Metabolic Syndrome and Vitamin D Levels in Patients with Obstructive Sleep Apnea Syndrome

Polymorphisms in LRP2 and CUBN genes and their association with serum vitamin D levels and sleep apnea

PURPOSE

Vitamin D deficiency has been associated with the occurrence of obstructive sleep apnea syndrome (OSAS). Megalin (LRP2) and cubilin (CUBN) are implicated in vitamin D metabolism, whereas LRP2 and CUBN polymorphisms have been previously associated with variable serum vitamin D levels. The present study aimed to evaluate the role of LRP2 rs2228171 c.8614C > T and CUBN rs1801222 c.758A > G polymorphisms in OSAS susceptibility, independently or in synergy with vitamin D levels.

METHODS

Vitamin D serum concentration of consecutive individuals was measured. PCR-RFLP was used for LRP2 rs2228171 and CUBN rs1801222 genotyping.

RESULTS

A total of 176 individuals was enrolled, including 144 patients with OSAS and 32 controls. Frequency of LRP2 rs2228171 c.8614 T and CUBN rs1801222 c.758G alleles was estimated at 22.4% and 79.8%, respectively. LRP2 and CUBN polymorphisms were not associated with OSAS occurrence (rs2228171Τ allele: 22.9% in OSAS group vs. 20.3% in controls, p = 0.651; rs1801222A allele 19.4% in OSAS group vs. 23.4% in controls, p = 0.471). Frequency of CUBN rs1801222A allele carriers was increased in patients with moderate or severe OSAS compared to mild OSAS (p = 0.028). Patients with OSAS homozygous for LRP2 CC and CUBN GG genotypes had lower vitamin D serum concentration compared to controls carrying the same genotype (18.0 vs 27.0 ng/mL, p = 0.006 and 19.0 vs 27.5 ng/mL, p = 0.007, respectively).

CONCLUSION

CUBN rs1801222 polymorphism may affect OSAS severity. Among other factors, low vitamin D concentration is associated with OSAS occurrence, irrespectively of LRP2 and CUBN polymorphisms.

Obstructive sleep apnea and vitamin D level: Has the dust settled?

Obstructive sleep apnea and vitamin D deficiency are associated with multiple complications with increased morbidity and mortality. However, the relationship between these two entities remains unclear, with clinical studies demonstrating contradictory results. This narrative review aims to present the current evidence and understanding of this relationship and discuss the possible mechanisms linking these two disease entities. Finally, we summarize and propose areas of opportunity for future research.

Obstructive sleep apnea and vitamin D: an updated systematic review and meta-analysis

PURPOSE  : Obstructive sleep apnea (OSA) is a chronic, sleep-related breathing disorder which leads to increased cardiovascular risks. Vitamin D deficiency is associated with various cardiometabolic complications, including increased cardiovascular morbidity and mortality. We aimed to analyze the difference in serum 25-hydroxyvitamin D (25-OHD) level, prevalence of vitamin D insufficiency and deficiency, and the effect of CPAP treatment on serum 25-OHD levels among adult patients with OSA.

METHODS

We pooled data from 18 observational studies involving 5592 individuals. Baseline parameters that might have contributed to the significant differences observed were also analyzed.

RESULTS

Patients with OSA had significantly lower serum 25-OHD levels (pooled d +  - 0.74 [95% CI: - 1.19 to - 0.28], p < 0.01) and higher prevalence of vitamin D deficiency (pooled log (odds ratio) 0.98 [95% CI: 0.30 to 1.67], p < 0.01) compared to those without OSA. Subgroup analysis demonstrated that these differences were significant only in moderate OSA and severe OSA. Neither age nor BMI nor geographical latitude contributed significantly to the differences observed in serum 25-OHD levels. The use of CPAP did not lead to significant changes in serum 25-OHD levels.

CONCLUSION

Patients with OSA have lower serum 25-OHD levels with a higher prevalence of vitamin D deficiency, regardless of age or BMI, pointing to an independent association between vitamin D and OSA.

