Acute Effect of Continuous Positive Airway Pressure (CPAP) on Weight in Patients with Obstructive Sleep Apnea
Authors List
Giovani F. Lima¹, Sara H. Silva¹, Mariana D. Fernandes¹, José Gilvam A. Lima Junior²,
Luciano F. Drager², Geraldo Lorenzi-Filho¹, Pedro R. Genta¹.
¹Laboratório do Sono, Divisão de Pneumologia do Instituto do Coração, Faculdade de
Medicina, Universidade de São Paulo, São Paulo, SP, BR. ²Unidade de Hipertensão, Faculdade
de Medicina, Universidade de São Paulo, São Paulo, SP, BR.
Introduction
CPAP has been shown to lead to a modest weight gain among obstructive sleep apnea (OSA) patients. Fluid accumulation after one week of CPAP has been observed and is a plausible mechanism leading to weight gain during OSA treatment. We hypothesized that fluid accumulation occurs during the first night of CPAP treatment leading to weight gain.
Methodology
Thirty-eight severe OSA subjects underwent baseline polysomnography (PSG). During the following night, participants were randomized to CPAP or a repeat baseline study (Control). Body weight was assessed twice during each study night, before bedtime and at wake-up (after voiding). Overnight urinary volume and osmolality were determined in the morning following PSG.
Results
Mean age (53±8 and 55±10 years), body-mass index (35.0±6.8 and 34.9±5.8 kg/m²), apnea-hypopnea index (74.2±26.9 and 68.4±22.2 events/h) and the
proportion of males (69 and 52%) were similar, Control and CPAP groups, respectively. Mean titrated CPAP was 8±2 cmH₂O.
Conclusions
CPAP led to weight gain during only one night. The concomitant reduction in urinary volume and nocturia episodes and increase in urinary osmolality suggest that fluid accumulation is the main mechanism involved.
Research Funding Source: Coordination for the Improvement of Higher Education Personnel– Brazil (CAPES) and São Paulo Research Foundation (FAPESP).
Giovani F. Lima¹, Sara H. Silva¹, Mariana D. Fernandes¹, José Gilvam A. Lima Junior²,
Luciano F. Drager², Geraldo Lorenzi-Filho¹, Pedro R. Genta¹.
¹Laboratório do Sono, Divisão de Pneumologia do Instituto do Coração, Faculdade de
Medicina, Universidade de São Paulo, São Paulo, SP, BR. ²Unidade de Hipertensão, Faculdade
de Medicina, Universidade de São Paulo, São Paulo, SP, BR.
Introduction
CPAP has been shown to lead to a modest weight gain among obstructive sleep apnea (OSA) patients. Fluid accumulation after one week of CPAP has been observed and is a plausible mechanism leading to weight gain during OSA treatment. We hypothesized that fluid accumulation occurs during the first night of CPAP treatment leading to weight gain.
Methodology
Thirty-eight severe OSA subjects underwent baseline polysomnography (PSG). During the following night, participants were randomized to CPAP or a repeat baseline study (Control). Body weight was assessed twice during each study night, before bedtime and at wake-up (after voiding). Overnight urinary volume and osmolality were determined in the morning following PSG.
Results
Mean age (53±8 and 55±10 years), body-mass index (35.0±6.8 and 34.9±5.8 kg/m²), apnea-hypopnea index (74.2±26.9 and 68.4±22.2 events/h) and the
proportion of males (69 and 52%) were similar, Control and CPAP groups, respectively. Mean titrated CPAP was 8±2 cmH₂O.
Conclusions
CPAP led to weight gain during only one night. The concomitant reduction in urinary volume and nocturia episodes and increase in urinary osmolality suggest that fluid accumulation is the main mechanism involved.
Research Funding Source: Coordination for the Improvement of Higher Education Personnel– Brazil (CAPES) and São Paulo Research Foundation (FAPESP).
