Altered hierarchy of protective responses against severe hypoglycemia in normal aging in healthy men

Self blood glucose monitoring in type 2 diabetes. A financial impact analysis based on UK primary care

BACKGROUND

UK consensus guidelines recommend limited use of self-monitoring of blood glucose (SMBG) in patients with type 2 diabetes using diet and exercise, metformin and/or a glitazone. This analysis quantifies the usage of and costs associated with SMBG in type 2 diabetes according to treatment regimen.

METHODS

Prevalence data for diabetes were assessed using UK Quality and Outcomes Framework returns for 2006/2007. Data on current SMBG prescribing expenditure were extracted from UK Prescription Pricing Agency Data for 2007. Prescribing data were extracted from the records of 40,651 patients with diabetes on the IMS Disease Analyzer (MediPlus) database. These were combined to arrive at mean usage and expenditure data per patient, broken down by treatment type. The analysis assumes that it is appropriate to use patients' treatment regimen alone to compare the frequency of SMBG in clinical practice with the frequency recommended in treatment guidelines; it does not take into account other valid reasons for SMBG.

RESULTS

Mean national expenditure on SMBG was 73.64 pound sterling per patient per year. Estimated mean weekly test strip usage by treatment was 2.5 (diet), 2.6 (glitazone monotherapy), 3.1 (metformin monotherapy) and 3.5 (sulphonylurea monotherapy). Combination oral therapy ranged from 3.3 to 4.1. Mean annual expenditure in patients with an identified treatment type was 62.06 pound sterling per patient, ranging from 9.83 pound sterling for diet-treated patients to 37.87 pound sterling for those on triple therapy, with insulin-treated patients incurring costs 3-5 times higher.

CONCLUSIONS

Based on the assumptions that the treatment regimen is the sole factor in determining the appropriate level of SMBG frequency, this study demonstrates that the use of SMBG exceeds current guidelines in certain treatment groups. The study estimates that the potential savings of up to 17 million pound sterling could be made each year if guidelines were followed more closely. There is a need for further research into SMBG use in patients with type 2 diabetes.

Hot flashes and fatigue relieved by metformin

OBJECTIVE

To describe 3 patients with long-standing hot flashes, excessive sweating, and fatigue whose symptoms were ameliorated with metformin.

METHODS

In this case series, we report the findings of laboratory evaluations, including assessments for thyroid, gonadal, adrenal, and pancreatic disorders, in 3 patients referred for endocrine evaluation. A 75-g oral glucose tolerance test with measurement of fasting and postprandial glucose and insulin concentrations was conducted. A trial of metformin, 500 mg twice daily, was initiated in all patients.

RESULTS

Evaluation of factors that are associated with hot flashes and increased sweating did not establish the cause of the patients' symptoms. The 3 patients had normal glucose tolerance test results and hyperinsulinemia. Metformin therapy markedly relieved the symptoms in all patients.

CONCLUSIONS

Hyperinsulinemia without hypoglycemia may produce a sympathoexcitatory response that manifests as hot flashes and increased sweating. Metformin may have sympathoinhibitory actions that alleviate these symptoms.

Effect of aging on A1C levels in individuals without diabetes: evidence from the Framingham Offspring Study and the National Health and Nutrition Examination Survey 2001-2004

OBJECTIVE

Although glycemic levels are known to rise with normal aging, the nondiabetic A1C range is not age specific. We examined whether A1C was associated with age in nondiabetic subjects and in subjects with normal glucose tolerance (NGT) in two population-based cohorts.

RESEARCH DESIGN AND METHODS

We performed cross-sectional analyses of A1C across age categories in 2,473 nondiabetic participants of the Framingham Offspring Study (FOS) and in 3,270 nondiabetic participants from the National Health and Nutrition Examination Survey (NHANES) 2001-2004. In FOS, we examined A1C by age in a subset with NGT, i.e., after excluding those with impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT). Multivariate analyses were performed, adjusting for sex, BMI, fasting glucose, and 2-h postload glucose values.

