Evidence gap on antihyperglycemic pharmacotherapy in frail older adults : A systematic review

[Therapy of physical frailty]

As an overarching geriatric syndrome, frailty describes a potentially reversible transitional stage between functional autonomy and irreversible disability. Thus, frailty addresses a "window of opportunity" in which functional limitations can be successfully treated. This article provides an overview of the therapeutic approaches and their scientific evidence.

The outcome of frailty in older people with diabetes as a function of glycaemic control and hypoglycaemic therapy: a review

INTRODUCTION

Frailty is an emerging and newly recognized complication of diabetes in older people. However, frailty is not thoroughly investigated in diabetes outcome studies.

AREAS COVERED

This manuscript reviews the effect of glycemic control and hypoglycemic therapy on the incidence of frailty in older people with diabetes.

EXPERT OPINION

Current studies show that both low glycemia and high glycemia are associated with frailty. However, most of the studies, especially low glycemia studies, are cross-sectional or retrospective, suggesting association, rather than causation, of frailty. In addition, frail patients in the low glycemia studies are characterized by lower body weight or lower body mass index (BMI), contrary to those in the high glycemia studies, who are either overweight or obese. This may suggest that frailty has a heterogeneous metabolic spectrum, starting with an anorexic malnourished (AM) phenotype at one end, which is associated with low glycemia and a sarcopenic obese (SO) phenotype on the other end, which is associated with high glycemia. The current little evidence suggests that poor glycemic control increases the risk of frailty, but there is a paucity of evidence to suggest that tight glycemic control would reduce the risk of incident frailty. Metformin is the only well-studied hypoglycemic agent, so far, to have a protective effect against frailty independent of glycemic control in the non-frail older people with diabetes. However, once frailty is developed, the choice of the best hypoglycemic agent for these patients will be affected by the metabolic phenotype of frailty. For example, sodium glucose transporter-2 (SGLT-2) inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1RA) are appropriate in the SO phenotype due to their weight losing properties, while insulin therapy may be considered early in the AM phenotype due to its anabolic and weight gaining benefits. Future studies are still required to further investigate the metabolic effects of frailty on older people with diabetes, determine the most appropriate HbA1c target, and explore the most suitable hypoglycemic agent in each metabolic phenotype of frailty.

Metabolic Characteristics of Frail Older People with Diabetes Mellitus-A Systematic Search for Phenotypes

Frailty in older people with diabetes is viewed as one homogeneous category. We previously suggested that frailty is not homogeneous and spans across a metabolic spectrum that starts with an anorexic malnourished (AM) frail phenotype and ends with a sarcopenic obese (SO) phenotype. We aimed to investigate the metabolic characteristics of frail older people with diabetes reported in the current literature to explore whether they fit into two distinctive metabolic phenotypes. We performed systematic review of studies published over the last 10 years and reported characteristics of frail older people with diabetes mellitus. A total of 25 studies were included in this systematic review. Fifteen studies reported frail patients' characteristics that could fit into an AM phenotype. This phenotype is characterised by low body weight, increased prevalence of malnutrition markers such as low serum albumin, low serum cholesterol, low Hb, low HbA1c, and increased risk of hypoglycaemia. Ten studies reported frail patients' characteristics that describe a SO phenotype. This phenotype is characterised by increased body weight, increased serum cholesterol, high HbA1c, and increased blood glucose levels. Due to significant weight loss in the AM phenotype, insulin resistance decreases, leading to a decelerated diabetes trajectory and reduced hypoglycaemic agent use or deintensification of therapy. On the other hand, in the SO phenotype, insulin resistance increases leading to accelerated diabetes trajectory and increased hypoglycaemic agent use or intensification of therapy. Current literature suggests that frailty is a metabolically heterogeneous condition that includes AM and SO phenotypes. Both phenotypes have metabolically distinctive features, which will have a different effect on diabetes trajectory. Therefore, clinical decision-making and future clinical studies should consider the metabolic heterogeneity of frailty.

Adherence to antidiabetic drug therapy and reduction of fatal events in elderly frail patients

BACKGROUND

To evaluate the protective effect of oral antidiabetic drugs in a large cohort of elderly patients with type 2 diabetes differing for age, clinical status, and life expectancy, including patients with multiple comorbidities and short survival.

