Management of Lateral Epicondylitis Using Transdermal Nitroglycerin: A Systematic Review.

Lateral epicondylitis (LE), also known as tennis elbow, is an overuse tendinopathy originating from the forearm extensor tendons of the elbow. An emerging therapy for the treatment of LE is the use of transdermal nitroglycerin (NTG) patches for pain relief and improved function. The aim of this systematic review was to assess the current literature on the effect of a transdermal NTG patch for the treatment of LE. A literature search using MEDLINE, EMBASE, SportDiscus, and the Cochrane Database of Systematic Reviews was conducted. Studies selected for inclusion were those in which patients were clinically diagnosed with LE, RCTs, observational studies, and only articles published in English. Studies were excluded if they involved patients <18 years of age or involved patients with a potential alternative source of elbow pain such as previous surgery to the elbow, a previous history of dislocation, fracture of the elbow or tendon rupture, or a referred pain source such as cervical radiculopathy or peripheral nerve involvement. Studies were also excluded if they involved patients who were already prescribed topical NTG for any other indication (i.e., angina), and if the studies had no measurement of symptom relief or measurement or functional scoring. The initial search strategy yielded 69 articles, out of which four met the eligibility criteria and were included in this systematic review. The studies showed improvement in elbow pain in the short-term and mid-term (up to six months), while one study that followed participants for a five-year duration post-treatment, showed no benefit. Three studies used an effective NTG dose of 1.25mg/24h and one study used an effective dose of 1.44mg/24h. Topical NTG was more effective when combined with a tendon rehabilitation program. The most commonly reported side effects of topical NTG were headaches and dermatitis. Overall, the current literature demonstrates that the use of NTG patches for LE improves short- and mid-term pain as well as elbow function. However, more studies are required to fully understand the effect of topical NTG on LE, particularly the effective dose range and the long-term benefits.

Oral contraceptives modulate the muscle metaboreflex in healthy young women.

There are known sex differences in blood pressure regulation. The differences are related to ovarian hormones that influence ß-adrenergic receptors and the transduction of muscle sympathetic nerve activity. Oral contraceptives (OC) modulate the ovarian hormonal profile in women and therefore may alter the cardiovascular response. We questioned if OC would alter the absolute pressor response to static exercise and influence the day-to-day variability of the response. Healthy men (n = 11) and women (n = 19) completed a familiarization day and 2 experimental testing days. Women were divided into those taking (W-OC, n = 10) and not taking (W-NC, n = 9) OC. Each experimental testing day involved isometric handgripping exercise, at 30% of maximal force, followed by circulatory occlusion to isolate the metaboreflex. Experimental days in men were 7-14 days apart. The first experimental testing in W-OC occurred 2-7 days after the start of the active phase of their OC. Women not taking OC were tested during the early and late follicular phase of the menstrual cycle as determined by commercial ovulation monitor. The increase in mean arterial pressure (MAP) during exercise was significantly lower in W-NC (95 ± 4 mm Hg) compared with men (114 ± 4 mm Hg) and W-OC (111 ± 3 mm Hg) (P < 0.05), with the differences preserved during circulatory occlusion. The rise in MAP was significantly correlated between the 2 testing days in men (r = 0.72, P < 0.01) and W-OC (r = 0.77, P < 0.05), but not in W-NC (r = 0.17, P = 0.67), indicating greater day-to-day variation in W-NC. In conclusion, OC modulate the exercise pressor response in women and minimize day-to-day variability in the exercise metaboreflex.

The effect of consistent practice of yogic breathing exercises on the human cardiorespiratory system.

The purpose of this investigation was to quantify the cardiovascular, respiratory, and cerebrovascular effects of two common yogic breathing exercises (YBE): bhastrika and chaturbhuj; and to determine the effect of their consistent practice on chemosensitivity. The first study was cross-sectional and compared experienced yogic breathers (YB) with matched controls; whereas the second was a 10-week longitudinal training study. The results support four major findings. First chaturbhuj resulted in a hypoxic stimulus in experienced YB compared to control [end-tidal oxygen tension (PETO2), YB: 77.5±5.7mmHg, P<0.05; control: 94.3±12.0mmHg]. Second, performance of chaturbhuj resulted in cyclic oscillations of mean arterial pressure (MAP), heart rate (HR), and middle cerebral artery velocity (MCAv) consistent with the phases of respiration. Third, post training, performance of bhastrika reduced PETO2 (end breath-hold: 90.8 8±12.1mmHg) compared to rest (100.1±7.4, P<0.05); it also resulted in significantly increased MAP at end breath-hold (96.7±13.0mmHg) compared to rest (83.0±6.6mmHg, P<0.05) and significantly increased mean MCAv (end breath-hold: 87.4±23.0cm/s, P<0.05; rest: 55.8±26.3cm/s). Fourth, experienced YB had lower central chemosensitivity than controls (YB: 3.4±0.4; control: 4.6±1.2L/min/mmHg; P<0.05). In conclusion, YBE significantly alter end-tidal gases, resulting in complex oscillations of cardiovascular and cerebrovascular variables, and if practiced consistently, may reduce chemosensitivity.