Dr Sarah Tonks explores the role of low level laser therapy in body-contouring treatments
French surgeon Mr Charles Dujarier first introduced the concept of lipoplasty in the 1920s. He attempted to remove the subcutaneous tissue from a dancer’s calves, but unfortunately ultimately caused gangrene and the death of the patient.1
The appetite for non-surgical body contouring has fuelled the development of non-invasive, comfortable and safe solutions for the reduction of fat and improvement of the silhouette. Liposuction successfully reduces fat and improves contour in a predictable fashion, nevertheless there is still a continuous demand for non-surgical and non-invasive methods that may be less dramatic and immediate, and come without the same level of risk and side effects.
The number of minimally invasive procedures increased by 137% from 2000 to 2012 in the US.2 These treatments are sometimes referred to as ‘lunch-time procedures’ because they have minimal down time and can often be completed in less than two hours.
Patients who are time-poor and do not have the opportunity to recuperate following surgery may select a non-invasive alternative in order to fit with lifestyle factors, or the patient may dislike the idea of having a surgical procedure. Cost can also be a factor; although when larger areas are treated it can often be just as cost effective to undergo liposuction rather than a non-surgical method due to the number of treatment sessions that may be needed. Periprocedural morbidity can be reduced by the use of non-invasive methods such as a reduction in infection, scarring and anaesthesia.3 This article will seek to clarify which methods are commonly available in the UK at the moment and introduce a new treatment modality for non-surgical body contouring which also has some interesting endocrine effects, in the form of a low-level light green laser.
Cryolipolysis, high intensity focused ultrasound, radiofrequency and low level laser are common treatment modalities available on the market in the UK.4 In a 2015 study it was indicated that both cryolipolysis and ultrasound cavitation are safe and effective for body contouring and decreasing abdominal adiposity. Both significantly reduced excess subcutaneous adipose tissue from the abdomen, as shown in the decrease in waist circumference and skinfold measurements. There was no significant difference between the two techniques with regard to reduction of fat thickness.3
Cryolipolysis, radiofrequency and ultrasound cavitation methods involve apoptosis or necrosis causing cell death, which reduces subcutaneous fat thickness and can all be achieved without changes in a patient’s lipid profile or liver function tests.3
After the fat cells are disturbed, the triglycerides are scattered in the interstitial tissue and transported through the vascular lymphatic system to the liver. They are metabolised by endogenous lipases to glycerol and free unsaturated fats. These unsaturated fats are transported to the liver where they are treated like other unsaturated fats. Unmetabolised triglycerides are combined with transporter proteins or lipoprotein complexes and end up as part of the lipoprotein pool.3
Cryolipolysis has been commercially available for the longest amount of time, with research consisting of in vitro and animal models, as well as randomised controlled trials in humans.4 The principle behind cryolipolysis is the idea that adipocytes are more susceptible to cooling than other skin cells. Application of cold temperatures triggers apoptosis which begins an inflammatory response and leads to the removal of the dead cells by macrophages.4
Ultrasound cavitation uses ultrasound energy through the skin to influence adipose tissue disruption as the subcutaneous tissue absorbs the energy. The ultrasonic waves create compression cycles that exert positive pressure and expansion cycles that exert negative pressure, which aims to prompt the mechanical disruption of fat cells. In addition to this, there is a thermal mechanism which destroys fat cells at temperatures above 58°C causing small coagulative areas of necrosis whilst surrounding tissues are unaffected.4 Ultrasound energy directed into the deeper fat layers can prompt cavities in the fat and decrease the overall thickness of the adipose layer without injury to the skin, vessels, nerves or connective tissue.3
Radiofrequency devices cause thermal injury using electrical energy. These devices have been traditionally used to tighten the skin and rhytides, as thermal damage results in contraction of collagen and remodelling, however they can also be used to selectively heat subcutaneous adipose tissue and induce lethal thermal damage whilst sparing the overlying and underlying tissues. Thermal exposures to 43-45°C over several minutes may result in a delayed adipocyte cell death.4
In comparison to the above-mentioned technologies, low level laser therapy is a unique treatment modality because it is not based on thermal tissue damage. The proposed mechanism of action is based on the concept of producing transient pores in the adipocytes, allowing lipids to leak out. This unique method of action is not one that is frequently discussed in the aesthetics industry and knowledge of this technology has not penetrated well. Equally there is little knowledge of this type of equipment in the public domain; therefore this article will seek to highlight some of the benefits and mode of action of this technology.