The Association of Serum 25(OH) Vitamin D Level with Severity of Obstructive Sleep Apnea Syndrome in Patients with Syndrome Z (the Interaction of Obstructive Sleep Apnea with Metabolic Syndrome)

Background: The interaction of obstructive sleep apnea syndrome (OSAS) with metabolic syndrome (MetS) is known as syndrome Z. The aim of this study was to investigate the association of serum vitamin D levels with severity of OSAS in patients with Syndrome Z. Methods: In this retrospective study, 270 patients with MetS and OSAS were included. Demographic data, lifestyle habits, anthropometric measurements, sleep characteristics, polysomnographic indices, and laboratory results were recorded from the patient files. Multivariable logistic regression analyses were performed to determine the associations of serum 25(OH)D3 levels with OSAS. Results: Of the 270 patients, 71.9% were female. The mean age was 46.86 ± 8.46 (33-72) years. Of the participants, 8.2% did not have OSAS (control group), while 30.4% had mild, 28.1% had moderate, and 33.3% had severe OSAS. There were significant differences in gender, waist circumference, hip circumference, waist/hip ratio, neck circumference, body mass index, apnea-hypopnea index, total sleep time, average SpO2 and Epworth sleepiness scale score, oxygen desaturation index, blood glucose, total cholesterol, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and 25(OH)D3 levels. There was a significant difference in serum 25(OH)D3 level with increasing severities of OSAS (none+mild to moderate+severe OSAS). After adjusting for potential confounding factors in multivariable logistic regression analyses, we found that serum 25(OH)D3 level was significantly associated with the severity of OSAS. Conclusions: Serum 25(OH)D3 level was significantly associated with the severity of OSAS in patients with Syndrome Z. Therefore, patients with MetS and OSAS should be investigated for the presence of vitamin D insufficiency and, if observed, referred for vitamin D treatment.

The association between serum vitamin D and obstructive sleep apnea: an updated meta-analysis

Background

The objective was to determine whether OSA patients have a low serum vitamin D level by systematic review and meta-analysis.

Methods

This study searched the following electronic bibliographic databases: Embase, Medline, Web of Science, PubMed, VIP, Wanfang, CNKI and SinoMed. All data were searched between January 2000 and August 2020. The quality of the included studies was estimated by two researchers according to the Newcastle–Ottawa Scale and Agency for Healthcare Research and Quality. All qualified studies and statistical analyses were conducted using RevMan 5.2.

Results

Twenty-nine eligible studies compromising 6717 participants met the inclusion criteria of the meta-analysis. The results revealed that the serum 25(OH)D level was significantly lower in OSA patients than the controls. According to the severity of the disease, subgroup analysis was performed; the results demonstrated that the serum 25(OH)D level was not decreased in mild OSA patients compared with the controls, while the serum 25(OH)D level in moderate and severe OSA patients was lower than that in the controls. Furthermore, based on ethnicity, BMI, PSG type, study quality and latitude, the subjects were divided into different subgroups for meta-analysis. The results revealed that the serum 25(OH)D level in all OSA subgroups was decreased compared with that in the control group.

Conclusions

The present meta-analysis shows that the serum vitamin D level was different between OSA patients and healthy people. OSA patients could have a low serum vitamin D level.

25-hydroxyvitamin D levels in patients with obstructive sleep apnea and continuous positive airway pressure treatment: a brief review

The aim of the present study is to summarize the information available, to time, regarding the relationship between obstructive sleep apnea (OSA) and vitamin-D (vD) levels. Moreover, the association between vD deficiency and OSA severity will also be examined. At the end of the present study the possible advantageous effect of CPAP on vD-levels will be summarized. Extensive literature search was conducted in PubMed, Scopus, The Cochrane Library and Embase database. 13 articles were found concerning OSA and vD, of which 2 articles included treatment with a CPAP. Patients with OSA exhibit low levels of vD in the blood serum, and women present an even lower mean value than men. Lack of VD in blood serum seems to be related to the severity of the OSA syndrome, and to the short duration of sleep. OSA patients with concurrent metabolic syndrome exhibit lower serum vD-levels, as compared with those without metabolic syndrome. Long-term continuous positive airway pressure treatment (CPAP) treatment can increase vD-levels in male OSA patients while no change is observed in women. OSA patients demonstrate lower levels of vD in multiple studies. The severity of the OSA may be associated with vD-levels and deficiency, however more studies are needed to assess that relationship due to contradictions in current bibliography. CPAP can increase vD-levels in male patients. The relation between vD and OSA and/or CPAP is important but recent; therefore further research is needed about the exact relationship to be clarified. Also, the effect of gender hormones on vD regulation in OSA patients should be further investigated.

Vitamin D deficiency in patients evaluated for obstructive sleep apnea: is it associated with disease severity?

PURPOSE

The aim of the present study was to assess vitamin D levels in a large cohort of OSA patients and to investigate possible correlations with clinical and polysomnographic parameters.

METHODS

In this cross-sectional study, 685 consecutive patients underwent type 1 polysomnography (PSG) for OSA diagnosis. They were grouped according to apnea-hypopnea index (AHI) as mild, moderate, and severe. Patients with AHI < 5 served as controls. Demographic, PSG data, and serum levels of vitamin D were measured and compared between groups.

