Table 3. Characteristics of included studies.

T2D: type 2 diabetes; OSA: obstructive sleep apnea; QOL: quality of life; PMB: portable multibiomedical; CPAP: continuous positive airway pressure; DM2: diabetes mellitus type 2; EB: emotional burden; SpO2: oxygen saturation.

No.	Author and year	Aim	Design	Population	Findings
1	Lee et al. (2023) [1]	How Asians' levels of sleep duration and the onset of diabetes were affected by their age, sex, and obesity.	Epidemiology study	Asians	The impact of sleep deprivation on the chance of developing T2DM during the length of the 16-year follow-up. Men and young, non-obese adults were the only ones who had this effect.
2	Bironneau et al. (2017) [2]	This cross-sectional study set out to find out whether patients with T2D have worse endothelial function as their OSA severity increases.	Cross-sectional	140 patients	Although moderate to severe obstructive sleep apnea (OSA) is relatively common, it has little effect on the function of the digital microvascular endothelial cells in T2D patients.
3	Nasir et al. (2022) [3]	To assess the link between quality of life and sleep in individuals with type 2 diabetes mellitus (T2DM), as well as its associated characteristics.	Cross-sectional	350 participants	According to this study, 32% of the population under study has poor sleep quality. Poor sleep quality is strongly correlated with nocturia, restless legs syndrome, and the EB component of type 2 diabetes (T2DM) discomfort.
4	Lou et al. (2012) [4]	The relationship between self-reported sleep length, sleep quality, and the prevalence of diabetes in an adult Chinese sample taken today.	Cross-sectional	Chinese adults	Short sleep length (6 hours) and poor sleep quality were both linked to a higher prevalence of diabetes, with higher rates among generally healthy Chinese individuals.
5	Hashimoto et al. (2020) [5]	The relationship between type 2 diabetes (T2D) patients' quality of life (QoL) and the sleep symptoms that lead to sleep disorders.	Cross-sectional	342 people with T2D	According to this study, sleep difficulties affect two-thirds of T2D patients. People who experienced frequent restroom breaks or excessive daytime sleepiness had a significantly lower quality of life than those who did not experience these symptoms.
6	Jain et al. (2017) [6]	Inpatients with type 2 diabetes will have their QOL and its factors evaluated as part of this cross-sectional comparative study.	Cross-sectional	50 patients	Patients with T2DM had lower QOL. The QOL of these patients is negatively impacted by a number of illness features. Regular sleeplessness may cause the QOL to further decline.
7	Lou et al. (2015) [7]	The purpose of this study is to examine sleep quality and quality of life in Chinese patients with type 2 diabetes mellitus (T2DM) and to evaluate the link between sleep quality and quality of life.	Cross-sectional	China adult	In T2DM, poor sleep is common and negatively correlated with quality of life. To improve diabetes patients' sleep quality, primary healthcare providers must incorporate sleep-related knowledge into diabetes self-management programs.
8	Li et al. (2016) [8]	The PMB recorder throughout a 24-hour period to examine how little sleep affects the blood pressure of people who put in a lot of extra work.	Cross-sectional	18 male	Lack of sleep may cause the sympathetic nervous system to become more active the next day, raising blood pressure. The PMB recorder proved effective for accurately assessing the association between ambient influences and blood pressure.
9	Ohkuma et al. (2013) [10]	The connection between type 2 diabetic patients' glucose levels, obesity, and sleep length.	Cross-sectional	4,870 Japanese	Independent of any relevant confounders, it has been demonstrated that sleep duration has a U-shaped relationship with obesity and HbA1c levels in type 2 diabetic patients. As a result, it may be a key modifiable component in the clinical care of these patients.
10	Martínez-Cerón et al. (2016) [9]	In patients with poorly controlled type 2 diabetes and OSA, the effect of CPAP on glycated hemoglobin (HbA1c) levels should be evaluated, and its causes should be determined.	Randomized clinical trial	50 patients	Compared to findings for a control group, continuous positive airway pressure (CPAP) therapy for six months improved glycemic control and insulin resistance in patients with poorly managed type 2 diabetes and OSA.
11	Gabryelska et al. (2021) [11]	The goal of the study was to evaluate how OSA patients' nocturnal oxygen saturation characteristics affected the emergence of DM2.	Cross-sectional	549 participants	While basal O2 is independent of apnea-hypopnea index (AHI), body mass index (BMI), and age as a predictor of DM2 in OSA patients, higher SpO2 nadir and basal SpO2 are connected with a delayed onset of DM2 in these patients.