The effectiveness, safety and epidemiology of the use of acarbose in the treatment of patients with type II diabetes mellitus. A model of medicine-based evidence

Gender representation in drug development studies for diabetes mellitus. A systematic review

BACKGROUND

During the last 20 years, the prevalence of diabetes mellitus (DM) has increased drastically, and so has the number of associated medicine and drug development studies. Despite knowing that men and women respond differently to DM medicines, biological gender differences still tend not to be prioritized during medicine development.

OBJECTIVE

This study examined gender representation in medicine development studies for DM.

METHOD

We conducted a systematic review, and in February 2022, we searched EMBASE (Excerpta Medica Database), MEDLINE (Medical Literature Analysis and Retrieval System Online) and PubMed using a block search strategy. Randomized controlled studies (RCTs) including people diagnosed with DM (any type) aged 18-65 years were included. The Consolidated Standards of Reporting Trial 2010 checklist was applied to assess the studies' reported quality. The results are presented in a narrative synthesis.

RESULTS

Nine studies met the inclusion criteria. On average, women represented 31.4% of study participants, and similarly, for each trial phase, women were less represented than men.

CONCLUSION

This review showed an unequal gender representation in drug development studies for DM, with women and men representing 31.4% and 68.6% of the study participants, respectively, in the included studies. However, gender differences in medical drug studies might be due to specific exclusion criteria, participants' behaviour toward attending in medicine development or the law in the country of origin.

Diabetes pharmacotherapy and effects on the musculoskeletal system

Persons with type 1 or type 2 diabetes have a significantly higher fracture risk than age-matched persons without diabetes, attributed to disease-specific deficits in the microarchitecture and material properties of bone tissue. Therefore, independent effects of diabetes drugs on skeletal integrity are vitally important. Studies of incretin-based therapies have shown divergent effects of different agents on fracture risk, including detrimental, beneficial, and neutral effects. The sulfonylurea class of drugs, owing to its hypoglycemic potential, is thought to amplify the risk of fall-related fractures, particularly in the elderly. Other agents such as the biguanides may, in fact, be osteo-anabolic. In contrast, despite similarly expected anabolic properties of insulin, data suggests that insulin pharmacotherapy itself, particularly in type 2 diabetes, may be a risk factor for fracture, negatively associated with determinants of bone quality and bone strength. Finally, sodium-dependent glucose co-transporter 2 inhibitors have been associated with an increased risk of atypical fractures in select populations, and possibly with an increase in lower extremity amputation with specific SGLT2I drugs. The role of skeletal muscle, as a potential mediator and determinant of bone quality, is also a relevant area of exploration. Currently, data regarding the impact of glucose lowering medications on diabetes-related muscle atrophy is more limited, although preclinical studies suggest that various hypoglycemic agents may have either aggravating (sulfonylureas, glinides) or repairing (thiazolidinediones, biguanides, incretins) effects on skeletal muscle atrophy, thereby influencing bone quality. Hence, the therapeutic efficacy of each hypoglycemic agent must also be evaluated in light of its impact, alone or in combination, on musculoskeletal health, when determining an individualized treatment approach. Moreover, the effect of newer medications (potentially seeking expanded clinical indication into the pediatric age range) on the growing skeleton is largely unknown. Herein, we review the available literature regarding effects of diabetes pharmacotherapy, by drug class and/or by clinical indication, on the musculoskeletal health of persons with diabetes.

Alpha-glucosidase inhibitors and hepatotoxicity in type 2 diabetes: a systematic review and meta-analysis

Alpha-glucosidase inhibitors (AGIs) was reported to be associated with several rare adverse hepatic events, but with inconsistent results. We aimed to investigate the risk of hepatotoxicity associated with the use of AGIs in patients with type 2 diabetes mellitus (T2DM), and performed a systematic review and meta-analysis. Fourteen studies (n = 2881) were eligible, all of which were RCTs. Meta-analysis of data regarding elevation of more than 3-fold the upper limit of normal (ULN) of AST and ALT showed statistically significant differences between AGIs treatment versus control (OR 6.86, 95% CI 2.50 to 18.80; OR 6.48, 95% CI 2.40 to 17.49). Subgroup analyses of elevation of more than 1.8-fold ULN of AST and ALT by dose of AGIs showed differential effects on AST and ALT (AST: OR 0.38 vs 7.31, interaction P = 0.003; ALT: OR 0.32 vs 4.55, interaction p = 0.02). Meta-analysis showed that AGIs might increase the risk of hepatotoxicity, and higher dose appeared to be associated with higher risk of hepatotoxicity. However, the evidence is limited with surrogate measures (i.e. ALT and AST), and no clinically important adverse events were observed.

