The effect of orlistat versus metformin on body composition and insulin resistance in obese premenopausal women: 3-month randomized prospective open-label study

The impact of metformin on weight and metabolic parameters in patients with obesity: A systematic review and meta-analysis of randomized controlled trials

There are conflicting data on the weight-reducing potential of metformin (MTF) in nondiabetic patients with obesity. The purpose of this systematic review and meta-analysis was to evaluate the effect of MTF on weight and cardiometabolic parameters in adults with overweight/obesity with or without nonalcoholic fatty liver disease (NAFLD) (CRD42018085512). We included randomized controlled trials (RCTs) in adults without diabetes mellitus, with mean body mass index (BMI) ≥ 25 kg/m2, with or without NAFLD, comparing MTF to placebo/control, lifestyle modification (LSM) or a US Food and Drug Administration-approved anti-obesity drug, reporting on weight or metabolic parameters, and extending over at least 3 months. We conducted a systematic search in MEDLINE, EMBASE, PubMed and the Cochrane Library without time limitation (until March 2022). We screened and selected eligible articles, abstracted relevant data, and assessed the risk of bias. All steps were in duplicate and independently. We conducted a random-effects model meta-analysis using Review Manager version 5.3, with prespecified subgroup analyses in case of heterogeneity. We identified 2650 citations and included 49 trials (55 publications). Compared to placebo, MTF was associated with a significant reduction in BMI (mean difference [MD] -0.56 [-0.74, -0.37] kg/m2; p < 0.0001), at doses ranging from 500 to 2550 mg/day, and with a significant percentage change in BMI of -2.53% (-2.90, -2.17) at the dose 1700 mg/day. There was no interaction by baseline BMI, MTF dose or duration, nor presence or absence of NAFLD. There was no significant difference between MTF and LSM. Orlistat was more effective than MTF (at doses of 1000-1700 mg/day) in terms of weight loss, with an MD in BMI of -3.17 (-5.88; -0.47) kg/m2, favouring the former. Compared to placebo/control, MTF improved insulin parameters, while no effect was detected when compared to LSM. A few small trials showed heterogenous effects on liver parameters in patients with NAFLD treated with MTF compared to placebo/control. There was a large variability in the expression of outcome measures and RCTs were of low quality. In conclusion, MTF was associated with a modest weight reduction in obese nondiabetic patients. Further high-quality and better powered studies are needed to examine the impact of MTF in patients with insulin resistance and NAFLD.

Protective and Therapeutic Effects of Orlistat on Metabolic Syndrome and Oxidative Stress in High-Fat Diet-Induced Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD) in Rats: Role on Nrf2 Activation

Metabolic dysfunction-associated fatty liver disease (MAFLD) is an excessive buildup of liver lipids closely associated with various kinds of undesirable metabolic effects and oxidative stress. We aimed to investigate the protective and therapeutic effects of orlistat on metabolic syndrome and oxidative stress parameters in high-fat diet (HFD) induced-MAFLD rats. Twenty-four male Sprague-Dawley rats were randomly divided into four groups (n = 6/group), i.e., Normal control (N), HFD, HFD + orlistat (HFD + O) (10 mg/kg/day administered concomitantly for 12 weeks as a protective model), and obese+orlistat (OB + O) (10 mg/kg/day administered 6 weeks after induction of obesity as a therapeutic model) groups. After 12 weeks, the HFD group had significantly increased Lee obesity index, serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total cholesterol, triglyceride, low-density lipoprotein levels, liver total cholesterol and triglyceride levels, insulin resistance and non-alcoholic steatohepatitis (NASH) together with decreased serum high-density lipoprotein level. Additionally, the HFD group also showed increased Nrf2 translocation to the nucleus with high Keap1 expression and increased liver oxidative stress parameters. Orlistat significantly improved all these alterations in HFD rats. We demonstrated that orlistat might have protective and therapeutic effects against HFD-induced MAFLD rats by its activation on Nrf2 signaling pathway, which subsequently improved metabolic syndrome and oxidative stress parameters.