RESULTS

OSA was diagnosed in 617 of the patients (90%). Of those, 94 (15%) had mild OSA, 150 (24%) moderate OSA, and 373 (61%) severe OSA. The risk of vitamin D deficiency (< 20 ng/mL) was observed in 38% of the cohort. OSA patients had lower vitamin D levels compared to controls (23 ng/mL vs 26 ng/mL, p = 0.006). The lowest levels of vitamin D [mean 21] (p < 0.001 among all groups) and the higher prevalence for vitamin D deficiency (45%) were observed in severe OSA patients. After multiparametric adjustments for age, gender, obesity, and comorbidities, severe OSA showed significant independent associations with the risk of vitamin D deficiency [OR (95% CI) 2.002 (1.049-3.819), p = 0.035].

CONCLUSIONS

A large proportion of patients referred for OSA evaluation had vitamin D deficiency, which was independently associated with severe OSA. However, further research is needed in order to determine the role of vitamin D in OSA patients.

The Relationship of Serum 25-Hydroxyvitamin-D Level with Severity of Obstructive Sleep Apnea in Patients with Type 2 Diabetes Mellitus

OBJECTIVE

To explore the association of serum vitamin-D levels with the severity of obstructive sleep apnea (OSA) in patients with type 2 diabetes mellitus (T2DM).

METHODS

A cross-sectional study of 136 patients with T2DM who underwent overnight polysomnography (PSG) tests and serum 25-hydroxyvitamin-D3 (25(OH)D3) level detections was conducted. Multivariable linear regression and logistic regression analyses were performed to determine the associations of serum 25(OH)D3 levels with apnea-hypopnea index (AHI) and obstructive sleep apnea (OSA).

RESULTS

The prevalence rates of OSA were 84.4% for male and 65.2% for female patients, respectively (p = 0.011). With increasing severities of OSA categories (none, mild, moderate and severe), patients were more likely to be male and obese, but there was no significant difference in serum 25(OH)D3 level ((mean ± standard deviation) 21.8 ± 8.8, 27.7 ± 14.6, 24.2 ± 9.8 and 26.8 ± 6.2 ng/mL, respectively, p=0.086). Serum 25(OH)D3 level was not significantly correlated with AHI (log-transformed), with the correlation coefficient of 0.133 (p=0.124). With adjustment for potential confounding factors, multivariable linear regression and logistic regression analyses showed that serum 25(OH)D3 level was not significantly associated with either AHI (log-transformed) or the risk of OSA, with the standardized regression coefficient (95% confidence interval (CI)) of 0.098 (-0.004-0.014, p=0.252) and the adjusted odds ratio (95% CI) of 1.055 (0.991-1.124, p=0.095), respectively.

CONCLUSION

Serum 25(OH)D3 level was not significantly associated with either AHI or the risk of OSA in patients with T2DM.

Hypovitaminosis D is associated with negative symptoms, suicide risk, agoraphobia, impaired functional remission, and antidepressant consumption in schizophrenia

Hypovitaminosis D has been associated with, respectively, major depressive disorder, schizophrenia (SZ), and cognitive disorders in the general population, and with positive and negative symptoms and metabolic syndrome in schizophrenia. The objective was to determine the prevalence of hypovitaminosis D and associated factors in a non-selected multicentric sample of SZ subjects in day hospital. Hypovitaminosis D was defined by blood vitamin D level < 25 nM. Depressive symptoms were assessed by the Calgary Depression Rating Scale Score and Positive and Negative Syndrome Scale Score. Anxiety disorders and suicide risk were evaluated by the Structured Clinical Interview for Mental Disorders. Functioning was evaluated with the Functional Remission of General Schizophrenia Scale. Hypovitaminosis D has been found in 27.5% of the subjects. In multivariate analysis, hypovitaminosis D has been significantly associated with, respectively, higher suicide risk (aOR = 2.67 [1.31-5.46], p = 0.01), agoraphobia (aOR = 3.37 [1.66-6.85], p < 0.0001), antidepressant consumption (aOR = 2.52 [1.37-4.64], p < 0.001), negative symptoms (aOR = 1.04 [1.01-1.07], p = 0.04), decreased functioning (aOR = 0.97[0.95-0.99], p = 0.01), and increased leucocytosis (aOR = 1.17 [1.04-1.32], p = 0.01) independently of age and gender. No association with alcohol use disorder, metabolic syndrome, peripheral inflammation, insulin resistance, or thyroid disturbances has been found (all p > 0.05). Despite some slight abnormalities, no major cognitive impairment has been associated with hypovitaminosis D in the present sample (all p > 0.05 except for WAIS similarities score). Hypovitaminosis D is frequent and associated with suicide risk, agoraphobia and antidepressant consumption in schizophrenia, and more slightly with negative symptoms. Patients with agoraphobia, suicide risk and antidepressant consumption may, therefore, benefit in priority from vitamin D supplementation, given the benefit/risk profile of vitamin D. Further studies should evaluate the impact of vitamin D supplementation on clinical outcomes of SZ subjects.