RESULTS

In the FOS and NHANES cohorts, A1C levels were positively associated with age in nondiabetic subjects. Linear regression revealed 0.014- and 0.010-unit increases in A1C per year in the nondiabetic FOS and NHANES populations, respectively. The 97.5th percentiles for A1C were 6.0% and 5.6% for nondiabetic individuals aged <40 years in FOS and NHANES, respectively, compared with 6.6% and 6.2% for individuals aged >or=70 years (P(trend) < 0.001). The association of A1C with age was similar when restricted to the subset of FOS subjects with NGT and after adjustments for sex, BMI, fasting glucose, and 2-h postload glucose values.

CONCLUSIONS

A1C levels are positively associated with age in nondiabetic populations even after exclusion of subjects with IFG and/or IGT. Further studies are needed to determine whether age-specific diagnostic and treatment criteria would be appropriate.

Nateglinide, alone or in combination with metformin, is effective and well tolerated in treatment-naïve elderly patients with type 2 diabetes

AIM

The aim of this work was to assess the efficacy and tolerability of nateglinide alone or in combination with metformin in elderly patients with type 2 diabetes (T2DM).

METHODS

Study 1 was a 12-week, multicentre, randomized, double blind and placebo-controlled study of nateglinide monotherapy (120 mg, before meals) in 66 drug-naïve patients with T2DM aged >or=65 years. Study 2 was a 104-week, multicentre, randomized, double blind and active-controlled study of nateglinide (120 mg, before meals) or glyburide (up to 5 mg bid) in combination with metformin (up to 1000 mg bid) in 69 treatment-naïve patients with T2DM aged >or=65 years. HbA(1c), fasting and postprandial glucose levels, and safety assessments were made.

RESULTS

In Study 1, nateglinide significantly reduced HbA(1c) from baseline (7.6 +/- 0.1% to 6.9 +/- 0.1%; Delta = -0.7 +/- 0.1%, p < 0.001) and compared with placebo (between-group difference = -0.5%, p = 0.004 vs. nateglinide). No hypoglycaemia was reported. In Study 2, combination therapy with nateglinide/metformin significantly reduced HbA(1c) from baseline (7.8 +/- 0.2% to 6.6 +/- 0.1%; Delta = -1.2 +/- 0.2%, p < 0.001), as did glyburide/metformin (7.7 +/- 0.1% to 6.5 +/- 0.1%; Delta = -1.2 +/- 0.1%, p < 0.001). There was no difference between treatments (p = 0.310). One nateglinide/metformin-treated patient experienced a mild hypoglycaemic episode compared with eight episodes in eight patients on glyburide/metformin; one severe episode led to discontinuation. Target HbA(1c) (<7.0%) was achieved by 60% of patients receiving nateglinide (Study 1) and 70% of nateglinide/metformin-treated patients (Study 2).

CONCLUSION

Initial drug treatment with nateglinide, alone or in combination with metformin, is well tolerated and produces clinically meaningful improvements in glycaemic control in elderly patients with T2DM.

Therapeutic options for elderly diabetic subjects: open label, randomized clinical trial of insulin glargine added to oral antidiabetic drugs versus increased dosage of oral antidiabetic drugs

