Management of type 2 diabetes mellitus in the elderly: special considerations

Diabetic nephropathy in the elderly

Renal impairment is frequent in aged diabetic patients, notably with type 2 diabetes. It results from a multifactorial pathogeny, particularly the combined actions of hyperglycaemia, arterial hypertension and ageing. Diabetic nephropathy (DN) is associated with an increased cardiovascular mortality. DN often leads to end stage renal failure (ESRF) which causes specific problems of decision and practical organization of extra-renal epuration in diabetic and aged patients. In the absence of renal biopsy, clinical signs are often insufficient to assess the diabetic origin of a nephropathy in an elderly diabetic patient. Prevention of DN is principally based on tight glycaemic and blood pressure control. The progression of renal lesions can be retarded by strict blood pressure control, notably by blocking of the renin-angiotensin system, if well tolerated in aged patients. It is absolutely necessary to avoid the worsening of renal lesions by potentially nephrotoxic products, notably non steroidal anti-inflammatory drugs (NSAIDs) and iodinated contrast media. At the stage of renal failure, it is important to adapt the antidiabetic treatment, and in the majority of the cases, to switch to insulin when glomerular filtration rate (GFR) is below 30 ml/mn/1.73 m2.

Mortality in people diagnosed with type 2 diabetes at an older age: a systematic review

OBJECTIVES

To review all published observational studies reporting on all-cause mortality in patients with type 2 diabetes to determine the degree of increased mortality when diagnosed at an older age.

DESIGN

Systematic literature search.

SETTING

The review included studies carried out in populations from Germany, United Kingdom, United States, Japan, Italy, Western Australia, Netherlands and Sweden.

MEASUREMENTS

Medline, CINAHL, EMBASE, National Research Register and Cochrane Reviews were systematically searched from 1975 to 2004. We identified observational studies that reported overall mortality for people diagnosed with type 2 diabetes when they were over the age of 60, compared with a non-diabetic population. Outcome measures were expressed as risk ratios or relative risks.

RESULTS

Among 14 eligible studies, one study reported reduced mortality for patients diagnosed with type 2 diabetes over the age of 60, whereas another found virtually no increased risk of mortality. However, 7 of the 14 studies reported increased mortality in all patients diagnosed when older, and 5 studies for certain subgroups only. A meta-analysis showed the combined relative risks (with 95% CI) of increased mortality for men diagnosed between the ages of 60 and 70 to be 1.38 (1.08-1.76) and 1.13 (0.88-1.45) for men diagnosed aged 70 years or older. A similar pattern was found for the same age groups for women, with combined relative risks of 1.40 (1.10-1.79) and 1.19 (0.93-1.52) respectively.

CONCLUSION

Increased mortality associated with a diagnosis of type 2 diabetes at an older age is lower than that reported for the general older diabetic population.

The effect of pioglitazone on glycemic and lipid parameters and adverse events in elderly patients with type 2 diabetes mellitus: A post hoc analysis of four randomized trials

OBJECTIVE

This analysis was conducted to evaluate the impact of pioglitazone (PIO), both as monotherapy and as part of combination therapy, on glycemic and lipid parameters and adverse events in elderly patients with type 2 diabetes.

METHODS

This was a post hoc analysis of pooled data, truncated at 1 year, from patients aged > or =65 years with type 2 diabetes in 4 multicenter, randomized, double-blind, parallel-group trials. For inclusion in these trials, patients were required to be between the ages of 35 and 75 years and to have had poorly controlled type 2 diabetes, a glycosylated hemoglobin (HbA(1c)) value between 7.5% and 11.0%, and stable or worsening glycemic control for at least 3 months. Blood samples were obtained at baseline and every 4 to 10 weeks thereafter for determination of HbA(1c), fasting plasma glucose (FPG), and lipid parameters (high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], triglycerides [TG], total cholesterol [TC], TC:HDL-C ratio, and free fatty acids).

