1.
Effect of Polyglucosamine on Weight Loss and Metabolic Parameters in Overweight and Obesity: A Systemic Review and Meta-Analysis.
Perna, S, Basharat, SNM, Ali, KF, Eid, A, Gasparri, C, Infantino, V, Faliva, MA, Naso, M, Cazzola, R, Cestaro, B, et al
Nutrients. 2020;(8)
Abstract
The use of dietary supplements for weight loss has gained significant momentum. Polyglucosamine, a chitosan derivative, is a dietary supplement increasingly used for weight loss. In this meta-analysis, we systematically summarized and quantified the key findings of four randomized, placebo-controlled clinical trials examining the effects of polyglucosamine supplementation and caloric restriction, and physical activity on body weight, body mass index (BMI), and waist circumference in subjects with overweight and obesity. The control group was set with a physical activity from 6-7 MET-h/week activity and up to 21 MET-h/week activity with caloric restriction. Compliance in the latter trials was reported via a follow-up questionnaire with the individual participants. The analysis included 399 subjects followed for a period ranging from 12 weeks to one year. Subjects' age ranged from 21-75 years, BMI from 26-45 kg/m2, and all were white European or Caucasian in ethnicity. The meta-analyzed mean differences for random effects showed that polyglucosamine supplementation improves weight loss by -1.78 kg [-2.78, -0.79], BMI by -1.52 kg/m2 [-3.58, 0.54], and improves waist circumference reduction by -1.45 cm [-2.77, -0.12]. In conclusion, the use of polyglucosamine supplementation in conjunction with lifestyle behavioral therapies can be effective for weight reduction. Further studies are needed to examine the long-term effects of polyglucosamine supplementation on weight loss and other metabolic parameters.
2.
Bariatric surgery, lifestyle interventions and orlistat for severe obesity: the REBALANCE mixed-methods systematic review and economic evaluation.
Avenell, A, Robertson, C, Skea, Z, Jacobsen, E, Boyers, D, Cooper, D, Aceves-Martins, M, Retat, L, Fraser, C, Aveyard, P, et al
Health technology assessment (Winchester, England). 2018;(68):1-246
Abstract
BACKGROUND Adults with severe obesity [body mass index (BMI) of ≥ 35 kg/m2] have an increased risk of comorbidities and psychological, social and economic consequences. OBJECTIVES Systematically review bariatric surgery, weight-management programmes (WMPs) and orlistat pharmacotherapy for adults with severe obesity, and evaluate the feasibility, acceptability, clinical effectiveness and cost-effectiveness of treatment. DATA SOURCES Electronic databases including MEDLINE, EMBASE, PsycINFO, the Cochrane Central Register of Controlled Trials and the NHS Economic Evaluation Database were searched (last searched in May 2017). REVIEW METHODS Four systematic reviews evaluated clinical effectiveness, cost-effectiveness and qualitative evidence for adults with a BMI of ≥ 35 kg/m2. Data from meta-analyses populated a microsimulation model predicting costs, outcomes and cost-effectiveness of Roux-en-Y gastric bypass (RYGB) surgery and the most effective lifestyle WMPs over a 30-year time horizon from a NHS perspective, compared with current UK population obesity trends. Interventions were cost-effective if the additional cost of achieving a quality-adjusted life-year is < £20,000-30,000. RESULTS A total of 131 randomised controlled trials (RCTs), 26 UK studies, 33 qualitative studies and 46 cost-effectiveness studies were included. From RCTs, RYGB produced the greatest long-term weight change [-20.23 kg, 95% confidence interval (CI) -23.75 to -16.71 kg, at 60 months]. WMPs with very low-calorie diets (VLCDs) produced the greatest weight loss at 12 months compared with no WMPs. Adding a VLCD to a WMP gave an additional mean weight change of -4.41 kg (95% CI -5.93 to -2.88 kg) at 12 months. The intensive Look AHEAD WMP produced mean long-term weight loss of 6% in people with type 2 diabetes mellitus (at a median of 9.6 years). The microsimulation model found that WMPs were generally cost-effective compared with population obesity trends. Long-term WMP weight regain was very uncertain, apart from Look AHEAD. The addition