Glycemic control in elderly persons with type 2 diabetes mellitus (T2DM) is challenging because they are more likely to have other age-associated medical conditions and to experience hypoglycemia during intensive therapy. A best therapeutic strategy for these patients has not yet been defined. We investigated the efficacy and safety of adding once-daily insulin glargine to patients' current oral antidiabetic drugs (OAD) regimen, compared to increasing the OAD doses. The study enrolled patients aged 65 years or more, with poor glycemic control. Patients were randomized to two groups and entered a 3-week titration period in which their actual therapy was adjusted to meet the study's glycemic goals, by either adding insulin glargine to current therapy (group A, 27 patients) or increasing current OAD dosages (group B, 28 patients). Thereafter, therapies were continued unchanged for a 24-week observation period. The mean therapeutic dosage of insulin glargine in group A was 14.9 IU/day (SD = 5.0 IU/day). During the observation period, mean levels of glycosylated hemoglobin (HbA1c) reduced by 1.5% in group A and 0.6% in group B (P = 0.381). An HbA1c level <7.0% was achieved by five patients in each group. Mean fasting blood glucose levels reduced by 29 and 15% in groups A and B, respectively (P = 0.029). Group A had fewer total hypoglycemic events (23 vs. 79, P = 0.030) and fewer patients experiencing any such event (9 vs. 17, P = 0.045). Neither a serious hypoglycemic event nor other adverse event occurred. These results suggest that, compared to increasing OAD dosage, the addition of insulin glargine to current OAD therapy is as effective but safer in terms of the risk for hypoglycemia in elderly patients with T2DM.

Hypoglycaemia in Type 2 diabetes

The primary cause of hypoglycaemia in Type 2 diabetes is diabetes medication-in particular, those which raise insulin levels independently of blood glucose, such as sulphonylureas (SUs) and exogenous insulin. The risk of hypoglycaemia is increased in older patients, those with longer diabetes duration, lesser insulin reserve and perhaps in the drive for strict glycaemic control. Differing definitions, data collection methods, drug type/regimen and patient populations make comparing rates of hypoglycaemia difficult. It is clear that patients taking insulin have the highest rates of self-reported severe hypoglycaemia (25% in patients who have been taking insulin for > 5 years). SUs are associated with significantly lower rates of severe hypoglycaemia. However, large numbers of patients take SUs in the UK, and it is estimated that each year > 5000 patients will experience a severe event caused by their SU therapy which will require emergency intervention. Hypoglycaemia has substantial clinical impact, in terms of mortality, morbidity and quality of life. The cost implications of severe episodes-both direct hospital costs and indirect costs-are considerable: it is estimated that each hospital admission for severe hypoglycaemia costs around pound1000. Hypoglycaemia and fear of hypoglycaemia limit the ability of current diabetes medications to achieve and maintain optimal levels of glycaemic control. Newer therapies, which focus on the incretin axis, may carry a lower risk of hypoglycaemia. Their use, and more prudent use of older therapies with low risk of hypoglycaemia, may help patients achieve improved glucose control for longer, and reduce the risk of diabetic complications.

Management of type 2 diabetes in treatment-naive elderly patients: benefits and risks of vildagliptin monotherapy

OBJECTIVE

The purpose of this study was to evaluate the efficacy and safety of vildagliptin in elderly patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Efficacy data from five double-blind, randomized, placebo- or active-controlled trials of >or=24 weeks' duration were pooled. Effects of 24-week vildagliptin monotherapy (100 mg daily) were compared in younger (<65 years, n = 1,231) and older (>or=65 years, n = 238) patients. Safety data from eight controlled clinical trials of >or=12-weeks' duration were pooled; adverse event profiles in younger (n = 1,890) and older (n = 374) patients were compared.

RESULTS

Mean baseline A1C and fasting plasma glucose (FPG) were significantly lower in older (70 years: 8.3 +/- 0.1% and 9.6 +/- 0.1 mmol/l, respectively) than in younger (50 years: 8.7 +/- 0.0% and 10.5 +/- 0.1 mmol/l, respectively) patients. Despite this, the adjusted mean change from baseline (AMDelta) in A1C was -1.2 +/- 0.1% in older and -1.0 +/- 0.0% in younger vildagliptin-treated patients (P = 0.092), and the AMDelta in FPG was significantly larger in older (-1.5 +/- 0.2 mmol/l) than in younger (-1.1 +/- 0.1 mmol/l, P = 0.035) patients. Body weight was significantly lower at baseline in older (83.4 +/- 1.0 kg) than in younger (92.0 +/- 0.6 kg) patients. Weight decreased significantly in the older subgroup (AMDelta -0.9 +/- 0.3 kg, P = 0.007), whereas smaller, nonsignificant decreases occurred in younger patients (AMDelta -0.2 +/- 0.1 kg). Adverse event rates were slightly higher in older than in younger subgroups but were lower among older, vildagliptin-treated subjects (63.6%) than in the pooled active comparator group (68.1%). Vildagliptin treatment did not increase adverse events among older patients with mild renal impairment (62.0%). Hypoglycemia was rare (0.8%) in the elderly patients, and no severe events occurred.

