Abstracts

Introduction

Excessive daytime sleepiness (EDS) is characterized by the increased need to take naps during the day at times when the individual should be alert and active¹1. Littner MR, Kushida C, Wise M, Davila DG, Morgenthaler T, Lee-Chiong T, et al. Practice parameters for clinical use of the multiple sleep latency test and the maintenance of wakefulness test. Sleep 2004; 28(1): 113-21.. It is subjacent to sleep fragmentation and its reduced efficiency²2. Ensrud KE, Blackwell TL, Redline S, Ancoli-Israel S, Paudel ML, Cawthon PM, et al. Sleep disturbances and frailty status in older community-dwelling men. J Am Geriatr Soc 2009; 57(11): 2085-93. ^{, 3}3. Roehrs T, Zorick F, Sicklesteel J, Wittig R, Roth T. Excessive daytime sleepiness associated with insufficient sleep. Sleep 1983; 6(4): 319-25., composing the scope of symptoms of sleep respiratory disorders, such as the Obstructive Sleep Apnea Syndrome (OSAS). However, there is evidence that EDS is not only a result of OSAS, since it can be an independent variable of this disease⁴4. Bixler EO, Vgontzas AN, Lin HM, Vela-Bueno A, Calhoun SL, Kales A. Excessive daytime sleepiness in a general population sample : the role of sleep apnea, age, obesity, diabetes, and depression. J Clin Endocrinol Metab 2005; 90(8): 4510-5.. For these cases, it is possible that obesity⁴4. Bixler EO, Vgontzas AN, Lin HM, Vela-Bueno A, Calhoun SL, Kales A. Excessive daytime sleepiness in a general population sample : the role of sleep apnea, age, obesity, diabetes, and depression. J Clin Endocrinol Metab 2005; 90(8): 4510-5.

5. Patel SR, Blackwell T, Redline S, Ancoli-Israel S, Cauley JA, Hillier TA, et al. The association between sleep duration and obesity in older adults. Int J Obes (Lond) 2009; 32(12): 1825-34. ^{- 6}6. Vorona RD, Winn MP, Babineau TW, Eng BP, Feldman HR, Ware JC, et al. Overweight and obese patients in a primary care population report less sleep than patients with a normal body mass index. Arch Intern Med 2005; 165(1): 25-30., the metabolic syndrome⁴4. Bixler EO, Vgontzas AN, Lin HM, Vela-Bueno A, Calhoun SL, Kales A. Excessive daytime sleepiness in a general population sample : the role of sleep apnea, age, obesity, diabetes, and depression. J Clin Endocrinol Metab 2005; 90(8): 4510-5. ^{, 7}7. Günes Z, Sahbaz M, Tugrul E, Günes H. Prevalence and risk factors for excessive daytime of sleepiness in rural western Anotolia (Turkey): the role of obesity and metabolic syndrome. Southeast Asian J Trop Med Public Health 2012; 43(3): 747-55., heart diseases⁸8. Sabanayagam C, Shankar A. Sleep duration and cardiovascular disease: results from the National Health Interview Survey. Sleep 2010; 33(8): 1037-42.

9. Empana JP, Dauvilliers Y, Dartigues JF, Ritchie K, Gariepy J, Jouven X, et al. Excessive daytime sleepiness is an independent risk indicator for cardiovascular mortality in community-dwelling elderly: the three city study. Stroke 2009; 40(4): 1219-24. ^{- 10}10. Ikehara S, Iso H, Date C, Kikuchi S, Watanabe Y, Wada Y, et al. Association of sleep duration with mortality from cardiovascular disease and other causes for Japanese men and women: the JACC study. Sleep 2009;32(3): 295-301., and depression¹¹11. Lessov-Schlaggar CN, Bliwise DL, Krasnow RE, Swan GE, Reed T. Genetic association of daytime sleepiness and depressive symptoms in elderly men. Sleep 2008; 31(8): 1111-7.

12. Chellappa SL, Araújo JF. Excessive daytime sleepiness in patients with depressive disorder. Rev Bras Psiquiatr. 2006; 28(2): 126-9. ^{- 13}13. Calati R, Gaspar-Barba E, Cruz-Fuentes CS, Nenclares A, Jimenez-Genchi A, Ronchi DD, et al. Excessive daytime sleepiness in depressed women. Psychiatry Res 2010; 179(2): 171-5. can be related to EDS.

