Editorial: Endocrine Frailty in the Elderly

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.

Vascular endothelial dysfunction may be an early predictor of physical frailty and sarcopenia: A meta-analysis of available data from observational studies

BACKGROUND

Physical frailty and sarcopenia (PF & S) are major public health problems in the older population and promising predictors of adverse cardiovascular outcomes. However, the underlying mechanisms linking physical frailty, sarcopenia and adverse cardiovascular outcomes are not well defined. We recently published a systematic review which highlighted early-stage vascular endothelial dysfunction (VED) as one of the potential underlying mechanisms of physical frailty and the role of inflammation in modulating this association.

OBJECTIVE AND METHOD

A meta-analysis was performed to estimate the pooled effect size of studies examining the relationship between VED and PF & S.

RESULTS

Out of 18 cross-sectional studies selected for the original review, 13 studies were excluded due to lack of available data for pooled analysis. The five remaining studies had a total of 6616 participants, of which the pooled sample size of the frail or sarcopenic cohort was 607 and robust or pre-frail or non-sarcopenic cohort was 6009. Mean age of the participants ranging from 64 to 80 years or over. In this analysis, high heterogeneity was observed among studies (99.35% of the variation between studies was due to heterogeneity). Parameters used to assess both PF & S and VED were very different across the studies.

CONCLUSION

The absence of a standardized and valid operational definition of frailty and sarcopenia is a principal limiting factors for frailty research and this is clearly reflected in our study findings. This limits the ability to interpret and define the effects of vascular endothelial dysfunction on these different parameters of frailty and sarcopenia. Similarly, assessment of vascular endothelial dysfunction was very heterogeneous with different parameters utilized across these studies.