CONCLUSIONS

Vildagliptin monotherapy was effective and well tolerated in treatment-naive elderly patients.

Lower risk of hypoglycemia with insulin detemir than with neutral protamine hagedorn insulin in older persons with type 2 diabetes: a pooled analysis of phase III trials

OBJECTIVES

To compare the safety and efficacy of insulin detemir with that of neutral protamine Hagedorn (NPH) insulin in older (aged >/=65) and younger (aged 18-64) persons with type 2 diabetes mellitus (DM).

DESIGN

Pooled, post hoc analysis of data from three open-label, randomized studies.

SETTING

Three multinational Phase III trials.

PARTICIPANTS

Four hundred sixteen older and 880 younger persons with DM, treated for 22 to 26 weeks with basal insulin plus mealtime insulin or oral agents.

MEASUREMENTS

Hemoglobin A(1c) (HbA(1c)), fasting plasma glucose, glucose variability, hypoglycemic episodes.

RESULTS

Mean treatment difference for HbA(1c) (insulin detemir-NPH insulin) indicated that insulin detemir was not inferior to NPH insulin for both age groups (0.035%, 95% confidence interval (CI)=-0.114-0.183 and 0.100%, 95% CI=-0.017-0.217, for older and younger persons, respectively). Relative risk of all hypoglycemic episodes (insulin detemir/NPH insulin) was 0.59 (95% CI-0.42-0.83) for older persons and 0.75 (95% CI-0.59-0.96) for younger persons. Adverse events were similar between treatments. Fasting plasma glucose was similar between treatments (mean treatment difference 0.97 mg/dL, 95% CI=-8.01-9.95, and 4.69 mg/dL, 95% CI=-2.30-11.67, for older and younger persons, respectively). Mean treatment difference for weight was -1.02 kg (95% CI -1.61 to -0.42) and -1.13 (95% CI -1.58 to -0.69) for older and younger persons, respectively.

CONCLUSION

Previously reported benefits of insulin detemir, particularly less hypoglycemia and less weight gain, compared with NPH insulin, were the same for older and younger persons with DM at similar levels of HbA(1c).

Gastric emptying, diabetes, and aging

Gastric emptying is mildly slowed in healthy aging, although generally remains within the normal range for young people. The significance of this is unclear, but may potentially influence the absorption of certain drugs, especially when a rapid effect is desired. Type 2 diabetes is common in the elderly, but there is little data regarding its natural history, prognosis, and management. This article focuses on the interactions between gastric emptying and diabetes, how each is influenced by the process of aging, and the implications for patient management.

Antihyperglycaemic therapy in elderly patients with type 2 diabetes: potential role of incretin mimetics and DPP-4 inhibitors

Management of elderly patients with type II diabetes is complicated by age-related changes in physiology, comorbidities, polypharmacy and heterogeneity of functional status. A minimum goal in antidiabetic treatment in this population is to achieve a level of glycaemic control that avoids acute complications of diabetes, adverse effects and reduction in quality of life. Hypoglycaemia is a particular problem in elderly patients, and many antidiabetic agents pose increased risk for hypoglycaemia. In addition, many standard agents pose risks for older patients because of reduced renal function and common comorbidities. Newer agents based on enhancing incretin activity, including the glucagon-like peptide-1 mimetics exenatide and liraglutide and the oral dipeptidyl peptidase-4 inhibitors sitagliptin and vildagliptin, may offer particular advantages in elderly patients with diabetes.

