The present study was an open-label clinical trial in which participants received 12 LLLT treatments. To keep the number of treatments consistent across study arms, study participants were randomized to one of three treatment frequencies: (1) three times a week for 4 weeks (group A); (2) twice a week for 6 weeks (group B); (3) once a week for 12 weeks (group C). This study was approved by the Mayo Clinic Institutional Review Board and written informed consent was obtained for all study participants.
Potential participants were recruited from the local community of Rochester, MN, between September 2016 and August 2017. This report is based on all participants who consented to study, passed study criteria, and went on to be treated in study. All study visits and treatments took place in Mayo Clinic—Rochester Campus. The study adheres to the consort guidelines on reporting clinical trials  as demonstrated in the consort diagram presented in Fig. 1.
Eligible subject had to have a BMI between 25.0 and 29.9 kg/m2 and be motivated to lose weight. All interested individuals called a central number and underwent a 10-min phone pre-screen. If they passed the telephone pre-screen, they were invited to attend an in-person consent visit. They were excluded if they did not meet study entry criteria which included criteria such as being under the age of 18, not meeting BMI criteria of 25–29.9 kg/m2, not consenting to study, being on a concurrent weight loss program (including weight-loss medicines or exercise programs), having a weight fluctuation of 20 lb or more in past 6 months, having a medical unstable condition, having a positive pregnancy test, having an infection or having had surgery or other external trauma in the area to be treated by the laser, having a condition that affects weight levels, having a significant psychiatric condition such as depression (as measured by the CESD-R), being photosensitive, or having any other condition which may hinder participation or adherence to study procedures.
After participants consented to participation, they signed a written informed consent and were screened for study eligibility. If they passed the post-consent screening procedures, they were invited to participate. If they accepted the invitation, they were assigned the next available subject ID number and allocated to the appropriate treatment group using the pre-prepared randomization envelopes. Participants attended their in-person study visits every week at approximately the same time (± 2 h) and same day of the week.
A computer-generated randomization schedule was prepared by the study statistician using blocks of size N = 6 to ensure that after every sixth participant was randomized and an equal number of subjects was assigned to each treatment group. Using this randomization schedule, sealed randomization envelopes were prepared by administrative staff within the Division of Biomedical Statistics and Informatics. These randomization envelopes were labeled according to subject ID number and contained an index card indicating the treatment assignment for the given subject.
LLLT—The LLLT device consists of a multiple-head low-level diode laser with six independent diode laser heads. Each diode emits 532 nm (green) laser light. In the active device (Erchonia1 LipoLaser; Erchonia Medical, Inc., McKinney, TX) , each diode generates a 17-mW output. The average number of treatments can vary, depending on the adipose makeup on the patient . In this trial, subjects underwent 12 treatments of LLLT at varying frequencies (1, 2, or 3 times per week). The laser used in this study was an Erchonia® Zerona™ v2.0 Laser. This LLLT has been approved by the Food and Drug Administration (FDA) as a non-invasive dermatological esthetic treatment to reduce the circumference of hips, waist, and thighs. Lasers were targeted at central adiposity in the abdomen region for 30 min and the central region of their back for another 30 min. The lasers were placed approximately 6 in. from the targeted area during the treatment cycle and each treatment occurred within 48 h to 7 days apart.
The Erchonia® Zerona™ 2.0 Laser (used in this study) has been approved by the FDA (K123237) as a non-invasive dermatological esthetic treatment which can be used by individuals intending to reduce circumference of hips, waist, and thighs. Justification for the assertion of anticipated safety and effectiveness of the Erchonia® Zerona 6 Headed Scanner (EZ6) for application to reducing body circumference is found through several FDA clearances for Erchonia® Low Level Laser devices for body circumference reduction indications. For all of the 510(k) clearances, the assigned Product Code is OLI, defined as follows:
Device: fat-reducing low-level laser
Regulation description: low-level laser system for esthetic use
Definition: non-invasive reduction in fat layer for body contouring
Technical method: use of low-level laser energy to create pores in adipocyte cells to release lipids (triglycerides)
Target area: adipocyte cells within the subcutaneous fat layer of the body; this could include abdomen (waist), thighs, and hips
Under 21 CFR 878,5400, the FDA identifies this generic type of device as: “A Low Level Laser System for Aesthetic Use is a device using low level laser energy for the disruption of adipocyte cells within the fat layer for the release of fat and lipids from these cells for non-invasive aesthetic use.”
The procedure administration protocol for each session was as follows:
The study participant is correctly fitted with the safety glasses.
The participant lies comfortably flat on his or her back on the procedure table such that the front area of the subject’s body is facing upwards.
The Erchonia® Zerona 6 Headed Scanner (EZ6) diodes are positioned at a distance of 6 in. above the subject’s lower and upper abdomen, stomach, centered along the body’s midline (the “line” that vertically “dissects” the body into two equal halves).
The Erchonia® Zerona 6 Headed Scanner (EZ6) is then activated for 30 min over the subject’s anterior (frontal) region. Each scanner emits to the subject a laser beam of approximately 17 mW with a wavelength of 532 nm, and creates a spiraling circle pattern that is totally random and independent from the others. These patterns overlap each other to guarantee total coverage within the target area of approximately 80 in.2/516 cm2.