RESULTS

Data from 891 elderly patients (age range, 69.1-69.8 years) were included: 282 who received PIO, 123 metformin (MET), 142 sulfonylurea (SU), 105 SU + PIO, 107 SU + MET, 63 MET + PIO, and 69 MET + SU. With a few exceptions, all treatment groups were similar at baseline. From baseline to week 52, none of the changes in HbA(1c) and FPG between each treatment group and its comparator were significant. The adjusted mean (SE) percent changes in HDL-C for the monotherapies were 17.95% (1.11) for PIO, 10.71% (1.70) for MET, and 5.17% (1.51) for SU (both comparisons, P < 0.05). For the combination therapies, the adjusted mean percent changes in HDL-C were 16.77% (1.84) for SUPIO versus 7.87% (1.75) for SUMET (P < 0.05), and 16.34% (2.34) for MET + PIO versus 0.11% (2.19) for METSU (P < 0.05). The adjusted mean percent changes in LDL-C for the monotherapies were 7.00% (1.28) for PIO, -0.68% (1.91) for MET, and -6.77% (1.73) for SU (both comparisons, P < 0.05). For the combination therapies, the adjusted mean percent change in LDL-C was significant for METPIO compared with METSU (13.62% [2.69] vs -4.32% [2.58], respectively; P < 0.05). The adjusted mean percent change in TG was significant for MET + PIO compared with MET + SU (-10.93% [4.44] vs 8.37% [4.15], respectively; P < 0.05). The adjusted mean percent changes in TC for the monotherapies were 6.16% (0.88) for PIO, -1.77% (1.35) for MET, and -6.90% (1.19) for SU (both comparisons, P < 0.05). For the combination therapies, the adjusted mean percent changes in TC were 2.67% (1.45) for SUPIO versus -1.40% (1.39) for SUMET (P < 0.05) and 7.89% (1.85) for METPIO compared with -1.19% (1.73) for METSU (P < 0.05). The differences in change in the TC:HDL-C ratio were not significant between groups. The adjusted mean changes in free fatty acids for the monotherapies were -0.14 (0.02) mmol/L for PIO, -0.001 (0.03) mmol/L for MET, and -0.07 (0.02) mmol/L for SU (both comparisons, P < 0.05). For the combination therapies, the adjusted mean change in free fatty acids was significant for SU + PIO compared with SUMET (-0.12 [0.03] vs 0.06 [0.03] mmol/L, respectively; P < 0.05). PIO monotherapy was associated with the lowest incidence of hypoglycemia (1.4%) among the 7 treatment groups. The SUPIO group had the highest incidence of weight gain (4.8%). The rate of deaths was <2% in all the treatment groups; no adverse event associated with death was considered related to study medication.

CONCLUSIONS

In this post hoc analysis of data from elderly patients participating in 4 randomized clinical trials, PIO effectively controlled glycemic and lipid parameters over 52 weeks and was well tolerated. The effects seen in this analysis were comparable to those in the overall study populations.

Barriers to initiating insulin therapy in patients with type 2 diabetes mellitus in public-sector primary health care centres in Cape Town

BACKGROUND

The majority of patients with type 2 diabetes mellitus in Cape Town who attend primary care community health centres (CHCs) have unsatisfactory glycaemic control. Insulin is rarely prescribed despite its being indicated for type 2 diabetic patients with inadequate metabolic control on maximum oral glucose-lowering agent (OGLA) therapy.

OBJECTIVE

The study examined barriers to initiating insulin therapy in poorly controlled type 2 diabetes patients on maximum OGLAs in CHCs in the Cape Town metropolis.

METHODS

Five focus group discussions and 10 in-depth semistructured individual interviews were conducted with 46 medical officers working at the CHCs. The discussions and interviews were transcribed and common themes were identified and categorised.

RESULTS

Doctor, patient, and system barriers to initiating insulin therapy were identified. Doctors' barriers include lack of knowledge, lack of experience with and use of guidelines related to insulin therapy, language barriers between doctor and patients, and fear of hypoglycaemia. Patient barriers were mistaken beliefs about insulin, non-compliance, lack of understanding of diabetes, use of traditional herbs, fear of injections, and poor socioeconomic conditions. System barriers were inadequate time, lack of continuity of care and financial constraints.

CONCLUSION

Suggestions for overcoming barriers include further education of doctors on insulin initiation and the use of standardised guidelines. In addition, a patient-centred approach with better communication between doctors and patients, which may be achieved by reorganising aspects of the health system, may improve patient knowledge, address mistaken beliefs, improve compliance and help overcome barriers. Further research is needed to investigate these recommendations and assess patients' and nurses' perceptions on initiating insulin therapy.

Effect of early addition of rosiglitazone to sulphonylurea therapy in older type 2 diabetes patients (>60 years): the Rosiglitazone Early vs. SULphonylurea Titration (RESULT) study

AIM

To compare the efficacy, safety and tolerability of adding rosiglitazone (RSG) vs. sulphonylurea (SU) dose escalation in older type 2 diabetes mellitus (T2DM) patients inadequately controlled on SU therapy.