Diabetes mellitus and dementia

Alzheimer's disease (AD) and diabetes mellitus (DM) are two of the most common and devastating health problems in the elderly. They share a number of common features amongst which high prevalence after 65 years, important impact of patient's quality of life, substantial health care costs. Reviews on the epidemiological studies on cognitive impairment in patients with DM found evidence of cross-sectional and prospective associations between type 2 DM and moderate cognitive impairment, on memory and executive functions. There is also evidence for an elevated risk of both vascular dementia and AD in patients with type 2 DM, albeit with strong interaction of other factors such as hypertension, dyslipidaemia and ApoE genotype. DM is an independent predictor of post-stroke dementia. DM being an atherogenic risk factor, it may increase the risk of dementia through associations with stroke, causing vascular dementia. In addition, vascular reactivity may be adversely affected by advanced glycosylation end products resulting in more subtle perfusion abnormalities. Cerebrovascular disease may exacerbate AD through direct interactions between the two pathological processes or through cognitive impairment secondary to cerebrovascular disease "unmasking" AD at an earlier stage than it would otherwise become apparent. The increased risk of AD may also be mediated by the exacerbation of B-amyloid neurotoxicity by advanced glycosylation end products identified in the matrix of neurofibrillary tangles and amyloid plaques in AD brains, or associations with insulin functions. Decreased cholinergic transport across the blood-brain barrier observed in diabetic animals may exacerbate cognitive impairment in AD. Many interventions could reduce the cognitive decline associated with DM, yet not enough are taken into account so far.

Management of Diabetes in Older Adults

Enhanced life expectancy and the aging of society have conspired with rising rates of obesity and physical inactivity to cause an unprecedented increase in diabetes prevalence worldwide. The disease and its chronic complications have unique presentations and challenges in the elderly. Postprandial hyperglycemia may be the predominant manifestation, comorbid health conditions are often present, and the risk of cardiovascular disease is vastly increased. Periodic screening is essential for early diagnosis and proper treatment. The principles of multidisciplinary management emphasizing nutrition, exercise, education, psychosocial care, attention to concomitant metabolic risk factors, and prudent use of pharmacologic agents are the mainstay of therapy for older adults. Treatment should be tailored to the individual patient, and the assistance of family and caregivers should be combined with rational utilization of community resources. An evidence-based, comprehensive, and proactive approach is needed to reduce the burden of morbidity and mortality from diabetes in the elderly.

Hypoglycaemia in elderly diabetic patients

Occurring in the elderly diabetic patients, hypoglycaemia may have serious consequences in terms of morbidity and mortality, but this severe prognosis is nowadays less frequently observed. The clinical manifestations may be somewhat different from those observed in young subjects: symptoms are less frequent, generally neurologic manifestations. The rate of severe hypoglycaemia remains low (about 1.4 episode per 100 patient-years), but increases rapidly in the very elderly and also with insulin therapy, co-morbid conditions especially renal insufficiency, and associated treatments, as well as with unawareness of symptoms. Prevention requires reinforced education for the patient and caregiver, particularly concerning diet, knowledge of signs of hypoglycaemia, and appropriate treatment. Self-monitoring of blood glucose, by the patient when possible, or by a familial or medical caregiver, should be encouraged in order to detect asymptomatic episodes of hypoglycaemia and better adapt antidiabetic treatment.

Altered glycemia and brain—update and potential relevance to the aging brain

Hyperglycemia characterizes diabetes mellitus and is linked to its chronic and acute complications. Cognitive dysfunction in diabetes occurs especially in longstanding disease and with poor glycemic control. Recent data in humans suggests that hyperglycemia causes acute cognitive dysfunction. The underlying mechanisms are unknown but deserve further research as diabetes is becoming epidemic and will likely contribute increasingly to premature cognitive decline. The primary side effect of diabetes treatment is hypoglycemia, particularly resulting from insulin treatment. CNS adaptations to acute and chronic hypoglycemia underlie the inability of some people to promptly recognize and defend against the risk of serious hypoglycemia. Data from human and animal models may help explain how altered glycemia affects brain function both acutely and chronically. Improved mechanistic understanding of altered glycemia's effects could prevent the adverse impact of diabetes upon the CNS and give new insights into effects that may exist in normal aging.