The participant then turns over to lie flat on his or her stomach such that the posterior treatment area of the subject’s body encompassing the region spanning from the participant’s back down though the central body region is facing upwards.
The Erchonia® Zerona 6 Headed Scanner (EZ6) diodes are positioned at a distance of 6 in. above the posterior treatment area, centered along the body’s midline, the same as for the anterior region.
The Erchonia® Zerona 6 Headed Scanner (EZ6) is then activated for 30 min over the subject’s posterior region. Each scanner emits to the subject a laser beam of approximately 17 mW with a wavelength of 532 nm over 15 min, and creates a spiraling circle pattern that is totally random and independent from the others. These patterns overlap each other to guarantee total coverage within the target area of approximately 80 in.2/516 cm2. This converts to each patient receiving approximately 59.2 MJ/cm2 in energy density in the front and the same amount in the back, per session.
The participant’s safety glasses are removed and the procedure administration session is over.
An Erchonia expert trained the study staff in-person on the use and maintenance of the LLLT on December 12, 2013 for a prior study utilizing LLLT. This training session has been documented. They were available for on-the-spot questions and for any online retraining, as needed. The study coordinators were under the direction of the nurse coordinator/supervisor (DFR).
Behavioral intervention—Upon study entry, the study coordinator completed a brief (10-min) individual behavioral intervention introducing and reviewing a patient education resource, the Mayo Clinic “My Weight Solution©” manual, with the study participant, and a copy was given to them to keep. Topics in this manual included motivational strategies, social support, goal-setting strategies, nutritional recommendations, and strategies for physical activity.
Outcomes and safety measures
The primary outcomes included (1) 3% body weight loss from baseline; (2) anthropometric measures of waist (WC) and hip circumference; (3) body composition measurements via InBody 770, a bioelectrical impedance (BIA) scale used to measure participant weight, height, and body composition analysis (intracellular water, extracellular water, dry lean mass, body fat mass), and estimate visceral fat ; (4) linear analogue self-assessment (LASA) to self-assess quality of life (QoL) [14,15,16]; (5) participant motivation to reduce weight, self-assessed at baseline prior to study interventions; (6) Body Areas Satisfaction Scale (BASS), a subscale from the Multidimensional Body-Self Relations Questionnaire (MBSRQ)  used to self-assess participants’ self-perceived body image and satisfaction of eight specific body areas [18, 19]; (7) Body Appreciation Scale (BAS), a scale to self-assess positive body image ; and (8) adherence to the study interventions recorded by staff as attendance to the laser treatments.
The safety measures included (1) adverse events, (2) concomitant medication, (3) self-reported depression using the Center for Epidemiologic Studies Depression Scale Revised (CESD-R), and (4) urine pregnancy tests.
Study visits were divided into three phases: screening (09/30/16 to 08/27/17), treatment (10/04/16 to 11/30/17), and post-treatment (11/11/16 to 03/05/18). All participants were in study for 6 months. The screen phase included a pre-screen phone interview and a combined consent/screen/randomization visit. Once randomized, participants entered the treatment phase based on their randomization schedule. If randomized to group A—the participant reported for treatment for 4 sequential weeks (3 times per week); if randomized to group B—the participant reported for treatment for 6 sequential weeks (2 times per week); if randomized to group C—the participant reported for treatment for 12 sequential weeks (1 time per week). One week after the last treatment, participants received a safety phone contact. Participants were required to complete an in-person study visits at weeks 4, 6, 12, and 26 during which time the study staff collected data pertaining to QoL (LASA), body image (BAS and BASS), safety (adverse events and concomitant medication), as well as vitals, BIA, and body measurements. In addition, during the final visit (week 26), satisfaction was measured via an end-of-study self-assessment survey.
The primary endpoint for this investigation was change in WC from baseline, and for this endpoint a reduction of 1.0 cm was considered clinically meaningful. Based on preliminary data from our previous study , we determined that for this randomized phase II study, a sample size of N = 20 per group would provide statistical power (one-tailed, alpha = 0.20) of approximately 80% to assess whether additional studies are warranted .
Data were summarized using mean ± SD for continuous variables and frequency percentages for nominal variables. Anthropometric measures at each of the study visits (weeks 4, 6, 12, and 26) were compared to baseline using the paired t test and compared across treatment groups using analysis of covariance with the baseline value included as the covariate. Three pairwise treatment group comparisons were of specific interest: the change in WC from baseline to week 4 was compared between those receiving LLLT three per week and those receiving LLLT twice and once per week; and the change in WC from baseline to week 6 was compared between those receiving LLLT twice per week and those receiving LLLT once per week. The results of these comparisons are summarized by presenting the effect estimate along with 90% confidence intervals and one-tailed p values. All other measures were analyzed using two-tailed tests. If the overall comparison across treatment groups was statistically significant at the p < 0.05 level, linear contrasts were used to perform pairwise treatment group comparisons. Data were managed using the REDCap tool hosted at Mayo Clinic , and analyses were conducted using SAS statistical software .