Use of antidiabetic drugs in elderly patients

Medical treatments of elderly, French patients with type 2 diabetes: results at inclusion in the GERODIAB Cohort

Prevalence of diabetes in the elderly increases, and half of the French diabetics are over the age of 75 years. The GERODIAB study is the first French multicentre, prospective, observational study designed to analyse over 5 years the influence of glycaemic control on morbidity-mortality in type 2 diabetics patients 70 years old and over. This study analysed the diabetic and geriatric factors associated with the treatment modalities, particularly insulin, at inclusion in the cohort. The cohort of 987 type 2 diabetics was divided into three groups according to the method of treatment. Slightly fewer than one-third of these patients (26.4%) were treated with insulin alone, 31% received insulin and oral antidiabetic drugs, and 42.7% oral antidiabetic drugs alone. The patients that received insulin alone were significantly older, had poorer glycaemic control (HbA1c = 7.9 ± 1.4, 7.8 ± 1.0 and 7.1 ± 1.2%, respectively; P < 0.001) and had greater alterations of glomerular filtration rate (GFR). HbA1c was below 6.5% in 15% of patients and 37.3% of patients had a GFR below 60 mL/min. The patients treated with insulin alone had significantly more hypoglycaemic episodes (respectively 53.3, 36.3 and 19.5%, P < 0.001), retinopathy, cardiovascular involvement and more specific geriatric complications, such as cognitive disorders (respectively 34.1, 31.4 and 23.6%, P = 0.006). In this specific population of elderly type 2 diabetic patients, diabetic and geriatric conditions significantly differed between the types of drug treatments. Considering low values of HbA1c and GFR, some patients seemed overtreated and other patients received inappropriate drugs.

A comparison on insulin regimen treatment of elderly (>70 years) and younger (<70 years) type 2 diabetic patients in actual clinical practice

The incidence of type 2 diabetes mellitus increases with age. However, there are few data about the most adequate type of insulin, or the most adequate insulin regimen, for elderly patients with diabetes. The present study compared insulin regimens in patients aged more than 70 years (100 subjects) with those aged less than 70 years (73 subjects) who attended a diabetes outpatient clinic. The weight, body mass index, diabetes-associated chronic complications, other cardiovascular risk factors, type of insulin, insulin regimen, total daily dose of insulin, weight-adjusted total daily dose of insulin, concomitant treatment with oral hypoglycaemic agents (OHA) and glycosylated haemoglobin (HbA1c) were compared between the two groups. Although both groups had the same level of metabolic control (HbA1c: 7.66 ± 0.91 in the elderly group vs. 7.62 ± 0.96 in the younger group), we have found that elderly subjects were more likely to be treated with a simple regimen, as shown by a higher use of basal insulin (15% in young patients and 41% in the elderly group; P < 0.001), lower use of fast-acting insulin (32.8% vs. 15%; P = 0.005), and fewer daily injections (45% vs. 22% received at least three injections each day; P = 0.001). There were no differences in the use of OHA; however, the majority of young patients were treated with metformin, whereas repaglinide was most commonly used in the elderly group. In conclusion, in everyday clinical practice, elderly subjects were treated with the simplest regimen and achieved the same level of metabolic control as young diabetic patients.

[Type 2 diabetes in the elderly, which specific features?]

Type 2 diabetes, whose prevalence has increased among elderly aged over 75 years, has a number of specific features which differ from that in young people: heterogeneous population, association with other cardiovascular risk factors and several comorbidities, different therapeutic constraints and risks, and lower life expectancy. By using a standardized geriatric assessment it is possible to determine therapeutic and glycemic goals for each patient. In the elderly, main complications of diabetes are hypoglycemia and foot lesions. In order to avoid malnutrition, lifestyle and dietary rules should not be too strict. Recommendations for the prescription of oral antidiabetic agents are the same for both elderly and young subjects, but with increased monitoring in the elderly because of the high risk of complications including iatrogenic hypoglycemia. Insulin therapy should be preferred.

Insulin initiation in elderly patients with type 2 diabetes in France: a subpopulation of the LIGHT study

OBJECTIVE

To examine the management of basal insulin analogue initiation in combination with oral antidiabetic drug (OAD) therapy in elderly patients with type 2 diabetes (aged ≥70 years) by physicians via comparison to the same treatment strategy in younger individuals (<70 years).

