Elevated obstructive sleep apnoea risk score is associated with poor healing of diabetic foot ulcers: a prospective cohort study

Prognostic factors for delayed healing of complex wounds in adults: A scoping review

Complex or hard-to-heal wounds continue to be a challenge because of the negative impact they have on patients, caregivers, and all the associated costs. This study aimed to identify prognostic factors for the delayed healing of complex wounds. Five databases and grey literature were the sources used to research adults with pressure ulcers/injuries, venous leg ulcers, critical limb-threatening ischaemia, or diabetic foot ulcers and report the prognostic factors for delayed healing in all care settings. In the last 5 years, a total of 42 original peer-reviewed articles were deemed eligible for this scoping review that followed the JBI recommendations and checklist PRISMA-ScR. The most frequent prognostic factors found with statistical significance coinciding with various wound aetiologies were: gender (male), renal disease, diabetes, peripheral arterial disease, the decline in activities of daily life, wound duration, wound area, wound location, high-stage WIfI classification, gangrene, infection, previous ulcers, and low ankle brachial index. It will be essential to apply critical appraisal tools and assessment risk of bias to the included studies, making it possible to make recommendations for clinical practice and build prognostic models. Future studies are recommended because the potential for healing through identification of prognostic factors can be determined, thus allowing an appropriate therapeutic plan to be developed.

The role of microRNAs in pathophysiology and diagnostics of metabolic complications in obstructive sleep apnea patients

Obstructive sleep apnea (OSA) is one of the most common sleep disorders, which is characterized by recurrent apneas and/or hypopneas occurring during sleep due to upper airway obstruction. Among a variety of health consequences, OSA patients are particularly susceptible to developing metabolic complications, such as metabolic syndrome and diabetes mellitus type 2. MicroRNAs (miRNAs) as epigenetic modulators are promising particles in both understanding the pathophysiology of OSA and the prediction of OSA complications. This review describes the role of miRNAs in the development of OSA-associated metabolic complications. Moreover, it summarizes the usefulness of miRNAs as biomarkers in predicting the aforementioned OSA complications.

The association between obstructive sleep apnoea and wound healing: a systematic review

Purpose

Obstructive sleep apnoea (OSA) is a common, significantly underdiagnosed sleep-related breathing disorder, characterised by upper airway collapse and resultant intermittent hypoxia. Oxygen plays an important role in collagen synthesis and as a result in wound healing. An association between OSA and wound healing has not been clearly delineated. A systematic review was performed to understand this association.

Methods

Randomised controlled trials, cohort, cross-sectional and case–control studies evaluating the relationship between OSA or OSA-related symptoms and wound healing in adult populations were searched in the systematic review using electronic databases PubMed, EMBASE and Ovid MEDLINE.

Main results

A total of 11 cohort studies and 1 case–control study with a total of 58,198,463 subjects were included. Most studies suggest that patients diagnosed with OSA or who are at high risk of having OSA are more likely to suffer from wound complications. Patients with OSA have been found to be at higher risk for post-operative wound infection and wound dehiscence. Contradictory results were obtained on time to heal, with one study concluding that individuals with OSA were more likely to heal earlier when compared to patients without OSA. Quality of evidence, however, was deemed very low due to high risk of bias.

Conclusions

This systematic review did identify an association between OSA and wound healing. However, due to the very low-quality evidence, further research is warranted to better characterise this association and investigate whether or not treating OSA can indeed affect wound healing.

