ABSTRACT:

Objectives:

The prevalence of sleep problems in elderly, such as insomnia, is a relevant issue in our society. Poor sleep quality is viewed by many as an inevitable result of aging. In this context, this study aimed to estimate the prevalence and associated factors of sleeping disturbances in elderly men and women (60 years and older).

Methods:

The present study is part of SABE Study (Health, Well-being and Aging), a cohort conducted in São Paulo, Brazil. The sample included in the present cross-sectional study comprised 1,334 elderly people aged 60 years or older. Sleep disturbances were assessed based on responses of study participants on whether they had experienced any sleep disturbance in the past month.

Results:

Among the elderly assessed, 44.9% had overall sleep disturbances, which were more frequent in women (51.5%) and in 75 to 79 years old (48.2%). According to the regression analysis, the variables gender, joint diseases, as well as nocturia and urinary incontinence, were associated with sleep disorders. Increase in sleep disturbances was found not to be linearly age-dependent.

Conclusions:

Gender, pain, urinary and nocturia incontinence were factors associated with sleep disorders. Thus, we might conclude that the absence of sleep disturbances in older adults depends on gender and health status.

Keywords:
Sleep; Elderly; Pain; Urinary incontinence

INTRODUCTION

There is consensus about the changes that occur in the characteristics of sleep throughout life¹1. Danker-Hopfe H. Growth and development of children with a special focus on sleep. Prog Biophys Mol Biol. 2011 Dec; 107(3): 333-8.. Its poor quality, experienced by elderly people, is seen by many as an inevitable result of aging. However, although there is a reduction in sleep-wake consolidation among the elderly²2. Geib LTC, Cataldo-Neto A, Wainberg R, Nunes ML. Sono e Envelhecimento. R Psiquiatr. 2003; 25(3): 453-65., the sleep quality in this population should not necessarily be poor. A systematic review by Smagula et al.³3. Smagula SF, Stone KL, Fabio A, Cauley JA. Risk factors for sleep disturbances in older adults: Evidence from prospective studies. Sleep Med Rev. 2015 Jan 15.suggests that chronological age is not an independent predictor of future sleep disorders.

The prevalence of such problems in the elderly, such as insomnia, for example, may lead to impairment of cognition and development of dementia, evidencing the important role of sleep in the decline of cognitive functions in this group⁴4. Yaffe K, Falvey CM, Hoang T. Connections between sleep and cognition in older adults. Lancet Neurol. 2014 Oct; 13(10): 1017-28.. On the other hand, the elderly tend to suffer less from acute sleep deprivation than younger adults. A recent study shows that total sleep duration was more important for cognition in a group of young adults (mean age = 23.1 years) than in older adults (62.7 years). Sleep disruptions, however, were shown to be detrimental to cognitive aspects in both groups⁵5. Wilckens KA, Woo SG, Kirk AR, Erickson KI, Wheeler ME. Role of sleep continuity and total sleep time in executive function across the adult lifespan. Psychol Aging. 2014; 29(3): 658-65..

Changes involving the onset and end times of sleep are expected during aging and do not necessarily indicate problems²2. Geib LTC, Cataldo-Neto A, Wainberg R, Nunes ML. Sono e Envelhecimento. R Psiquiatr. 2003; 25(3): 453-65.. Thus, older people who sleep earlier than other adults may have 7.5 consecutive hours of good quality sleep, and not report poor quality upon awakening⁶6. Lockey S, Foster R. Sleep: a Very Short Introduction. Nova York: Oxford University Press; 2012.. In addition, sleep episodes of nine hours or more were associated with decreased cognitive performance in the elderly⁷7. Malek-Ahmadi M, Kora K, O'Connor K, Schofield S, Coon D, Nieri W. Longer self-reported sleep duration is associated with decreased performance on the montreal cognitive assessment in older adults. Aging Clin Exp Res. 2016..