METHODS

This subanalysis of a longitudinal observational study took place in a clinical setting across 761 health centres in France. A total of 1802 patients with type 2 diabetes (519 aged ≥70 years and 1283 aged <70 years) participated. The primary endpoint of this study was to assess the management of basal insulin analogue initiation along with OADs in elderly patients (aged ≥70 years) by physicians. Secondary endpoints included HbA(1c), percentage of patients achieving HbA(1c) target (<7.0%), fasting plasma glucose, weight change (kg) and hypoglycaemia.

RESULTS

The initial mean (standard deviation [SD]) basal insulin analogue dose was similar in the elderly and younger patient subgroups (0.18 [0.09] IU/kg vs. 0.18 [0.11] IU/kg, respectively; not significant [NS]). The mean (SD) number of injections per day was also comparable between age groups (1 [0.2] per day vs. 1 [0.3] per day, respectively for elderly and younger patients; NS). Three months after initiation of long-acting insulin analogue therapy, 3.5% (n = 18) of elderly patients ceased insulin treatment. At study end, the mean (SD) HbA(1c) for elderly patients was 7.6% (0.9%), and for younger patients it was 7.5% (0.9%). Also, the rate of overall hypoglycaemia was comparable in the elderly and younger patients (0.38 [1.2] events/patient/month vs. 0.35 [1.0] events/patient/month, respectively; NS). Limitations of this study include the possibility of inaccurate patient recall of hypoglycaemic events and deficiencies in the adverse events reporting system.

CONCLUSION

Basal insulin analogues were successfully initiated in elderly patients in combination with OAD therapies and were shown to provide effective glycaemic control. Levels of hypoglycaemia were also similar to those seen in younger patients.

Prescription patterns for diabetes mellitus and therapeutic implications: a population-based analysis

OBJECTIVE

To analyze drug prescriptions for insulin and oral antidiabetic drugs in type 1 and type 2 diabetes mellitus patients seen in the Brazilian Public Healthcare System (Unified Health System - SUS) in Ribeirao Preto, SP, Brazil.

SUBJECTS AND METHODS

All the patients with diabetes seen in the SUS in the western district of Ribeirao Preto, SP, Brazil between March/2006 and February/2007 were included in the study.

RESULTS

A total of 3,982 patients were identified. Mean age of the patients was 60.6 years, and 61.0% were females. Sixty percent of the patients were treated with monotherapy. Doses of oral antidiabetic drugs were lower in monotherapy than in polytherapy. Ten patients received doses of glibenclamide or metformin above the recommended maximum doses, and in elderly patients there was no reduction in drug doses.

CONCLUSION

Monotherapy with oral antidiabetic drugs was the predominant procedure, and the doses were not individualized according to age.

Dipeptidyl peptidase-4 inhibitors in the elderly: more benefits or risks?

Several studies have shown a high prevalence of type 2 diabetes mellitus (T2DM) in the elderly, characterized by a paucity of symptoms, which represents an obstacle for an early diagnosis. Frequently, T2DM in the elderly is diagnosed when a complication occurs, among which are cognitive disorders and/or affective disturbances. Moreover, hypoglycemia is a frequent side effect of therapeutic treatment with insulin, sulfonylureas or glinides, while other treatments (metformin, acarbose, thiazolidinediones, glucagon-like peptide-1 [GLP-1] receptor agonists, and dipeptidyl peptidase-4 [DPP4] inhibitors) are capable of reducing hyperglycemia without inducing hypoglycemia. Thus, considering that older persons are a very heterogeneous group of individuals, management of T2DM in the elderly is challenging but there are no available specific treatment goals or treatment algorithms for older diabetic patients. Metformin is the recommended first-line therapy in all T2DM patients. When metformin is not sufficient to achieve the desired therapeutic targets, a second drug can be added. Available options include sulfonylureas, meglitinides, alfa-glucosidase inhibitors, pioglitazone, insulin, GLP-1 receptor agonists, and DPP-4 inhibitors. The most intriguing therapy for older patients is the one based on the so-called incretins, i.e., gastrointestinal hormones that, mainly secreted in the postprandial phase, stimulate insulin secretion and inhibit glucagon secretion. The two most important human incretins are GLP-1 and glucose-dependent insulinotropic peptide (GIP). These hormones potentiate the acute effects of glucose on pancreatic alfa and beta cells, thus stimulating insulin secretion, and only GLP-1 inhibits glucagon secretion in a glucose-dependent manner (that is, only when glucose levels are increased); as a result, they reduce hyperglycemia with virtually no hypoglycemic risk. Due to their characteristics, DPP-4 inhibitors seem to be particularly interesting as potential agents for the treatment of older patients with T2DM.