Does Obstructive Sleep Apnoea Syndrome Influence the Development and Treatment of Diabetic Foot? A Brief Narrative Review

Both obstructive sleep apnoea syndrome (OSAS) and diabetes mellitus (DM) are common conditions that often coexist and share many similar risk factors. Diabetic foot is a common complication of DM, which may lead to lower-limb amputation. OSAS is considered a risk factor for type 2 DM (T2DM). There is also evidence that OSAS may be linked with the development, as well as the healing of diabetic foot. Multiple mechanisms triggered by sleep fragmentation and intermittent hypoxaemia in OSAS could contribute to the development of diabetic foot ulcers (DFUs). More interestingly, emerging evidence implies a favourable impact of continuous positive airway pressure (CPAP) treatment on DFU healing. Healing DFUs and minimising recurrence rates remains a challenge for health care professionals. In this context, management of OSAS might prove a useful therapeutic adjunct for DFUS. However, data is still limited and randomised controlled trials are needed to further explore this interesting potential.

Advances in the study of OSA and diabetic foot

Diabetic foot is one of the most serious and painful chronic complications of diabetic patients, especially elderly diabetic patients. It has a high rate of death, disability and amputation. Obstructive sleep apnea (OSA) is a treatable chronic sleep disorder. Existing evidence suggests that OSA may promote the development and delay the healing of diabetic foot, and continuous positive airway pressure therapy may promote the healing of ulcers. Therefore, in the multidisciplinary diagnosis and treatment of diabetes, cooperation with sleep medicine should be strengthened, and the basic and clinical research on diabetic foot combined with OSA should be strengthened, so as to reduce the amputation rate, improve the cure rate and reduce the incidence of cardiovascular events.

Severe Intermittent Hypoxia Modulates the Macrophage Phenotype and Impairs Wound Healing Through Downregulation of HIF-2α

BACKGROUND

Obstructive sleep apnea is prevalent in patients with diabetic foot ulcers, while the effect of intermittent hypoxia on wound healing is unclear. The objective of this study was to investigate the effect of severe intermittent hypoxia on wound healing.

METHODS

C57BL/6 mice were exposed to 5 weeks of severe intermittent hypoxia or normoxia. The wound healing rate were assessed. The gene expression of CD206 and HIF-2α was tested in vivo and in vitro. Inflammatory factors in RAW264.7 macrophages were measured to investigate the effect of intermittent hypoxia on macrophage polarization. The proliferation of HUVECs and HaCaT cells was also assessed after exposure to intermittent hypoxia.

RESULTS

Severe intermittent hypoxia decreased wound healing at day 3. The expression of CD206 and HIF-2α was significantly decreased after exposure to severe intermittent hypoxia. In vitro, severe intermittent hypoxia significantly promoted M1 phenotype polarization of RAW264.7 macrophages and increased the expression of proinflammatory factors (IL-1β and TNF-α). Severe intermittent hypoxia also decreased the proliferation of HUVECs cultured in endothelial cell medium and HaCaT cells cultured in high glucose DMEM.

CONCLUSION

Severe intermittent hypoxia could lead to M1 but not M2 macrophage polarization through downregulation of HIF-2α, and then lead to impaired wound healing.

Obesity and Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is characterized by upper airway collapse during sleep. Chronic intermittent hypoxia, sleep fragmentation, and inflammatory activation are the main pathophysiological mechanisms of OSA. OSA is highly prevalent in obese patients and may contribute to cardiometabolic risk by exerting detrimental effects on adipose tissue metabolism and potentiating the adipose tissue dysfunction typically found in obesity. This chapter will provide an update on: (a) the epidemiological studies linking obesity and OSA; (b) the studies exploring the effects of intermittent hypoxia and sleep fragmentation on the adipose tissue; (c) the effects of OSA treatment with continuous positive airway pressure (CPAP) on metabolic derangements; and (d) current research on new anti-diabetic drugs that could be useful in the treatment of obese OSA patients.