Consumption of Mesona chinensis attenuates postprandial glucose and improves antioxidant status induced by a high carbohydrate meal in overweight subjects

Edible plants constitute a potential source for controlling postprandial hyperglycemia and oxidative stress. The objective of this study was to investigate in vitro antioxidant and intestinal α-glucosidase inhibitory activities of Mesona chinensis (MC). In addition, the acute effect of MC on postprandial glucose and plasma antioxidant status after the consumption of a high carbohydrate (HC) meal by overweight subjects was also determined. The results showed that total phenolic and flavonoid contents in the extract were 212.37 ± 5.64 mg gallic acid equivalents/g dried extract and 23.44 ± 2.50 mg catechin equivalents/g dried extract, respectively. MC extract markedly inhibited the intestinal maltase and sucrose with the IC50 values of 4.66 ± 0.22 mg/mL and 1.30 ± 0.43 mg/mL, respectively. However, MC extract had no inhibitory activity against pancreatic α-amylase. In addition, MC extract had antioxidant properties including DPPH radical scavenging activity, superoxide radical scavenging activity (SRSA), hydroxyl radical scavenging activity (HRSA), trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), and ferrous ion cheating activity (FICP). The significant decrease in postprandial plasma glucose, triglyceride and malondialdehyde levels, and the increase in plasma antioxidant capacity (FRAP and ORAC) were observed in overweight subjects receiving a HC meal together with MC extract (1 g). The finding supports that MC helps normalize and enhance antioxidant defense induced by a HC meal, suggesting that MC may have the potential for the prevention of chronic conditions and diseases associated with overweight and obesity.

Safety and efficacy of acarbose in the treatment of diabetes in Chinese patients

Acarbose is an α-glucosidase inhibitor that is commonly used to control postprandial blood glucose. It functions as a competitive and reversible inhibitor of small intestinal brush border glucosidase, blocks the degradation of starch and sucrose, and delays the absorption of glucose and fructose in the alimentary tract. The starch content of a diet might alter the hypoglycemic effects of acarbose because of its mechanism of action. Chinese individuals consume a typical Eastern diet, which is characterized by a high intake of whole grains, legumes, vegetables, fruits, and fish. These dietary habits allow acarbose to be used extensively in the People’s Republic of China. Several Chinese-based studies have demonstrated that the use of acarbose as a monotherapy had similar effects on other anti-diabetes agents in decreasing glycosylated hemoglobin (HbA_1c) and blood glucose levels, and acarbose in combination with other anti-diabetic drugs could further reduce blood glucose and decrease the mean amplitude of glycemic excursions. Importantly, acarbose is safe and well tolerated, with a low incidence of adverse effects. This article provides a comprehensive review of the safety and efficacy of acarbose for the treatment of diabetes in Chinese patients.

In vitro inhibitory effects of plant-based foods and their combinations on intestinal α-glucosidase and pancreatic α-amylase

Background

Plant-based foods have been used in traditional health systems to treat diabetes mellitus. The successful prevention of the onset of diabetes consists in controlling postprandial hyperglycemia by the inhibition of α-glucosidase and pancreatic α-amylase activities, resulting in aggressive delay of carbohydrate digestion to absorbable monosaccharide. In this study, five plant-based foods were investigated for intestinal α-glucosidase and pancreatic α-amylase. The combined inhibitory effects of plant-based foods were also evaluated. Preliminary phytochemical analysis of plant-based foods was performed in order to determine the total phenolic and flavonoid content.

Methods

The dried plants of Hibiscus sabdariffa (Roselle), Chrysanthemum indicum (chrysanthemum), Morus alba (mulberry), Aegle marmelos (bael), and Clitoria ternatea (butterfly pea) were extracted with distilled water and dried using spray drying process. The dried extracts were determined for the total phenolic and flavonoid content by using Folin-Ciocateu’s reagent and AlCl₃ assay, respectively. The dried extract of plant-based food was further quantified with respect to intestinal α-glucosidase (maltase and sucrase) inhibition and pancreatic α-amylase inhibition by glucose oxidase method and dinitrosalicylic (DNS) reagent, respectively.

