Immediate effect of mud pack on resting cardiovascular parameters in hypertensive individuals – A single-arm pilot study

1 Background

Hypertension (HTN) is a major modifiable risk factor for cardiovascular diseases and stroke [1]. Currently, 3.5 billion adults have non-optimal systolic BP levels and 874 million adults have systolic blood pressure (BP) ≥ 140 mmHg. Thus, approximately one in four adults have HTN [2]. The prevalence of HTN has increased from 4.5% of 6.1 billion people in 2000 to 7% of 6.9 billion people in 2010 and is anticipated to rise to 1.6 billion adults in 2025 [3]. In India The 2019–2020 National Family Health Survey (NFHS-5) indicated that the prevalence of HTN was 24% among men and 21% among women, marking an upsurge from the rates of 19 and 17% in the prior cycle (2015–2016) [1]. HTN is considered the main risk factor for cardiovascular, renal, neurological, and ophthalmologic disorders and the leading cause of morbidity and mortality worldwide [3]. Pharmacological therapy has been found to be efficacious in treating hypertension. Pharmaceutical therapies like angiotensin-converting enzyme inhibitors, angiotensin 2 receptor blockers, diuretics, beta-blockers, and calcium channel blockers have been found to be efficacious in treating HTN [4]. Various classes of anti-hypertensives can lower BP but their adverse effects like dry cough, skin rashes, vitiligo, dizziness, and gastrointestinal disturbances limit their usage. Non-pharmacological therapies include weight loss, dietary changes, increased physical activity, cessation of alcohol, quitting smoking, mindfulness practices, acupuncture, biofeedback, home monitoring, and food supplements recommended for all hypertensive patients [5]. The complication of HTN like cardiovascular diseases can be reduced by up to 15% by lifestyle modifications alone [6]. This created greater attention toward naturopathy a system of medicine where drugs are not the primary therapeutic modality utilized.

Mud therapy is a relatively inexpensive, and effective naturopathic treatment method used to treat various ailments like headache, constipation, conjunctivitis, glaucoma, indigestion, insomnia, itching, and allergy, reduces intestinal heat, and promotes peristalsis [6]. Mud baths and local mud application have been employed for many years to treat musculoskeletal conditions like osteoarthritis of the knee, tennis elbow, plantar fasciitis by reducing inflammation, reducing pain and improving function and quality of life [7–9]. Direct mud application found to have chemical properties which contribute to the therapeutic effect of mud [10]. Mud has both organic and inorganic materials. The inorganic component is largely composed of minerals like sodium, magnesium, and zinc whereas humic acid is composed of a large portion of organic material which is responsible for the water-retaining properties of the mud. Studies reported that mud has an anti-inflammatory effect by modifying myeloperoxidase, glutathione peroxidase, nitric oxide, and beta-endorphin in serum levels and reduces proinflammatory cytokine IL-8 and anti-inflammatory cytokine transforming growth factor levels [8,9]. Although numerous studies have demonstrated the BP-reducing effects of mud therapy [11,12], no study has investigated the immediate effect of applying mud packs (MP) to the abdomen and eyes on BP in hypertensive patients.

2 Materials and methods

3 Results

Table 1 depicts the demography of the included patients. Table 2 shows the cardiovascular parameters taken immediately after the treatment of MP on the abdomen and eyes for 20 min and found a significant reduction of the resting cardiovascular parameters. The SBP reduced from 150.53(12.52) to 129.10(11.27) (p < 0.001), DBP from 91.67(10.73) to 85.70(8.50) (p = 0.023), PP from 58.87(12.61) to 43.40(10.37) (p < 0.001), MAP from 111.29(9.68) to 100.17(8.16) (p < 0.001), RPP from 122.02(21.80) to 96.78(13.23) (p < 0.001), and DOP from 90.13(15.56) to 75.25(11.09) (p < 0.001). Though there was a decrease in PR from 80.97(12.16) to 75.23(10.00) (p = 0.082), it was not statistically significant.

4 Discussion

The present study showed that a single session (20 min) of MP on the abdomen, and eyes showed a significant reduction in cardiovascular parameters such as SBP, PP, MAP, RPP, and DOP, in patients with hypertension. Similar results were observed in the previous study with MP on the abdomen and eyes among the healthy volunteers. They reported that a single session of 20 min on MP reduces the BP variables and improved heart rate variability indices. From this, they derived a conclusion that MP may induce parasympathetic dominance; however, their study was different from our study because they have given the intervention to healthy individuals [8]. During the initial phase, applying a cold MP to the abdomen and eyes may cause instant vasoconstriction, leading to an elevation in arterial pressure. Subsequently, the stimulation of afferent baroreceptors follows due to the heightened arterial pressure. This stimulation triggers a reflexive reduction in efferent sympathetic outflow to the heart and blood vessels, alongside the activation of parasympathetic outflow. As a consequence, this activation may contribute to a decrease in heart rate, stroke volume, and vascular resistance, ultimately resulting in the observed reduction of BP in this study. The BP-lowering impact of the MP may be attributed to its thermal effects [15]. HTN is one of the important risk factors for nearly all types of cardiovascular diseases such as coronary artery disease, left ventricular hypertrophy, cardiac arrhythmias, and cerebral stroke, renal failure. SBP, DBP, and MAP are key factors in determining the risk of developing cardiovascular disease in many populations. Increased SBP and normal or low DBP are indicators of cardiovascular disease [16]. RPP is an indirect indicator of myocardial oxygen consumption and cardiac function [17]. The DoP is regarded as a sign of cardiac workload, whereas PP is regarded as an easily accessible marker of vascular stiffness and a predictor of cardiovascular diseases [18]. Application of MP on the abdomen and eyes may affect the cardiovascular parameters positively and thereby reduce the risk of cardiovascular disorders. However, this study lacks a control group, and we had no control over the environmental temperature. Furthermore, we did not determine the mineral and other content of the mud used, and most importantly, we only assessed the short-term effects of MPs in patients with primary hypertension.

5 Conclusion

The study’s findings suggest that applying an MP to the abdomen and eyes for 20 min can reduce BP in hypertensive patients. However, future randomized controlled trials with a larger sample size and longer follow-up periods are necessary to further validate these results.