POCU1b, the n-Butanol Soluble Fraction of Polygoni Cuspidati Rhizoma et Radix, Attenuates Obesity, Non-Alcoholic Fatty Liver, and Insulin Resistance via Inhibitions of Pancreatic Lipase, cAMP-Dependent PDE Activity, AMPK Activation, and SOCS-3 Suppression

This study investigated the effects of the n-BuOH soluble fraction of Polygoni Cuspidati 80% ethanol extract (POCU1b) on high-fat diet (HFD)-induced obesity, non-alcoholic fatty liver (NAFL), and insulin resistance (IR) to find a safe and more effective agent. HPLC profiling of POCU1b identified seven marker compounds. POCU1b increased glycerol release, cyclic adenosine monophosphate (cAMP) level, and inhibited phosphodiesterase (PDE) activity. Seven weeks of POCU1b treatment decreased body weight gain, weight and adipocyte size in fat tissues, serum lipids, and triglyceride and lipid droplets in the livers of HFD-fed rats. POCU1b improved blood glucose, insulin sensitivity, and impaired insulin secretion in the pancreas. Further, POCU1b ameliorated adiponectin, leptin, IL-6 and TNF-α levels, increased AMPK and p-ACC expression, activated CPT-1 activity, and suppressed FAS mRNA, SOCS-3 protein expression, and NF-κB DNA-binding activity. When compared with the Xenical^®-treated group, a positive group, the action of POCU1b on body weight was more effective than that of Xenical. POCU1b did not show side effects, such as oily spotting and loss of appetite. These results suggest that POCU1b possesses therapeutic or preventive potential for obesity, NAFL and IR via inhibitions of pancreatic lipase and cAMP-dependent PDE activity, AMPK activation, and SOCS-3 suppression, without oily spotting and loss of appetite.

Effects of metformin in obesity treatment in different populations: a meta-analysis

OBJECTIVE

Some studies have shown that metformin can reduce body weight. However, metformin has not been officially approved as a medicine for weight loss because its effect on different populations remains inconsistent. This meta-analysis aimed to summarize the weight loss effect of metformin quantitatively.

METHOD

The randomized controlled and high-quality case-control trials of metformin monotherapy in obesity treatment were eligible. Baseline body mass index (BMI) was chosen as a self-control to compare the changes in BMI of different populations before and after treatment. All changes were calculated as differences between the final and initial BMI values (with negative values indicating a decrease). Results were presented as weighted mean difference (WMD) with a 95% confidence interval (CI 95%). Subgroup analysis was performed based on baseline BMI, age, daily dose, and duration of medication.

RESULTS

A total of 21 trials (n = 1004) were included, and the meta-analysis of metformin treatment in different populations showed that metformin has a modest reduction in the BMI of included participants (WMD -0.98; 95% CI, -1.25 to -0.72), and the reduction of BMI was most significant in the simple obesity population (WMD -1.31; 95% CI, -2.07 to -0.54). The subgroup analysis showed that metformin treatment significantly reduced BMI in obesity patients with a BMI >35kg/m² (WMD -1.12; 95% CI, -1.84 to -0.39) compared with before treatment. BMI in the high dose group decreased by 1.01 units (WMD-1.01; 95% CI, -1.29 to -0.73) and BMI did not continue to decrease significantly after treatment of more than 6 months.

CONCLUSION

Patients treated with metformin experienced about a one-unit reduction in BMI at the end of treatment. But whether this decreased value produced enough weight loss (5% of baseline body weight) to qualify as a "weight loss drug" as current guidelines require, requires larger specific randomized control trials.

Lean Women on Metformin and Oral Contraceptives for Polycystic Ovary Syndrome Demonstrate a Dehydrated Osteosarcopenic Phenotype: A Pilot Study

Scarce data exist on the body composition of lean women with polycystic ovary syndrome (PCOS) on treatment with metformin and oral contraceptives (OCs). Thirty-four lean (body mass index 18.5–24.9 kg/m²) women (17 with PCOS on metformin and OCs treatment for six months and 17 controls) aged 18–40 years were assessed for body composition parameters (fat, muscle, glycogen, protein masses, bone masses, and body water compartments) and phase angles. PCOS patients demonstrated lower muscle, glycogen and protein masses (U = 60, p = 0.003), along with a lower bone mineral content and mass (U = 78, p = 0.021; U = 74, p = 0.014) than their healthy counterparts, while total and abdominal fat masses were similar between the two groups. PCOS patients also exhibited increased extracellular body water (U = 10, p < 0.001) and decreased intracellular water, compatible with low-grade inflammation and cellular dehydration. Key differences in body composition between women with PCOS and controls demonstrated an osteosarcopenic body composition phenotype in PCOS patients. A confirmation of these findings in larger studies may render osteosarcopenia management a targeted adjunct therapy in women with PCOS.

Lipid Hydrolase Enzymes: Pragmatic Prolongevity Targets for Improved Human Healthspan?

