Obesity medications and the treatment of type 2 diabetes

Compound dark tea ameliorates obesity and hepatic steatosis and modulates the gut microbiota in mice

Dark tea is a fermented tea that plays a role in regulating the homeostasis of intestinal microorganisms. Previous studies have found that dark tea can improve obesity and has a lipid-lowering effect. In this study, green tea, Ilex latifolia Thunb (kuding tea) and Momordica grosvenori (Luo Han Guo) were added to a new compound dark tea (CDT), to improve the taste and health of this beverage. High-fat diet-fed C57BL/6J mice were treated with low- (6 mg/mL) or high- (12 mg/mL) concentrations of CDT for 18 weeks to assess their effect on lipid metabolism. Our results suggest that low- and high-concentrations of CDT could reduce body weight by 15 and 16% and by 44 and 38% of body fat, respectively, by attenuating body weight gain and fat accumulation, improving glucose tolerance, alleviating metabolic endotoxemia, and regulating the mRNA expression levels of lipid metabolism-related genes. In addition, low concentrations of CDT were able to reduce the abundance of Desulfovibrio, which is positively associated with obesity, and increase the abundance of Ruminococcus, which are negatively associated with obesity. This study demonstrates the effect of CDT on ameliorating lipid metabolism and provides new insights into the research and development of functional tea beverages.

Diabetes medications as potential calorie restriction mimetics-a focus on the alpha-glucosidase inhibitor acarbose

The field of aging research has grown rapidly over the last half-century, with advancement of scientific technologies to interrogate mechanisms underlying the benefit of life-extending interventions like calorie restriction (CR). Coincident with this increase in knowledge has been the rise of obesity and type 2 diabetes (T2D), both associated with increased morbidity and mortality. Given the difficulty in practicing long-term CR, a search for compounds (CR mimetics) which could recapitulate the health and longevity benefits without requiring food intake reductions was proposed. Alpha-glucosidase inhibitors (AGIs) are compounds that function predominantly within the gastrointestinal tract to inhibit α-glucosidase and α-amylase enzymatic digestion of complex carbohydrates, delaying and decreasing monosaccharide uptake from the gut in the treatment of T2D. Acarbose, an AGI, has been shown in pre-clinical models to increase lifespan (greater longevity benefits in males), with decreased body weight gain independent of calorie intake reduction. The CR mimetic benefits of acarbose are further supported by clinical findings beyond T2D including the risk for other age-related diseases (e.g., cancer, cardiovascular). Open questions remain regarding the exclusivity of acarbose relative to other AGIs, potential off-target effects, and combination with other therapies for healthy aging and longevity extension. Given the promising results in pre-clinical models (even in the absence of T2D), a unique mechanism of action and multiple age-related reduced disease risks that have been reported with acarbose, support for clinical trials with acarbose focusing on aging-related outcomes and incorporating biological sex, age at treatment initiation, and T2D-dependence within the design is warranted.

Stereochemical Structure Activity Relationship Studies (S-SAR) of Tetrahydrolipstatin

Tetrahydrolipstatin (THL), its enantiomer, and an additional six diastereomers were evaluated as inhibitors of the hydrolysis of p-nitrophenyl butyrate by porcine pancreatic lipase. IC₅₀s were found for all eight stereoisomers ranging from a low of 4.0 nM for THL to a high of 930 nM for the diastereomer with the inverted stereocenters at the 2,3,2'-positions. While the enantiomer of THL was also significantly less active (77 nM) the remaining five stereoisomers retained significant inhibitory activities (IC₅₀s = 8.0 to 20 nM). All eight compounds were also evaluated against three human cancer cell lines (human breast cancers MCF-7 and MDA-MB-231, human large-cell lung carcinoma H460). No appreciable cytotoxicity was observed for THL and its seven diastereomers, as their IC₅₀s in a MTT cytotoxicity assay were all greater than 3 orders of magnitude of camptothecin.

Predictors of weight loss and maintenance in patients treated with antiobesity drugs

BACKGROUND

The prevalence of obesity and related diseases has increased enormously in the last few decades, becoming a very important medical and social issue. Because of the increasing number of people who need weight loss therapies and the high costs associated with these, the search for reliable predictors of success for weight loss and weight maintenance treatments has become a priority.

OBJECTIVE

A literature review was undertaken to identify possible predictors of outcome of weight loss and weight maintenance in patients treated with antiobesity drugs.

RESULTS

For the majority of variables, published data are not sufficient to define their role on final outcomes. Among all considered factors, only early response to treatment appeared to be a reliable positive predictor, and diabetes a negative predictor of weight loss and maintenance.

CONCLUSION

To date, no definitive results have been obtained. Due to the great benefits of reliable predictors of outcome associated to currently available antiobesity drugs and those under development, identifying these predictors has to be supported and encouraged.

