The Relationship Between Leptin Levels and CPAP Treatment: A Cluster Analysis

Abstract Background: Leptin is an appetite-suppressing hormone, released by adipose tissues, that plays an important role in severe obstructive sleep apnea syndrome (OSAS). However, it is unclear whether leptin levels are a useful OSAS biomarker. This study assessed the effect of continuous positive airway pressure (CPAP) treatment for OSAS according to leptin levels using a cluster classification based on OSAS clinical features. Methods: Hierarchical cluster analysis was performed on 97 patients with OSAS who had been diagnosed via polysomnography. We also evaluated the adherence of CPAP data after 6 months of CPAP administration. Results: Cluster 1 (49 subjects, 50.5%) had severe OSAS, were obese, and had normal leptin levels. Cluster 2 (6 subjects, 6.2%) had the most severe OSAS, were obese, normal leptin levels, and high adiponectin levels. Cluster 3 (11 subjects, 11.3%) had the most severe OSAS, severe obesity, and the highest leptin levels. Cluster 4 (31 subjects, 32%) had the most severe OSAS, severe obesity, and high leptin levels. After CPAP treatment, EDS improved in all clusters. In Clusters 3 and 4, leptin levels were significantly reduced after treatment. Conclusions: To establish if leptin can be a biomarker for CPAP treatment, it is necessary to elucidate the mechanisms of lipid metabolism, leptin, and ventilatory responses in OSAS patients, for which further studies are necessary.