Table of Contents
Background on Obstructive Sleep Apnea and Cardiovascular Risks
Obstructive Sleep Apnea (OSA) is a prevalent condition characterized by repeated episodes of upper airway obstruction during sleep, leading to significant health consequences such as excessive daytime sleepiness, impaired cognitive function, and increased risk of cardiovascular diseases (CVD) (Zdravkovic et al., 2022). The association between OSA and cardiovascular risks is primarily due to intermittent hypoxia and heightened sympathetic nervous system activity, which can lead to hypertension and heart failure (Floras, 2018). The physiological mechanisms underlying these risks are still being explored, but it is evident that untreated OSA can exacerbate existing cardiovascular conditions, thereby increasing morbidity and mortality rates among affected individuals (Lal et al., 2021).
The Role of Vitamin D in Cardiovascular Health and OSA
Vitamin D, a vital fat-soluble vitamin, is crucial for various bodily functions, including bone health and immune system regulation. Recent studies have highlighted its potential role in cardiovascular health. Vitamin D deficiency has been linked to hypertension and an increased risk of heart disease (Marquina et al., 2020). In the context of OSA, vitamin D may mitigate some of the cardiovascular risks associated with the condition by modulating inflammatory responses and improving endothelial function (Loh et al., 2023). The relationship between vitamin D levels and OSA is complex, as lower levels of vitamin D are often observed in patients with OSA, potentially exacerbating the condition (Loh et al., 2023).
Table 1: Summary of Vitamin D’s Effects on Cardiovascular Health
| Parameter | Effect of Vitamin D |
|---|---|
| Blood Pressure | Reduces systolic and diastolic levels (Gao et al., 2024) |
| Endothelial Function | Improves endothelial function (Mozos & Marginean, 2015) |
| Inflammatory Markers | Lowers hsCRP levels (Radkhah et al., 2023) |
| Autonomic Function | Enhances heart rate variability (Cetin et al., 2022) |
Mechanisms of SGLT-2 Inhibitors in Hypertensive Patients
Sodium-glucose cotransporter-2 (SGLT-2) inhibitors, such as Dapagliflozin, represent a novel class of diabetic medications that have gained recognition for their cardiovascular benefits beyond glycemic control (Wiviott et al., 2019). These agents work by promoting urinary glucose excretion, thereby reducing blood glucose levels and leading to weight loss and lower blood pressure (Zinman et al., 2015). Furthermore, SGLT-2 inhibitors have been shown to reduce the risk of hospitalization for heart failure and improve overall cardiovascular outcomes in patients with type 2 diabetes (Wiviott et al., 2019; Zinman et al., 2015).
Table 2: Cardiovascular Benefits of SGLT-2 Inhibitors
| Benefit | Mechanism of Action |
|---|---|
| Blood Pressure Reduction | Diuretic effect leading to volume contraction |
| Heart Rate Variability Improvement | Enhances autonomic function |
| Cardiac Remodeling | Reduces myocardial stress and fibrosis |
| Anti-inflammatory Effects | Lowers inflammatory markers such as hsCRP |
Study Design: Evaluating Dapagliflozin and Vitamin D3
A randomized controlled trial was conducted involving patients diagnosed with OSA and hypertension. The study aimed to evaluate the combined effects of Dapagliflozin and Vitamin D3 on metabolic parameters, quality of life, and cardiovascular health over a 16-week period. Patients were divided into four groups: (i) Dapagliflozin alone, (ii) Vitamin D3 alone, (iii) Dapagliflozin plus Vitamin D3, and (iv) a control group with no treatment (Loh et al., 2024).
The main parameters assessed included anthropometry, blood pressure, heart rate variability, lipid profiles, endothelial function, and quality of life using the World Health Organization Quality of Life (WHOQoL) instrument and the Epworth Sleepiness Scale (ESS).
Table 3: Study Group Distribution
| Group | Number of Patients | Treatment Received |
|---|---|---|
| Group 1 (Dapagliflozin) | 36 | Dapagliflozin 10 mg daily |
| Group 2 (Vitamin D3) | 41 | Vitamin D3 (varied doses based on levels) |
| Group 3 (Combination) | 39 | Dapagliflozin + Vitamin D3 |
| Group 4 (Control) | 37 | No treatment |
Impact of Combined Therapy on Quality of Life and Sleepiness
The results revealed significant improvements in metabolic outcomes for patients receiving the combination therapy of Dapagliflozin and Vitamin D3. Patients exhibited substantial reductions in blood pressure, waist circumference, and HbA1c levels compared to the control group. The combination therapy also led to enhancements in quality of life scores, notably in social relationships and emotional well-being, as well as a reduction in daytime sleepiness, as measured by the ESS (Loh et al., 2024).