METHODS

A total of 227 T2DM patients from 48 centres in the USA and Canada, aged > or =60 years, were randomized to receive RSG (4 mg) or placebo once daily in combination with glipizide 10 mg twice daily for 2 years in a double-blind, parallel-group study. Previous SU monotherapy was (1/4) to (1/2) maximum recommended dose for > or =2 months prior to screening with fasting plasma glucose (FPG) > or =7.0 and < or =13.9 mmol/l. Treatment options were individualized, and escalation of study medication was specifically defined.

RESULTS

Disease progression (time to reach confirmed FPG > or =10 mmol/l while on maximum doses of both glipizide and study medication or placebo) was reported in 28.7% of patients uptitrating SU plus placebo compared with only 2.0% taking RSG and SU combination (p < 0.0001). RSG + SU significantly decreased HbA(1c), FPG, insulin resistance, plasma free fatty acids and medical care utilization and improved treatment satisfaction compared with uptitrated SU.

CONCLUSIONS

Addition of RSG to SU in older T2DM patients significantly improved glycaemic control and reduced disease progression compared with uptitrated SU alone but without increasing hypoglycaemia. These benefits were associated with increased patient treatment satisfaction and reduced medical care utilization with regards to emergency room visits and length of hospitalization. Early addition of RSG is an effective treatment option for older T2DM patients inadequately controlled on submaximal SU monotherapy.

Use of antidiabetic drugs in elderly patients

The objective of this review of the literature is to analyze the results of studies including diabetic patients aged 70 years and older. Although the risk of treatment is greater in this population because of co-morbid conditions and altered renal function, information on the pharmacokinetics and pharmacodynamics of antidiabetic drugs remains limited. Long-term experience with sulfonylureas is sufficient to establish certain general rules of use; but for biguanides and alpha-glucosidase inhibitors, problems of tolerance limit use; further data are needed on glinides and glitazones. Use of insulin or insulin analogs is frequent and prescription should be adapted to achieve an acceptable balance between the risk of hypoglycaemia and therapeutic goals.

Differences in Diabetes Management of Nursing Home Patients Based on Functional and Cognitive Status

OBJECTIVES

To describe practice patterns regarding diabetes management among nursing home (NH) physicians and to identify variation in this practice based on patient characteristics.

DESIGN

Mailed survey.

PARTICIPANTS

Nursing home physicians from the American Medical Directors Association (AMDA) Foundation Long-Term Care Research Network (n = 142), as well as other members of AMDA who were Certified Medical Directors (CMD) (n = 68) and members who were not CMD certified (n = 45). Response rates to the survey were 51%, 33%, and 23%, respectively.

MEASUREMENTS

Physician and facility characteristics were queried. Responses to 12 items pertaining to diabetes management and 5 items pertaining to use of specific oral diabetes medications were evaluated in the context of 3 different patient profiles that reflected different combinations of functional and cognitive impairment. Responses were based on the physicians' perception of how they manage diabetes under these specified patient profiles.

RESULTS

Responses from members of the Research Network indicated highly significant variability (P < .01) between the 3 patient profiles for all of the 12 management items. Ordering a special diet, monitoring lipid panel, and ordering routine ophthalmology was less likely for the patient profile with both functional and cognitive impairment (P < .01). These differences among the patient profiles for these 3 interventions were present in the responses from all 3 categories of physicians (Research Network, CMD, and non-CMD members of AMDA). There was no statistically significant variability among the 3 patient profiles for any of the 3 physician groups regarding the likelihood of using of any of the 5 classes of oral diabetic medications. Non-CMD physicians were more likely to have less NH experience; otherwise, there were no differences among the 3 physician groups.

CONCLUSIONS

Nursing home physicians appear to alter the approach to diabetes management based on the functional and/or cognitive status of the patient. This was particularly true for those physicians who were members of the AMDA Foundation Research Network. These findings have implications for initiatives designed to guide clinical practice as well as efforts by regulatory bodies to evaluate appropriate care. Further research is needed to measure the actual impact of different approaches to diabetes management on relevant outcomes in this population.