The role of sulphonylureas in the management of type 2 diabetes mellitus

The sulphonylureas act by triggering insulin release from the pancreatic beta cell. A specific site on the adenosine triphosphate (ATP)-sensitive potassium channels is occupied by sulphonylureas leading to closure of the potassium channels and subsequent opening of calcium channels. This results in exocytosis of insulin. The meglitinides are not sulphonylureas but also occupy the sulphonylurea receptor unit coupled to the ATP-sensitive potassium channel. Glibenclamide (glyburide), gliclazide, glipizide and glimepiride are the primary sulphonylureas in current clinical use for type 2 diabetes mellitus. Glibenclamide has a higher frequency of hypoglycaemia than the other agents. With long-term use, there is a progressive decrease in the effectiveness of sulphonylureas. This loss of effect is the result of a reduction in insulin-producing capacity by the pancreatic beta cell and is also seen with other antihyperglycaemic agents. The major adverse effect of sulphonylureas is hypoglycaemia. There is a theoretical concern that sulphonylureas may affect cardiac potassium channels resulting in a diminished response to ischaemia. There are now many choices for initial therapy of type 2 diabetes in addition to sulphonylureas. Metformin and thiazolidinediones affect insulin sensitivity by independent mechanisms. Disaccharidase inhibitors reduce rapid carbohydrate absorption. No single agent appears capable of achieving target glucose levels in the majority of patients with type 2 diabetes. Combinations of agents are successful in lowering glycosylated haemoglobin levels more than with a single agent. Sulphonylureas are particularly beneficial when combined with agents such as metformin that decrease insulin resistance. Sulphonylureas can also be given with a basal insulin injection to provide enhanced endogenous insulin secretion after meals. Sulphonylureas will continue to be used both primarily and as part of combined therapy for most patients with type 2 diabetes.

Hypoglycemia in Type 1 Diabetes Mellitus

Spontaneous hypoglycemia is uncommon in the general (nondiabetic) population, but iatrogenic hypoglycemia is rife in patients with type 1 diabetes mellitus, among whom hypoglycemia constitutes a barrier to optimal glycemic control. The obligate dependence on exogenous insulin, together with the current imperfection in insulin therapies, generates degrees of blood glucose fluctuations that often exceed physiological boundaries in these patients. Downward swings in blood glucose levels, if sustained, result in hypoglycemia and significant morbidity and mortality. Hypoglycemia in type 1 diabetes indicates an imbalance between caloric supply and glucose use in response to insulin or exercise. Counterregulatory mechanisms that auto-correct iatrogenic hypoglycemia often become progressively impaired in these patients. This defective counterregulation, together with the imperfections in insulin delivery, set the stage for significant morbidity from iatrogenic hypoglycemia. Recurrent episodes of iatrogenic hypoglycemia induce a state of hypoglycemia unawareness and defective counterregulation, which defines the syndrome of hypoglycemia-associated autonomic failure (HAAF). The reduced awareness of, and counterregulatory responses to, hypoglycemia in patients with HAAF lead to worsening episodes of severe hypoglycemia. Approaches to the prevention of hypoglycemia include glucose monitoring, patient education, meal planning, and medication adjustment. In patients with HAAF, scrupulous avoidance of iatrogenic hypoglycemia may restore the symptomatic and counterregulatory responses to hypoglycemia. Behavioral training focusing on recognition of the more subtle symptoms and signs of evolving hypoglycemia may be beneficial to some patients with HAAF. A methodical search for the pattern and etiology of iatrogenic hypoglycemia is a prerequisite for the identification of the best preventive approach. With proper education, patients with type 1 diabetes and their physicians can learn to prevent or minimize the risk of hypoglycemia while pursuing excellence in glycemic control.

