Effect of kidney transplantation on sleep-disordered breathing in patients with End Stage Renal Disease: a polysomnographic study.

BACKGROUND

Sleep-disordered breathing (SDB) is common in patients with end-stage renal disease (ESRD). SDB is associated with comorbidities such as hypertension, diabetes mellitus, and obesity, interplaying with metabolic derangements in the form of uremia, acidosis, and hypervolemia. Renal transplant has been observed to correct most of these metabolic derangements and to control progression of comorbidities. While SDB is highly prevalent among patients in the pretransplant stage, it remains to be seen whether the beneficial aspects of transplant are extended to improvement in SDB in patients with ESRD.

METHODS

Eighteen patients undergoing thrice-weekly hemodialysis (HD) for ESRD at the transplant clinic of All India Institute of Medical Sciences (AIIMS), New Delhi, underwent detailed clinical, laboratory, and polysomnographic evaluation. The average number of apneas and hypopneas per hour of sleep, ie, Apnea-Hypopnea Index (AHI), was used to define the severity of sleep apnea. All patients underwent polysomnography (PSG) within 24 h of the last HD and after three months of living-donor transplant.

RESULTS

Of 18 patients, there were 14 males and four females. The median age was 28 years (range 19-50 years). They had already spent a median period of six months (range 3-31 months) on HD before inclusion. The prevalence of SDB (AHI ≥ 5/h) was 44.4% (8/18) before transplant, which decreased to 5.6% (1/18) after transplant (p = 0.016). The oxygen desaturation index had a median value of 5.8 events/h (range 0.1-35.4) in the pretransplant stage, which decreased to 0 events/h (range 0-6.6) in the post-transplant stage (p = 0.035).

CONCLUSION

There was a significant improvement in the prevalence and severity of SDB after transplant. Whether improvement in SDB is sustained on a long-term follow-up remains to be seen.