Compelling evidence suggests that lipid metabolism, which plays critical roles in fat storage, cell membrane maintenance, and cell signaling, is intricately linked to aging. Lipid hydrolases are important enzymes that catalyze the hydrolysis of more complex lipids into simpler lipids. Diverse interventions targeting lipid hydrolases can prolong or shorten life in model organisms. For example, the genetic removal of or RNAi knockdown against a phospholipase can reduce lifespan in Caenorhabditis elegans, Drosophila melanogaster, and Mus musculus. The removal of lysosomal acid lipase results in premature death in mice, while its overexpression in nematodes generates lean, long-lived individuals. The overexpression or inhibition of diacylglycerol lipase leads to enhanced or reduced longevity, respectively, in both worms and flies. Lifespan can also be extended by knocking down triacylglycerol lipases in yeast, overexpressing fatty acid amide hydrolase in worms, or removing hepatic lipase in a mouse model of coronary disease. Conversely, flies lacking the triacylglycerol lipase Brummer are obese and short lived. Linking sphingolipids and aging, removing the sphingomyelinase inositol phosphosphingolipid phospholipase shortens chronological lifespan in Saccharomyces cerevisiae, while inhibiting an acid sphingomyelinase in worms or inactivating alkaline ceramidase in flies extends lifespan. The clinical potential of manipulating these enzymes is highlighted by the FDA-approved obesity drug orlistat, which is an inhibitor of pancreatic and hepatic lipases that induces weight loss and improves insulin/glucose homeostasis. Additional research is warranted to better understand how these lipid hydrolases impact aging and to determine if clinical interventions targeting them are capable of improving human healthspan.

Effects of vitamin D supplementation on insulin resistance and dyslipidemia in overweight and obese premenopausal women

INTRODUCTION

Vitamin D deficiency is a common problem, and it is related to increased risk of obesity, metabolic syndrome, atherosclerosis, and cardiovascular disease. Vitamin D has a beneficial effect on dyslipidemia and insulin secretion. We aimed to investigate the impact of vitamin D3 supplementation on anthropometric and laboratory parameters in overweight and obese premenopausal women.

MATERIAL AND METHODS

Seventy-two overweight and 50 obese vitamin-D-deficient premenopausal women (mean age: 43.1 ±10.4 years) were included in the study. Baseline mean 25-hydroxyvitamin D [25(OH)D] level was 6.1 (min.-max. = 2.9-15.8) ng/ml in overweight and was 5.6 (min.-max. = 3.0-22.0) ng/ml in obese subjects. At baseline and at the sixth month of supplementation, serum 25(OH)D, intact parathormone (iPTH), calcium, phosphorus, homeostasis model assessment of insulin resistance (HOMA-IR), and lipid profiles were assessed.

RESULTS

Following vitamin D3 supplementation in overweight and obese subjects, serum 25(OH)D increased from 6.1 to 34.7 ng/ml and 5.6 to 34.7 ng/ml, respectively (p < 0.001). At the sixth month of supplementation in both overweight and obese subjects, a significant reduction was detected in HOMA-IR (p < 0.001), low-density lipoprotein cholesterol (LDL-C) (p = 0.046, p = 0.044; respectively) and iPTH levels (p ≤ 0.001, p < 0.001; respectively). A negative adjusted correlation was found between changes in 25(OH)D and HOMA-IR (r = -0.581, p < 0.001; r = -0.389, p = 0.005; respectively). A 1 ng/ml increase in serum 25(OH)D level led to a 0.30-fold reduction in HOMA-IR level (p = 0.002).

CONCLUSIONS

Our results support the effect of vitamin D3 supplementation in HOMA-IR and LDL-C improvement in both obese and overweight subjects. Further studies focused on low serum 25(OH)D levels with insulin resistance and dyslipidemia are needed.

Sarcopenic obesity in older adults: aetiology, epidemiology and treatment strategies

The prevalence of obesity in combination with sarcopenia (the age-related loss of muscle mass and strength or physical function) is increasing in adults aged 65 years and older. A major subset of adults over the age of 65 is now classified as having sarcopenic obesity, a high-risk geriatric syndrome predominantly observed in an ageing population that is at risk of synergistic complications from both sarcopenia and obesity. This Review discusses pathways and mechanisms leading to muscle impairment in older adults with obesity. We explore sex-specific hormonal changes, inflammatory pathways and myocellular mechanisms leading to the development of sarcopenic obesity. We discuss the evolution, controversies and challenges in defining sarcopenic obesity and present current body composition modalities used to assess this condition. Epidemiological surveys form the basis of defining its prevalence and consequences beyond comorbidity and mortality. Current treatment strategies, and the evidence supporting them, are outlined, with a focus on calorie restriction, protein supplementation and aerobic and resistance exercises. We also describe weight loss-induced complications in patients with sarcopenic obesity that are relevant to clinical management. Finally, we review novel and potential future therapies including testosterone, selective androgen receptor modulators, myostatin inhibitors, ghrelin analogues, vitamin K and mesenchymal stem cell therapy.