METHODS

A nested case-control study was carried out by including the cohort of 188,983 patients from Lombardy (Italy), aged ≥ 65 years, who received ≥ 3 consecutive prescriptions of antidiabetic agents (mostly metformin and other older conventional agents) during 2012. Cases were the 49,201 patients who died for any cause during follow-up (up to 2018). A control was randomly selected for each case. Adherence to drug therapy was measured by considering the proportion of days of the follow-up covered by the drug prescriptions. Conditional logistic regression was used to model the risk of outcome associated with adherence to antidiabetic drugs. The analysis was stratified according to four categories of the clinical status (good, intermediate, poor, and very poor) differing for life expectancy.

RESULTS

There was a steep increase in comorbidities and a marked reduction of the 6-year survival from the very good to the very poor (or frail) clinical category. Progressive increase in adherence to treatment was associated with a progressive decrease in the risk of all-cause mortality in all clinical categories and at all ages (65-74, 75-84 and ≥ 85 years) except for the frail patient subgroup aged ≥ 85 years. The mortality reduction from lowest to highest adherence level showed a tendency to be lower in frail patients compared to the other categories. Similar although less consistent results were obtained for cardiovascular mortality.

CONCLUSIONS

In elderly diabetic patients, increased adherence to antidiabetic drugs is associated with a reduction in the risk of mortality regardless of the patients' clinical status and age, with the exception of very old patients (age ≥ 85 years) in the very poor or frail clinical category. However, in the frail patient category the benefit of treatment appears to be less than in patients in good clinical conditions.

Cardiovascular Risk Factor Control in 70- to 95-Year-Old Individuals: Cross-Sectional Results from the Population-Based AugUR Study

Cardiovascular risk factors such as high glucose, LDL-cholesterol, blood pressure, and impaired kidney function are particularly frequent in old-aged individuals. However, population-based data on the extent of cardiovascular risk factor control in the old-aged population is limited. AugUR is a cohort of the mobile “70+”-year-old population of/near Regensburg, recruited via population registries. We conducted cross-sectional analyses assessing the proportion of AugUR participants with LDL-cholesterol, HbA1c, or blood pressure beyond recommended levels and their association with impaired creatinine- and cystatin-based estimated glomerular filtration rate (eGFR, <60 mL/min/1.73 m2) or urine albumin–creatinine ratio (UACR, ≥30 mg/g). Among 2215 AugUR participants, 74.7% were taking lipid-, glucose-, blood-pressure-lowering, or diuretic medication. High LDL-cholesterol at ≥116 mg/dL was observed for 76.1% (51.1% among those with prior cardiovascular events). We found HbA1c ≥ 7.0% for 6.3%, and high or low systolic blood pressure for 6.8% or 26.5%, respectively (≥160, <120 mmHg). Logistic regression revealed (i) high HbA1c levels associated with increased risk for impaired kidney function among those untreated, (ii) high blood pressure with increased UACR, and (iii) low blood pressure with impaired eGFR, which was confined to individuals taking diuretics. Our results provide important insights into cardiovascular risk factor control in individuals aged 70–95 years, which are understudied in most population-based studies.

Metabolic Impact of Frailty Changes Diabetes Trajectory

Diabetes mellitus prevalence increases with increasing age. In older people with diabetes, frailty is a newly emerging and significant complication. Frailty induces body composition changes that influence the metabolic state and affect diabetes trajectory. Frailty appears to have a wide metabolic spectrum, which can present with an anorexic malnourished phenotype and a sarcopenic obese phenotype. The sarcopenic obese phenotype individuals have significant loss of muscle mass and increased visceral fat. This phenotype is characterised by increased insulin resistance and a synergistic increase in the cardiovascular risk more than that induced by obesity or sarcopenia alone. Therefore, in this phenotype, the trajectory of diabetes is accelerated, which needs further intensification of hypoglycaemic therapy and a focus on cardiovascular risk reduction. Anorexic malnourished individuals have significant weight loss and reduced insulin resistance. In this phenotype, the trajectory of diabetes is decelerated, which needs deintensification of hypoglycaemic therapy and a focus on symptom control and quality of life. In the sarcopenic obese phenotype, the early use of sodium-glucose transporter-2 inhibitors and glucagon-like peptide-1 receptor agonists is reasonable due to their weight loss and cardio-renal protection properties. In the malnourished anorexic phenotype, the early use of long-acting insulin analogues is reasonable due to their weight gain and anabolic properties, regimen simplicity and the convenience of once-daily administration.

