Clinical Chemistry and the Geriatric patient

1. Clinical Chemistry and the Geriatric patient

2. Aging means to grow older • Several physiological changes occur as people age • These changes are gradual • Deterioration results from time-dependent, • irreversible changes • These changes will be reflected in clinical laboratory test results

3. Life expectancy is increasing, for persons born in 1900(47years) to (77years) for persons born in 2001 • This gain is due to improved sanitation, better medical care and increased use of preventive health services • Geriatrics is the branch of health care concerned with the care of the aged, including physiological, pathological, psychological, economic and sociological problems

4. Gerontology is the study of the aging processThe demand on the health care system by geriatric patients is different from that of the rest of the population Health care will need to shift its emphasis to meet the need of chronically ill As the population ages, increase in chronic diseases such as cancer, arthritis, hypertension and diabetes are expected

5. This means more physician office visits, hospital stays and laboratory tests • The clinical laboratory professional must treat the patient with dignity and respect. They must be aware of special considerations regarding the collection of blood samples, development of reference intervals, effect of medications on chemistry results. • They must understand the effects of aging on laboratory values

6. Current Theories of Aging • 1- Random Genetic Damage • -Mutation • -Background Radiation Damage e.g ultraviolet rays which may cause chromosome or DNA damage • -errors in chromosomal translocation or transcription • 2- glycation of Proteins • Interfere with both cell structure and function

7. 3- Developmental Theories • -Immune and Neuroendocrine System • ..Immune system declines with age e.gthymic atrophy, reduction of B and T cell population, decreased response to neoantigens, misfolding of proteins which may lead to amyloidosis • 4- Genetically Programmed Theory • defects in apoptosis.. • 5-Free Radicals(OH, O2, NO…) • Cause damage to cells • N.B delay of aging in rodents was accomplished by calorie restriction

8. Diseases and Disorders commonly associated With Aging • Atherosclerosis( e.g myocardial infarct, renal disease, stroke) Cancer Diabetes mellitus Hyperparathyroidism Hyperthyroidism Hypothyroidism Monoclonal gammopathies(e.g multiple myeloma) osteoporosis

9. The Top Ten Leading Causes of Death (Age 65 and Older) • heart disease • Cancer • Stroke • Chronic lower respiratory disease • Accidental death due to unintentional injury • Diabetes • Alzheimer disease • Influenza or pneumonia • Nephritis, nephrotic syndrome or nephrosis • Septicemia

10. Changes in Selected Clinical Chemistry Analytes With Age • A- Increase • GGT • ALP(women) • Alpa-1 antitrypsin • Amylase • AST • BUN • CK • Gammma globulin • Fasting Glucose • HDL

11. Increase • Inorganic Phosphate • LDH • PCO2 • K • Total Cholesterol • Triacylglycerol • TSH • Uric Acids

12. Decrease • Albumin • Aldosterone • Bilirubin • Creatinine Clearance • DHEA • Growth Hormone • PO2 • T3 • Total Protein • Transferrinss

13. Unchanged • Chloride • Cortisol • Free T4 • Haptoglobin • Insulin(fasting) • PH or Slight decrease • Na • T4 or Slight decrease • Thyroid-binding globuli(TBG)

14. Endocrine Function Changes • Changes in the production of hormones by sex organs, thyroid, pituitary and adrenal glands • The most notable changes relate to the gonadal and thyroid hormones • A decrease in the gonadal production of estrogen in women(menopause) and of testosterone in men(andropause) • The adrenal production of dehydroepiandrosterone(DHEA) and DHEA sulfate(adrenopause)

15. Decrease in the growth hormone-insulin-like growth factor(IGF) axis(somatopause) • Hormone replacement regimens are being developed as a strategy to delay or prevent some of the consequences of aging • Dysregulation of apoptosis may be the cause of diseases such as cancer and neurodegenerative disorders(e.g Alzheimer and Parkinson diseases) • The major consequences of estrogen deficiency are osteoporosis and CHD.

16. Major risk factors of osteoporosis include diet, inactive life style, genetic predisposition, smoking, endocrine disturbances and medications • The greatest problem secondary to osteoporosis is hip fracture • An association between hypovitaminosis D and secondary hyperparathyroidism and osteoporotic changes in the elderly

17. The prevelance of hypertension also increases with age, about 60% of people older than 60 years having the condition. • Causes include increased peripheral resistance due to atherosclerosis, chronic renal and endocrine disorders and multiple medications. • There is also a decline in the efficiency of homeostatic regulation.s

18. Diabetes mellitus and insulin resistance increase with aging. • Consequences of D.M such as retinopathy, nephropathy and CVD also increase • Renal function changes as indicated by kidney function tests is common in elderly. • Hepatic function disorders are observed in elderly.

19. Pulmonary Function and Electrolyte Changes • PO2 decreases • PCO2 increases • Na/Cl no changes • K slight increase • Respiratory-related diseases are prevalent in elderly people. • Diseases include chronic bronchitis, chronic obsrtuctive pulmonary disease, neoplasia, lung infections particularly T.B and pneumonia

20. Cardiovascular and Lipid Changes • Atherosclerosis develops slowly followed by hypertension, hemorrhage, thrombosis, stroke and CHD • Hyperlipidemia plays major role in atherosclerotic process and risk for CHD • Cholesterol, triglyceride, HDL levels increase with aging

21. Enzymes • The following enzymes show increased activity: • AST • ALP • GGT • CK • LDH • Amylase

22. Establishing Reference Intervals for the Elderly • It is difficult to establish RI for the elderly due to differences in physiological and pathological condition of each individual, however the following factors should be considered when interpreting clinical laboratory results: • Exercise, Medications, Mobility, Nutritional status, personal habits, Alcohol use, Smoking, Chronic disorders, trauma………and special conditions