A repeated cross-sectional survey of severe hypoglycaemia in 178 Type 1 diabetes mellitus patients performed in 1984 and 1998

AIMS

To study the prevalence of severe hypoglycaemia (SH) in relation to risk factors in Type 1 diabetic (T1 DM) patients over a period of 14 years.

METHODS

We performed a cross-sectional survey of a cohort of 178 T1 DM patients registered at our out-patient clinic in 1984 to be repeated in 1998. An identical questionnaire was sent to the patients in the beginning of 1985 and 1999, respectively, regarding the problem of SH in the preceding year. Additional clinical data were obtained from the patients' medical records on insulin treatment, long-term complications, morbidity, and co-medication.

RESULTS

At follow up, the use of multiple insulin injection therapy had increased from 71% to 98% (P < 0.001) and daily self-monitoring of blood glucose (SMBG) from 17% to 48% (P < 0.001). Twenty-seven percent were treated with direct-acting insulin analogues in 1998. An increasing number of patients reported unawareness of hypoglycaemia, 54% vs. 40% (P < 0.01), and nocturnal events were more frequent, 83% vs. 76% (P < 0.05). The prevalence of SH had increased from 17% to 27% (P < 0.05) and a slight decrease of HbA1c, 7.6% to 7.4% (P < 0.05) was documented.

CONCLUSION

We conclude that despite more frequent use of multiple injection therapy and SMBG, the prevalence of SH has increased by > 50% over 14 years. A multiple logistic regression analysis of risk factors for SH explained less than 10% of the variance, implicating only unawareness of hypoglycaemia and HbA1c.

Diabetes in the elderly: problems of care and service provision

Diabetes is common in the elderly and old UK citizens, affecting between 10% and 25%. There is considerable associated morbidity and mortality, with dementia being a common problem. The diabetic elder is also at risk of drug side-effects. Most of the evidence base for treatment is based on trials performed in younger diabetic subjects or older nondiabetic subjects; however, we can practice evidence-biased medicine whilst awaiting the results of ongoing trials. The older persons national service framework (NSF) may share some similarities with the diabetes NSF; it was 1 year late, and had no clear funding, amongst several other worries. Residential care, which is more likely to be required by diabetic elders, is also under-funded with major concerns about the quality of care for the diabetic resident. The little evidence that we have regarding care of the older diabetic person also suggests inadequacies. Given the likelihood that we will have to manage with present resources, managed clinical networks may be one way to cope.

Symptoms of hypoglycaemia in people with diabetes

The symptoms of hypoglycaemia are fundamental to the early detection and treatment of this side-effect of insulin and oral hypoglycaemic therapy in people with diabetes. The physiology of normal responses to hypoglycaemia is described and the importance of symptoms of hypoglycaemia is discussed in relation to the treatment of diabetes. The symptoms of hypoglycaemia are described in detail. The classification of symptoms is considered and the usefulness of autonomic and neuroglycopenic symptoms for detecting hypoglycaemia is discussed. The many external and internal factors involved in the perception of symptoms are reviewed, and symptoms of hypoglycaemia experienced by people with Type 2 diabetes are addressed. Age-specific differences in the symptoms of hypoglycaemia have been identified, and are important for clinical and research practice, particularly with respect to the development of acquired hypoglycaemia syndromes in people with Type 1 diabetes that can result in impaired awareness of hypoglycaemia. In addition, the routine assessment of hypoglycaemia symptoms in the diabetic clinic is emphasized as an important part of the regular review of people with diabetes who are treated with insulin.

