Background: We studied whether musclin function in humans is related to glycemic control, body composition, and cardiorespiratory capacity. Methods: A cross-sectional study was performed in sedentary adults with or without metabolic syndrome (MS). Serum musclin was measured by enzyme-linked immunosorbent assay. Insulin resistance (IR) was evaluated by the homeostatic model assessment (HOMA-IR). Body composition was determined by dual-energy X-ray absorptiometry and muscle composition by measuring carnosine in the thigh, a surrogate of fiber types, through proton magnetic resonance spectroscopy. Cardiorespiratory capacity was assessed through direct ergospirometry. Results: The control (n=29) and MS (n=61) groups were comparable in age (51.5±6.5 years old vs. 50.7±6.1 years old), sex (72.4% vs. 70.5% women), total lean mass (58.5%±7.4% vs. 57.3%±6.8%), and peak oxygen consumption (VOpeak) (31.0±5.8 mL O2./kg.min vs. 29.2±6.3 mL O2/kg.min). Individuals with MS had higher body mass index (BMI) (30.6±4.0 kg/m2 vs. 27.4± 3.6 kg/m2), HOMA-IR (3.5 [95% confidence interval, CI, 2.9 to 4.6] vs. 1.7 [95% CI, 1.1 to 2.0]), and musclin (206.7 pg/mL [95% CI, 122.7 to 387.8] vs. 111.1 pg/mL [95% CI, 63.2 to 218.5]) values than controls (P˂0.05). Musclin showed a significant relationship with HOMA-IR (β=0.23; 95% CI, 0.12 to 0.33; P˂0.01), but not with VOpeak, in multiple linear regression models adjusted for age, sex, fat mass, lean mass, and physical activity. Musclin was significantly associated with insulin, glycemia, visceral fat, and regional muscle mass, but not with BMI, VCO2peak, maximum heart rate, maximum time of work, or carnosine. Conclusion In humans, musclin positively correlates with insulinemia, IR, and a body composition profile with high visceral adiposity and lean mass, but low body fat percentage. Musclin is not related to BMI or cardiorespiratory capacity.

Objective: This pilot human trial demonstrates the ability of the investigational newborn hearing screening device to provide acoustic stimulation to produce evoked potentials, as well as its ability to capture and acquire auditory evoked potentials, especially the auditory brainstem response (ABR) wave V. This pilot study also demonstrates the ease of recognizing and identifying ABR waves in the graphical presentation of the evoked potentials over time. Methods: Fourteen normal-hearing adults or a total of twenty-eight (28) normal-hearing adult ears underwent auditory brainstem response testing using the investigational hearing screening device. A commercially available auditory brainstem response detection device was used to confirm that the acquired ABR waves of the investigational device are normal. The ABR waves displayed by the investigation device were also reviewed by the clinical audiologists to determine their recognizability and identifiability. Results: The pilot trial demonstrates the ability of the investigational newborn hearing screening device in providing acoustic stimulation to produce evoked potentials, and in acquiring and capturing ABR waves, specifically the wave V, among normal-hearing adult ears. The clinical audiologists recognized and identified the ABR wave V among the evoked potentials at 40dB, 60dB, and 80dB acoustic stimulation. About eighty-nine percent (89.2%) of all ears tested had identifiable and recognizable wave V upon acoustic stimulation at 40dB. Conclusion The investigational hearing screening device: (1) can provide acoustic stimulation to produce evoked potentials, (2) can accurately capture and acquire these evoked potentials, (3) can present these evoked potentials in a voltage per time graphical display which an audiologist and trained HCP can easily read and interpret (diagnostic ABR), and (4) can present wave V auditory brainstem potentials that can be easily identified by an audiologist and trained HCP (screening ABR).
Infant, Newborn ; Acoustics ; Pilot Projects