Pathophysiology of the anorexia of aging

Nutrition, frailty, and sarcopenia

Frailty and sarcopenia are important concepts in the quest to prevent physical dependence, as geriatrics are shifting towards identifications of early stages of disability. Definitions of both sarcopenia and frailty are still developing, and both concepts clearly overlap in their physical aspects. Malnutrition (both undernutrition and obesity) plays a key role in the pathogenesis of frailty and sarcopenia. The quality of the diet along the lifespan has a close relation with the incidence of both entities, and nutritional interventions may be able to reduce the incidence or revert either of them. This brief review explores the role of energy and protein intake and other key nutrients on muscle function. Nutrition may be a key element of multimodal interventions for frailty and sarcopenia. The results of the "Sarcopenia and Physical fRailty IN older people: multi-componenT Treatment strategies" (SPRINTT) trial will offer key insights on the effect of such interventions in frail, sarcopenic older individuals.

Sarcopenia and post-hospital outcomes in older adults: A longitudinal study

INTRODUCTION

Sarcopenia poses a significant problem for older adults, yet very little is known about this medical condition in the hospital setting. The aims of this hospital-based study were to determine: (i) the prevalence of sarcopenia; (ii) factors associated with sarcopenia; and (iii) the association of sarcopenia with adverse clinical outcomes post-hospitalisation.

METHODS

This is a longitudinal analysis of consecutive patients aged ≥70 years admitted to a Geriatric Management and Evaluation Unit (GEMU) ward. Sarcopenia was classified using the European Working Group on Sarcopenia in Older People (EWGSOP) algorithm, which included: handgrip strength, gait speed, and muscle mass using Bioelectrical Impedance Analysis (BIA). Outcomes were assessed at 12-months post-hospital discharge, and included both mortality and admission to a hospital Emergency Department (ED). Kaplan-Meier methods were used to estimate survival, with Cox proportion hazard models then applied. All regression analyses controlled for age, sex, and co-morbidity.

RESULTS

172 patients (72% female) with a mean (SD) age of 85.2 (6.4) years were included. Sarcopenia was present in 69 (40.1%) of patients. Patients with sarcopenia were twice as likely to die in the 12-months post-hospitalisation (HR, 95% CI=2.23, 1.15-4.34), but did not have an increased likelihood of ED admission.

CONCLUSIONS

Sarcopenia showed an independent association with 12-month post-hospital mortality in older adults. With the new recognition of sarcopenia as a medical condition with its own unique ICD-10-CM code, awareness and diagnosis of sarcopenia in clinical settings is paramount.

Anorexia of Aging: Risk Factors, Consequences, and Potential Treatments

Older people frequently fail to ingest adequate amount of food to meet their essential energy and nutrient requirements. Anorexia of aging, defined by decrease in appetite and/or food intake in old age, is a major contributing factor to under-nutrition and adverse health outcomes in the geriatric population. This disorder is indeed highly prevalent and is recognized as an independent predictor of morbidity and mortality in different clinical settings. Even though anorexia is not an unavoidable consequence of aging, advancing age often promotes its development through various mechanisms. Age-related changes in life-style, disease conditions, as well as social and environmental factors have the potential to directly affect dietary behaviors and nutritional status. In spite of their importance, problems related to food intake and, more generally, nutritional status are seldom attended to in clinical practice. While this may be the result of an “ageist” approach, it should be acknowledged that simple interventions, such as oral nutritional supplementation or modified diets, could meaningfully improve the health status and quality of life of older persons.

Evidence for partial pharmaceutical reversal of the cancer anorexia-cachexia syndrome: the case of anamorelin

A major component of the cancer anorexia-cachexia syndrome is a decline in food intake. Up until now none of the drugs that improve appetite also improve skeletal muscle. Recent studies have suggested that the oral ghrelin-analog, anamorelin, increased food intake and muscle mass. Unfortunately, it does not increase muscle power. Its regulatory future is uncertain, although it has important clinical effects.

Peptides and aging: Their role in anorexia and memory

The rapid aging of the world's population has led to a need to increase our understanding of the pathophysiology of the factors leading to frailty and cognitive decline. Peptides have been shown to be involved in the pathophysiology of frailty and cognitive decline. Weight loss is a major component of frailty. In this review, we demonstrate a central role for both peripheral peptides (e.g., cholecystokinin and ghrelin) and neuropeptides (e.g., dynorphin and alpha-MSH) in the pathophysiology of the anorexia of aging. Similarly, peripheral peptides (e.g., ghrelin, glucagon-like peptide 1, and cholecystokinin) are modulators of memory. A number of centrally acting neuropeptides have also been shown to modulate cognitive processes. Amyloid-beta peptide in physiological levels is a memory enhancer, while in high (pathological) levels, it plays a key role in the development of Alzheimer's disease.

Understanding the gastrointestinal tract of the elderly to develop dietary solutions that prevent malnutrition

Although the prevalence of malnutrition in the old age is increasing worldwide a synthetic understanding of the impact of aging on the intake, digestion, and absorption of nutrients is still lacking. This review article aims at filling the gap in knowledge between the functional decline of the aging gastrointestinal tract (GIT) and the consequences of malnutrition on the health status of elderly. Changes in the aging GIT include the mechanical disintegration of food, gastrointestinal motor function, food transit, chemical food digestion, and functionality of the intestinal wall. These alterations progressively decrease the ability of the GIT to provide the aging organism with adequate levels of nutrients, what contributes to the development of malnutrition. Malnutrition, in turn, increases the risks for the development of a range of pathologies associated with most organ systems, in particular the nervous-, muscoskeletal-, cardiovascular-, immune-, and skin systems. In addition to psychological, economics, and societal factors, dietary solutions preventing malnutrition should thus propose dietary guidelines and food products that integrate knowledge on the functionality of the aging GIT and the nutritional status of the elderly. Achieving this goal will request the identification, validation, and correlative analysis of biomarkers of food intake, nutrient bioavailability, and malnutrition.

