Long-Term Changes in Sleep Disordered Breathing in Renal Transplant Patients: Relevance of the BMI

Sleep disordered breathing (SDB), as defined by the Apnea Hypopnea Index (AHI), is a highly prevalent disturbance in end stage kidney disease. SDB improves early on after renal transplantation but long-term changes in AHI in these patients have not been studied. We studied the long-term changes in AHI in a series of 221 renal transplant patients (mean age: 47 ± 12 years; 70% males) over a median follow up of 35 months. Data analysis was made by the generalized estimating equations method (GEE). On longitudinal observation, the median AHI rose from 1.8 (Interquartile range: 0.6–5.0) to 2.9 (IQR: 1.0–6.6) and to 3.6 (IQR: 1.7–10.4) at the second and third visit, respectively (p = 0.009 by the GEE model and the proportion of patients with moderate to severe SDB rose from 8% to 20%. Longitudinal changes in minimum oxygen saturation (minSaO2) mirrored those in the AHI. In adjusted analyses, repeated measurements of BMI (p < 0.009) emerged as the strongest independent longitudinal correlate of AHI and MinSaO2. The AHI worsens over time in renal transplant patients and longitudinal changes of this biomarker are directly related to simultaneous changes in BMI. Overweight/obesity, a potentially modifiable risk factor, is an important factor underlying the risk of SDB in this population.

Download Full-text

Sleep‐Disordered Breathing and 24‐Hour Ambulatory Blood Pressure Monitoring in Renal Transplant Patients: Longitudinal Study

Journal of the American Heart Association ◽

10.1161/jaha.120.016237 ◽

2020 ◽

Vol 9 (13) ◽

Author(s):

Francesca Mallamaci ◽

Rocco Tripepi ◽

Graziella D'Arrigo ◽

Vincenzo Panuccio ◽

Giovanna Parlongo ◽

...

Keyword(s):

Blood Pressure ◽

Risk Factor ◽

Renal Transplant ◽

Ambulatory Blood Pressure ◽

Sleep Disordered Breathing ◽

Interquartile Range ◽

Apnea Hypopnea Index ◽

Transplant Patients ◽

Renal Transplant Patients

Background Sleep‐disordered breathing ( SDB ) is considered a strong risk factor for hypertension in the general population. This disturbance is common in end‐stage kidney disease patients on long‐term hemodialysis and improves early on after renal transplantation. Whether SDB may be a risk factor for hypertension in renal transplant patients is unclear. Methods and Results We investigated the long‐term evolution of simultaneous polysomnographic and 24‐hour ambulatory blood pressure (BP) monitoring recordings in a cohort of 221 renal transplant patients. Overall, 404 paired recordings were made over a median follow‐up of 35 months. A longitudinal data analysis was performed by the mixed linear model. The apnea‐hypopnea index increased from a median baseline value of 1.8 (interquartile range, 0.6–5.0) to a median final value of 3.6 (interquartile range, 1.7–10.4; P =0.009). Repeated categorical measurements of the apnea‐hypopnea index were directly associated with simultaneous 24‐hour, daytime, and nighttime systolic ambulatory BP monitoring (adjusted analyses; P ranging from 0.002–0.01). In a sensitivity analysis restricted to 139 patients with at least 2 visits, 24‐hour, daytime, and nighttime systolic BP significantly increased across visits ( P <0.05) in patients with worsening SDB (n=40), whereas the same BP metrics did not change in patients (n=99) with stable apnea‐hypopnea index. Conclusions In renal transplant patients, worsening SDB associates with a parallel increase in average 24‐hour, daytime, and nighttime systolic BP . These data are compatible with the hypothesis that the link between SDB and hypertension is causal in nature. Clinical trials are, however, needed to definitively test this hypothesis.

Download Full-text