There is an association between EDS and the changes in the autonomic cardiovascular control, which could predispose to heart disease¹⁴14. Lombardi C, Parati G, Provini F, Vetrugno R, Plazzi G, Vignatelli L, et al. Daytime sleepiness and neural cardiac modulation in sleep-related breathing disorders. J Sleep Res 2008; 17(3): 263-70.. Empana et al.⁹9. Empana JP, Dauvilliers Y, Dartigues JF, Ritchie K, Gariepy J, Jouven X, et al. Excessive daytime sleepiness is an independent risk indicator for cardiovascular mortality in community-dwelling elderly: the three city study. Stroke 2009; 40(4): 1219-24. observed that EDS influenced the 33% increase in the risk of death for heart disease among the elderly, thus indicating to be an independent cardiovascular risk factor. Studies show that the reduced sleep duration can also be involved in the increased mortality due to cardiovascular dysfunction²2. Ensrud KE, Blackwell TL, Redline S, Ancoli-Israel S, Paudel ML, Cawthon PM, et al. Sleep disturbances and frailty status in older community-dwelling men. J Am Geriatr Soc 2009; 57(11): 2085-93. ^{, 8}8. Sabanayagam C, Shankar A. Sleep duration and cardiovascular disease: results from the National Health Interview Survey. Sleep 2010; 33(8): 1037-42. ^{, 10}10. Ikehara S, Iso H, Date C, Kikuchi S, Watanabe Y, Wada Y, et al. Association of sleep duration with mortality from cardiovascular disease and other causes for Japanese men and women: the JACC study. Sleep 2009;32(3): 295-301.. The risk for this condition can be indirectly estimated by waist circumference¹⁵15. Sarno F, Monteiro CA. Importância relativa do índice de massa corporal e da circunferência abdominal na predição da hipertensão arterial. Rev Saúde Pública 2007; 41(5): 788-96..

Psychiatric disorders also presented association with EDS, especially depression¹¹11. Lessov-Schlaggar CN, Bliwise DL, Krasnow RE, Swan GE, Reed T. Genetic association of daytime sleepiness and depressive symptoms in elderly men. Sleep 2008; 31(8): 1111-7. ^{, 16}16. Tsuno N, Jaussent I, Dauvilliers Y. Determinants of excessive daytime sleepiness in a French community-dwelling elderly population. J Sleep Res 2007; 16(4): 364-71., since this condition is considered to be a major public health issue among the elderly¹⁷17. Chapman DP, Perry GS. Depression as a major component of public health for older adults. Prev Chronic Dis 2008; 5(1): A22.. Jaussent et al.¹⁸18. Jaussent I, Bouyer J, Ancelin ML, Akbaraly T, Pérès K, Ritchie K, et al. Insomnia and daytime sleepiness are risk factors for depressive symptoms in the elderly. Sleep 2011; 34(8): 1103-10. observed that the EDS is an independent risk factor for the occurrence of depression. Chellapa and Araújo¹²12. Chellappa SL, Araújo JF. Excessive daytime sleepiness in patients with depressive disorder. Rev Bras Psiquiatr. 2006; 28(2): 126-9. found a strong association between EDS and severe depression. Lessov-Schlagga et al.¹¹11. Lessov-Schlaggar CN, Bliwise DL, Krasnow RE, Swan GE, Reed T. Genetic association of daytime sleepiness and depressive symptoms in elderly men. Sleep 2008; 31(8): 1111-7. verified a relationship between depression symptoms and EDS among men. On the other hand, Calati et al.¹³13. Calati R, Gaspar-Barba E, Cruz-Fuentes CS, Nenclares A, Jimenez-Genchi A, Ronchi DD, et al. Excessive daytime sleepiness in depressed women. Psychiatry Res 2010; 179(2): 171-5. did not find any association between depression and EDS among women.

There seems to be an association between obesity and EDS⁴4. Bixler EO, Vgontzas AN, Lin HM, Vela-Bueno A, Calhoun SL, Kales A. Excessive daytime sleepiness in a general population sample : the role of sleep apnea, age, obesity, diabetes, and depression. J Clin Endocrinol Metab 2005; 90(8): 4510-5.

5. Patel SR, Blackwell T, Redline S, Ancoli-Israel S, Cauley JA, Hillier TA, et al. The association between sleep duration and obesity in older adults. Int J Obes (Lond) 2009; 32(12): 1825-34.