Results

The phytochemical analysis revealed that the total phenolic content of the dried extracts were in the range of 230.3-460.0 mg gallic acid equivalent/g dried extract. The dried extracts contained flavonoid in the range of 50.3-114.8 mg quercetin equivalent/g dried extract. It was noted that the IC₅₀ values of chrysanthemum, mulberry and butterfly pea extracts were 4.24±0.12 mg/ml, 0.59±0.06 mg/ml, and 3.15±0.19 mg/ml, respectively. In addition, the IC₅₀ values of chrysanthemum, mulberry and butterfly pea extracts against intestinal sucrase were 3.85±0.41 mg/ml, 0.94±0.11 mg/ml, and 4.41±0.15 mg/ml, respectively. Furthermore, the IC₅₀ values of roselle and butterfly pea extracts against pancreatic α-amylase occurred at concentration of 3.52±0.15 mg/ml and 4.05±0.32 mg/ml, respectively. Combining roselle, chrysanthemum, and butterfly pea extracts with mulberry extract showed additive interaction on intestinal maltase inhibition. The results also demonstrated that the combination of chrysanthemum, mulberry, or bael extracts together with roselle extract produced synergistic inhibition, whereas roselle extract showed additive inhibition when combined with butterfly pea extract against pancreatic α-amylase.

Conclusions

The present study presents data from five plant-based foods evaluating the intestinal α-glucosidase and pancreatic α-amylase inhibitory activities and their additive and synergistic interactions. These results could be useful for developing functional foods by combination of plant-based foods for treatment and prevention of diabetes mellitus.

Efficacy and adverse effects of nateglinide in early type 2 diabetes. Comparison with voglibose in a cross-over study

An open-label prospective cross-over trial was performed to compare the efficacy and adverse effects of nateglinide with those of voglibose on Japanese early type 2 diabetes (who were oral hypoglycemic agent naïve and whose HbA(1C) levels were between 7.0 and 7.9% before treatment). Fourteen patients received 270 mg/day of nateglinide and 15 patients received 0.6 mg/day of voglibose. After 12 weeks of either therapy, the drugs were switched and treatment was continued for another 12 weeks. After 3-month treatment with each drug, HbA(1C) value decreased significantly (baseline HbA(1C) 7.24 +/- 0.42%, 6.70 +/- 0.47% with nateglinide: p<0.01, 6.93 +/- 0.62% with voglibose: p<0.05) but the difference in the effect between nateglinide and voglibose was not significant (p = 0.121). Symptoms related to hypoglycemia (e.g., increased appetite, palpitation, sweating, tremor) were scarcely observed with either voglibose or nateglinide treatments. Abdominal fullness/borborygmi was frequently reported, with variable severity, by patients on voglibose but this was absent or mild in those on nateglinide. After completion of both arms of the study, more patients favored nateglinide than voglibose. Our results suggest that nateglinide is an effective and safe drug in the treatment of early type 2 diabetes, similar to voglibose.

Is there a role for alpha-glucosidase inhibitors in the prevention of type 2 diabetes mellitus?

Type 2 diabetes mellitus is a major health problem associated with excess morbidity and mortality. As the prevalence of this metabolic disorder is rapidly increasing and current treatment fails to stabilise the disease in most patients, prevention should be considered as a key objective in the near future. People who develop type 2 diabetes pass through a phase of impaired glucose tolerance (IGT). Defects in the action and/or secretion of insulin are the two major abnormalities leading to development of glucose intolerance. Any intervention in the impaired glucose tolerance phase that reduces resistance to insulin or protects the beta-cells, or both, should prevent or delay progression to diabetes.Acarbose, miglitol and voglibose act by competitively inhibiting the alpha-glucosidases, a group of key intestinal enzymes involved in the digestion of carbohydrates. They decrease both postprandial hyperglycaemia and hyperinsulinaemia, and thereby may improve sensitivity to insulin and release the stress on beta-cells. These compounds do not induce hypoglycaemia and have a good safety profile, although gastrointestinal adverse effects may limit long-term compliance to therapy. The recent placebo-controlled prospective STOP-noninsulin-dependent diabetes mellitus (STOP-NIDDM) trial demonstrated that acarbose 100mg three times daily reduces the risk of developing type 2 diabetes in patients with IGT (relative risk reduction of 25% after a mean follow-up of 3.3 years). The 6-year Early Diabetes Intervention Trial (EDIT), comparing the effect of acarbose 50mg three times daily to that of metformin, showed a trend to a positive effect of acarbose compared with placebo, in a mid-term 3-year analysis, which should be confirmed in the final analysis. To our knowledge, no such prevention intervention trials have been or are currently being performed with miglitol or voglibose. In conclusion, because of its absence of toxicity and its particular mechanism of action on gastrointestinal tract and indirect consequences on both insulin action and beta-cell function, acarbose may be used to prevent type 2 diabetes. If the ongoing EDIT trial confirms the positive results of the recent STOP-NIDDM trial, acarbose could be used, either as an alternative or in addition to changes in lifestyle, to delay development of diabetes in patients with IGT. However, the best dosage of acarbose for this specific indication remains to be specified, especially when all three important parameters, efficacy, tolerance and cost, are taken into consideration.