The role of glimepiride in the effective management of Type 2 diabetes

Type 2 diabetes mellitus, a disorder of impaired insulin secretion and insulin resistance, has reached epidemic proportions. The effective management of Type 2 diabetes is of vital concern to clinicians. The identification of high-risk individuals and lifestyle management can help control diabetes; however, most patients require pharmacologic intervention. The goals of pharmacologic therapy are to achieve adequate glycemic control while avoiding hypoglycemia and weight gain and to minimize the risk of future micro- and macrovascular complications. There are a number of available glucose-lowering agents from which to choose. This review focuses on the sulfonylureas, the first oral agents introduced for the management of Type 2 diabetes, which are effective, well-tolerated, and well-established drugs, Second-generation sulfonylureas are now widely used in the management of Type 2 diabetes. The most recent addition, glimepiride, can be used in combination with metformin, the thiazolidinediones, alpha-glucosidase inhibitors, and insulin. The unique properties of glimepiride may provide advantages over other currently available insulin secretagogues.

Novel drug delivery systems for insulin: clinical potential for use in the elderly

Diabetes mellitus is a very common disease in the elderly and its complications are responsible for excess morbidity/mortality, loss of independence and impaired quality of life. Recent studies, while not performed in the elderly, have outlined the importance of achieving tight glycaemic control in order to prevent complications. Eighty years after its discovery, subcutaneous insulin remains a major treatment for diabetes. It is used as a first-line agent in type 1 diabetes, and in type 2 diabetes when oral antihyperglycaemic agents combined with diet and exercise fail to achieve an appropriate metabolic control. To avoid injections, other routes of insulin administration have been studied, including oral, dermal and rectal routes but they were not found to be appropriate for clinical use. Buccal or nasal insulin combined with absorption enhancers proved to have interesting properties. Inhaled insulin appears to be suitable for use in patients with diabetes because of its better bioavailability and a pharmacokinetic profile that mimics the time kinetics of insulin secretion after a meal. Clinical studies were conducted among small numbers of patients with type 1 or type 2 diabetes who had been treated with subcutaneous insulin. Inhaled insulin was given three times daily, just before meals, and was combined with a bedtime subcutaneous injection of long-acting insulin. In patients with type 1 or type 2 diabetes the metabolic control achieved with inhaled insulin was similar to that obtained with a subcutaneous insulin regimen. Tolerance of inhaled insulin was good and treatment satisfaction was better than that with the subcutaneous regimen. Insulin inhalation appears to be an interesting way of insulin delivery for elderly patients with diabetes. However, no studies have been conducted in elderly patients with diabetes to assess this route's acceptability, convenience and ease of use in this particular population. In addition, it is necessary to conduct pharmacokinetic studies in the elderly because lung aging might reduce the bioavailability of inhaled insulin.

Treatment of patients over 64 years of age with type 2 diabetes: experience from nateglinide pooled database retrospective analysis

OBJECTIVE

To evaluate the impact of renal impairment (RI) (estimated creatinine clearance [Cl(cr)] <60 ml/min per 1.73 m(2)) and low baseline HbA(1c) (<7.5%) on comorbidity in patients with type 2 diabetes, and to assess the efficacy and safety of nateglinide monotherapy in these patients and in subgroups of patients over age 64 years (elderly) and elderly with RI.

RESEARCH DESIGN AND METHODS

Retrospective subgroup analyses were performed on pooled data from all completed nateglinide studies (12 randomized, double blind trials and 1 open trial) in patients with type 2 diabetes. A total of 3,702 patients with > or =1 postbaseline safety evaluation received monotherapy with nateglinide (n = 2,204), metformin (n = 436), glyburide (n = 293), or placebo (n = 769). Efficacy (HbA(1c)) was evaluated in pooled data from four studies with similar design using 120 mg nateglinide (n = 544) versus placebo (n = 521). Evaluations were performed in the overall population and subgroups of patients over age 64 years. Specific considerations were given to RI, comorbidity, and baseline HbA(1c).

RESULTS

Patients over age 64 years (n = 1,170) represented 31.6% of the study population. Undiagnosed RI was common in the elderly with 83.4% of all patients being in this subgroup. Patients over 64 years with RI had a higher prevalence of cardio- and microvascular comorbidity compared with the overall population and all patients over age 64 years. Statistically significant HbA(1c) reductions versus placebo were observed with nateglinide in patients over age 64 years and elderly with RI patients at study end point (-0.9% and -1.1% in each subgroup, P < 0.01). Nateglinide was well tolerated with a low incidence of hypoglycemia in all subgroups, including those with RI and low baseline HbA(1c).

CONCLUSIONS

RI and comorbidity are common in patients over age 64 years with type 2 diabetes. Nateglinide was effective and well tolerated in all treated patients. In subgroups in which metformin and long-acting sulfonylureas must be used with caution, nateglinide had a low risk of adverse events and hypoglycemia.