6. Vorona RD, Winn MP, Babineau TW, Eng BP, Feldman HR, Ware JC, et al. Overweight and obese patients in a primary care population report less sleep than patients with a normal body mass index. Arch Intern Med 2005; 165(1): 25-30. ^{- 7}7. Günes Z, Sahbaz M, Tugrul E, Günes H. Prevalence and risk factors for excessive daytime of sleepiness in rural western Anotolia (Turkey): the role of obesity and metabolic syndrome. Southeast Asian J Trop Med Public Health 2012; 43(3): 747-55. ^{, 19}19. Theorell-Haglöw J, Berne C, Janson C, Sahlin C, Lindberg E. Associations between short sleep duration and central obesity in women. Sleep 2010; 33(5): 593-8.. Vorona⁶6. Vorona RD, Winn MP, Babineau TW, Eng BP, Feldman HR, Ware JC, et al. Overweight and obese patients in a primary care population report less sleep than patients with a normal body mass index. Arch Intern Med 2005; 165(1): 25-30. observed that individuals with overweight/obesity slept less than people with BMI lower to that established by the World Health Organization. Carmelli et al.²⁰20. Carmelli D, Cliwise DL, Swan GE, Reed T. genetic factors in self-reported snoring and excessive daytime sleepiness: a twin study. Am J Respir Crit Care Med 2001; 164(6): 949-52. verified the correlation between obesity and EDS among twins. Other researchers observed that, regardless of sleep duration, male elderly with increased BMI presented decreased slow-wave sleep²¹21. Rao MN, Blackwell T, Redline S, Stefanick ML, Ancoli-israel S, Stone KL, et al. Association between sleep architecture and measures of body composition. Sleep 2009; 32(4): 483-90..

Several studies have shown that EDS is an independent risk factor for accidents²2. Ensrud KE, Blackwell TL, Redline S, Ancoli-Israel S, Paudel ML, Cawthon PM, et al. Sleep disturbances and frailty status in older community-dwelling men. J Am Geriatr Soc 2009; 57(11): 2085-93. and mortality for heart disease⁹9. Empana JP, Dauvilliers Y, Dartigues JF, Ritchie K, Gariepy J, Jouven X, et al. Excessive daytime sleepiness is an independent risk indicator for cardiovascular mortality in community-dwelling elderly: the three city study. Stroke 2009; 40(4): 1219-24., and, when associated to respiratory sleep disorders it increases general mortality among the elderly²³23. Gooneratne NS, Richards KC, Joffe M, Lam RW, Pack F, Staley B, et al. Sleep disordered breathing with excessive daytime sleepiness is a risk factor for mortality in older adults. Sleep.2011; 34(4): 435-42.. Therefore, it is necessary to observe to what point the presence of EDS is affected by or affects variables such as obesity⁶6. Vorona RD, Winn MP, Babineau TW, Eng BP, Feldman HR, Ware JC, et al. Overweight and obese patients in a primary care population report less sleep than patients with a normal body mass index. Arch Intern Med 2005; 165(1): 25-30. ^{, 7}7. Günes Z, Sahbaz M, Tugrul E, Günes H. Prevalence and risk factors for excessive daytime of sleepiness in rural western Anotolia (Turkey): the role of obesity and metabolic syndrome. Southeast Asian J Trop Med Public Health 2012; 43(3): 747-55., depression¹¹11. Lessov-Schlaggar CN, Bliwise DL, Krasnow RE, Swan GE, Reed T. Genetic association of daytime sleepiness and depressive symptoms in elderly men. Sleep 2008; 31(8): 1111-7. and cardiovascular morbidity⁸8. Sabanayagam C, Shankar A. Sleep duration and cardiovascular disease: results from the National Health Interview Survey. Sleep 2010; 33(8): 1037-42.

9. Empana JP, Dauvilliers Y, Dartigues JF, Ritchie K, Gariepy J, Jouven X, et al. Excessive daytime sleepiness is an independent risk indicator for cardiovascular mortality in community-dwelling elderly: the three city study. Stroke 2009; 40(4): 1219-24. ^{- 10}10. Ikehara S, Iso H, Date C, Kikuchi S, Watanabe Y, Wada Y, et al. Association of sleep duration with mortality from cardiovascular disease and other causes for Japanese men and women: the JACC study. Sleep 2009;32(3): 295-301.; this theme is widely discussed in literature, and there is disagreement among specialists.