Is There an Association between Sleep Disorders and Diabetic Foot? A Scoping Review

Diabetic foot is associated with a low quality of life since physical disabilities, mood disturbances and psychological disorders are frequent. One of the most important biological processes to ensure quality of life is sleep. Sleep disorders can impair glycemic control in patients with diabetes mellitus or even cause long-term type 2 diabetes mellitus. The aim of this study is to carry out a scoping review about the association between sleep cycle disorders and diabetic foot. PubMed, Scopus, CINAHL, PEDro, Cochrane Library, SCIELO and EMBASE databases were chosen for the search and the following terms were used: "diabetic foot","sleep*","rest-activity","mood" and"behavior". All the studies should include outcome variables about sleep and diabetic foot. Finally, 12 articles were selected, all of whichwere observational. The most frequent variables were those regarding diabetic foot ulcer aspects and diabetic neuropathy on one side, and obstructive sleep apnea, sleep duration and sleep quality on the other side. The results suggest that there is a possible association between obstructive sleep apnea and the presence or history of diabetic foot ulcers. No direct associations between sleep quality or sleep duration and diabetic foot or diabetic foot ulcer variables have been found.

Association of sleep-disordered breathing and wound healing in patients with diabetic foot ulcers

STUDY OBJECTIVES

Sleep-disordered breathing (SDB) is prevalent and associated with an increased risk of morbidity and mortality. However, whether SDB has an adverse impact on wound healing in patients with diabetic foot ulcers (DFUs) is uncertain. The purpose of this study was to investigate the association of SDB with wound healing in patients with DFUs.

METHODS

A total of 167 patients with DFUs were enrolled between July 2013 and June 2019 at West China Hospital (Chengdu, China) to assess the association of SDB with wound healing, ulcer recurrence, and all-cause mortality.

RESULTS

Whereas there was no significant association between apnea-hypopnea index (AHI) and wound healing, total sleep time (per hour: hazard ratio [HR], 1.15; 95% confidence interval [CI], 1.01-1.30; P = .029), sleep efficiency (per 10%: HR, 1.20; 95% CI, 1.04-1.37; P = .012), and wakefulness after sleep onset (per 30 minutes: HR, 0.89; 95% CI, 0.82-0.97; P = .008) were associated with wound healing. Total sleep time (per hour: odds ratio, 0.71; 95% CI, 0.51-0.97; P = .035) and sleep efficiency (per 10%: odds ratio, 0.68; 95% CI, 0.47-0.97; P = .033) were also associated with ulcer recurrence. Mean oxygen saturation (per 3%: HR, 0.68; 95% CI, 0.49-0.94; P = .021) and percentage of sleep time with oxygen saturation < 90% (per 10%: HR, 1.25; 95% CI, 1.03-1.53; P = .026) were significantly associated with mortality.

CONCLUSIONS

SDB is highly prevalent in patients with DFUs but its severity, as conventionally measured by AHI, is not associated with wound healing. Sleep fragmentation and hypoxemia are stronger predictors of poor wound healing, high ulcer recurrence, and increased risk of death in patients with DFUs.

Improvements in Sleep Quality Are Maintained at a Minimum of 2 Years Following Hip Arthroscopy for Femoroacetabular Impingement Syndrome

PURPOSE

To present the results of a mid-term follow-up study on sleep quality at a minimum of 2 years after hip arthroscopy for femoroacetabular impingement syndrome.

METHODS

Original inclusion criteria were consecutive patients undergoing primary hip arthroscopy for cam/pincer correction between March 1, 2017, and July 1, 2017, who did not respond to nonoperative management, whereas exclusion criteria were revision arthroscopy, gluteus medius repair, contralateral procedure during the follow-up period, and known sleep disorders. Patients who had followed up at 6 months were contacted at a minimum of 2 years following their surgery. In total, 37 of 55 (67.3%) were available for follow-up. New Pittsburgh Sleep Quality Index (PSQI) scores were obtained and compared with previously reported scores at preoperative and 6-month time points. The PSQI ranges from 0 to 21, with a score of ≥5 indicating poor sleep quality. Point biserial correlations and χ² tests of associations were used to investigate associations between demographics, preoperative patient-reported outcome measures, and the incidence of poor sleep quality at 2 years postoperatively.

