Changes in cortisol levels by continuous positive airway pressure in patients with obstructive sleep apnoea: Meta-analysis of 637 individuals

Meta-analysis and construction of simple-to-use nomograms for approximating testosterone levels gained from weight loss in obese men

BACKGROUND

Obesity-induced hypogonadism, which manifests as erectile dysfunction and a lack of libido, is a less visible and under-recognized obesity-related disorder in men.

OBJECTIVE

We examined the impact of weight loss on total (TT) and free testosterone (FT) levels, and constructed nomograms to provide an easy-to-use visual aid for clinicians.

MATERIALS AND METHODS

Meta-analysis was conducted using RevMan (v5.3) and expressed in standardized mean differences (SMD) for testosterone. Parallel-scale nomograms were constructed from baseline and target body mass index values to estimate the gain in testosterone.

RESULTS

In total, 44 studies were included, comprising 1,774 participants and 2,159 datasets, as some studies included several datasets at different time points. Weight loss was controlled by low calorie diet (LCD) in 19 studies (735 participants, 988 datasets), by bariatric surgery (BS) in 26 studies (1,039 participants, 1,171 datasets), and by both in one study. The median follow-up was 26 weeks (interquartile range = 12-52). The range of baseline mean age was 21-68 yr, BMI: 26.2-71.2 kg/m2 , TT: 7-20.2 nmol/L and FT: 140-583 pmol/L. TT levels increased after weight loss by LCD: SMD (95%CI) = 2.5 nmol/L (1.9-3.1) and by BS: SMD = 7.2 nmol/L (6.0-8.4); the combined TT gain was 4.8 nmol/L (3.9-5.6). FT levels increased after weight reduction by LCD: SMD = 19.9 pmol/L (7.3-32.5) and by BS: SMD = 58.0 pmol/L (44.3-71.7); the combined gain was 42.2 pmol/L (31.4-52.9). Greater amounts of total and free testosterone could be gained by weight loss in men with higher baseline BMI, or lower levels of SHBG, TT and FT, while gain in TT was relatively greater in older and FT in younger age. Age-stratified nomograms revealed that compared to older men (> 40 yr), younger men (≤ 40 yr) gained less TT but more FT for a given weight loss.

DISCUSSION AND CONCLUSION

Both TT and FT levels increased after weight loss, relatively greater with higher baseline BMI, or lower levels of SHBG, TT and FT. Nomograms constructed from a large number of participants with a wide range of BMI and testosterone values provide an evidence-based and simple-to-use tool in clinical practice.

Mandibular advancement devices decrease systolic pressure during the day and night in patients with obstructive sleep apnea: A systematic review and meta-analysis

The aim of this systematic review and meta-analysis was to analyze whether or not mandibular advancement devices (MADs) produce changes in blood pressure in patients with obstructive sleep apnea (OSA) in relation to use time and if the device is used at night or day.

MATERIALS AND METHOD

A systematic review of the literature and meta-analysis was carried out in accordance with PRISMA guidelines. In the bibliographic search, a total of four databases were consulted: PubMed-Medline, Scopus, Web of Science, and Cochrane. Of the 622 articles initially revealed, 160 duplicates were eliminated. After applying the selection criteria, 17 articles were included for the qualitative analysis and 4 for the meta-analysis. The studies were combined using a random effects model with the inverse method of variance, determining the mean differences in systolic and diastolic pressure before and after treatment using the MAD splint as the effect size. Day/night circadian effect and treatment time were analyzed using meta-regression with a mixed-effects model.

RESULTS

MAD treatment was not found to affect diastolic pressure. By combining the four studies with the control group in a meta-analysis (I2 = 75%; z =  - 0.15; p-value = 0.882), the mean difference in diastolic pressure between the MAD group and the control group was estimated at - 0.06 (- 0.86; 0.74). The meta-regression also showed no significant effect of day/night (p = 0.560) or treatment time (p = 0.854) on diastolic pressure. When combining the four studies with the control group (I2 = 84%%; z =  - 1.47; p-value = 0.142), a non-significant mean difference in systolic pressure between the MAD group and the control group of - 0.99 (- 2.31; 0.33) was estimated in the meta-analysis. However, when assessing the effect of day/night or treatment time on systolic blood pressure using a meta-regression, the latter showed significant covariates that reduce systolic blood pressure values in the model at night (p < 0.001) and in relation to treatment time (p < 0.001).