We conducted this study with an elderly population with the objective of assessing possible associations between EDS and obesity, depression and risk of cardiovascular dysfunction, and also to find out if these relations are different among men and women or in relation to aging.

Methods

Study design and variables

It is a cross-sectional population-based study carried out in the city of Campina Grande, Paraíba, in 2010, including elderly inhabitants of the urban zone. Individuals from the community aged more than 60 years old with mental and physical skills to perform the assigned tests were included. Elderly in institutional environment and unskilled to answer to the methodologies of the study were excluded from the research.

EDS was diagnosed by the Epworth Sleepiness Scale. EDS was diagnosed by more than 10 points in that scale²⁴24. Bertolazi AN, Fagondes SC, Hoff LS, Pedro VD, Saldanha S, Barreto M, et al. Portuguese-language version of the Epworth sleepiness scale: validation for use in Brazil. J Bras Pneumol 2009; 35(9): 877-83.. The depression diagnosis was determined by the Geriatric Depression Scale, which classified as medium depression scores from 11 to 20, and moderate/severe depression scores higher than 21 points²⁵25. Giavoni A, Melo GF, Parente I, Dantas G. Elaboração e validação da escala de depressão para idosos. Cad Saúde Pública 2008; 24(5): 975-82.. BMI was an indicator of nutritional status: values lower than 18.4 kg/m² are considered as low weight; between 18.5 and 24.9 kg/m², eutrophy; between 25 and 29.9 kg/m², overweight; and 30 kg/m² or higher, obesity²⁶26. Cervi A, Franceschini CC, Priore E. Análise crítica do uso do índice de massa corporal para idosos. Rev Nutr 2005; 18(6): 765-75. ^{, 27}27. Santos DM, Sichieri R. Índice de massa corporal e indicadoresantropométricos de adiposidade em idosos. Rev Saúde Pública 2005; 39(2): 163-8..

The risk of cardiovascular dysfunction was estimated by waist circumference, in which for men values between 94 and 101 were classified as increased, and values higher than 102 cm were substantially increased; for women, values from 80 and 87 cm were considered as increased and those higher than 88 cm were considered as substantially increased²⁷27. Santos DM, Sichieri R. Índice de massa corporal e indicadoresantropométricos de adiposidade em idosos. Rev Saúde Pública 2005; 39(2): 163-8. ^{, 28}28. World Health Organization. Obesity: Preventing and Managing the Global Epidemic. Report. Geneva; 1997.. Gender and age of the participants were also collected as identification.

Height was measured in centimeters by a wall-mounted stadiometer from WISO(r), with 0.1 cm precision, while the mass of the elderly participants was measured by a GEOM(r) digital scale, with 150 kg capacity and 100 g precision. Finally, waist circumference was measured by a non-elastic metric tape in the mid-region between the last rib and the iliac crest²⁸28. World Health Organization. Obesity: Preventing and Managing the Global Epidemic. Report. Geneva; 1997.. All of the anthropometric measures and the application of the instruments were conducted by trained students of the Physical Therapy and Psychology courses, and the concordance of measurements was estimated.

Population and Sample

This study was part of a larger project that aimed at estimating the prevalence of EDS; therefore, the obtainment of an ideal sample was based on the following equation: {[µ² x p (1-p)] x c}/ε² , where µ is the confidence limit for a 5% probability error (µ = 1.96), p is the estimated outcome prevalence (p = 20%), c is the correction coefficient of the sample (c = 1.2), considering that it is a conglomerate sample, and ε is the margin of error of the estimates for estimated prevalence (ε = 6%). Therefore, the estimated sample is comprised of 205 participants. Besides, the elderly population of the city of Campina Grande, Paraíba, was considered to be infinite.

The sample was proportional to the population of elderly individuals of each health district of the urban zone of the city of Campina Grande, Paraíba. Elderly participants were randomly selected in the four health districts. In each district, one Basic Family Health Unit was sorted out. The streets of these selected units were analyzed from one end to another, in both sides, skipping nine houses from the corner chosen to be the starting point, similarly to the method used by the Brazilian Institute of Geography and Statistics (IBGE) for random distribution. Such alternation is given by the ratio between the total number of households in the neighborhood and the number of elderly people to be visited. In case there were no elderly people in the selected household, the next house should be verified and, if necessary, the previous one. If there was more than one elderly person in the house, data collection was conducted with all of them.

