1. Clinical Chemistry and the Geriatric patient
Part 2

2. Diseases and Disorders Commonly Associated with Aging Pulmonary Function and Electrolyte Changes
Several known anatomic and physiologic changes occur in pulmonary function during the aging process.
pulmonary function is more affected by personal habits, such as smoking, and by environmental pollution.
Decreased vital (lung) capacity found in most elderly people causes arterial pO2 to decrease whereas pCO2 increases slightly or remain the same.
An increase in bicarbonate would compensate for the increase in pCO2 and maintain the blood pH value, which is reported to remain fairly constant or to decrease only slightly.

3. Sodium remains fairly constant from young adulthood to older age.
Diseases and Disorders Commonly Associated with Aging Pulmonary Function and Electrolyte Changes
The electrolytes sodium, potassium, and chloride all show little change in healthy elderly people from values seen in younger adults.
Sodium remains fairly constant from young adulthood to older age.
Chloride values are also fairly constant but have been found to be slightly higher in people older than 90 years.
Potassium, however, increases slightly from age 60 to 90.
Respiratory-related diseases are prevalent in elderly people and account for 25% of all deaths in those older than 85.
Include chronic bronchitis, chronic obstructive pulmonary disease (COPD), neoplasia, and lung infections, particularly tuberculosis and pneumonia.

4. Diseases and Disorders Commonly Associated with Aging Cardiovascular and Lipid Changes
Atherosclerosis, a type of arteriosclerosis, is the major cause of death from cardiovascular disease in the United States.
Atherosclerosis develops slowly over the years and results of atherosclerosis include hypertension, hemorrhage, thrombosis, stroke, and coronary heart disease (CHD) also called ischemic heart disease
risk for CHD are HDL and LDL cholesterol, total cholesterol, and triglycerides.
HDL values less than about 35 mg/dL indicating a high risk and values more than 35 mg/dL indicating a low risk.
Arteriosclerosis: stiffing of the arteries while Atherosclerosis is the process which causes stiffing of the arteries

5. Enzyme Changes
Enzymes do not appear to follow any particular age-related pattern; they may increase, decrease, or remain the same during the aging process.
Men
Women
AST, GGT, LD, amylase 
ALT
Marginal  –
ALP
(until 90)  CK
 (60-69)
 (70-90)
 (60-70)
 > 70

6. CLINICAL CHEMISTRY RESULTS AND AGING
Clinical laboratorians must understand other factors that may affect clinical chemistry results in the elderly.
What preanalytical variables (e.g., diet, posture, medications) relating to the elderly affect clinical chemistry results?
How does the aging process affect interpretation of drug levels in the elderly?
What are the effects of exercise and nutrition on the elderly and chemistry results?

7. CLINICAL CHEMISTRY RESULTS AND AGING Establishing Reference Intervals for the Elderly
It is difficult to establish Reference Intervals 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

8. Preanalytical variables relating to the patient include:
CLINICAL CHEMISTRY RESULTS AND AGING Preanalytical Variables, the Elderly, and Chemistry Results
Preanalytical variables relating to the patient include:
diet, gender, posture (e.g., sitting or lying), personal habits (e.g., smoking and alcohol consumption), body composition, physical activity, and prescribed medications.
Body mass and height also decrease after about age 60.
These changes, in turn, may affect the levels of various analytes (e.g., creatinine)
Several physical and physiologic changes of aging can affect the collection and quality of a specimen.
Diseases such as arthritis, malnutrition, or dehydration, in addition to the aging process itself, there may be a decrease in muscle tone and skin elasticity (i.e., flabby skin).

9. CLINICAL CHEMISTRY RESULTS AND AGING Therapeutic Drug Monitoring in the Elderly
With the normal aging process, there are many changes in how the body handles drugs.
Absorption, distribution, metabolism, and excretion of a drug are all affected by the aging process.
For example, gastric emptying time may be prolonged in the elderly, causing a delay in drug absorption.
Metabolism or biotransformation of drugs, which is handled primarily by the liver, may be impaired as a result of an age-related decrease in hepatic mass and blood flow.

10. CLINICAL CHEMISTRY RESULTS AND AGING Therapeutic Drug Monitoring in the Elderly
Renal mass and blood flow both decrease with advancing age. Serum albumin may also be decreased because of protein energy malnutrition, which affects drugs that are transported bound to albumin.
For drugs principally excreted in the urine, caution should be exercised in treatment to prevent any overdosing or toxic effects.
Because the effects of drugs are more likely to be exaggerated in the elderly, laboratorians should be knowledgeable of the principles of therapeutic drug monitoring and the affects of aging on therapeutic drug monitoring.

11. CLINICAL CHEMISTRY RESULTS AND AGING Effects of Nutrition on the Elderly and Chemistry Results
Elderly people are at increased risk for poor nutritional status (e.g., protein-calorie malnutrition) compared with younger adults, as a result of both physiologic and psychological factors, including:
age-related changes in taste and smell;
malabsorption caused by medications
or changes in stomach acidity;
and mobility, disability, depression, and poverty.

12. Low-fiber diets may lead to diverticulitis and colon cancer.
CLINICAL CHEMISTRY RESULTS AND AGING Effects of Nutrition on the Elderly and Chemistry Results
A protein-calorie deficit can lead to decreased resistance to infection and lymphopenia.
Excessive calories result in obesity and the probability of type 2 diabetes.
Deficiencies in vitamins A, C, and E (the antioxidants) may lead to atherosclerosis and an increased risk for cancer.
Low-fiber diets may lead to diverticulitis and colon cancer.
Through nutritional assessment, it may be possible to prevent and identify nutritional deficiencies in elderly people, preventing many chronic diseases of aging and promoting better health