CONCLUSIONS

Only systolic pressure appears to be affected by the use of the MAD in patients with OSA, and this decrease in systolic pressure is greater at night and when treatment time is longer.

Association between obstructive sleep apnea and low bone mass in adults: a systematic review and meta-analysis

Introduction

This study aimed to synthesize existing evidence on the potential association between obstructive sleep apnea (OSA) and low bone mass in adults.

Methods

Electronic searches of four main databases were performed. The inclusion criteria consisted of observational studies investigating the relationship between OSA and bone mass, osteoporosis, fractures, or bone metabolism markers in adult population. Bone mineral density (BMD) and T score of lumbar and femur neck, incidence of osteoporosis and fractures, bone metabolism marker levels were extracted as primary outcomes.

Results

Among the 693 relevant publications, 10 studies consisting of 158,427 participants met with the inclusion and exclusion criteria. Meta-analysis showed a significant lower BMD of lumbar (mean difference (MD) = - 0.03; 95% CI - 0.05, - 0.01; I2 = 46%), femur neck (MD = - 0.06; 95% CI - 0.12, 0.00; I2 = 71%), and a significant lower T score of lumbar (MD = - 0.42; 95% CI - 0.79, - 0.05; I2 = 63%) in the OSA group. The results suggested that both male (odds ratio (OR) = 2.03; 95% CI 1.23, 3.35; I2 = 38%) and female (OR = 2.56; 95% CI 1.96, 3.34; I2 = 0%) had higher risk of osteoporosis in the OSA group. Besides, meta-analysis also showed that bone-specific alkaline phosphatase was significantly lower in OSA patients (MD = - 1.90; 95% CI - 3.48, - 0.32; I2 = 48%).

Conclusions

A potential association between OSA and lower bone mass in adults is preliminarily proved. It also seems plausible that both male and female with OSA have a higher risk of osteoporosis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41105-023-00481-1.

Effects of continuous positive airway pressure therapy on glucose metabolism in patients with obstructive sleep apnoea and type 2 diabetes: a systematic review and meta-analysis

Obstructive sleep apnoea is a highly prevalent chronic disorder and has been shown to be associated with disturbed glucose metabolism and type 2 diabetes. However, the evidence from individual clinical trials on the effect of continuous positive airway pressure (CPAP) treatment on glycaemic control in patients with co-existing obstructive sleep apnoea and type 2 diabetes remains controversial. A systematic review of randomised controlled trials assessing the effect of CPAP on glycaemic control in patients with obstructive sleep apnoea and type 2 diabetes was conducted using the databases MEDLINE, Embase, Cochrane and Scopus up to December 2022. Meta-analysis using a random-effect model was performed for outcomes that were reported in at least two randomised controlled trials. From 3031 records screened, 11 RCTs with a total of 964 patients were included for analysis. CPAP treatment led to a significant reduction in haemoglobin A1c (HbA1c) (mean difference -0.24%, 95% CI -0.43- -0.06%, p=0.001) compared to inactive control groups. Meta-regression showed a significant association between reduction in HbA1c and hours of nightly CPAP usage. CPAP therapy seems to significantly improve HbA1c and thus long-term glycaemic control in patients with type 2 diabetes and obstructive sleep apnoea. The amount of improvement is dependent on the hours of usage of CPAP and thus optimal adherence to CPAP should be a primary goal in these patients.

