آزمون روابط دو طرفه بین کیفیت زناشویی و اختلال در خواب: یک مطالعه پیگیری 4 ساله در یک گروه کره ای

Objective Both poor marital quality and sleep disturbances are risk factors for a broad range of mental and physical health morbidities. The purpose of the study was to investigate bidirectional relationships between marital quality and sleep disturbance and the moderating effects of age and gender. Methods Data from 1081 married individuals who participated in the Korean Genome and Epidemiology Study were analyzed. A marital quality questionnaire and the Pittsburgh Sleep Quality Index were used to assess marital quality and sleep disturbances at baseline and 4-year follow-up. Relevant covariates including sociodemographics, health status, health behaviors, and depressive symptoms were also measured. Results Hierarchical multiple regression models revealed that there was a significant interaction between marital quality and age predicting sleep disturbance (P = .017). While there was no association between marital quality and sleep disturbances for the younger group (ages 45–54; n = 680), persons with lower marital quality were more likely to have greater sleep disturbances 4 years later for the older group (ages 55–74; n = 401). By contrast, sleep disturbance was a significant predictor of marital quality 4 years later, regardless of age or gender (P = .025). Conclusion Poor marital quality is a risk factor for sleep disturbance for older adults but not for middle-aged individuals. In turn, sleep disturbance may lead to lower marital quality for all age groups. Clinicians should be aware of the bidirectional relationships between marital and sleep problems for more effective treatments for both.

It has been well documented that marital quality contributes not only to one's mental health outcomes, including depression and anxiety, but also to various physical health outcomes [1], [2] and [3]. Sleep, a major health behavior, also has critical implications for health, from various psychiatric conditions, such as depression and substance abuse [4] to physical health conditions, such as cardiovascular and metabolic diseases [5] and [6]. Thus, both marital and sleep problems are risk factors for a broad range of mental and physical health morbidities. Furthermore, an emerging body of literature has indicated that marital quality and sleep disturbances are closely linked to one another, affecting health and well-being [7]. Most married individuals sleep with their partners and people with low marital quality can be vulnerable to sleep disturbances [8], [9] and [10]. Sense of security and emotional down-regulation are essential for a good night's sleep. However, marital relationships evaluated as low quality often induce negative mood and high alertness, which may contribute to poor sleep [11]. Conversely, individuals with sleep difficulties may be at greater risk for low marital quality [12] and [13]. That is, people with disturbed sleep often exhibit high irritability and low tolerance for negative stimuli, which in turn can promote conflictual interactions between partners [14]. Recently, a conceptual framework linking marital quality and sleep via biopsychosocial pathways has been proposed [7]. According to this model, marital functioning and sleep may have a reciprocal relationship through chronobiological (e.g., sleep–wake cycle) [15], behavioral (e.g., physical activity and substance use) [16], psychological (e.g., psychological distress, depression, and anxiety) [4], [11] and [14], and physiological (e.g., hypothalamic–adrenal–pituitary axis, autonomic nervous system, and inflammation processes) [17] and [18] mechanisms. This model also posits moderating effects of various vulnerability factors such as personality, psychiatric disorders, socioeconomic status, and gender on the relationship between marital quality and sleep [2], [4], [11], [19] and [20]. More recently, this conceptual framework has been expanded to include the impact of the covariation between marital functioning and sleep on mental and physical health through various physiological pathways [21]. Although reciprocal relationships between marital quality and sleep have been implicated by this model, clear inferences on bidirectional associations have not been possible due to lack of longitudinal data and direct tests of bidirectionality within a sample. Recently, a couple of studies attempted to provide some direct evidence for the bidirectional nature of the relationship between sleep and marital quality. In a study of 29 couples, Hasler and Troxel [22] tested whether sleep efficiency predicted the marital interactions the following day and vice versa for 7 days, and the results showed gender-specific effects. While poor sleep predicted more negative marital interactions for males only, increased negative marital interactions predicted lower sleep efficiency for females only. Rauer and Elsheikh [23] provided a different perspective focusing on physical and psychological abuse between marital partners. In 215 couples with school-aged children, they found that both husbands and wives with sleep disturbance were more likely to engage in psychological abuse toward their partners 11 months later. However, the level of partner violence did not predict later sleep disturbance, for which they did not provide any plausible explanations. These studies have provided some novel preliminary data and invaluable insights on directionality of the relationships between sleep and marital functioning. However, the inconsistent findings within and between studies, small sample sizes, and short follow-up durations call for further studies with a larger sample and with a longer follow-up duration. The current study utilized data from a community-based epidemiological study with a 4-year follow-up duration to determine directionality of the relationship between sleep disturbances and marital quality. Substantially longer follow-up duration of 4 years, compared to days or months from previous studies, allowed us to examine long-term effects of more persistent sleep and marital problems. Based on the theoretical framework proposed by Troxel et al. [7] and [21], we hypothesized that lower levels of marital quality would predict higher levels of sleep disturbances 4 years later. We also hypothesized that the reverse relationship would be true; higher levels of sleep disturbances would predict lower levels of marital quality 4 years later. In addition, we tested moderating effects of gender on the relationships between marital quality and sleep. Although it has been suspected that the links between relationship functioning and sleep quality may be stronger for women than men due to women's greater sensitivity to both marital and sleep problems [2] and [24], there have been no studies directly testing this hypothesis. Age was also explored as a moderator. Marital quality in older couples may influence sleep differently in comparison with younger couples, as many aspects of the aging process lead to changes in sleep [25]. With a wider range of age (45 to 74 years) compared with previous studies, the current study tested differences between middle-aged (age range 45–54) versus older adults (age range 55–74) in the relationship between marital quality and sleep disturbances. We chose 55 as the age cut-off to reflect the average retirement age for Korean men [26], and other life course events (i.e., children leaving the household) that may affect one's marital dynamics as well as the pattern and quality of sleep [25] and [27]. Retirement and experiencing empty nest syndrome often lead to feelings of loss and distress, and require individuals to adjust to new daily routines and couples to renegotiate their marital roles [28]. Examining bidirectional relationships between marital quality and sleep disturbances may contribute to a better understanding of mechanisms linking close relationship functioning with mental and physical health outcomes. Furthermore, identifying vulnerable populations for marital and sleep problems may have implications for clinical practices.