Clinical databases of patients receiving antidepressants. The missing link between research and practice?

BACKGROUND

In the last 10 years the use of antidepressants has increased drastically. Unfortunately, the epidemiology of these compounds has shown significant gaps between recommendations derived from randomised controlled trials and current clinical practice.

METHODS

We argue for the need to develop and maintain clinical databases of patients receiving antidepressants as a way of bridging this situation.

RESULTS

In addition to experimental data generated in selected patients and settings, observational databases of large cohorts of typical patients, followed in typical settings, should be developed and maintained. Clinical databases could collect information on patient social and demographic characteristics, clinical symptoms, diagnosis and pharmacological and non-pharmacological treatments. In addition, they can provide accurate estimates of probabilities of different outcomes and on factors that affect outcome.

CONCLUSION

Clinical databases should not be seen as another expensive administrative task for busy doctors. Clinical databases should be developed, organised and utilised only by clinicians who are interested in monitoring their clinical practice and want to provide patients, relatives and the public with information on prognosis and outcome in their specific context of care. Maintaining clinical databases is a routine process, nested in everyday clinical activity, which aims at constituting a permanent link between research and practice.

Improved Glycemic Control and Lipid Profile in a Randomized Study of Pioglitazone Compared with Acarbose in Patients with Type 2 Diabetes Mellitus

OBJECTIVE

To assess the efficacy of pioglitazone treatment in comparison with that of acarbose treatment in patients with type 2 diabetes mellitus.

PARTICIPANTS AND METHODS

In this randomized, parallel-group, open-label study patients were assigned to treatment with either pioglitazone (n = 129) or acarbose (n = 136). During a 1-week run-in patients commenced an individualized dietary regimen which was maintained throughout the study. Patients received the assigned study medication for 26 weeks. Serum glycosylated hemoglobin (HbA1c) levels, insulin resistance and lipid profiles were determined at baseline and at endpoint.

RESULTS

Mean HbA1c was reduced from 8.98+/-1.20% to 7.82+/-1.95% with pioglitazone treatment and from 9.03+/-1.32% to 8.55+/-1.96% with acarbose treatment during the 26-week study. The change from baseline to endpoint was significantly greater for pioglitazone compared with acarbose when analyzed for all patients (p < 0.001) and for those who had (p = 0.009) or had not (p < 0.001) received previous medication for diabetes mellitus. Compared with acarbose, pioglitazone produced a significantly greater decrease in fasting glucose, insulin and insulin resistance (p < 0.001 for each). Triglycerides were decreased by 71.1+/-184.1 mg/dl with pioglitazone compared with 38.1+/-171.3 mg/dl with acarbose (p = 0.001 for difference between groups). High density lipoprotein (HDL)-cholesterol level was increased by 7.8+/-10.2 mg/dl with pioglitazone compared with a decrease of 0.8+/-24.1 mg/dl with acarbose (p < 0.001). While serum low density lipoprotein (LDL)-cholesterol levels remained unchanged with both treatment regimens, the decrease from baseline in very low density lipoprotein (VLDL)-cholesterol was significantly greater with pioglitazone than with acarbose (p < 0.04). Pioglitazone decreased systolic blood pressure by 5.6+/-17.7mm Hg compared with a 0.4+/-18.4mm Hg increase during acarbose treatment (p < 0.001). Pioglitazone caused a significantly greater decrease compared with acarbose in serum levels of gamma-glutamyl aminotransferase (p < 0.001) and alanine aminotransferase (p = 0.004).

CONCLUSIONS

Six months of pioglitazone treatment decreased insulin resistance and improved glycemic control to a significantly greater extent than acarbose treatment. Pioglitazone was also associated with a significantly improved lipid profile, suggesting a reduction in risk of coronary heart disease.