Although there is consensus about changes in sleep during aging with an impact on quality, especially by increasing the duration of more superficial stages¹1. Danker-Hopfe H. Growth and development of children with a special focus on sleep. Prog Biophys Mol Biol. 2011 Dec; 107(3): 333-8., much remains to be clarified on the subject. In this context, the present study aimed to estimate the prevalence and factors associated with sleep disorders in the elderly of both genders living in the city of São Paulo.

METHODS

The present work is part of the Health, Well-being and Aging Study (SABE).

To assess the sleep quality, participants answered whether or not they had any difficulty in the month prior to the survey. The sample considered for this cross-sectional study consisted of 1,334 elderly individuals aged 60 years and over, living in the city of São Paulo and interviewed in 2010.

The multivariate analysis consisted of the use of Poisson regression with robust estimation, which allows the direct estimation of prevalence ratios (PR)⁸8. Barros AJ, Hirakata VN. Alternatives for logistic regression in cross-sectional studies: an empirical comparison of models that directly estimate the prevalence ratio. BMC Med Res Methodol. 2003; 20: 3-21. by approximation to cumulative incidence ratios. The outcome variable was “sleep difficulty”; the “age” variable was used as an independent variable, in the form of five-year age groups and as the exposure variable, in a continuous form. The number of people per room represents the average number of dwellers divided by the number of rooms. The International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF), validated in Portuguese⁹9. Tamanini JTN, Dambros M, D'Ancona CAL, Palma PCR, Netto Jr. NR. Validação para o português do "International Consultation on Incontinence Questionnaire-Short Form" (ICIQ-SF). Rev Saúde Pública. 2004; 38(3): 438-44., was used to evaluate urinary incontinence (UI).

The original SABE study is in conformity with the principles set out in the Declaration of Helsinki and has received the approval of the respective ethics committees of the countries involved. In Brazil, it was approved by the Research Ethics Committee of the School of Public Health of Universidade de São Paulo and by the National Research Ethics Committee (COEP 83/06, March 14, 2006).

RESULTS

Among the elderly, 44.9% presented difficulties with sleep, being more frequent in the female sex (51.5% of women have difficulties, as well as 34.5% of men) and among the individuals aged75 to 79 years (48.2%). As with age, the average number of people per room was not a factor with a significant repercussion on the difficulty to sleep (Table 1).

We highlight the health problems as statistically significant factors associated with sleep difficulty. Among those complaining of sleep problems, 52.6% had diabetes mellitus (DM), 59.2% had joint diseases and 53.4% mentioned pain or discomfort (p<0.05).

Table 1 shows the distribution of the elderly according to the variables: (1) difficulty sleeping; (2) sociodemographic; and (3) health.

We evaluated the possible collinearity between nocturia and incontinence, although the mean Variance Inflation Factor (VIF) was 1.90 and no variable had VIF>5.00, satisfying the usual criteria for collinearity¹⁰10. Hair Jr. JF, Anderson RE, Tatham RL, Black WC. Multivariate Data Analysis. 3ª ed. Nova York: Macmillan Publishing Company; 1995.. In the sample, both variables were independent (Crammer coefficient=0.04 and Fisher exact test with p=0.149). Thus, nocturia and the UI score were not shown to be associated variables, so they were included in the regression analysis.

Body aches and joint disease were associated with each other (p<0.01), but remained together in the regression analysis because they were collinear. According to this analysis, gender, joint diseases, nocturia and UI were variables associated with difficulty sleeping (Table 2).