Potential Diagnostic and Monitoring Biomarkers of Obstructive Sleep Apnea-Umbrella Review of Meta-Analyses

Obstructive sleep apnea (OSA) is a prevalent, underdiagnosed disease that imposes a significant impact on the health and wellbeing of patients and a financial burden on individuals, their families, and society. Development of new methods of testing other than an overnight sleep study, such as measurement of serum or plasma biomarkers, may provide an easier diagnostic process to identify patients with OSA and allow earlier initiation of treatment, which might prevent serious comorbidities. We conducted a systematic review and quality assessment of available meta-analyses regarding potential diagnostic and monitoring biomarkers of obstructive sleep apnea. A total of 14 sets of candidate biomarkers displayed differences in levels or concentrations in OSA patients compared to non-OSA controls, and decreased after OSA treatment: CRP, IL-6, TNF-α, Il-8, HCY, ICAM-1, VCAM-1, VEGF, TC, LDLc, HDLc, TG, leptin, MDA, ALT, AST, IGF-1, adiponectin, and cortisol. This review summarizes the evidence for OSA-associated potential biomarkers and demonstrates that the quality of available studies, as measured by AMSTAR2, is often low and associated with a high risk of bias.

Sleep, testosterone and cortisol balance, and ageing men

Sleep serves important biological functions, and influences health and longevity through endocrine and metabolic related systems. Sleep debt, circadian misalignment and sleep disruption from obstructive sleep apnea is widespread in modern society and accumulates with life because recovery sleep is not completely restorative. Accumulated disordered sleep throughout life impacts the ageing process and the development of age-related diseases. When epidemiological and interventional studies are considered collectively, sleep loss and lower sleep duration are associated with lower morning, afternoon and 24-h testosterone; as well as higher afternoon, but not morning or 24-h cortisol. These reciprocal changes imbalances anabolic-catabolic signaling because testosterone and cortisol are respectively the main anabolic and catabolic signals in man. Fixing testosterone-cortisol balance by means of a novel dual-hormone clamp mitigates the induction of insulin resistance by sleep restriction and provided the first proof-of-concept that the metabolic harm from sleep loss can be ameliorated by approaches that do not require sleeping more. Obstructive sleep apnea is associated with lower testosterone, even after controlling for age and obesity whereas the conclusion that continuous positive airway pressure therapy has no effect on testosterone is premature because available studies are underpowered and better-quality studies suggest otherwise. High dose testosterone therapy induces OSA, but more physiological dosing may not; and this effect may be transient or may dissipate with longer term therapy. Studies investigating the origin of the diurnal testosterone rhythm, the effect of circadian misalignment on testosterone-cortisol balance, and methods to mitigate metabolic harm, are required.

A Review of a Recent Meta-Analysis Study on Obstructive Sleep Apnea

This paper summarizes a recent meta-analysis of various topics in obstructive sleep apnea (OSA). In addition to cardiovascular disease and neurocognitive dysfunction, a wide variety of diseases have been associated with OSA, and associations with cancer have also been reported. Although continuous positive airway pressure is a very effective treatment, the results have shown that it does not reduce the incidence of various complications. It has been reported that uvulopalatopharyngoplasty was effective, and robotic surgery for the tongue root and hypoglossal nerve stimulation were also effective. The effectiveness of various medications to reduce daytime sleepiness has also been demonstrated. Although exercise lowered the apnea-hypopnea index, it was not related to changes in body composition, and it was also reported that exercise combined with weight control were effective. Additionally, interesting and clinically meaningful meta-analysis results were summarized and presented.

Characteristics of aldosterone-producing adenomas in patients without plasma renin activity suppression

Primary aldosteronism (PA) usually accompanies suppressed plasma renin activity (PRA) through a negative feedback mechanism. While some cases of PA with unsuppressed PRA were reported, there have been no studies about the characteristics of PA with unsuppressed PRA; thus, these characteristics were examined herein. Nine patients with unsuppressed PRA and 86 patients with suppressed PRA were examined. All patients underwent segmental adrenal venous sampling (sAVS) and adrenalectomy, and were pathologically confirmed to have cytochrome P450 11B2 (CYP11B2)-positive aldosterone-producing adenoma according to international histopathology consensus criteria. Unsuppressed and suppressed PRA were defined as PRA levels of > 1.0 and ≤ 1.0 ng/mL/hr, respectively, in multiple blood samples obtained in the resting position. The unsuppressed PRA group had higher morning cortisol levels (12.6 [8.5, 13.5] vs. 8.5 [7.1, 11.0] μg/dL, P = 0.03) and higher cortisol levels after a 1 mg dexamethasone suppression test (DST) (2.2 [1.6, 2.5] vs. 1.3 [1.0, 1.9] μ g/dL, P = 0.004) than the suppressed PRA group. The unsuppressed PRA group also showed higher aldosterone levels on the non-surgical side during sAVS (P = 0.02 before adrenocorticotropic hormone (ACTH) stimulation, P = 0.002 after ACTH stimulation), a higher intensity of CYP17 expression in the resected adrenal gland (P = 0.02), and a lower clinical complete success rate 1 year after surgery (P = 0.04) compared with those in the suppressed PRA group. These findings suggest that PA should not be ruled out by unsuppressed PRA among patients with hypertension, particularly when their cortisol levels remain unsuppressed in the 1 mg DST. Meanwhile, it should be acknowledged that patients with unsuppressed PRA have higher aldosterone levels on the non-surgical side, and a lower likelihood of postoperative complete clinical success is to be expected.