Statistical Analysis

In order to analyze the relationship between EDS and depression, overweight/obesity and risk factor for cardiovascular dysfunction, the Pearson chi-square Test was used in 2x2 contingency situations and linear association, when contingency presented an ordinal characteristic. There was also adjustment for gender and age group (60 - 69 years old, 70 - 79 years old, and 80 years old or more), in the attempt to verify any influence of these variables on the relationship between EDS and overweight/obesity, depression and increased and substantially increased waist circumference. Therefore, a 5% significance level was adopted in order to avoid the type I error. The Statistical Package for the Social Sciences (SPSS), version 17.0, was used.

Ethical Procedures

The study was approved by the Ethics Committee of Universidade Estadual da Paraíba, based on Resolution n. 196/96 of the National Health Council, with protocol 0299.0.133.000-09. The participants signed duplicates of the Informed Consent Form, which explicated the objectives of the research and those in charge of it. The authors declared there was no conflict of interests.

Results

EDS was prevalent in 53 cases (31.5%; 95%CI; 27.9 - 35.0) among the 168 analyzed elderly people, which represent 81.9% of the estimated sample. The obtained loss is a result of refusals to participate in the study. Age ranged from 60 to 98 years old, mean of 72.34 ± 7.8 years, and 122 (72.6%) were women. Depression affected 72 participants (42.9%; 95%CI; 39.1 - 46.7). BMI was higher than 25 kg/m² in 95 patients (64.6%; 95%CI; 60.9-68.3). Waist circumference was increased in 129 members of the sample (79.6%; 95%CI; 76.4 - 82.7) (Table 1).

Table 2 presents the crude association between study variables and EDS. There was no difference in the frequency of depression among the elderly with EDS (50.1%) and without EDS (39.1%). Elderly with BMI higher than 30 kg/m² presented more prevalence of EDS than those with BMI below this threshold (p = 0.03), being 42.6% of obese people, which means 2.5 times more risk of developing EDS. The increased or substantially increased cardiovascular dysfunction was associated with the occurrence of EDS: elderly with EDS had 2.07 times more chances of having cardiovascular risk.

After gender adjustment, it was observed that depression is a variable associated with EDS only among men [11 (78.6%) and 9 (21.4%); p = 0.005], being depression 3.6 times more prevalent among the elderly with EDS (Table 3). Women presented relationship between obesity and occurrence of EDS [16 (42.1%); p = 0.01]. The increased or substantially increased waist circumference was associated with EDS only among male participants [16 (57.1%); p = 0.02] (Tabela 3).

Age group adjustment (data not shown) revealed association between overweight [7 (41.2%)] and obesity [10 (62.5%)] and EDS among the elderly women aged from 70 to 79 years old (p = 0.02); age group had no influence on the other found associations.

Discussion

In this study, male elderly participants with depression and increased waist circumference had more prevalence of EDS. Elderly obese women were associated with EDS only for the age group of 70 - 79 years old. In this population study with elderly people living in a country city of Northeast Brazil, it was possible to find: high prevalence of depression, overweight/obesity and increased waist circumference, which are known as a risk factor for cardiovascular disease¹⁵15. Sarno F, Monteiro CA. Importância relativa do índice de massa corporal e da circunferência abdominal na predição da hipertensão arterial. Rev Saúde Pública 2007; 41(5): 788-96..

EDS is a public health issue. This condition is an independent risk factor for morbidity and mortality resulting from cardiovascular disease⁹9. Empana JP, Dauvilliers Y, Dartigues JF, Ritchie K, Gariepy J, Jouven X, et al. Excessive daytime sleepiness is an independent risk indicator for cardiovascular mortality in community-dwelling elderly: the three city study. Stroke 2009; 40(4): 1219-24., as well as general mortality²³23. Gooneratne NS, Richards KC, Joffe M, Lam RW, Pack F, Staley B, et al. Sleep disordered breathing with excessive daytime sleepiness is a risk factor for mortality in older adults. Sleep.2011; 34(4): 435-42.. There are reports that both the reduction and the excessive sleep can increase the risk of mortality due to cardiovascular disease⁸8. Sabanayagam C, Shankar A. Sleep duration and cardiovascular disease: results from the National Health Interview Survey. Sleep 2010; 33(8): 1037-42. ^{, 10}10. Ikehara S, Iso H, Date C, Kikuchi S, Watanabe Y, Wada Y, et al. Association of sleep duration with mortality from cardiovascular disease and other causes for Japanese men and women: the JACC study. Sleep 2009;32(3): 295-301.. In this study, the increased circumference, which is an indirect measurement of the risk for cardiovascular dysfunction, was associated with EDS, and was observed only among male participants.