Clinical review of glimepiride

This article reviews the pharmacological and clinical aspects of glimepiride, the latest second-generation sulfonylurea for treatment of Type 2 diabetes mellitus (DM). Glimepiride therapy ameliorates the relative insulin secretory deficit found in most patients with Type 2 DM. It is a direct insulin secretagogue; indirectly, it also increases insulin secretion in response to fuels such as glucose. Its action to augment insulin secretion requires binding to a high affinity sulfonylurea receptor, which results in closure of ATP-sensitive potassium channels in the beta-cells of the pancreas. The question has been raised whether insulin secretagogues by acting on vascular or myocardial potassium channels may prevent ischaemic preconditioning, a physiological adaptation that could affect the outcome of coronary heart disease, but there is evidence against this concern being applicable to glimepiride. Glimepiride's antihyperglycaemic efficacy is equal to other secretagogues. It has pharmacokinetic properties that make it less prone to cause hypoglycaemia in renal dysfunction than some other insulin secretagogues, particularly glyburide (also known as glibenclamide in Europe). Its convenient once daily dosing may enhance compliance for diabetic patients who often also require medications for other co-morbid conditions, such as hypertension, hyperlipidaemia and cardiac disease. Glimepiride is approved for monotherapy, for combination with metformin and with insulin. Clinically, its reduced risk of hypoglycaemia makes it preferable to some other insulin secretagogues when attempting to achieve recommended glycaemic control (haemoglobin A(1c) (HgbA(1c)) 7%). Using suppertime neutral protamine Hagedorn (NPH) and regular insulin with morning glimepiride in overweight diabetic patients achieves glycaemic goals more quickly than insulin alone and with lower insulin doses.

Hypoglycaemic counter-regulation at normal blood glucose concentrations in patients with well controlled type-2 diabetes

BACKGROUND

Intensive treatment to achieve good glycaemic control in diabetic patients is limited by a high frequency of hypoglycaemia. The glucose concentrations at which symptoms and release of counter-regulatory hormones takes place have not been studied in patients with well controlled type-2 diabetes.

METHODS

We studied seven well controlled, non-insulin treated, type-2 diabetic patients (mean HbA1c [corrected according to Diabetes Control and Complications Trial] 7.4%, SD 1.0) and seven healthy controls matched for age, sex, and body mass index with a stepped hyperinsulinaemic hypoglycaemic glucose clamp. Symptoms, cognitive function, and counter-regulatory hormone concentrations were measured at each glucose plateau, and the glucose value at which there was a significant change from baseline was calculated.

FINDINGS

Symptom response took place at higher whole-blood glucose concentrations in diabetic patients than in controls. Counter-regulatory release of epinephrine, norepinephrine, growth hormone, and cortisol showed a similar pattern--eg, at blood glucose concentrations of 3.8 mmol/L [SD 0.4] vs 2.6 [0.3] for epinephrine.

INTERPRETATION

Glucose thresholds for counter-regulatory hormone secretion are altered in well controlled type-2 diabetic patients, so that both symptoms and counter-regulatory hormone release can take place at normal glucose values. This effect might protect type-2 diabetic patients against episodes of profound hypoglycaemia and make the achievement of normoglycaemia more challenging in clinical practice.

Type 2 diabetes mellitus, cognitive impairment and dementia

AIMS

We set out to examine the evidence for an association between cognitive impairment or dementia and the presence of Type 2 diabetes mellitus (DM). We also sought evidence of potential mechanisms for such an association.

METHODS

A literature search of three databases was performed and the reference lists of the papers so identified were examined, using English language papers only.

RESULTS

We found evidence of cross-sectional and prospective associations between Type 2 DM and cognitive impairment, probably both for memory and executive function. There is also evidence for an elevated risk of both vascular dementia and Alzheimer's disease in Type 2 DM albeit with strong interaction of other factors such as hypertension, dyslipidaemia and apolipoprotein E phenotype. Both vascular and non-vascular factors are likely to play a role in dementia in diabetes.

CONCLUSIONS

Current classification structures for dementia may not be adequate in diabetes, where mixed pathogenesis is likely. Further research into the mechanisms of cognitive impairment in Type 2 DM may allow us to challenge the concept of dementia, at least in these patients, as an irremediable disease.