pulmonary Diffusing Capacity
  • Respiratory Function Tests


  • Nitric Oxide