DISCUSSION

The present study found a higher prevalence of sleep disorders in women. In fact, the literature shows gender differences for various aspects of health. Longevity may also be associated with greater morbidity, which may lead to sleep disorders among the elderly¹¹11. Oliveira BHD, Yassuda MS, Cupertino APFB, Neri AL. Relações entre padrão do sono, saúde percebida e variáveis socioeconômicas em uma amostra de idosos residentes na comunidade - Estudo PENSA. Ciênc Saúde Coletiva. 2010; 15(3): 851-60.^,1212. Noia AS, Secoli SR, Duarte YAO, Lebrao ML, Lieber NSR. Fatores associados ao uso de psicotrópicos por idosos residentes no Município de São Paulo. Rev Esc Enferm. 2012; 46: 38-43.. In addition, Oliveira et al.¹³13. Oliveira MF, Bezerra VP, Silva AO, Alves MSCF, Moreira MASP, Caldas CP. Sintomatologia de depressão autorreferida por idosos que vivem em comunidade. Ciênc Saúde Coletiva. 2012; 17(8): 2191-98. suggest that the causes of the greatest sleep problems among women are related to their association with stress-related factors, such as family conflicts and a higher incidence of depression. These factors, both isolated and combined, can negatively impact sleep.

In this study, advanced age was not associated with sleep disorders. The group of 80 years or more was a protective factor for these disorders, which may suggest good sleep quality, although it has not been directly evaluated. On the other hand, some studies have mentioned the exact opposite: constant decline in sleep quality with age¹⁴14. Bliwise DL. Normal aging. In: Kryger MH, Roth T, Dement WH, editors. Principles and practice of sleep medicine. Philadelphia: Saunders; 2000. p. 26-42., which does not appear to be linear.

Araújo and Ceolim¹⁵15. Araújo CLO, Ceolim MF. Sleep quality of elders living in long-term care institutions. Rev Esc Enferm USP. 2010; 44(3): 619-26. observed worse sleep quality in individuals aged 70 to 79 years. These authors indicate that quality is more affected by health problems than by chronological age¹⁵15. Araújo CLO, Ceolim MF. Sleep quality of elders living in long-term care institutions. Rev Esc Enferm USP. 2010; 44(3): 619-26.. Corroborating this finding, data from the Health, Aging and Retirement Survey in Europe (2011/2012) show that people aged between 60 and 69 years reported fewer sleep problems than those aged 50 to 59 years.

In addition, in a study conducted by Marquié et al. ¹⁶16. Marquié JC, Folkard S, Ansiau D, Tucker P. Effects of age, gender, and retirement on perceived sleep problems: results from the VISAT combined longitudinal and cross-sectional study. Sleep. 2012; 35: 1115-21., an increase in difficulty was observed both in maintaining sleep and in falling asleep again, as well as increasing the occurrence of early arousal in individuals around 50 years of age. This tendency remained constant, reducing at least in the case of early awakening, around 70 years of age. One of the authors’ explanations is that retirement would have altered the daily routine of individuals to the point of improving sleep quality. Retirement and social isolation seem to be psychosocial characteristics that interfere²2. Geib LTC, Cataldo-Neto A, Wainberg R, Nunes ML. Sono e Envelhecimento. R Psiquiatr. 2003; 25(3): 453-65.^,1717. Menna Barreto L, Wey D. Ontogênese do sistema de temporização - a construção e as reformas dos ritmos biológicos ao longo da vida humana. Psicologia USP. 2007; 18(2): 133-53.. This idea corroborates the hypothesis that social support represents an important strategy to improve the quality in question¹⁸18. Costa SV, Ceolim MF, Neri AL. Problemas de sono e suporte social: estudo multicêntrico Fragilidade em Idosos Brasileiros. Rev Latino-Am Enferm. 2011; 19(4): 9-17..

The association between the health of the elderly and the quality of their sleep has been established in several studies¹¹11. Oliveira BHD, Yassuda MS, Cupertino APFB, Neri AL. Relações entre padrão do sono, saúde percebida e variáveis socioeconômicas em uma amostra de idosos residentes na comunidade - Estudo PENSA. Ciênc Saúde Coletiva. 2010; 15(3): 851-60.. Health problems lead to its reduction and, paradoxically, the use of benzodiazepines as a solution to the difficulty of falling asleep can lead to side and harmful effects¹²12. Noia AS, Secoli SR, Duarte YAO, Lebrao ML, Lieber NSR. Fatores associados ao uso de psicotrópicos por idosos residentes no Município de São Paulo. Rev Esc Enferm. 2012; 46: 38-43.. These substances are also an example of inappropriate drugs for the elderly, according to Beers-Fick¹⁹19. Gorzoni ML, Fabbri RMA, Pires SL. Medicamentos potencialmente inapropriados para idosos. Rev Assoc Med Bras. 2012; 58(4): 442-6. criteria, given the high risk of side effects. Thus, the adoption of medications to improve the quality of sleep in a population that generally uses several others for different problems can generate situations that are more harmful than beneficial.