Depression was considered as the main public health problem among the elderly¹⁷17. Chapman DP, Perry GS. Depression as a major component of public health for older adults. Prev Chronic Dis 2008; 5(1): A22.. Duarte and Rego³⁰30. Duarte MB, Rego M. Comorbidade entre depressão e doenças clínicas em um ambulatório de geriatria. Cad Saúde Pública 2007; 23(3): 691-700. found a 23.4% prevalence of depression among the interviewed elderly, while Oliveira, Gomes and Oliveira³¹31. Oliveira DAAP, Gomes L, Oliveira RF. Prevalência de depressão em idosos que frequentam centros de convivência. Rev Saúde Pública 2006; 40(4): 734-36. observed the occurrence of depression in 31% of the elderly attending community centers. The association between depression and EDs has been previously reported¹²12. Chellappa SL, Araújo JF. Excessive daytime sleepiness in patients with depressive disorder. Rev Bras Psiquiatr. 2006; 28(2): 126-9. ^{, 18}18. Jaussent I, Bouyer J, Ancelin ML, Akbaraly T, Pérès K, Ritchie K, et al. Insomnia and daytime sleepiness are risk factors for depressive symptoms in the elderly. Sleep 2011; 34(8): 1103-10., even though Calati et al.¹³13. Calati R, Gaspar-Barba E, Cruz-Fuentes CS, Nenclares A, Jimenez-Genchi A, Ronchi DD, et al. Excessive daytime sleepiness in depressed women. Psychiatry Res 2010; 179(2): 171-5. did not observe significant frequency of depression among women with EDS. However, in their study, the analyzed women had mean age of 34.17 ± 11.37 years old. Bixler et al.⁴4. Bixler EO, Vgontzas AN, Lin HM, Vela-Bueno A, Calhoun SL, Kales A. Excessive daytime sleepiness in a general population sample : the role of sleep apnea, age, obesity, diabetes, and depression. J Clin Endocrinol Metab 2005; 90(8): 4510-5. investigated a general population sample and concluded that depression is the main factor associated with EDS. Lessov-Schlaggar et al.¹¹11. Lessov-Schlaggar CN, Bliwise DL, Krasnow RE, Swan GE, Reed T. Genetic association of daytime sleepiness and depressive symptoms in elderly men. Sleep 2008; 31(8): 1111-7. studied elderly twins in the United States and observed an association between depression and EDS only among men. The authors believe that this superposition is owed to genes that determine both dysfunctions. The authors in this study do not entirely agree with this explanation, since there is great interaction between genes and environmental factors; many times, genes are only active in specific circumstances of the environment, which is called norms of reaction, in genetics³¹31. Oliveira DAAP, Gomes L, Oliveira RF. Prevalência de depressão em idosos que frequentam centros de convivência. Rev Saúde Pública 2006; 40(4): 734-36..

Depression is the most frequent mood disorder among the elderly, affecting especially women²⁹29. Gallo PR. Comparação dos indicadores de adiposidade escore Z do IMC, circunferência abdominal e razão cintura/altura na identificação de alterações cardiometabólicas [dissertação de mestrado]. São Paulo: Faculdade de Saúde Pública da USP; 2011. , considering the negligence in self-care, lack of self-esteem and worsening of pre-existing conditions. One of the most prominent symptoms of depression is insomnia, which can lead to EDS. However, Jaussent et al.¹⁸18. Jaussent I, Bouyer J, Ancelin ML, Akbaraly T, Pérès K, Ritchie K, et al. Insomnia and daytime sleepiness are risk factors for depressive symptoms in the elderly. Sleep 2011; 34(8): 1103-10. considered EDS and insomnia as independent risk factors for depression.