of a VLCD to a WMP was not cost-effective compared with a WMP alone. RYGB was cost-effective compared with no surgery and WMPs, but the model did not replicate long-term cost savings found in previous studies. Qualitative data suggested that participants could be attracted to take part in WMPs through endorsement by their health-care provider or through perceiving innovative activities, with WMPs being delivered to groups. Features improving long-term weight loss included having group support, additional behavioural support, a physical activity programme to attend, a prescribed calorie diet or a calorie deficit. LIMITATIONS Reviewed studies often lacked generalisability to UK settings in terms of participants and resources for implementation, and usually lacked long-term follow-up (particularly for complications for surgery), leading to unrealistic weight regain assumptions. The views of potential and actual users of services were rarely reported to contribute to service design. This study may have failed to identify unpublished UK evaluations. Dual, blinded numerical data extraction was not undertaken. CONCLUSIONS Roux-en-Y gastric bypass was costly to deliver, but it was the most cost-effective intervention. Adding a VLCD to a WMP was not cost-effective compared with a WMP alone. Most WMPs were cost-effective compared with current population obesity trends. FUTURE WORK Improved reporting of WMPs is needed to allow replication, translation and further research. Qualitative research is needed with adults who are potential users of, or who fail to engage with or drop out from, WMPs. RCTs and economic evaluations in UK settings (e.g. Tier 3, commercial programmes or primary care) should evaluate VLCDs with long-term follow-up (≥ 5 years). Decision models should incorporate relevant costs, disease states and evidence-based weight regain assumptions. STUDY REGISTRATION This study is registered as PROSPERO CRD42016040190. FUNDING The National Institute for Health Research Health Technology Assessment programme. The Health Services Research Unit and Health Economics Research Unit are core funded by the Chief Scientist Office of the Scottish Government Health and Social Care Directorate.
3.
Metformin induces significant reduction of body weight, total cholesterol and LDL levels in the elderly - A meta-analysis.
Solymár, M, Ivic, I, Pótó, L, Hegyi, P, Garami, A, Hartmann, P, Pétervári, E, Czopf, L, Hussain, A, Gyöngyi, Z, et al
PloS one. 2018;(11):e0207947
Abstract
BACKGROUND Metformin is the first-choice drug for patients with Type 2 diabetes, and this therapy is characterized by being weight neutral. However, in the elderly an additional unintentional weight loss could be considered as an adverse effect of the treatment. OBJECTIVES We aimed to perform a meta-analysis of placebo-controlled studies investigating the body weight changes upon metformin treatment in participants older than 60 years. MATERIALS AND METHODS PubMed, EMBASE and the Cochrane Library were searched. We included at least 12 week-long studies with placebo control where the mean age of the metformin-treated patients was 60 years or older and the body weight changes of the patients were reported. We registered our protocol on PROSPERO (CRD42017055287). RESULTS From the 971 articles identified by the search, 6 randomized placebo-controlled studies (RCTs) were included in the meta-analysis (n = 1541 participants). A raw difference of -2.23 kg (95% CI: -2.84 --1.62 kg) body weight change was detected in the metformin-treated groups as compared with that of the placebo groups (p<0.001). Both total cholesterol (-0.184 mmol/L, p<0.001) and LDL cholesterol levels (-0.182 mmol/L, p<0.001) decreased upon metformin-treatment. CONCLUSIONS Our meta-analysis of RCTs showed a small reduction of body weight together with slight improvement of the blood lipid profile in patients over 60 years. With regard to the risk of unintentional weight loss, metformin seems to be a safe agent in the population of over 60 years. Our results also suggest that metformin treatment may reduce the risk of major coronary events (-4-5%) and all-cause mortality (-2%) in elderly diabetic populations.