Balamurugan Tangiisuran, PhD Discipline of Clinical Pharmacy

School of Pharmaceutical Sciences Universiti Sains Malaysia b.tangiisuran@gmail.com

Age-related Physiological Changes and Functional Decline

• Types of Changes Expected with Age: – Overall decline in body system function

– Variable decline in specific organs and systems

– Different presentations of diseases and symptoms

Age-related Physiological Changes and Functional Decline

• Factors contributing to variations in Functional Decline

–Aging process

–Disease

–Adverse environmental factors

–Adverse lifestyles

Age-related Physiological Changes and Functional Decline

• System and organs most affected by aging – CV system – Pulmonary system – CNS and brain – Renal system and kidneys – Liver – Immune system – GI system – Endocrine system

Effects of aging on the CV SYSTEM

• Overall system function – generally sufficient for needs of aging adults

• Heart – Size of heart stays the same – Heart wall thickens with age – Diastolic filling rate decreases, with atrial

contribution to ventricular filling normal – Systolic BP at rest increases, with end systolic

volume and ejection fraction not significantly altered

Effects of aging on the CV SYSTEM

• Peripheral circulation –Maximal oxygen consumption decreases –Beta-adrenergic modulation decreases,

alpha-adrenergic response normal – Stroke volume increases, counteracting

decreased heart rate

Effects of aging on the Pulmonary System

• Trachea and Central Airways increase in size, leading to: – More anatomic dead space – Decreased lung weight

• Chest wall thickens, leading to: – Loss of elastic recoil in the lung – Increased closing volume – Decreased maximum expiratory flow – Increased risk for respiratory failure

Effects of aging on the Central Nervous System and Brain

• Brain mass and cerebral blood flow decreases, leading to: – Decreased coordination – Prolonged reaction time – Impairment of short-term memory – Decreased sensory conduction time – More permeable BBB

Effects of aging on the Central Nervous System and Brain

• Serotonin system changes affect neuronal functions such as: – Pain – Feeding – Sleep – Sexual behavior – Cardiac regulation – Cognition

Effects of aging on the Kidneys and Renal SystemKidneys and Renal System

• Anatomic changes: –Kidney size

decreases –Number of

glomeruli decreases

–Renal tubules changes

–Renal vasculature changes

Effects of aging on the Kidneys and Renal SystemKidneys and Renal System

• Functional changes –Mean ClCr rate decreases –Renal blood flow declines –Conservation of sodium is reduced due to:

• Lower plasma renin activity • Urinary aldosterone excretion

Effects of aging on the Liver

• Overall function less affected by age than other organs

• Liver size decreases • Hepatic blood flow

decreases, leading to altered metabolic clearance of certain drugs

Effects of aging on the Immune System

• Cell-mediated responses decrease

• Humoral responses decrease

• Thymus size decreases • T-cell function is altered • B-cells produce less

antibodies

Effects of aging on the Gastrointestinal System

• Oral cavity: – Traumatic oral

lesions –Xerostomia

Effects of aging on the Gastrointestinal System

• Stomach – Gastric muscular atrophies – Gastric mucosa thins – Submucosa is infiltrated with elastic fibers – Gastric secretion decreases – pH increases

• once thought to be a consequences of aging, is now thought related to latent H.pylori infections which result in gastric mucosal atrophy and loss of acid producing parietal cells

– Gastric emptying slows

Effects of aging on the Gastrointestinal System

• Small Intestine and Colon – Nutrition absorption

decreases (e.g., vitamn D, calcium)

– Motility remains intact

– Constipation and fecal incontinence is common

Effects of aging on the Endocrine system

• Regulatory and feedback mechanism deteriorate

• Binding affinities and receptors decrease

• Glucose tolerance decreases

• Production of sex hormones decreases

DrDr. . BalamuruganBalamurugan TangiisuranTangiisuran | | School of Pharmaceutical School of Pharmaceutical SciencesSciences

b.tangiisuran@gmail.com

@DrTangiisuran

http://geriatricpharmacy.wordpress.com/