Association Between Cushing’s Syndrome and Sleep Apnea: Results From the National Inpatient Sample

Background

Cushing’s syndrome is a metabolic disorder related to excess cortisol production. Patients with Cushing’s syndrome are at risk for the development of other comorbid medical conditions such as hypertension, diabetes, obesity, and obstructive sleep apnea. Obstructive sleep apnea has been well associated with endocrine disorders such as acromegaly and hypothyroidism. However, its causal association with Cushing’s syndrome is still unclear. We utilized a national database to study the prevalence of sleep apnea in Cushing’s syndrome.

Hypothesis

We hypothesized that patients with Cushing’s syndrome might have an increased prevalence of sleep apnea.

Methods

Patients aged above 18 years from the NIS database between 2017 and 2018 with a diagnosis of Cushing’s syndrome and sleep apnea were extracted using the 10th revision of the International Classification of Diseases (ICD-10) codes, with code E24 representing Cushing’s syndrome and G47.3 representing sleep apnea. The prevalence of sleep apnea and other comorbid medical conditions were identified using the ICD-10 codes. Logistic regression analysis was performed to examine the association between Cushing’s syndrome and sleep apnea.

Results

Cushing’s syndrome was prevalent in 0.037% (2,248 of 6,023,852) of all inpatient hospitalizations. Patients with Cushing’s syndrome were slightly younger (mean age: 54 ± 16 versus 58 ± 20) and more likely to be females (76%, 1,715 out of 2,248) and had higher rates of sleep apnea (21.9% versus 8.7%, p < 0.000) and obstructive sleep apnea (OSA) (18.6% versus 7.2%, p < 0.000) when compared to the general population. Cushing’s syndrome is independently associated with sleep apnea, with an unadjusted odds ratio (OR) of 2.94 (p < 0.01) and an adjusted odds ratio (aOR) of 1.79 after adjusting for demographics and other risk factors for sleep apnea and comorbid medical conditions (p < 0.01).

Conclusions

Cushing’s syndrome is associated with increased prevalence of sleep apnea and independent predictor of sleep apnea. Further prospective studies are recommended to validate the causal association. The high prevalence and coexistence of both these disorders validate screening for sleep apnea as part of routine workup in patients with Cushing’s syndrome and vice versa.

Sleep Problems in Chronic Inflammatory Diseases: Prevalence, Treatment, and New Perspectives: A Narrative Review

Epidemiological studies have shown that individuals with sleep problems are at a greater risk of developing immune and chronic inflammatory diseases. As sleep disorders and low sleep quality in the general population are frequent ailments, it seems important to recognize them as serious public health problems. The exact relation between immunity and sleep remains elusive; however, it might be suspected that it is shaped by others stress and alterations of the circadian rhythm (commonly caused by for example shift work). As studies show, drugs used in the therapy of chronic inflammatory diseases, such as steroids or monoclonal antibodies, also influence sleep in more complex ways than those resulting from attenuation of the disease symptoms. Interestingly, the relation between sleep and immunity appears to be bidirectional; that is, sleep may influence the course of immune diseases, such as inflammatory bowel disease. Thus, proper diagnosis and treatment of sleep disorders are vital to the patient's immune status and, in effect, health. This review examines the epidemiology of sleep disorders and immune diseases, the associations between them, and their current treatment and novel perspectives in therapy.