This month's roundup will focus on the latest evidence on management of obesity. According to the World Health Organization (WHO) obesity prevalence has tripled since 1975 and is a major public health concern due to risk of diabetes, cardiovascular disease cancer and musculoskeletal disorders (WHO, 2020). General guidance from the National Institute for Clinical Excellence (NICE) outlining obesity management, recommends a combination of lifestyle, pharmacological and surgical interventions to promote weight loss (NICE, 2014). Pharmacological interventions are reserved for children over the age of 12 and adults who have not be successful with lifestyle interventions alone. Focussing on research on pharmacotherapy for obesity management since publication of the NICE guidance, five papers will be presented; two review papers (Avenall et al, 2018; Khalil et al 2020), two papers reviewing prescribing practice of clinicians (Lumsden et al, 2020; Sqaudrito et al, 2020) and one paper exploring the views of patients prescribed anti-obesity medication, orlistat (Hollywood and Ogden, 2016)
The REBALANCE systematic review
A large mixed methods systematic review of 236 studies aimed to establish the feasibility, acceptability and cost effectiveness of bariatric treatment including pharmacotherapy, orlistat. Twelve studies in the review reported on outcomes of randomised controlled trials comparing orlistat with placebo. In all of the studies participants, adopted a low calorie diet and lifestyle changes in addition to orlistat. Outcome measures were weight loss at specific timepoints up to a maximum of 48 months. Meta-analysis of the included studies reported a significant effect on weight loss in the group given orlistat. In addition, groups receiving orlistat had a higher incidence of gastro-intestinal side effects with those receiving a dose of 120 mg experience more than those prescribed 60 mg. This suggest that despite side effects, orlistat is an effective intervention for promoting weight loss in people who are obese, and an intervention recommended in NICE guidance.
Pharmacological treatment for obesity in adults
A second review, reported on nine systemic reviews that reported on three pharmacotherapies, namely liraglutide, orlistat and naltrexone/buprupion. When compared with placebo all drugs were more effective at weight loss than placebo and all drugs achieved the recommended 5% reduction in weight loss within 3 months of starting treatment. Whilst these results suggest that pharmacotherapy for obesity management is effective, it should be noted, similar to Avenall et al (2018), most studies included drug treatment with lifestyle interventions and low calorie diets. There were limitations noted in the studies reviewed, such as the influence of individual characteristics that may influence drug effect, for example genetics, behavioural and environmental features. Nevertheless, it appears that the drug therapy is effective in achieving weight loss. Choice of drug will be dependent on local formularies and on pre-existing comorbidities. Prescribers should therefore adopt a person centred approach to prescribing and refer to local guidance when caring for people with obesity who may benefit from drug therapy.
Anti-obesity drug prescribing practice in Italy
This retrospective observational study investigated prescribing practice of clinicians in Italy caring for people with obesity. It reviewed case notes for 1300 patients in eight general practices to establish the uptake of anti-obesity prescribing. In those meeting criteria for anti-obesity medication (n = 830, 63.8%), no-one was prescribed orlistat and only seven patients were prescribed liraglutide and only prescribed in the presence of type 2 diabetes suggesting suboptimal adherence to clinical guidelines. Whilst this study did not explore with clinicians the reason for low prescribing rates, it suggests that one reason may be that clinicians do not perceive obesity as a modifiable medical condition, which, if treated, may reduce the risk of cardiovascular disease, diabetes and joint disorders. The authors also hypothesise that clinicians may also be concerned that adherence to treatment may be low due to gastrointestinal side effects of some treatment. Furthermore, the authors suggest that some clinicians may consider people with obesity as a population who are responsible for their own condition and, as a result should adopt effective self-management strategies rather than seeking medical interventions to manage the condition. These hypotheses should be further investigated in future research, thus providing evidence for behaviour change in clinicians caring for this population.
Prescribing for obesity in the USA
Similar low rates of anti-obesity prescriptions were reported in a study conducted in the USA. Data were retrospective collected from 37 general practice clinic in the state of North Carolina.. Over 170 000 cases notes were analysed and, of those, 62% (n =124 740) were overweight or obese (BMI > 30) and had higher incidence co-morbidities compared to those with normal weight. Despite the high incidence of obesity and no change in weight during the study period, a minority or the study population (6%) were an official diagnosis of obesity and only 1% of those eligible prescribed anti-obesity medication. The authors suggest that reasons for this under prescribing may be due to under-reporting of obesity, absence of training for clinicians caring for people with obesity, and concerns around medicines safety. This viewpoint has been corroborated a study of 94 primary care providers in the USA suggesting a need for education and training in obesity management (Ganara and Laurent, 2017). The authors conclude that there is an opportunity to improve the health and wellbeing of people with obesity by developing effective interventions to improve reporting and medical management.
Orlistat: the patients' perspective
The final article in this month's roundup explored the experience of patients who had gained weight 18 months after receiving a prescription of orlistat. Semi-structured interviews were conducted with 10 patients and transcripts thematically analysed by the researchers. Findings suggest that some participants attributed treatment failure to the medication and associated side effects, in particular gastro-intestinal symptoms such as flatulence and diarrhoea. Others attributed weight gain to psychological or external factors out with their control. For example, one participant reported a 3-month recovery from a flu-like illness as a factor that impeded adherence to the weight loss and lifestyle programme prescribed alongside orlistat. Another attributed their lack of weight loss to their physiological make up and acceptance that being overweight was part of their identity and treatment interventions were never effective. This pessimism with weight loss strategies was evident in the final theme, which suggested that there was a perception that of the inevitability of orlistat failure. There are some limitations to this study, first, it specifically sought out views of people who had not had sustained weight loss with orlistat, and, secondly, has a very small sample size. Therefore, results are not generalisable to the wider population prescribed this treatment. However, it does suggest that, similar to other pharmacological interventions, prior to prescribing orlistat and other weight loss medications an exploration of service users perceptions of obesity and their readiness to change dietary and lifestyle habits is vital.
There appears to be reticence amongst clinicians to prescribe treatment [for obesity] and, for some patients, scepticism of its efficacy
Conclusion
A number of high quality reviews have demonstrated efficacy of drug treatment to support weight loss in people who are obese, yet there appears to be reticence amongst clinicians to prescribe treatment and, for some patients, scepticism of its efficacy. These barriers to implementing interventions aimed at reducing the burden of obesity on healthcare require further in-depth, robust exploration, followed by design of complex inter professional interventions to optimise health and well-being in this population.