Biphasic insulin aspart 30: better glycemic control than with premixed human insulin 30 in obese patients with Type 2 diabetes

AIM

This 3-month study compared the effect on overall glycemic control of adding biphasic insulin aspart 30 (BIAsp30) and premixed human insulin 30/70 (BHI30) to metformin (met) in insulin-naïve, obese patients (30 males/20 females) with Type 2 diabetes (T2DM). MATERIAL/SUBJECTS: At baseline, patients had a mean age of 58.7 yr, glycated hemoglobin (HbA1c) 9.5%, and body mass index 34+/-2 kg/m2. Patients received either twice-daily BIAsp30 (no.=20) or twice-daily BHI30 (no.=30), and continued to receive maximal doses (2000 mg) of met for the duration of the study, but sulphonylurea oral antidiabetic drugs were discontinued. Primary efficacy endpoint was the change in HbA1c in both groups at study end. Safety endpoints included hypoglycemic episodes and weight gain.

RESULTS

Both groups reduced HbA1c by end of trial: BIAsp30 + met by 2.5% [2.16-2.86%; 95% confidence interval (CI)]; BHI30 + met by 1.18% (0.98- 1.39%; 95% CI), giving a significantly better HbA1c reduction with BIAsp30 + met (1.33%; p<0.05). Post-prandial plasma glucose decreased in both groups, by 6.38 mmol/l in patients treated with BIAsp30 + met, and by 4.34 mmol/l in those treated with BHI30 + met (p<0.05). Fasting plasma glucose also decreased in both groups, with a slightly larger decrease seen in BIAsp30 patients than in BHI30 patients (7.36 mmol/l at end of study vs 7.82 mmol/l; p=ns). Subjects treated with BIAsp30 gained less weight than those receiving BHI30 (0.3+/-0.1 kg vs 1.2+/-0.4 kg). There was no significant difference in the frequency or number of hypoglycemic episodes between groups.

CONCLUSIONS

Adding BIAsp30 to met in obese patients with T2DM results in better glycemic control and less weight gain than adding BHI30.

The benefits of early intervention in obese diabetic patients with FBCx: a new dietary fibre

BACKGROUND

Obesity and diabetes have become epidemic in the US. Dietary fibres have been reported to reduce the absorption of dietary fat, prevent weight gain, and reduce blood lipid levels. In the current double-blind study, obese patients with type 2 diabetes were recruited for a 3-month study to examine the health effects of a new dietary fibre, FBCx.

METHODS

Sixty-six participants were recruited and were randomized into FBCx or placebo groups. They were instructed to take two 1-g tablets per fat-containing meal and not to change their eating patterns or daily routine. Three-day dietary records and fasting blood samples were collected prior to enrollment in the study and at the end of months 1, 2 and 3.

RESULTS

Dietary records showed that some participants changed their eating patterns; therefore body weight data were adjusted according to energy intake. As a group, in the 30 days leading into the study, all participants experienced an average weight gain of 1.0 +/- 0.4 kg, while those in the placebo group continued to gain weight during the study, those in the FBCx group maintained their weight. Those in the FBCx group required more energy to maintain their body weight while those in the placebo group required less (p < 0.05). Participants with hypertriglyceridemia showed a reduction (-0.48 +/- 0.24 mmol/L, - 8.2%) in total cholesterol with FBCx, while those with placebo had an increase (0.24 +/- 0.21 mmol/L, 5.2%, p < 0.05). Adiponectin was increased in the FBCx but reduced in the placebo group (p < 0.05).

CONCLUSIONS

FBCx has thus shown promising benefits in weight maintenance, a reduction of blood lipids and an increase in adiponectin levels. It can be easily incorporated into a diabetic management regimen.

Pharmacotherapy for weight loss in adults with type 2 diabetes mellitus

BACKGROUND

Obesity is closely related to type 2 diabetes and long-term weight reduction is an important part of the care delivered to obese persons with diabetes.

OBJECTIVES

To assess the efficacy of pharmacotherapy for weight loss in adults with type 2 diabetes.

SEARCH STRATEGY

Computerized searches were performed of MEDLINE (January 1966 to May 2004), EMBASE (January 1974 to May 2004, Web of Science (January 1981 to May 2004, and other electronic bibliographic databases, supplemented with hand searches of reference lists and selected journals.

SELECTION CRITERIA

Randomized, controlled trials were included where pharmacotherapy was used as the primary strategy for weight loss among adults with type 2 diabetes. Published and unpublished literature in any language and with any study design was included.

DATA COLLECTION AND ANALYSIS

Two reviewers abstracted data and the quality of included studies was evaluated by assessing potential attrition, as well as selection and measurement bias, and a Jadad score was obtained. Effects were combined using a random effects model.