In a study of healthy older adults who were physically active and exposed to light in the morning, no sleep fragmentation was observed²⁰20. Ceolim MF. Sleep/wake cycle and physical activity in healthy elderly people. Sleep Research Online. 2000; 3(3): 87-95.. The results suggest that fragmentation and other changes are consequences of habits and living conditions, and not a biological factor inherent to aging itself.

In the present study, pain in general and joint pain were associated with difficulty falling asleep, corroborating the literature. It is important to emphasize, however, that due to the transversal character of this work, it is not possible to establish the direction of this association. The reduction of sleep quality has been related to musculoskeletal pain both in adults²¹21. Kundermann B, Krieg JC, Schreiber W, Lautenbacher S. The effect of sleep deprivation on pain. Pain Res Manag. 2004; 9(1): 25-32.^,2222. Smith MT, Haythornthwaite JA. How do sleep disturbance and chronic pain inter-relate? Insights from the longitudinal and cognitive-behavioral clinical trials literature. Sleep Med Rev. 2004; 8: 119-32. and in children and adolescents²³23. Molina J, Dos Santos FH, Terreri MT, Fraga MM, Silva SG, Hilário MO, et al. Sleep, stress, neurocognitive profile and health-related quality of life in adolescents with idiopathic musculoskeletal pain. Clinics. 2012 Oct; 67(10): 1139-44.. Some authors suggest that pain can lead to poor sleep quality in the same way that it leads to an increase in the perception of other daily stressors, due to the greater sensitivity caused by the painful state²³23. Molina J, Dos Santos FH, Terreri MT, Fraga MM, Silva SG, Hilário MO, et al. Sleep, stress, neurocognitive profile and health-related quality of life in adolescents with idiopathic musculoskeletal pain. Clinics. 2012 Oct; 67(10): 1139-44.^,2424. Graham JE, Streitel KL. Sleep quality and acute pain severity among young adults with and without chronic pain: the role of biobehavioral factors. J. Behav Med. 2010; 33(5): 335-45..

In summary, in view of the results obtained in this study, it is observed that there is also an association between pain and sleep difficulties in this age, as in children, adolescents and young adults. On the other hand, a characteristic of the elderly is the occurrence of UI, which presents itself as involuntary urine loss and, when present in women, has a negative effect on the quality of sleep²⁵25. Fonseca DC, Galdino DAA, Guimarães LHCT, Alves DAG. Avaliação de qualidade do sono e sonolência excessiva diurna em mulheres idosas com incontinência urinária. Rev Neurocienc. 2010; 18(3): 294-9., which may contribute to a higher prevalence of sleep difficulty in the female sex. It is worth noting, however, that, although less prevalent, UI also occurs in men²⁶26. Blanes L, Pinto RTC, Santos VLCG. Urinary incontinence: Knowledge and attitudes in São Paulo. Braz J Urol. 2001; 27(3): 281-8.. Regardless of gender, it was associated with difficulty falling asleep in the elderly participants of this study. Other studies have shown that behavioral changes such as avoiding excessive fluid before bedtime and minimizing caffeine and citrus fruits due to the bladder irritant effect reduce UI²⁷27. Honório MO, Santos SMA. Incontinência Urinária: impacto no cotidiano e na qualidade de vida. Rev Bras Enferm. 2009; 62(1): 51-6. and consequently improve sleep quality.

CONCLUSION

The difficulty in falling asleep in elderly residents of the city of São Paulo, participants of this study, is related to female sex, joint diseases, UI and nocturia. Thus, promoting the health of the elderly is the first step towards improving their quality of sleep.

References

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