Frailty Syndrome — Etiopathogenesis, Assessment, Management and Prevention

Frailty Syndrome — Etiopathogenesis, Assessment, Management and Prevention A. 20 High-Yield Points Definition and Concept

Definition: Frailty is the condition in which a person loses the ability to carry out important, practised social activities of daily living when exposed to psychological or physical stress. It must be distinguished from disability — frailty is a state of pre-disability, now recognised as a public health priority.

Epidemiology: By Fried's definition, about 6.9% of the older population is frail. Females are more often frail than males of the same age. Sarcopenia, its main substrate, affects 13–24% aged 60–70 and about 50% over age 80.

Frailty threshold: Vitality peaks between 20 and 30 years, then VO2max, cardiac output, balance and muscle strength gradually decline. Exercise delays the decline; disease accelerates it. If a person lives long enough, everyone eventually crosses the frailty threshold.

Pathway: Healthy → Frailty → Disability → Hospitalisation → Institutionalisation → Death, with recovery still possible from the earlier stages. A stressful event precipitates the frail person into disability.

Two conceptual models: the phenotype model (a biological syndrome with a pathophysiological substrate) and the cumulative deficit model of Rockwood (frailty equals an increasing number of deficits and disabilities; essentially a comorbidity index).

Comparison of the three frailty scales — must memorise: Cardiovascular Health Study (Fried) Study of Osteoporotic Fractures (SOF) IANA FRAIL scale Weight loss (10 lb in a year) Weight loss Fatigue Exhaustion (self-report) Inability to rise from a chair 5 times without using Resistance (climb one flight of arms stairs) Weakness (grip strength, lowest 20%) Reduced energy level Aerobic (walk one block) Walking speed (15 ft, slowest 20%) — Illnesses (more than 5) Low physical activity (kcal/week, lowest — Loss of weight (5%)

Core mechanism: In most people frailty results from failure to generate adequate muscle power and/or failure of executive function to use the available power appropriately. The backdrop is normal physiological ageing, which interacts with genes, lifestyle, environment and disease.

Five major causes: disease · pain · decreased food intake · decline in executive function · excess muscle loss (sarcopenia).

Disease to frailty: Many diseases produce an excess of cytokines, which reduce muscle mass, food intake and cognitive function, and also lower the anabolic hormone testosterone.

Congestive heart failure — the classic model: falling VO2max, then left-sided failure causes intestinal wall oedema → bacterial translocation → endotoxin (lipopolysaccharide) → immune activation and TNF-alpha release → anorexia, muscle loss, weight loss, hypoalbuminaemia, hypocholesterolaemia. - Best predictors of poor outcome in CHF are weight loss and hypocholesterolaemia. - Angiotensin II cleaves actomyosin, clearing muscle protein via the ubiquitin–proteasome system; ACE inhibitors reverse weight loss and frailty in some CHF patients.

Other diseases: - COPD — reduced endurance, poor intake, raised resting metabolic rate and thermic energy of eating, low testosterone, high cytokines. - Diabetes mellitus — low testosterone, raised angiotensin II, raised cytokines, peripheral neuropathy, sarcopenia, reduced executive function, accelerated atherosclerosis; mortality is increased in frail diabetics. - Anaemia — reduced endurance and strength, orthostasis, falls, reduced mobility, increased disability and mortality; erythropoietin and darbepoetin-alpha reverse many of these.

Reversible causes not to be missed: Polymyalgia rheumatica — painful muscles with proximal myopathy, raised ESR, and corticosteroids completely reverse the frailty; this totally reversible condition is often misdiagnosed. Also hyperthyroidism, hypothyroidism, hypoadrenalism (insidious onset) and arthritis or pain leading to immobility and muscle loss.

Anorexia of ageing (decreased food intake): causes are multifactorial — - Social: isolation, dysphoria - Sensory: decline in smell, rise in taste threshold - Gastric: decreased fundal compliance and adaptive relaxation leading to rapid antral filling and early satiety - Hormonal: excess cholecystokinin from the duodenum after a fatty meal; high circulating cytokines - In men: falling testosterone leads to rising leptin and greater anorexia — men lose more food intake over the lifespan.

MEALS-ON-WHEELS mnemonic for treatable weight loss: Medications (digoxin, theophylline, cimetidine) · Emotional (depression) · Alcoholism, elder abuse, anorexia tardive · Late-life paranoia · Swallowing problems · Oral factors · Nosocomial infections (e.g. tuberculosis) · Wandering and other dementia-related causes · Hyperthyroidism, hypercalcaemia, hypoadrenalism · Enteral problems (gluten enteropathy) · Eating problems · Low-salt, low-cholesterol and other therapeutic diets · Stones (cholecystitis).

