Diabetes and Daytime Sleeping: Systematic Review

Background: The relationship between sleep disturbance and diabetes is dual-sided. Chronic sleep disturbance increases the chance of developing insulin resistance, while diabetes reduces sleep quality. Objective: To address the aspects of insufficient sleep, diabetes mellitus, and their mutual interactions and interlinkages. The main objectives is to address the role and effect of diabetes on sleep. Methods: systematic review. A systematic search was done in PubMed, MEDLINE through Clarivate, Web of Science through Clarivate, and EBSCO. Studies retrieved were managed in Rayyan–Intelligent systematic reviews website for duplicate removal and screening. Results: DM is one of the most widespread illnesses in the world. In addition to directly disrupting sleep due to nocturia, polyuria, diabetic neuropathy, and neuropathy pain, DM has also been linked to a number of chronic illnesses, including obstructive sleep apnea, cardiovascular issues, hypertension, cerebrovascular accidents, and depression, all of which can lower quality of life and negatively affect sleep. The patient may not bring the sleep issues during their visit to healthcare providers, with acute issues taking precedence during their visit. Conclusion: DM causes night sleep disturbances which eventually lead to daytime sleeping. Sleep education should be considered an essential part in the diabetic management armamentarium.


INTRODUCTION
"Diabetes mellitus is defined by chronic hyperglycemia caused by a malfunction in carbohydrate, lipid, and protein metabolism" [1]. "Type 2 diabetes mellitus (T2DM) is the most common type of diabetes, accounting for 90% of cases and impacting over 460 million people worldwide, with forecasts predicting an increase to over 700 million in only 25 years. T2DM is primarily caused by insulin resistance in skeletal muscle, liver, and adipose tissue, which finally leads to pancreatic -cell dysfunction and failure" [2]. "These deficiencies lead to a chronic hyperglycemic condition, which, if addressed, can lead to significant consequences such as macrovascular and microvascular illness. Over the last century, there has been an inverse fall in sleep duration, mirroring the secular rise in T2DM" [3].
"Sleep is important for regulating many physiologic functions that relate to metabolism. Because of this, there is substantial evidence to suggest that sleep habits and sleep disorders are related to diabetes risk" [4].
"Sleep deprivation and diabetes have a two-way link. Chronic sleep disruption increases the risk of developing insulin resistance, while diabetes reduces sleep quality. Sleep disruptions, both qualitative and quantitative, considerably increase the chance of acquiring diabetes. When considering the quantitative element, it should be noted that both short and long durations of sleep are related with a higher prevalence of diabetes, with 7-8 h per day posing the lowest risk, albeit the underlying mechanisms and causes in both scenarios may differ" [5].
"Sleep disturbances are substantially more common in diabetics than in individuals without diabetes. Multiple factors may contribute to insomnia in diabetics, including peripheral neuropathy-related discomfort or pain, restless legs syndrome, periodic limb movements, and rapid changes in blood glucose levels during the night, resulting in hypoglycemic and hyperglycemic episodes, nocturia, and associated depression" [6]. "Diabetes patients have a considerably higher chance of developing depression than their nondiabetic counterparts, and depression is one of the major causes contributing to poor sleep in this population. Furthermore, diabetes has numerous effects on the central nervous system, including changes in neurobehavioral and neurotransmitter functioning, as well as autonomic activities, and can negatively affect endocrine functions, causing sleep problems" [7].

Aim
The purpose of this paper is to discuss the issues of insufficient sleep, diabetes mellitus, and their mutual interactions and interconnections. The primary goal is to investigate the role and impact of diabetes on sleep.

Sample and Study Groups
PubMed and EBSCO Information Services were chosen as the search databases for the publications used within the study, as they are high-quality sources. PubMed is one of the biggest digital libraries on the internet, created by the National Center for Biotechnology Information (NCBI), which is part of the United States National Library of Medicine. Topics concerning the aspects of insufficient sleep, diabetes mellitus, and their mutual interactions and interlinkages. The main objectives is to address the role and effect of diabetes on sleep were used in the making of the article. The founded articles were screened by titles, and reviewing the abstracts.
Inclusion criteria: the articles were selected based on the relevance to the project which should include one of the following topics; 'Diabetes mellitus, Sleep quality, Quality of life, Sleep disturbance, Nocturnal hypoglycemia'.
Exclusion criteria: all other articles which do not have one of these topics as their primary end, or repeated studies, and reviews studies were excluded.

