Sleep Breath DOI 10.1007/s11325-014-1070-1
ORIGINAL ARTICLE
Is the chronotype associated with obstructive sleep apnea? Lenise Jihe Kim & Fernando Morgadinho Coelho & Camila Hirotsu & Lia Bittencourt & Sergio Tufik & Monica Levy Andersen
Received: 24 June 2014 / Revised: 21 September 2014 / Accepted: 10 October 2014 # Springer-Verlag Berlin Heidelberg 2014
Abstract Purpose Chronotype and obstructive sleep apnea (OSA) appear to have a similar lifelong evolution, which could indicate a possible effect of morningness or eveningness in the apneahypopnea index (AHI). The present study aimed to examine the prevalence of chronotypes in a representative sample of São Paulo city residents and to investigate the effect of chronotypes on the severity of OSA. Methods We performed a cross-sectional analysis using the São Paulo Epidemiologic Sleep Study (EPISONO). All participants underwent a full-night polysomnography and completed the Morningness-eveningness, Epworth Sleepiness Scale, and UNIFESP Sleep questionnaires. Chronotypes were classified as morning-type, evening-type, and intermediate. Results Morning-type individuals represented 52.1 % of the sample, followed by intermediate (39.5 %), and evening-type (8.4 %) individuals. After stratifying the sample by body mass index (BMI) (>26.8 kg/m2) and age (>42 years), we observed increased AHI values in morning- and evening-type individuals. Conclusion We demonstrated, for the first time, an age- and BMI-related effect of morning- and evening-types in OSA severity, suggesting that the intermediate chronotype might play a role as a protective factor in older and overweight patients.
L. J. Kim : F. M. Coelho : C. Hirotsu : L. Bittencourt : S. Tufik : M. L. Andersen Departamento de Psicobiologia, Universidade Federal de São Paulo, São Paulo, Brazil F. M. Coelho (*) Departamento de Neurologia e Neurocirurgia, Universidade Federal de São Paulo (UNIFESP), Rua Napoleão de Barros, 925, Vila Clementino, São Paulo 04024-002, Brazil e-mail: [email protected]
Keywords Obstructive sleep apnea . Chronotype . Age . Body mass index . Sleep duration . Epidemiology
Introduction Circadian rhythms are regulated by genetic and environmental components. The association of intrinsic and extrinsic factors modulates physiological and individual sleep schedules [1]. Circadian preferences are classified as chronotypes, including morning-type, evening-type, and intermediate [2]. Chronotype is a heritable characteristic, emerging during childhood [3]. Moreover, other non-modifiable factors contribute to chronotype manifestation, including gender, age [4], and, as recently reported, birth season [5]. Age plays a unique role in chronotype determination because the circadian sleep rhythm has an important ontogenic component. In general, children are morning-type and progressively transit to evening-type during adolescence until a maximum at approximately 20 years old. However, during adulthood, individuals might resume a morning-type pattern [6]. The prevalence of obstructive sleep apnea syndrome (OSAS) is associated with age [7]. The São Paulo Epidemiologic Sleep Study (EPISONO) indicated a 7.4 % prevalence of OSAS in young adults (20–29 years), reaching 86.9 % after the age of 70 [8]. Therefore, chronotype and OSAS exhibit a similar age-related characteristic that could indicate the potential influence of circadian preference in the severity of sleep apnea. However, the direct association between chronotype and prevalence of sleep apnea is not well known. According to the United Nations [9], the city of São Paulo is the 6th most populous urban region in the world with approximately 11,821,876 inhabitants (IBGE, www.ibge. gov.br). Economically, São Paulo has the highest contribution to the gross domestic product (GDP) of Brazil,
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representing 11.7 %. The intense migrations from Africa and Europe during the 18th and 19th centuries contributed to the high characteristic miscegenation in São Paulo [10]. Therefore, the current mixed population of São Paulo is globally representative and can be considered an adequate sample to study chronotype prevalence. The present study aimed to examine the prevalence of morningness, eveningness, and intermediate chronotypes using an epidemiological study design in São Paulo. In addition, we aimed to investigate the effect of chronotypes on the severity of obstructive sleep apnea (OSA) using polysomnography (PSG), the gold standard test for diagnosing sleep disorders.
