Guleria R, Goswami R, Shah P, Pande J N, Kochupillai N
Department of Medicine, All India Institute of Medical Sciences, New Delhi.
Indian J Med Res. 1996 Nov;104:299-303.
To understand the pathophysiology of dyspnoea in patients with hyperthyroidism, lung function, maximum inspiratory, expiratory respiratory muscle pressures (MIP and MEP) and intensity of dyspnoea (after six minutes walking test) were recorded in 12 consecutive patients with active Graves' disease. Reassessment was done after achieving euthyroidism with 8-12 wk of carbimazole therapy. Patients covered similar distance during 6 min walking before and after carbimazole therapy. However, there was a significant reduction in dyspnoea following euthyroidism. This was accompanied by significant decrease in respiratory rate, minute ventilation, forced expiratory volume in one second (FEV1%) and improvement in the forced vital capacity (FVC). No significant changes in tidal volume (TV) and maximum-midexpiratory flow rates (MMEFR), MIP and MEP were observed. Lung function parameters, MIP and MEP did not correlate with the severity of dyspnoea. Serum T4 levels correlated inversely with the distance covered during 6 min walking test, MIP and MEP. To conclude, increased breathing effort in presence of reduced FVC may lead to dyspnoea during hyperthyroid phase in patients with active Graves' disease. Lack of correlation between the severity of dyspnoea and abnormalities in lung function suggests that other mechanisms of dyspnoea may also operate in these patients.
为了解甲状腺功能亢进患者呼吸困难的病理生理学，对12例连续的活动性格雷夫斯病患者记录了肺功能、最大吸气、呼气呼吸肌压力（MIP和MEP）以及呼吸困难强度（6分钟步行试验后）。在接受8 - 12周的卡比马唑治疗达到甲状腺功能正常后进行重新评估。卡比马唑治疗前后患者在6分钟步行中走过的距离相似。然而，甲状腺功能正常后呼吸困难明显减轻。这伴随着呼吸频率、分钟通气量、一秒用力呼气量（FEV1%）显著降低以及用力肺活量（FVC）改善。未观察到潮气量（TV）和最大呼气中期流速（MMEFR）、MIP和MEP有显著变化。肺功能参数、MIP和MEP与呼吸困难的严重程度无关。血清T4水平与6分钟步行试验中走过的距离、MIP和MEP呈负相关。总之，在活动性格雷夫斯病患者的甲状腺功能亢进期，FVC降低时呼吸努力增加可能导致呼吸困难。呼吸困难严重程度与肺功能异常之间缺乏相关性表明这些患者可能还存在其他导致呼吸困难的机制。