Table 4: Changes in Quality of Life and Sleepiness Scores
| Parameter | Group 1 (Dapagliflozin) | Group 2 (Vitamin D3) | Group 3 (Combination) | Group 4 (Control) |
|---|---|---|---|---|
| ESS Score | 8.0 ± 4.8 | 8.6 ± 5.8 | 7.6 ± 5.2 | 9.1 ± 5.7 |
| WHOQoL Overall Quality | 3.97 ± 0.69 | 3.78 ± 0.57 | 3.88 ± 0.69 | 3.61 ± 0.72 |
| Emotional Health Score | 94.0 ± 12.74 | 89.74 ± 18.14 | 100.0 ± 0.0 | 95.0 ± 22.0 |
FAQ Section
What is the significance of vitamin D3 for OSA patients?
Vitamin D3 plays a crucial role in cardiovascular health, and its deficiency is linked to increased cardiovascular risks, which are prevalent in OSA patients.
How do SGLT-2 inhibitors benefit patients with hypertension?
SGLT-2 inhibitors lower blood glucose levels, aid in weight loss, improve blood pressure, and provide cardioprotective effects by reducing heart failure hospitalizations.
Can vitamin D3 and SGLT-2 inhibitors be used together?
Yes, the combination has been shown to have synergistic effects, improving metabolic outcomes and quality of life in patients with obstructive sleep apnea and hypertension.
What improvements were seen in the study participants?
Participants who received the combination therapy exhibited significant reductions in blood pressure, waist circumference, HbA1c levels, and improvements in quality of life and sleepiness scores.
References
- Zdravkovic, M., Popadic, V., Klasnja, S., Milic, N., Rajovic, N., & Divac, A. (2022). Obstructive sleep apnea and cardiovascular risk: a review of the literature and clinical management strategy. Hypertens Res, 47(11), 3085-3098. https://doi.org/10.1038/s41440-024-01852-y
- Floras, J. S. (2018). Sleep apnea and cardiovascular disease: an enigmatic risk factor. Circ Res, 122(12), 1741-1764
- Lal, C., Weaver, T. E., Bae, C. J., & Strohl, K. P. (2021). Excessive daytime sleepiness in obstructive sleep apnea. Mechanisms and clinical management. Ann Am Thorac Soc, 18(5), 757-768
- Marquina, C., Mousa, A., & Scragg, R. (2020). Vitamin D and cardiometabolic disorders: a review of current evidence, genetic determinants and pathomechanisms. Obes Rev, 20(2), 262-277
- Loh, H. H., Sukor, N., & Lim, Q. H. (2023). Obstructive sleep apnea and vitamin D level: has the dust settled? Clin Respir J, 17(5), 497-503
- Wiviott, S. D., Raz, I., Bonaca, M. P., Mosenzon, O., Kato, E. T., & Cahn, A. (2019). Dapagliflozin and cardiovascular outcomes in type 2 diabetes. N Engl J Med, 380(4), 347-357
- Zinman, B., Wanner, C., Lachin, J. M., Fitchett, D., Bluhmki, E., & Hantel, S. (2015). Empagliflozin, cardiovascular outcomes, and mortality in type 2 diabetes. N Engl J Med, 373(22), 2117-2128
- Gao, M., Bhatia, K., Kapoor, A., Badimon, J., Pinney, S. P., & Mancini, D. M. (2024). SGLT2 inhibitors, functional capacity, and quality of life in patients with heart failure: a systematic review and meta-analysis. JAMA Netw Open, 7(4), e245135
- Radkhah, N., Zarezadeh, M., Jamilian, P., & Ostadrahimi, A. (2023). The impact of Vitamin D supplementation on lipid profiles: an umbrella review of meta-analyses. Adv Nutr, 14(6), 1479-1498. https://doi.org/10.2147/DMSO.S233538
- Krajewska, M., & Witkowska-Sedek, E. (2022). Sex differences in Vitamin D metabolism, serum levels and action. Br J Nutr, 128(11), 2115-2130. https://doi.org/10.1017/S0007114522000149