duration in weekend from the sleep duration in weekdays. Additionally, the type of workload (fixed or shift work) was evaluated to exclude possible influences on the results. Chronotype determination Chronotype was assessed by a Portuguese version of the Morningness-eveningness questionnaire [13]. Scores range between 16–86, and chronotypes were classified as evening-type (16–41), intermediate (42– 58), and morning-type (59–86) [2]. Daytime somnolence Sleepiness was assessed by the Epworth Sleepiness Scale. Total scores
ORIGINAL ARTICLE
Is the chronotype associated with obstructive sleep apnea? Lenise Jihe Kim & Fernando Morgadinho Coelho & Camila Hirotsu & Lia Bittencourt & Sergio Tufik & Monica Levy Andersen
Received: 24 June 2014 / Revised: 21 September 2014 / Accepted: 10 October 2014 # Springer-Verlag Berlin Heidelberg 2014
Abstract Purpose Chronotype and obstructive sleep apnea (OSA) appear to have a similar lifelong evolution, which could indicate a possible effect of morningness or eveningness in the apneahypopnea index (AHI). The present study aimed to examine the prevalence of chronotypes in a representative sample of São Paulo city residents and to investigate the effect of chronotypes on the severity of OSA. Methods We performed a cross-sectional analysis using the São Paulo Epidemiologic Sleep Study (EPISONO). All participants underwent a full-night polysomnography and completed the Morningness-eveningness, Epworth Sleepiness Scale, and UNIFESP Sleep questionnaires. Chronotypes were classified as morning-type, evening-type, and intermediate. Results Morning-type individuals represented 52.1 % of the sample, followed by intermediate (39.5 %), and evening-type (8.4 %) individuals. After stratifying the sample by body mass index (BMI) (>26.8 kg/m2) and age (>42 years), we observed increased AHI values in morning- and evening-type individuals. Conclusion We demonstrated, for the first time, an age- and BMI-related effect of morning- and evening-types in OSA severity, suggesting that the intermediate chronotype might play a role as a protective factor in older and overweight patients.
L. J. Kim : F. M. Coelho : C. Hirotsu : L. Bittencourt : S. Tufik : M. L. Andersen Departamento de Psicobiologia, Universidade Federal de São Paulo, São Paulo, Brazil F. M. Coelho (*) Departamento de Neurologia e Neurocirurgia, Universidade Federal de São Paulo (UNIFESP), Rua Napoleão de Barros, 925, Vila Clementino, São Paulo 04024-002, Brazil e-mail: [email protected]
Keywords Obstructive sleep apnea . Chronotype . Age . Body mass index . Sleep duration . Epidemiology
Introduction Circadian rhythms are regulated by genetic and environmental components. The association of intrinsic and extrinsic factors modulates physiological and individual sleep schedules [1]. Circadian preferences are classified as chronotypes, including morning-type, evening-type, and intermediate [2]. Chronotype is a heritable characteristic, emerging during childhood [3]. Moreover, other non-modifiable factors contribute to chronotype manifestation, including gender, age [4], and, as recently reported, birth season [5]. Age plays a unique role in chronotype determination because the circadian sleep rhythm has an important ontogenic component. In general, children are morning-type and progressively transit to evening-type during adolescence until a maximum at approximately 20 years old. However, during adulthood, individuals might resume a morning-type pattern [6]. The prevalence of obstructive sleep apnea syndrome (OSAS) is associated with age [7]. The São Paulo Epidemiologic Sleep Study (EPISONO) indicated a 7.4 % prevalence of OSAS in young adults (20–29 years), reaching 86.9 % after the age of 70 [8]. Therefore, chronotype and OSAS exhibit a similar age-related characteristic that could indicate the potential influence of circadian preference in the severity of sleep apnea. However, the direct association between chronotype and prevalence of sleep apnea is not well known. According to the United Nations [9], the city of São Paulo is the 6th most populous urban region in the world with approximately 11,821,876 inhabitants (IBGE, www.ibge. gov.br). Economically, São Paulo has the highest contribution to the gross domestic product (GDP) of Brazil,
Sleep Breath
representing 11.7 %. The intense migrations from Africa and Europe during the 18th and 19th centuries contributed to the high characteristic miscegenation in São Paulo [10]. Therefore, the current mixed population of São Paulo is globally representative and can be considered an adequate sample to study chronotype prevalence. The present study aimed to examine the prevalence of morningness, eveningness, and intermediate chronotypes using an epidemiological study design in São Paulo. In addition, we aimed to investigate the effect of chronotypes on the severity of obstructive sleep apnea (OSA) using polysomnography (PSG), the gold standard test for diagnosing sleep disorders.
duration in weekend from the sleep duration in weekdays. Additionally, the type of workload (fixed or shift work) was evaluated to exclude possible influences on the results. Chronotype determination Chronotype was assessed by a Portuguese version of the Morningness-eveningness questionnaire [13]. Scores range between 16–86, and chronotypes were classified as evening-type (16–41), intermediate (42– 58), and morning-type (59–86) [2]. Daytime somnolence Sleepiness was assessed by the Epworth Sleepiness Scale. Total scores