Reports of low level laser light therapy (LLLT) were first published in 1970 by Endre Mester in Hungary, who noted hair regrowth in mice exposed to a 694 nm ruby laser. He subsequently used a helium-neon 632.8 nm laser to stimulate wound healing in animal models and clinical studies.5
In more recent years this innovative technology has generated an exceptional level of interest across many medical disciplines because of its ability to modulate cellular metabolism to induce beneficial clinical effects.6 LLLT has been shown to alter gene expression,7 cellular proliferation,8 intracellular pH balance,9 mitochondrial membrane potential,10 generation of reactive oxygen species11 and calcium ion level,12 proton gradient13 and cellular oxygen consumption,14 as well as a reduction in cholesterol and triglyceride levels.6
Currently LLLT is used by osteopaths and chiropractors, although it is often regarded with skepticism by the medical profession in general.15 With more research on LLLT taking place, it is becoming an emerging technology in the field of non-surgical body contouring.
The mechanism is based on the absorption of red and near infrared light. According to the first law of photochemistry the observable biological effect after LLLT can only occur in the presence of a photoacceptor molecule that is capable of absorbing the photonic energy emitted.16 No photothermal mechanisms are associated with these devices so no heating sensation occurs. Cytochrome c oxidase, the terminal respiratory chain enzyme, has been identified as a photoreceptor target of LLLT.17 Cytochrome c oxidase is responsible for establishing the electrochemical gradient required for adenosine triphosphate synthesis.18
This enzyme is a membrane protein that has been indicated to absorb photonic energy. After laser irradiation at 633 nm, the mitochondrial membrane potential and proton gradient increases, which causes changes in the mitochondria, increasing the rate at which cytochrome c oxidase transfers electrons from cytochrome c to dioxygen.18 Such modulation of cell metabolism has been suggested to be associated with an increase in lipid peroxidation, which is the oxidative degeneration of membrane-bound cholesterol, resulting in breakdown of the membrane structure and function.18 Furthermore, the upregulation of reactive oxygen species can directly impact the cellular redox state and affect gene expression via activation of specific cell signalling pathways.18
LLLT excites cytochrome c oxidase which upregulates ATP synthesis and upregulates bioenergetics, which initiates the secondary messenger system to send an amplifying signal that diffuses throughout the cell to influence cell activity.19
LLLT provokes a shift of the intracellular redox state to an oxidative state, and activates redox sensitive transcription factors such as nuclear factor kappa B and activator protein-1, upregulating the expression of genes.19 It is thought that these transcription factors can influence membrane proteins and may alter the permeability of adipocytes.18 It is unclear at this time whether the transitory pore induced by laser therapy is the direct result of upregulated gene expression via transcription factor activation, lipid peroxidation by increased superoxide dismutase production or an exocytosis-like event.1
Clinical studies indicating the effectiveness of LLLT have used red diodes emitting light at a wavelength of 635 nm applied for 40 minutes (20 minutes to front and back) three times weekly for two weeks18 or green diodes emitting light at 532 nm for 30 minutes (15 minutes to front and back) three times weekly for two weeks.20 The 635 nm diode LLLT red diode laser device obtained marketing clearance from the FDA in 2010. It was tested on reduction of waist, thigh, hip and upper abdomen circumference and shown to give a reduction of 4.5 inches in combined body circumference when used once per week for 40 minutes.21
The green LLLT device at 532 nm received FDA clearance in 2013. The 532 nm device was cleared using the same protocols. Three treatments were administered each week for two weeks and measurements of the waist, hip, and thigh circumference were taken. There was a mean decrease in measurements of 3.9 inches after the two week period.20
In a randomised study the LLLT technology also had an interesting effect on the endocrine system. Body weight is regulated by endocrine and neural components controlling energy intake and expenditure. This regulatory process is responsible for preventing even small imbalances between energy and expenditure. Regulation is a complex interplay of hormonal and neural signals. Leptin is an adipose-derived hormone, which acts primarily in the hypothalamus to influence appetite, energy expenditure and neuroendocrine function. Leptin is coded by the Ob (Lep) gene. Under normal function leptin suppresses hunger, however when the adipocyte is enlarged then leptin is overproduced and the corresponding receptor becomes resistant.22 There have been studies suggesting that laser therapy can modulate gene expression of leptin and this is a potential mechanism for further clinical efficacy.22
There are few studies specifically looking at the association of LLLT and leptin, however in one study 22 patients aged 18-65 participated in a non-controlled, non-randomised study and received low level laser treatments (Zerona, Erchonia Medical Inc.) three times a week for two weeks. Fasting leptin panels (a type of blood tests) were performed pre procedure and at two weeks after the final procedure. Patients maintained normal eating and exercise habits throughout the study. There was a mean reduction in leptin of 50%. The mean baseline leptin measurement of 29.49 was reduced to 14.60, a statistically significant change of p=<0.0001(1).
Body contouring will doubtless continue to rise in popularity as treatment modalities improve in efficacy and more patients are interested in exploring non-surgical options. It is an interesting development to have a device that has effects on the endocrine metabolism and may have further reaching benefits above those of simply reducing the measurements of adipose tissue in a patient. Further work looking at the endocrine effects of LLLT would be welcomed. There may be some interesting health benefits with this modality as we also see a reduction in cholesterol and triglyceride levels, which could have interesting cardiovascular benefits.