Developments in Obesity Treatment Session, ECO 2013Wednesday, May 15, 2013
This morning, on the last day of the 20th European Congress on Obesity in Liverpool, I attended a session that looked at clinical outcomes in obesity management.
The first talk, given by Karlson from Norway looked at predictors of weight-loss outcomes in about 200 individuals undergoing a program that included several week-long in-patient stays at a rehabilitation centre over the course of a year with follow-up “maintenance” provider-patient contacts. Although the average weight loss at 12 months was only around 10 Kg, the variability in weight-loss response increased, with a substantial number of patients achieving weight loss comparable with bariatric surgery, while others regained much of the initial weight loss. In their analyses, initial weight loss, type 2 diabetes, mental health related quality of life, younger age and employment status were the strongest predictors of success. The other variable that influenced outcomes appeared to be the frequency of visits to the patients’ family doctors.
This was followed by a presentation by Nick Finer (London, UK), who reviewed the improvements in blood pressure in patients treated with the combination of phentermine and extended-release topiramate (marketed by Vivus Pharmacetuicals in the US as Qsymia®) in the CONQUER trial, a 56-week double blind placebo-controlled RCT. Overall, treated individuals experienced approximately 7 mmHg average fall in systolic blood pressure that was sustained over the year of treatment. Irrespective of hypertension status about a third of treated patients achieved a rather impressive greater than 15% weight loss. Not surprisingly, those who lost the most weight, experienced the greatest reduction in blood pressure (-10/-6 mmHg), despite reduction in blood pressure medications in a substantial number of hypertensive patients. Thus, there is no doubt that treatment with PT/TPM combination can result in substantial improvement in blood pressure control, that appear directly related to the degree of weight loss.
Ed Hendricks (US) addressed the issue of whether or not phentermine is actually addictive, a notion that is largely based on similarities in molecular structure of phentermine with amphetamines. Based on a prospective observation of 72 patients treated with rather high doses of phentermine (50+ mg/d) for at least 12 months, who agreed to discontinue their phentermine for 48 hours, there was no evidence for “withdrawal” based on a modified Amphetamine Withdrawal Questionnaire, with the exception of recurrence of hunger (as one might expect). Thus, these findings do not support the notion that abrupt discontinuation following the long-term use of phentermine results in phentermine “dependency” or “addiction”.
William Shanahan, Chief Medical Officer of Arena Pharmaceuticals talked about how treatment with lorcaserin, which will become available for obesity treatment in the US in June (Belviq®), results in a significant decrease in Framingham general cardiovascular risk scores, especially in men. Again, the greatest reduction in risk scores were seen in the patients with the greatest degree of weight loss response on lorcaserin.
Kyra Sim, from the University of Sydney, Australia, described substantial cost savings of obesity treatment in women seeking fertility treatments. This prospective randomised controlled trial included 49 women willing to undergo a three-month weight-loss intervention program using VLCD for 6 weeks followed by a moderately calorie-deficit diet and exercise recommendations. Mean weight loss in the intervention group was about 7%. Fertility rates were 48% in the intervention group vs 18% in the control group – in addition, the cost of each live baby in the intervention group was about one-third in that of the control group.
Marina Reeves, from the University of Queensland, Australia, discussed the issue of substantial weight gain commonly seen in women who survive breast cancer (fortunately, an increasing proportion of women with BC). 90 women with a 1st diagnosis of stage 1-111 breast cancer were enrolled in either a behavioural intervention that involved telephone counselling aiming for a 5-10% weight loss or a usual care group. At 6 months, women in the intervention group (which had a 20% drop out rate), lost about 5% of body weight and showed some increase in moderate to vigorous physical activity, and improvements in fatigue. Overall these findings speak to the feasibility of conducting a larger prospective study to examine the impact of this intervention on longer-term outcomes in breast cancer survivors.
Disclaimer: I have previously received honoraria for consulting from both Arena and Vivus