RESULTS

Preoperatively, 94.5% of patients (52/55) had a PSQI of ≥5 with a mean PSQI score of 9.8 ± 4.2. Statistically significant improvements were observed at both 6 (PSQI: 2.2 ± 0.2, P < .001) and 24 months (PSQI: 4.3 ± 3.9) postoperatively compared to baseline (P < .001, both). The mean PSQIs at 2 years and 6 months postoperatively were not statistically different (P = .06). A total of 21.7% (10/46) of patients continued to experience poor sleep quality at 6 months postoperatively, whereas a total of 29.7% (11/37) did so at 2 years postoperatively (P = .36). No preoperative factors were associated with poor sleep quality (P > .05 all).

CONCLUSIONS

The early improvements in sleep quality observed 6 months postoperatively from an original small cohort were maintained at a mean 2.8-year follow-up in those who responded. However, approximately 30% of hip arthroscopy patients still experience poor sleep quality.

LEVEL OF EVIDENCE

IV, therapeutic case series.

A potential widespread and important role for sleep-disordered breathing in pressure injury development and delayed healing among those with spinal cord injury

Soft tissue pressure injuries commonly occur in those with spinal cord injury. They add an immeasurable medical, emotional, and social burden to those who suffer a spinal cord injury and ultimately can cause death due to sepsis when they ulcerate and become infected. Hence it is notable that (i) obstructive sleep apnea and other forms of sleep-disordered breathing are highly prevalent among those with spinal cord injury; (ii) several of the pathophysiologic consequences of sleep-disordered breathing, including hypoxemia, ischemia, oxidative stress, and endothelial dysfunction, would be expected to increase susceptibility to pressure injuries, worsen their severity, and slow or prevent their healing; and (iii) there is emerging clinical evidence that sleep-disordered breathing can have a significant role in the pathogenesis of other types of chronic wounds and that treatment of sleep-disordered breathing can aid in the healing of these wounds. These findings raise the possibility that sleep-disordered breathing may have a widespread and important role in the development, severity, and persistence of pressure injuries in those with spinal cord injury and that treatment of sleep-disordered breathing may be an effective adjunct in their prevention and healing. Studies to determine if there is a functional relationship between sleep-disordered breathing and pressure injuries in individuals with spinal cord injury are warranted.

Prevalence of Obstructive Sleep Apnea in Patients With Diabetic Foot Ulcers

Objectives: Diabetic foot ulcers (DFUs) are a considerable burden on patients and the healthcare service system. Patients with DFUs have many risk factors that might contribute to obstructive sleep apnea (OSA). The purposes of this study were to assess the prevalence of OSA and associated features in patients with DFUs. Methods: Between July 2017 and June 2019, we recruited 245 consecutive patients who sought for treatment at West China Hospital because of DFUs. Polysomnography data from 127 Patients were included in the final analysis. Results: Of the 127 patients, with a median age of 64 years (interquartile range, 55-73 years; range, 36-86 years) and a mean body mass index (BMI) 24.09 ± 0.37 kg/m², 91 (72%) were men. The prevalence of OSA [apnea-hypopnea index (AHI) ≧5/h] was 92% in men and 97% in women (P = 0.304). Moderate to severe OSA (AHI ≧15/h) was noted in 44 men (48%) and 26 women (72%) (P = 0.015). The risk factors associated with the severity of OSA were sex, age, smoking, alcohol use, and duration of diabetes. After multivariable adjustment, duration of diabetes and age were independent predictive factors of the severity of OSA. No significant association was observed between BMI, waist circumference, Epworth score, and the severity of OSA. There were no significant associations between OSA and ischemic heart disease, cerebral infarction, hypertension, diabetic retinopathy, diabetic kidney disease, and peripheral artery disease. Conclusions: The prevalence of OSA was high in patients with DFUs, with moderate to severe OSA accounting for more than half of the patients. Age and duration of diabetes were independent predictive factors of the severity of OSA.