Statistical Analysis
The data will be analysed without the use of any software. The data was extracted using a specified form that included (publication title, author's name, objective, summary, results, and outcomes). To ensure validity and minimise errors, each member's results were doublerevised.
During the article selection process, studies and their results were double-reviewed to ensure that we enrol research related to the purpose of our study and to avoid or reduce inaccuracies in the findings.

RESULTS
Diabetes is one of the most common diseases worldwide. Diabetes, in addition to causing direct sleep disturbances due to nocturia, polyuria, diabetic neuropathy, and neuropathy pain, has been linked to a number of chronic illnesses such as obstructive sleep apnea, cardiovascular complications, hypertension, cerebrovascular accidents, and depression, all of which can affect sleep and quality of life. The patient may not bring up the sleep concerns during their visit to healthcare providers, as urgent issues may take precedence. In the T2D population, the prevalence of sleeplessness (symptoms) is 39%, and it may be connected with poor glycemic management.

DISCUSSION
Clinical studies have revealed that up to onethird of diabetic patients had concomitant sleep problems, compared to 8.2% of non-diabetic controls [16]. "According to a research poll done at the University of Pittsburgh, more than half of type 2 DM patients are likely to report being "bad sleepers." Patients with type 2 diabetes had a higher risk of having a low Pittsburgh Sleep Quality Index (PSQI)" [17]. "(The PSQI is a validated tool for assessing sleep quality and pattern in older persons.) It distinguishes poor sleepers from normal sleepers by examining seven aspects of sleep over a onemonth period)" [17]. Common insomnia characteristics, such as sleep latency and efficiency, are included as measurements in these indexes. The same study discovered that sleep quality was highly linked with other diabetic quality of life measures [18]. Patients with other chronic medical disorders are more likely to develop sleeplessness in general.
Poor sleep and insomnia have been linked to a drop in gamma-aminobutyric acid levels in studies (GABA). Patients with depression had reduced GABA levels as well [19]. "GABA is produced in substantial quantities in the pancreas. It has also been demonstrated to prevent apoptosis in rodent beta cells. The principal enzyme (GAD) involved in the manufacture of GABA, glutamate decarboxylase, has been associated to type 1 diabetes" [20]. When GABA levels are low, it is possible that GABA is one of the neurotransmitters implicated in sleep quality in diabetics.
A Taiwanese study discovered that a lack of sleep was linked to a higher prevalence of diabetes [21]. Another study conducted "in Taiwan discovered that both short and long sleep durations were independently linked with newly diagnosed diabetes" [22]. "A meta-analysis of the dose-response connection between sleep length and the risk of type 2 diabetes showed that those who obtain 7-8 hours of sleep per day have the lowest risk of T2DM, whereas short and long sleep duration are associated with a higher risk of T2DM" [23].
"Subjective sleep disruptions have been recorded in more than one-third of type 2 diabetes patients, which may be due to anxiety about poor blood glucose control and diabetic consequences" [24]. Previous research, however, found an inconsistent connection between perceived sleep disruptions and blood glucose levels. Some studies have found an inverse relationship between subjective sleep disruptions and poor glycemic management in type 2 diabetes patients [25], "while others have found no relationship between subjective sleep disturbances and serum haemoglobin A1c (HbA1c) level as an indicator of glucose status" [26]. Nevertheless, studies that found a link between HbA1c level and poor sleep quality did not properly eliminate or control for major risk factors associated with poor sleep quality [27]. Shankar et al. discovered that "perceived insufficient rest/sleep is independently linked with CVDs, diabetes mellitus, and obesity in a study on perceived insufficient rest included in the Behavioral Risk Factor Surveillance System (BRFSS) of the United States" [28].