Research article

Autoadjusting-CPAP effect on serum Leptin concentrations in Obstructive Sleep Apnoea patients

Marta Drummond¹ , João C Winck¹ , João T Guimarães² , Ana C Santos³ , João Almeida¹ and José A Marques¹

¹Pulmonology Department, Hospital de São João, Alameda Hernâni Monteiro, 4200-319 Porto, Portugal

²Clinical Pathology Department and Biochemistry Department Hospital de São João, Alameda Hernâni Monteiro 4200-319 Porto, Portugal

³Epidemiology Department, Hospital de São João, Alameda Hernâni Monteiro, 4200-319 Porto, Portugal

author email corresponding author email

BMC Pulmonary Medicine 2008, 8:21doi:10.1186/1471-2466-8-21

Published:	1 October 2008

Abstract

Background

Leptin is an hormone that regulates body weight. Studies have shown increasing leptin concentrations according to body mass index (BMI) and intermittent hypoxia.

Our aim is to evaluate the basal leptin levels in OSA patients and its possible relation to OSA severity, independently of confounders and investigate the Autoadjusting-CPAP effect on leptin values.

Methods

In ninety eight male patients with moderate to severe OSA leptin serum levels were evaluated before therapy, 9 days and 6 months after therapy.

Results

In this group mean age was 55.3 years, mean BMI was 33.2 Kg/m2 and mean Apnoea- Hypopnea Index (AHI) was 51.7/h. Mean basal serum leptin value was 12.1 ug/L. Univariate analysis showed a significant correlation between serum leptin values and BMI (R = 0.68; p < 0.001), waist-hip ratio (R = 0.283; p = 0.004) and AHI (R = 0.198; p = 0.048); in stepwise multiple regression analysis only BMI (p < 0.001) was a predictor of serum leptin values.

One week after therapy, mean leptin serum level decreased to 11.0 ug/L and 6 months after it was 11.4 ug/L. (p = 0.56 and p = 0.387, respectively)

Conclusion

Baseline leptin serum levels positively correlate with BMI, fat distributioand OSA severity.

BMI is the only predictor of basal leptin levels.

Treatment with Autoadjusting-CPAP has a small effect on leptin levels.