Influence of sleep quality and time on fat metabolism and leptin levels in physically active young adults.

Resumen

INTRODUCTION: A lower fat oxidation at rest (BFox) is associated with a poorer quality of sleep [1]. Only one-night sleep restriction doesnot influence maximal fat oxidation (MFO) during exercise, but it remains unknown if this restriction maintained over time may affect MFO.The aim of the study was to observe the association between the sleep quality and duration, and the maximal fat oxidation during exerciseand blood leptin concentrations in healthy adults.METHODS: Eighty physically active participants (30 women) 18 to 40 years old were included in this study. Height was measured usingheight measuring instruments. To evaluate body composition (body weight, fat mass, and fat-free mass) a bioimpedance was used. Pittsburgh sleep quality index (PSQI) scale was used to assess the sleep quality. Indirect calorimetry at rest and during MFO exercise test wasmeasured using the open-circuit gas analyzer (Jaeger MasterScreen). Fasting blood sample for leptin analysis was taken from the antecubital vein and analyzed using the MILLIPLEX® Map kit “Human Metabolic Hormone Magnetic Bead Panel Immunoassay”. Simple linearregression models were conducted to examine the independent association of sleep quality with fat metabolism and plasma leptin concentrations. We also conducted multiple linear regression models to test these associations after adjusting by cofoundersRESULTS: We observed no association between sleep latency score and MFO (P>0.05) but we observed an inverse association after including sex and age in the model (all P<0.035). An inverse association was detected between sleep duration score with MFO (P=0.03) evenwhen age was included in the model (P=0.022), but this association disappeared when sex, FMI and VO2max were included (P>0.076). Weshowed an inverse association between sleep latency with MFO relativized to the lean total mass (MFO-LTM) and leg lean mass (MFO-LLM)(P<0.012), even when the model includes cofounders (P< 0.048). MFO-LTM and MFO-LLM showed an inverse association with sleep duration score in unadjusted model (P<0.019), even when was adjusted by age (P<0.033), but it disappeared when sex, FMI and VO2max wereincluded in the model (P>0.105). PSQI global score was negatively associated with MFO-LTM and MFO-LLM (P<0.041), also when wereadjusted for age (P<0.043), but not when adjusted for sex, FMI and VO2max (P>0.138). A direct association was found between PSQI globalscore with leptin (P=0.037), even when age, sex and FMI were included in the model (P<0.028), but not when was included VO2max(P=0.234)CONCLUSION: Results suggest that maximal fat oxidation during exercise could improve directly by the quality and quantity of sleep. Infact, it has been reported previously that insomnia or trouble sleeping is associated with obesity, which could be regulated by a reductionin leptin hormone, which suppresses appetite and increase fat oxidation.