Chocolate-candy consumption and 3-year weight gain among postmenopausal U.S. women

OBJECTIVE

To test the hypothesis that greater chocolate-candy intake is associated with more weight gain in postmenopausal women.

METHODS

A prospective cohort study involved 107,243 postmenopausal American women aged 50-79 years (mean = 60.7) at enrollment in the Women's Health Initiative, with 3-year follow-up. Chocolate-candy consumption was assessed by food frequency questionnaire, and body weight was measured. Linear mixed models, adjusted for demographic, socio economic, anthropomorphic, and behavioral variables, were used to test our main hypotheses.

RESULTS

Compared with women who ate a 1 oz (∼28 g) serving of chocolate candy <1 per month, those who ate this amount 1 per month to <1 per week, 1 per week to < 3 per week and ≥3 per week showed greater 3-year prospective weight gains (kg) of 0.76 (95% CI: 0.66, 0.85), 0.95 (0.84, 1.06), and 1.40 (1.27, 1.53), respectively, (P for linear trend<0.0001). Each additional 1 oz/day was associated with a greater 3-year weight gain (kg) of 0.92 (0.80, 1.05). The weight gain in each chocolate-candy intake level increased as BMI increased above the normal range (18.5-25 kg/m(2)), and was inversely associated with age.

CONCLUSIONS

Greater chocolate-candy intake was associated with greater prospective weight gain in this cohort of postmenopausal women.

Obesity in the ageing man

As the population is ageing globally, both ageing and obesity are recognized as major public health challenges. The aim of this narrative review is to present and discuss the current evidence on the changes in body composition, energy balance and endocrine environment that occur in the ageing man. Obesity in the ageing man is related to changes in both body weight and composition due to alterations in energy intake and total energy expenditure. In addition, somatopenia (decreased GH secretion), late-onset hypogonadism (LOH), changes in thyroid and adrenal function, as well as changes in appetite-related peptides (leptin, ghrelin) and, most importantly, insulin action are related to obesity, abnormal energy balance, redistribution of the adipose tissue and sarcopenia (decreased muscle mass). A better understanding of the complex relationship of ageing-related endocrine changes and obesity could lead to more effective interventions for elderly men.

Reduced fasting plasma levels of diazepam-binding inhibitor in adolescents with anorexia nervosa

OBJECTIVE

Altered expression and/or function, both peripherally and centrally, of various neuropeptides is involved in the neurophysiology of anorexia nervosa (AN). Diazepam-binding inhibitor (DBI) is an interesting peptide for understanding this crosstalk. The aim of this work was to assess fasting plasma levels of DBI and leptin in patients with AN.

METHOD

Twenty-four AN adolescents were recruited together with 10 age-comparable healthy controls. Neuropeptide determinations were performed on plasma samples by enzyme-linked immunosorbent assays. Patients with AN were further characterized for the presence of a depressive state or anxiety by using, respectively, the Children's Depression Inventory or the State-Trait Anxiety Inventory form Y.

RESULTS

Levels of both plasma DBI and leptin were reduced in patients with AN (∼40 and ∼70%, respectively). DBI levels displayed a tendency to increase in the presence of a depressive state, although not with anxiety, whereas leptin levels correlated exclusively with body mass index.

DISCUSSION

These data further extend our knowledge of neuropeptide dysfunction in AN, and plasma DBI may represent a marker for this disease, in particular considering its correlation with comorbid mood disorders.

Risk factors for body composition abnormalities in systemic sclerosis

The aim of this study was to evaluate the body composition (BC), bone mineral density (BMD), and the food intake in women with systemic sclerosis (SSc) compared to a control group, in order to identify main risk factors for BC abnormalities in SSc. Sixty-one SSc women and 67 age- and gender-matched controls were included. Spine, femur, and total body BMD measurements were performed using dual-energy X-ray absorptiometry. BC measurements included total lean (LM), fat mass (FM), and relative skeletal muscle mass index (RSMI) assessment. The food intake was calculated from 3-day food records and transformed into energy and nutrients. The 61 SSc patients [30 with diffuse cutaneous disease (dcSSc) and 31 with limited cutaneous SSc (lcSSc)] had significantly lower body mass index (BMI), LM, and FM, as well as lower BMD values compared to controls. Besides, the group with dcSSc, but not those with lcSSc, showed significantly lower BC and BMD measurements than controls. There was a significant inverse correlation between disease duration and BMI, LM, and RSMI. The total energy, macronutrients, and essential amino acids intakes were similar between patients and controls. After multivariate analysis, longer disease duration was the only risk factor associated with sarcopenia (RSMI below 5.45 kg/m(2); OR = 1.36, 95% CI 1.07-1.7). The present study showed an abnormal BC and a lower BMD, especially in dcSSc women, regardless of current food intake. Longer disease duration was associated with a higher risk of sarcopenia in SSc patients.