Effect of Orlistat Versus Metformin in Various Aspects of Polycystic Ovarian Syndrome: A Systematic Review of Randomized Control Trials

Background

Polycystic ovarian syndrome (PCOS), a commonly prevalent endocrinopathy among reproductive age group women, is most often associated with obesity. Increased insulin resistance appears to be the central pathophysiologic mechanism responsible for various complications of PCOS. This makes 'weight loss' as the first-line treatment approach in PCOS. So various trials have tried to compare metformin (an insulin-sensitizing agent) and orlistat (an anti-obesity drug) aiming to achieve weight loss and hence higher ovulation rate for the group of obese PCOS patients. Keeping an eye on all these background facts, we designed this systematic review and metaanalysis to compare the effects of metformin and orlistat on various aspects of PCOS and to pick the better among the two drugs.

Materials and Methods

This is a systemic review of randomized control trials that studied the effectiveness of orlistat versus metformin in terms of improvement in ovulation rate, weight loss, lipid profile, etc. Systematic literature search over the period January 2000-December 2016 was performed in the following electronic databases: Medline, embase, google scholar, pubmed and The Cochrane Library and only randomized controlled clinical trials were included in our study. All authors carefully went through all sources of information independently.

Results

According to this study, weight loss, testosterone level after 4 weeks of treatment, total serum cholesterol and triglyceride level showed significant fall in orlistat-treated group.

Conclusion

Our review shows that orlistat is a more effective drug than metformin and should be the preferred drug in obese PCOS in combination with weight loss.

Efficacy of orlistat in non-alcoholic fatty liver disease: A systematic review and meta-analysis

In the present meta-analysis, the efficacy and safety of orlistat in the treatment of non-alcoholic fatty liver (NAFLD) and non-alcoholic steatohepatitis (NASH) were evaluated. PubMed, Embase, the Cochrane Library, Web of Science, and Wan Fang data were searched for controlled trials of orlistat in patients with NAFLD or NASH, published before August 2017. Three randomized controlled trials and four single-arm trials were included. The involved participants with NAFLD or NASH (330 patients) were analyzed for clinical outcomes including alteration in hepatic histological variables and biomarkers of liver function. Improvements were observed in levels of alanine aminotransferase [standard mean difference (SMD)=-1.41; P=0.01], aspartate aminotransferase (SMD=-2.06; P=0.0005), γ-glutamyl transpeptidase (SMD=-1.91; P=0.05), glucose [mean difference (MD)=-0.51; P=0.01], triglycerides (MD=-0.93; P=0.01), homeostasis model assessment of insulin resistance index (MD=-1.05; P=0.04) and body mass index (MD=-1.97; P=0.02), but not in liver fibrosis score (SMD=-0.14; P=0.71). On sub-analyses of the different patient groups, no significant differences were observed in patients with NASH. Taken together, these findings demonstrate that orlistat could serve as a therapeutic drug to improve biochemical indicators of liver damage, but not as first-choice drug for the management of NAFLD or NASH; thus suggesting a novel palliative drug only for the treatment of NAFLD.

Effect of orlistat or metformin in overweight and obese polycystic ovary syndrome patients with insulin resistance

The aim of this study was to evaluate the effect of orlistat or metformin combined with Diane-35 on anthropometric, hormonal and metabolic parameters in overweight and obese polycystic ovary syndrome (PCOS) patients with insulin resistance (fasting insulin > 10 mIU/L). A total of 240 PCOS women were randomly allocated to orlistat plus Diane-35(OD group), metformin plus Diane-35(MD group), orlistat plus metformin plus Diane-35(OMD group) or Diane-35 (D group). Body weight, BMI, waist and hip circumference, blood pressure, endocrine profile, lipid profile and insulin resistance were assessed at baseline and after 3 months. Significant reductions in waist and hip circumference, serum LH, total testosterone and uric acid were observed in all groups compared with baseline. TG and TC significantly decreased in the OD group. Homeostasis model assessment insulin resistance (HOMA-IR) index was reduced in the OD (p = .015), MD (p = .001) and OMD (p = .004) groups. Body weight, BMI, systolic BP and HDL-C significantly changed in the OD and OMD group compared with the D group (p < .05). Side effects were less with orlistat than metformin. This study demonstrated that orlistat is more effective in reducing weight and lipid profile than metformin. Besides, orlistat has mild side-effects and is better tolerated compared with metformin.