Reduction of care-relevant risks to older patients during and after acute hospital care (ReduRisk) - study protocol of a cluster randomized efficacy trial in a stepped wedge design

BACKGROUND

Older patients are at an increased risk of hospitalization, negatively affecting their health and quality of life. Such patients also experience a lack of physical activity during their inpatient stay, as well as being at increased risk of delirium and inappropriate prescribing. These risk factors can accumulate, promoting a degree of morbidity and the development of cognitive impairment.

METHODS

Through the ReduRisk-program, patients at risk of functional impairment, immobility, falls, delirium or re-hospitalization shortly after hospital discharge, will be identified via risk-screening. These patients will receive an individually tailored, multicomponent and risk-adjusted prevention program. The trial will compare the effectiveness of the ReduRisk-program against usual care in a stepped-wedge-design, with quarterly cluster randomization of six university hospital departments into intervention and control groups. 612 older adults aged 70 years or more are being recruited. Patients in the intervention cluster (n = 357) will receive the ReduRisk-program, comprising risk-adjusted delirium management, structured mobility training and digitally supported planning of post-inpatient care, including polypharmacy management. This study will evaluate the impact of the ReduRisk-program on the primary outcomes of activities of daily living and mobility, and the secondary outcomes of delirium, cognition, falls, grip strength, health-related quality of life, potentially inappropriate prescribing, health care costs and re-hospitalizations. Assessments will be conducted at inpatient admission (t0), at discharge (t1) and at six months post-discharge (t2). In the six-month period following discharge, a health-economic evaluation will be carried out based on routine health insurance data (t3).

DISCUSSION

Despite the importance of multicomponent, risk-specific approaches to managing older patients, guidelines on their effectiveness are lacking. This trial will seek to provide evidence for the effectiveness of a multicomponent, risk-adjusted prevention program for older patients at risk of functional impairment, immobility, falls, delirium and re-hospitalization. Positive study results would support efforts to improve multicomponent prevention and the management of older patients.

TRIAL REGISTRATION

German Clinical Trials Register, DRKS00025594, date of registration: 09/08/2021.

Impact of frailty metabolic phenotypes on the management of older people with type 2 diabetes mellitus

AIMS

To provide a pathophysiological basis for distinguishing metabolic variants of the frailty phenotype in older adults with type 2 diabetes.

METHODS

We have made an in-depth review of the possible mechanisms in diabetes, ageing and frailty that will alter allow us to describe phenotypic changes which might assist in predicting responses to particular glucose-lowering therapy.

RESULTS

Our review has enable us to describe with some confidence a sarcopenic obese phenotype and an anorexic malnourished phenotype.

CONCLUSIONS

By identifying these two phenotypes we can predict which would be most responsive to certain classes of therapy and where therapies may be ill-advised. This represents the first novel approach in this area. Further work is being planned to develop this hypothesis. Geriatr Gerontol Int 2021; 21: 614-622.

Newer anti-diabetic therapies with low hypoglycemic risk-potential advantages for frail older people

The prevalence of diabetes is increasing due to increasing aging of the population. Hypoglycemia is a common diabetes-related complication in old age especially in patients with multiple comorbidities and frailty. Hypoglycemia and frailty appear to have a bidirectional relationship reenforcing each other in a negative downhill spiral that leads to an increased risk of adverse events including disability and mortality. The incidence of hypoglycemia in this age group is usually underestimated due to its atypical clinical presentation and difficult recognition by health care professionals. Guidelines generally recommend a relaxed glycemic control in frail older people with diabetes mainly due to the fear of anti-diabetic medications-induced hypoglycemia. The new anti-diabetic therapies of sodium-glucose co-transporter-2 (SGLT-2) inhibitors and glucagon like peptide-1 receptor agonists (GLP-1RA) have consistently shown a cardio-renal protective effect independent of their glycemic control. Contrary to the traditional hypoglycemic agents that either increase insulin stimulation or insulin sensitization with a potential hypoglycemic risk especially sulfonylureas, the new therapies have a novel anti-diabetic mechanisms of action that have a negligible risk of hypoglycemia. The new therapies appear to be both effective and well tolerated in old age. With appropriate patients' selection, most older people will be eligible for the new therapies if well tolerated and no contraindications. In frail older people, we suggest a pragmatic approach of the use of the new therapies based on the concept of the weight status rather than the frailty status. Frail patients with normal or excess weight are likely to gain most from the new therapies due to its favorable metabolic properties in this group, while the use in the underweight frail patients should be largely avoided especially in those with persistent anorexia and weight loss.