Physical activity, chronotype and sleep in metabolic syndrome: Preliminary data

INTRODUCTION: Metabolic syndrome (MS) is a complex of interrelated risk factors such as abdominal obesity, high blood pressure, dyslipidemia and high fasting glycemia, which increase the possibility of developing numerous chronic-degenerative diseases [1]. Several hypotheses have been postulated to explain the increase in the prevalence of metabolic syndrome, including diet and insufficient physical activity (PA). In addition, in recent years the sleep deprivation [2] and the chronotype [3] have proven to be emerging risk factors for MS. Aim of the study was to investigate possible relationships between PA levels, chronotype and sleep behaviour in subjects with MS. METHODS: We recruited 257 adults (150 F; 107 M) with MS in care at Fondazione IRCCS, Istituto Nazionale Tumori, Milan, Italy. All participants underwent anthropometric and blood sample evaluations and filled in: Godin-Shephard Leisure Time Physical Activity Questionnaire (GSLTPAQ), reduced Morningness-Eveningness Questionnaire (rMEQ) and Pittsburgh Sleep Quality Index (PSQI), to detect PA levels, chronotype and sleep behaviour, respectively. All analyses were performed using the STATA 12 statistical package. RESULTS: Compared to females, males with MS were more active with a significantly higher GSLTPAQ score (25 ± 19.4 vs 20 ± 17.5, respectively; p= 0.03). In both genders, E-Type was the most active chronotype even if there were no statistical differences between chronotypes. Both females and males with MS were bad sleeper, but the females showed a significantly higher PSQI score (7 ± 3.4 vs 5.4 ± 3.4, respectively; p= 0.001). In both genders E-Type was the chronotype showing the worst sleep even if there were no statistical differences between chronotypes. Finally, both females and males were divided on the basis of the severity of MS (3 parameters vs > 3 parameters). E-Types of both genders presented a severe MS compared to the others chronotypes (p< 0.05). In addition, compared to subjects with mild MS, severe MS seems to be associated with lower levels of PA as well as with a poor sleep quality in both genders even if there were no statistical differences between the two groups. CONCLUSION: In conclusion, it seems that a hypothetical subject more at risk of MS could be female E-Type with insufficient levels of PA and poor sleep quality. These findings could represent the basis for physical activity interventions aimed at improving lifestyle habits as a primary prevention of MS.