MAIN RESULTS

A sufficient number of studies were available for a quantitative synthesis for fluoxetine, orlistat, and sibutramine. Twenty two randomized controlled trials were included in the review, with a total of 296 participants for fluoxitine, 2036 for orlistat, and 1047 for sibutramine. Pharmacotherapy produced modest reductions in weight for fluoxetine (5.1 kg (95% confidence interval [CI], 3.3 - 6.9) at 24 to 26 weeks follow up; orlistat 2.0 kg (CI, 1.3 - 2.8) at 12 to 57 weeks follow-up, and sibutramine 5.1 kg (CI, 3.2 - 7.0) at 12 to 52 weeks follow-up. Glycated hemoglobin also modestly and significantly reduced for fluoxetine and orlistat. Gastrointestinal side effects were common with orlistat; tremor, somnolence and sweating with fluoxetine; and palpitations with sibutramine. Some studies, using a variety of study designs, were available on other drugs and a significant decrease in weight was noted in three studies of mazindol, one of phenmetrazine, two of phentermine. No studies were identified that fit inclusion criteria for pseudophedrine, ephedra, sertraline, yohimbine, amphetamine or its derivatives, bupropion, topiramate, benzocaine, threachlorocitric acid, sertraline, and bromocriptine.

AUTHORS' CONCLUSIONS

Fluoxetine, orlistat, and sibutramine can achieve statistically significant weight loss over 12 to 57 weeks. The magnitude of weight loss is modest, however, and the long-term health benefits remain unclear. The safety of sibutramine is uncertain. There is a paucity of data on other drugs for weight loss or control in persons with type 2 diabetes.

Effect of thiazolidinediones on body weight in patients with diabetes mellitus

Treatment of diabetes mellitus with medications, including insulin, sulfonylureas, and thiazolidinediones (TZDs), often leads to weight gain through a variety of mechanisms. Weight gain can have adverse consequences for patients with type 2 diabetes, many of whom are overweight or obese, because obesity is linked to insulin resistance and other medical consequences such as cardiovascular disease. TZDs improve glycemic control and insulin sensitivity in patients with type 2 diabetes, despite their potential to cause weight gain. Studies have attempted to elucidate the mechanisms behind the apparent paradox of TZDs improving insulin sensitivity while causing weight gain. Data indicate that with TZD treatment, there is a favorable shift in fat distribution from visceral to subcutaneous adipose depots that is associated with improvements in hepatic and peripheral tissue sensitivity to insulin. Although weight gain may occur with TZD therapy, it is not inevitable. A weight-management program combining a low-calorie, low-sodium diet with education and behavior modification has been shown to be effective in patients with type 2 diabetes being treated with TZDs. Further research is needed to define the optimal dietary modifications that can be used universally in TZD-treated patients to minimize weight gain while effectively treating insulin resistance and hyperglycemia.

Psychological aspects of diabetes mellitus

Diabetes mellitus (DM) presents itself in two forms: insulin-dependent (type 1 DM) and non-insulin-dependent (type 2 DM). Although type 2 DM usually has an adult onset, in recent years there has been a significant rise in the number of children diagnosed with type 2 DM in the United States. Reasons for this increased frequency are believed to be a larger percentage of children who are overweight, a family history of diabetes, and a considerable increase in the use of psychotropic medication in children. The diagnosis of DM is a significant stressor not only for patients but also for their environment. Children with DM are sometimes stigmatized by their peers and relatives who do not understand the illness or are frightened by it. Some children also may need to alter several of their customary routines and are often scared to participate in activities in which they were previously engaged. The family's response to the diagnosis of DM may have a negative effect on glycemic control. Differences have been found in the way patients with type 1 DM and type 2 DM cope with and adapt to their diagnosis.

Is weight loss possible in patients treated with thiazolidinediones? Experience with a low-calorie diet

BACKGROUND

Weight gain is a frequent side-effect of thiazolidinediones, possibly related to fluid retention and stimulation of pre-adipocyte differentiation.

METHODS

We report our experience with a low-calorie diet (800 cal, sodium content 1500 mmol/day) combined with behavior modification on eight patients treated with thiazolidinediones (six pioglitazone and two rosiglitazone).

RESULTS

All patients had reported previous weight gain following treatment with thiazolidinediones. All patients lost weight over 12 weeks in the program with their mean +/- SD body weight falling from 270 +/- 54 lbs (123 +/- 25 kg) to 244 +/- 61 lbs (111 +/- 28 kg) (p < 0.01). The weight loss observed was no different from that observed in 16 age- and gender-matched patients with type 2 diabetes not treated with thiazolidinediones (from 263 +/- 54 lbs (120 +/- 25 kg) to 239 +/- 52 lbs (109 +/- 24 kg); p < 0.01). Glycemic control improved while reducing insulin treatment. Blood pressure control also improved and antihypertensive medications were decreased. The degree and time course of weight loss is no different from that in patients treated with other diabetic therapies and is associated with improved glycemic and blood pressure control.

CONCLUSIONS

We conclude that a program of caloric restriction and behavior modification is effective in leading to weight loss in patients treated with thiazolidinediones. This effect is reassuring, since thiazolidinediones stimulate adipogenesis.