Efficacy and safety of saxagliptin in older patients with type 2 diabetes mellitus

OBJECTIVE

To assess the safety and efficacy of saxagliptin (5 mg once-daily) in older patients (≥65 years of age) with inadequately controlled type 2 diabetes.

RESEARCH DESIGN AND METHODS

In this retrospective subgroup analysis, data from five randomized, double-blind, placebo-controlled, multicenter, 24-week, phase 3 trials were included. The primary studies evaluated saxagliptin 5 mg once-daily (monotherapy or add-on) in patients aged 18-77 years with HbA(1c) ≥7.0% (four studies) or ≥7.5% (add-on to glyburide study) versus placebo.

MAIN OUTCOME MEASURES

The primary efficacy endpoint of each study included in this pooled analysis was HbA(1c) change from baseline to week 24.

RESULTS

In the five-study pooled population, 279 (16.6%) patients were at least 65 years old; 142 received saxagliptin 5 mg once-daily and 137 received placebo. Treatment groups were well-balanced for baseline characteristics within each study. In older patients, the HbA(1c) adjusted mean change from a baseline of 8.1% was -0.73 ± 0.16% (mean ± SEM) with saxagliptin compared with -0.17 ± 0.14% for placebo from a baseline of 8.0%. Adverse event rates were similar with saxagliptin 5 mg once-daily compared with placebo in older patients.

CONCLUSION

The pooled subgroup analysis of saxagliptin 5 mg once-daily monotherapy and add-on therapy trials demonstrated clinically relevant and significant efficacy for reducing HbA(1c) in older (≥65 years) patients. Saxagliptin was well-tolerated in older patients with a low incidence of hypoglycemia and no weight gain.

Role of vildagliptin in managing type 2 diabetes mellitus in the elderly

BACKGROUND

The prevalence of type 2 diabetes (T2DM) increases with age. Older patients have an increased likelihood for T2DM-related morbidity and mortality. The objective of this review is to provide an overview of the challenges in managing T2DM in the elderly, with an emphasis on prevention of hypoglycaemia and the role of the DPP-4 inhibitor vildagliptin in this patient population.

METHODS

A search of PubMed was conducted (from 2003 to 2010) to identify English-language articles relevant to the management of elderly patients with T2DM, with an emphasis on vildagliptin treatment. A limitation of this review is that it does not provide an overview of the entire class of dipeptidyl-peptidase-4 (DPP-4) inhibitors.

FINDINGS

Management of T2DM in elderly patients is complicated by numerous factors, including a high prevalence of cardiovascular risk factors and other comorbidities and a high frequency of polypharmacy issues. Hypoglycaemia may pose the greatest barrier to optimal glycaemic control in elderly patients, who are less likely to recognise and respond to hypoglycaemic episodes, leading to increased frequency and severity of events. Data on the DPP-4 inhibitor vildagliptin indicate that reductions in A1C in elderly patients are at least as good as those observed in younger patients and are achieved with minimal risk of hypoglycaemia. T2DM in older individuals is associated with relative hyperglucagonaemia and elevated postprandial glucose (PPG). Vildagliptin treatment appears to address both these defects. Vildagliptin improves the ability of alpha- and beta-cells to respond appropriately to changes in plasma glucose levels. This, in the face of high glucose levels, results in reduced inappropriate glucagon secretion and PPG excursions. In the face of low glucose, however, the protective glucagon response is well-preserved. These factors help explain the efficacy and minimal risk of hypoglycaemia observed with vildagliptin in elderly patients.

CONCLUSION

The elderly population with T2DM poses unique treatment challenges and have not been particularly well-represented in clinical trials, highlighting the need for additional studies to better define appropriate glucose targets and to ascertain the best strategies for achieving and maintaining appropriate glycaemic levels. Because vildagliptin does not expose patients to hypoglycaemic risk, it seems particularly suited to oral therapy of T2DM in the elderly.