Noninvasive Body Fat Burn Monitoring from Exhaled Acetone with Si-doped WO3-sensing Nanoparticles.

Obesity is a global health threat on the rise, and its prevalence continues to grow. Yet suitable biomedical sensors to monitor body fat burn rates in situ, to guide physical activity or dietary interventions toward efficient weight loss, are missing. Here, we introduce a compact and inexpensive breath acetone sensor based on Si-doped WO3 nanoparticles that can accurately follow body fat burn rates in real time. We tested this sensor on 20 volunteers during exercise and rest and measured their individual breath acetone concentrations in good agreement with benchtop proton transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS). During exercise, this sensor reveals clearly the onset and progression of increasing breath acetone levels that indicate intensified body fat metabolism, as validated by parallel venous blood ß-hydroxybutyrate (BOHB) measurements. Most importantly, we found that the body fat metabolism was especially pronounced for most volunteers during fasting for 3 h after exercise, with strong variation between subjects, and this was displayed correctly by the sensor in real-time. As a result, this simple breath acetone sensor enables easily applicable and hand-held body fat burn monitoring for personalized and immediate feedback on workout effectiveness that can guide dieting as well.

The effect of highly selective vagotomy on sick-listing in peptic ulcer patients.

The amount of sick-listing in 75 patients operated on with highly selective vagotomy (HSV) was studied during two periods, the first consisting of 12 months and ending 1 year before operation and the second period, also consisting of 12 months, starting 1 year after operation. Patients with suspected ulcer recurrences were excluded and only patients who, at the 1-year postoperative follow-up study, were without symptoms suggestive of ulcer recurrence are included. The median amount of sick days was 31.3 for the period preceding and 37.2 (NS) after the operation. Before operation 60% of all sick-leave diagnoses were ulcer or gastritis, compared with 20% after operation. A 50% increase in infectious diseases and lumbago occurred. Psychiatric disorders rose from 1 to 16 occasions. We therefore conclude that patients apparently cured of chronic ulcer disease change target and develop symptoms elsewhere. The study shows no potential economic benefits of HSV, at least not with regard to a diminishing amount of sick days after operation.