Some authors report that obesity and EDS can be a result of the reduced quantity and efficiency of sleep⁶6. Vorona RD, Winn MP, Babineau TW, Eng BP, Feldman HR, Ware JC, et al. Overweight and obese patients in a primary care population report less sleep than patients with a normal body mass index. Arch Intern Med 2005; 165(1): 25-30. ^{, 19}19. Theorell-Haglöw J, Berne C, Janson C, Sahlin C, Lindberg E. Associations between short sleep duration and central obesity in women. Sleep 2010; 33(5): 593-8., and such variables are not analyzed in this study. Watson et al.³²32. Lewontin RC. A tripla hélice - gene, organismo e ambiente. São Paulo: Companhia das Letras; 2002. studied twins with different lifestyles and observed that obesity was secondary to decreasing sleeping hours. Sleep restriction can lead to the decreased metabolism of sugars, and also change the sensation of satiety, causing obesity³²32. Lewontin RC. A tripla hélice - gene, organismo e ambiente. São Paulo: Companhia das Letras; 2002.. This is a possible explanation for the increased prevalence of obesity and increased abdominal circumference in people with EDS.

In this study, the increased BMI linearly followed the increased proportion of EDs cases, especially among obese people (Table 2). This association occurred in women with obesity (Table 3). These data are in accordance with the results by Bixler et al.⁴4. Bixler EO, Vgontzas AN, Lin HM, Vela-Bueno A, Calhoun SL, Kales A. Excessive daytime sleepiness in a general population sample : the role of sleep apnea, age, obesity, diabetes, and depression. J Clin Endocrinol Metab 2005; 90(8): 4510-5., who state that depression and obesity are usually present in cases of EDS when adjusted to gender, educational level and income. Carmelli et al.²⁰20. Carmelli D, Cliwise DL, Swan GE, Reed T. genetic factors in self-reported snoring and excessive daytime sleepiness: a twin study. Am J Respir Crit Care Med 2001; 164(6): 949-52. concluded there is genetic relationship between obesity and EDS among women. On the contrary, Ng and Tan³⁴34. Ng TP, Tan WC. Prevalence and determinants of excessive daytime sleepiness in an Asian multi-ethnic population. Sleep Med 2005; 6(6): 523-9. show that the increased BMI does not increase the chances of EDS, even with odds ratio of 1.43 (0.99 - 2.04).

The relationship between EDS and the variables depression, obesity and risk of cardiovascular disease still seems to be unknown in literature, and some researchers treat them as predictive factors⁵5. Patel SR, Blackwell T, Redline S, Ancoli-Israel S, Cauley JA, Hillier TA, et al. The association between sleep duration and obesity in older adults. Int J Obes (Lond) 2009; 32(12): 1825-34. ^{, 7} 7. Günes Z, Sahbaz M, Tugrul E, Günes H. Prevalence and risk factors for excessive daytime of sleepiness in rural western Anotolia (Turkey): the role of obesity and metabolic syndrome. Southeast Asian J Trop Med Public Health 2012; 43(3): 747-55.of EDs, while others see them as consequences of EDS⁶6. Vorona RD, Winn MP, Babineau TW, Eng BP, Feldman HR, Ware JC, et al. Overweight and obese patients in a primary care population report less sleep than patients with a normal body mass index. Arch Intern Med 2005; 165(1): 25-30. ^{, 9}9. Empana JP, Dauvilliers Y, Dartigues JF, Ritchie K, Gariepy J, Jouven X, et al. Excessive daytime sleepiness is an independent risk indicator for cardiovascular mortality in community-dwelling elderly: the three city study. Stroke 2009; 40(4): 1219-24.. Due to the type of sectional design adopted in this study, the relationship of causality between EDS and obesity, risk for cardiovascular disease and depression cannot be confirmed yet. However, it is possible to observe there is an association between EDS and the aforementioned variables, being the gender of the individual a possible confusion variable of the studied relationships, which is not verified for the age group variable.

Conclusion

In the studied sample of elderly people, an association between EDS and depression was found only among men, and such a fact was also verified between EDS and risk for cardiovascular disease. On the other hand, EDs and obesity showed to be related only among women aged from 70 to 79 years old. It was also observed that the gender of the studied elderly was a confusion variable, which was not true for the age group variable. Therefore, the relationship between EDS and depression, obesity and risk for cardiovascular disease is not the same for elderly men and women.

References

Publication Dates

History