Sarcopenia — the engine of frailty: - Defined as lean tissue more than 2 SD below young adults. - Best measure is appendicular skeletal mass by DEXA divided by height squared; MRI, CT, bioelectrical impedance and ultrasound are alternatives. - Sarcopenic obesity ("fat frail") — those who stay fat while losing muscle have the highest future disability and mortality. - Myosteatosis (fat infiltration into muscle) is a separate condition linked to insulin resistance via altered insulin-receptor substrate and GLUT transporter function.

Determinants of muscle loss: best predictors are age, energy intake, physical activity, IGF-1, testosterone and cytokines. Also hypovitaminosis D (reduced strength, more falls); testosterone falls about 1% per year from age 30 in men; myostatin acts via activin IIb receptors; motor unit firing rate falls after age 80; CNTF declines; TNF-alpha and IL-6 excess reduce strength; high homocysteine and peripheral vascular disease impair muscle blood flow. Sarcopenia may originate at birth — grip strength correlates with birth weight in the Hertfordshire cohort.

Screen everyone, then assess. Use a rapid validated tool first — the FRAIL scale is the simplest and quickest. Then confirm and characterise with a fuller measure. - Phenotype tools: Fried phenotype, Frailty Trait Scale, FRAIL index. - Cumulative deficit tools: Frailty Index, Clinical Frailty Scale. - Frailty is one of the three core functional dimensions of CGA, with basic ADLs and IADLs. Remember the hierarchy rule — do not test frailty in someone already severely ADL-dependent. - Progranulin is described as a biomarker of frailty.

Management algorithm using the FRAIL screen — the single most examinable table:

Principle of management: Frailty may have a single reversible cause — for example anaemia, where correction with iron, folate, vitamin B12 or erythropoietin reverses the frailty. More often it is due to the interplay of hormones and cytokines with disease and poor-quality nutrition, requiring careful assessment of causative factors and a multifaceted treatment regimen.

Prevention and other therapies: - Exercise is the central preventive measure — it delays the slope towards the frailty threshold; creatine with exercise may improve muscle performance. - Testosterone replacement increases muscle mass even in non-hypogonadal males, and pharmacological or replacement doses improve muscle strength, power and function. Selective androgen receptor modulators — steroidal (nandrolone, oxymetholone, oxandrolone) and non-steroidal (2-quinoline, coumarin, phthalimide, bicalutamide, acetothiolutamide) — are under investigation. - Vitamin D — regular sun exposure 15–30 minutes a day without sunblock, or 800–1000 IU/day, especially in long-term-care residents. - Deprescribing and treating reversible disease are as important as exercise and nutrition.

Kim and Rockwood, NEJM 2024 — the current definitive review. Assessing older patients for frailty enables clinicians to tailor clinical care, including decisions about stressful treatments. Management is stratified into four stages — robust, pre-frailty, frailty and end-stage frailty — with thresholds such as Fried phenotype 0, Frailty Index below 0.10, and Clinical Frailty Scale 1–3 defining "robust." This concept of "frailty-guided clinical care" is the major shift since the textbook.

NHS England and BGS — proactive frailty care (2023–2025). In December 2023 NHS England published Proactive care: providing care and support to people living at home with moderate and severe frailty. The pathway is: identify the cohort (including by electronic frailty index, eFI), confirm with the Clinical Frailty Scale, then perform a CGA covering physical, functional, social, environmental and psychological domains alongside a medication review. The original eFI is being replaced nationally by the eFI2, available to primary care from 2025. The BGS Joining the dots (2023) and Be proactive (2024) supersede the 2014 "Fit for Frailty" guidance.

ICFSR Global Consensus on Exercise (2025). Structured exercise prescriptions should be customised and monitored like any other medical treatment, considering dose–response relationships, with a multifaceted regimen of aerobic, resistance, balance and flexibility training through structured and incidental activity.

Italian National CGA Guideline (2024). Across 117 studies, CGA reduced hospitalisation, mortality, institutionalisation and delirium risk, improved appropriateness of drug prescription, and maintained functional activities. CGA remains the definitive management vehicle for frailty.

WHO ICOPE — intrinsic capacity as the mirror image of frailty. ICOPE screens six domains — mobility, cognition, nutrition, vision, hearing and psychological well-being — with confirmed deficits triggering full assessment and a personalised prevention and care plan. Intrinsic capacity (reserve) and frailty (deficits) are two faces of the same coin.

Indian data — much higher burden than Western figures. LASI wave-1 (26,058 adults aged 60 and above, Fried phenotype) found frailty in 29.2% and pre-frailty in 58.8%, higher among women (37.3%), the illiterate (37%) and rural residents (31%), ranging from 14.5% in Uttarakhand to 41.3% in Arunachal Pradesh, and strongly associated with depression. A 2025 systematic review and meta-analysis of 330,007 community-dwelling Indians found a pooled frailty prevalence of 36% (48% by frailty index, 31% by Fried phenotype). In LASI, the most discriminant frailty component was grip strength in men (79.1%) and physical activity in women (81.6%).