Glimepiride in type 2 diabetes mellitus: a review of the worldwide therapeutic experience

BACKGROUND

Sulfonylureas (SUs) have been used for many years as first-line therapy for patients with type 2 diabetes mellitus whose blood glucose levels have not been effectively controlled by diet and exercise alone. Glimepiride is a once-daily SU that was introduced in 1995. Since then, a considerable body of evidence has been amassed regarding its use in type 2 diabetes.

OBJECTIVE

This review provides a comprehensive summary of available data on the pharmacology, pharmacokinetics, efficacy, and safety profile of glimepiride in the treatment of type 2 diabetes. It also examines the use of glimepiride to achieve and maintain good glycemic control in patients with type 2 diabetes in current clinical practice.

METHODS

Relevant articles were identified through a search of MEDLINE for English-language studies published from 1990 to 2002. The search terms used were glimepiride, sulfonylureas, and type 2 diabetes mellitus. The manufacturer of glimepiride provided additional information.

RESULTS

Glimepiride differs from other SUs in a number of respects. In clinical studies, glimepiride was generally associated with a lower risk of hypoglycemia and less weight gain than other SUs. Results of other studies suggest that glimepiride can be used in older patients and those with renal compromise. There is evidence that glimepiride preserves myocardial preconditioning, a protective mechanism that limits damage in the event of an ischemic event. Glimepiride can be used in combination with other oral antidiabetic agents or insulin to optimize glycemic control.

CONCLUSION

Based on the evidence to date, glimepiride is an effective and well-tolerated once-daily antidiabetic drug and provides an important treatment option for the management of type 2 diabetes.

Repaglinide: a review of its therapeutic use in type 2 diabetes mellitus

Repaglinide, a carbamoylmethyl benzoic acid derivative, is the first of a new class of oral antidiabetic agents designed to normalise postprandial glucose excursions in patients with type 2 diabetes mellitus. Like the sulphonylureas, repaglinide reduces blood glucose by stimulating insulin release from pancreatic beta-cells, but differs from these and other antidiabetic agents in its structure, binding profile, duration of action and mode of excretion. In clinical trials of up to 1-year's duration, repaglinide maintained or improved glycaemic control in patients with type 2 diabetes mellitus. In comparative, 1-year, double-blind, randomised trials (n = 256 to 544), patients receiving repaglinide (0.5 to 4mg before 3 daily meals) achieved similar glycaemic control to that in patients receiving glibenclamide (glyburide) < or = 15 mg/day and greater control than patients receiving glipizide < or = 15 mg/day. Changes from baseline in glycosylated haemoglobin and fasting blood glucose levels were similar between patients receiving repaglinide and glibenclamide in all studies; however, repaglinide was slightly better than glibenclamide in reducing postprandial blood glucose in I short term study (n = 192). Patients can vary their meal timetable with repaglinide: the glucose-lowering efficacy of repaglinide was similar for patients consuming 2, 3 or 4 meals a day. Repaglinide showed additive effects when used in combination with other oral antidiabetic agents including metformin, troglitazone, rosiglitazone and pioglitazone, and intermediate-acting insulin (NPH) given at bedtime. In 1-year trials, the most common adverse events reported in repaglinide recipients (n = 1,228) were hypoglycaemia (16%), upper respiratory tract infection (10%), rhinitis (7%), bronchitis (6%) and headache (9%). The overall incidence of hypoglycaemia was similar to that recorded in patients receiving glibenclamide, glipizide or gliclazide (n = 597) [18%]; however, the incidence of serious hypoglycaemia appears to be slightly higher in sulphonylurea recipients. Unlike glibenclamide, the risk of hypoglycaemia in patients receiving repaglinide was not increased when a meal was missed in 1 trial. In conclusion, repaglinide is a useful addition to the other currently available treatments for type 2 diabetes mellitus. Preprandial repaglinide has displayed antihyperglycaemic efficacy at least equal to that of various sulphonylureas and is associated with a reduced risk of serious hypoglycaemia. It is well tolerated in a wide range of patients, including the elderly, even if a meal is missed. Furthermore, glycaemic control is improved when repaglinide is used in combination with metformin. Thus, repaglinide should be considered for use in any patient with type 2 diabetes mellitus whose blood glucose cannot be controlled by diet or exercise alone, or as an adjunct in patients whose glucose levels are inadequately controlled on metformin alone.