Reduced Serum Vitamin D Levels Are Associated with Insulin Resistance in Patients with Obstructive Sleep Apnea Syndrome

Background and objectives: Obstructive sleep apnea syndrome (OSAS) is associated with cardiovascular and metabolic risk factors, such as insulin resistance. Furthermore, OSAS has been associated with decreased levels of vitamin D (Vit D). The aim of the study was to assess the association between Vit D levels (expressed as 25(OH)D serum levels) and insulin resistance in patients with OSAS. Materials and Methods: Serum 25(OH)D levels were measured in consecutive subjects who had undergone polysomnography and pulmonary function testing. OSAS patients were divided into those with (homeostatic model assessment [HOMA-IR] ≥ 2) and without insulin resistance (HOMA-IR < 2). Results: Overall, 92 patients (81 males) were included in the study. OSAS patients with insulin resistance significantly differed from those without insulin resistance in terms of the body-mass index (BMI) (36.3 ± 5.8 compared to 32 ± 5.6 kg/m², respectively, p = 0.001), apnoea-hypopnoea index (AHI) (57.4 ± 28.9 compared to 40.9 ± 27.9 events/h, respectively, p = 0.009) and indices of hypoxia during sleep. Patients with OSAS and insulin resistance had lower levels of serum 25 (OH) D compared with OSAS but without insulin resistance (19.3 ± 11.5 vs 26.7 ± 12.2 ng/mL, respectively, p = 0.005). Regression analysis demonstrated a negative association of 25(OH)D levels (β = −0.048, odds ratio [OR]: 0.953, 95% confidence interval [CI]: 0.913–0.995, p = 0.030) and a positive association of BMI (β = 0.110, OR: 1.116, 95% CI: 1.007–1.237, p = 0.036) with insulin resistance. Conclusions: Vit D insufficiency was significantly more frequent among OSAS patients with insulin resistance. Both low 25(OH)D levels and high BMI were associated with the risk of insulin resistance in this population.

Hypovitaminosis D is associated with depression and anxiety in schizophrenia: Results from the national FACE-SZ cohort

OBJECTIVE

Hypovitaminosis D has been associated with respectively major depressive disorder, schizophrenia (SZ) and cognitive disorders in the general population, and with positive and negative symptoms and metabolic syndrome in schizophrenia. The objectives were (i) to determine the prevalence of hypovitaminosis D and associated factors (with a focus on depression and cognition) in a national non-selected multicentric sample of community-dwelling SZ subjects (ii) to determine the rate of SZ patients being administered vitamin D supplementation and associated factors.

METHODS

A comprehensive 2 daylong clinical and neuropsychological battery was administered in 140 SZ subjects included between 2015 and 2017 in the national FondaMental Expert Center (FACE-SZ) Cohort. Hypovitaminosis D was defined by blood vitamin D level <25 nM. Depressive symptoms were assessed by the Positive and Negative Syndrome Scale depressive subscore and current anxiety disorder by the Structured Clinical Interview for Mental Disorders.

RESULTS

Hypovitaminosis D has been found in 21.4% of the subjects and none of them had received vitamin D supplementation in the previous 12 months. In multivariate analysis, hypovitaminosis D has been significantly associated with respectively higher depressive symptoms (aOR = 1.18 [1.03-1.35], p = 0.02) and current anxiety disorder (aOR = 6.18 [2.15-17.75], p = 0.001), independently of age and gender. No association of hypovitaminosis D with respectively positive and negative symptoms, cognitive scores or other biological variables has been found (all p > 0.05), however, a trend toward significance has been found for metabolic syndrome (p = 0.06). Vitamin D supplementation has been administered during the previous 12 months in only 8.5% of the subjects but was associated with lower depressive symptoms (aOR = 0.67 [0.46-0.98], p = 0.04) and lower rate of current anxiety disorder (aOR = 0.06 [0.01-0.66], p = 0.02) compared to patients with hypovitaminosis D.

CONCLUSION

Hypovitaminosis D is frequent and associated with depressive symptoms and anxiety disorders in schizophrenia. Vitamin D supplementation is associated with lower depressive and anxiety symptoms, however patients with hypovitaminosis D remain insufficiently treated.