Injections of the gut hormone oxyntomodulin may help healthy, overweight people lose weight, a new study shows.
Oxyntomodulin is one of several hormones made by the body that are thought to regulate satiety, or feeling full.
The latest oxyntomodulin study comes from Steve Bloom, FMedSci, and colleagues at Imperial College London. They studied 15 healthy, overweight men and women, publishing the results online in the International Journal of Obesity.
For four days, each participant injected his or her abdomen with oxyntomodulin or salt water (placebo) before meals. They repeated the four-day cycle three times.
In the first cycle, everyone got salt water as they learned how to give themselves the shots. After that, they spent one cycle on the hormone and the other on the placebo, though they didn’t know which was which.
About the Group
Participants were healthy and 23-49 years old (average age was 37). They were overweight or obese, judging by their BMI (body mass index), which ranged from 25 to 39.
Overweight BMIs start at 25; obese BMIs start at 30.
All participants were nonsmokers. They weren’t dieting or taking weight loss drugs. Their weight had been stable for at least three months before the study. Before joining the study, participants completed a questionnaire to screen out anyone with abnormal eating patterns.
The researchers advised women of childbearing age who took part in the study to use contraceptives and submit regular urine samples for pregnancy tests.
Participants started each cycle at the researchers’ lab. They had been instructed to fast the night before and to avoid alcohol and strenuous exercise for 24 hours before coming to the lab.
At the lab, participants gave themselves their first injection. Half an hour later, they were fed a meal of chicken curry, mushroom stroganoff, or chicken tagliatelle (a type of pasta).
All participants rated the food as appealing. They also had similar hunger ratings before eating. Those who had just gotten the hormone shot ate about 128 fewer calories at the meal, the study shows.
Participants provided their own meals for the rest of each cycle, giving themselves the injections half an hour before each meal.
Participants wore devices that tracked how many calories they burned. They burned about 143 more calories per day while using the hormone shots, compared with the placebo injections, the study shows.
On the last day of each cycle, participants took a lab test to see how many calories they burned at rest. The hormone shots didn’t seem to affect calories burned at rest, write Bloom and colleagues.
Participants lost about a pound when they used the hormone shots for four days. It’s not clear if they lost body mass or fluids, the researchers note.
One participant reported feeing more nauseous while taking the hormone shots. No other adverse events were reported during the study.
The study was short, so it doesn’t show long-term results. Because the medication is a naturally occurring hormone, side effects are expected to be minimal, the researchers note.
Last year, Bloom’s team reported in the journal Diabetes that people who got the hormone shots lost about 5 pounds in four weeks, compared with about a pound lost by the comparison group.
Bloom is involved in two patent applications related to oxyntomodulin, the journal states.
By Miranda Hitti, reviewed by Ann Edmundson, MD
SOURCES: Wynne, K. International Journal of Obesity, April 18, 2006; online edition. WebMD Medical News: “Hormone Injection May Trigger Weight Loss.” News release, Imperial College London.