Miscellaneous

Peak Flow

Bone Density

Albumin

1

Description
Albumin is a protein that transports many small molecules in the blood (http://adam.about.com/encyclopedia/003480.htm?terms=albumin). As an example, bilirubin, calcium, progesterone, and drugs are often transported via albumin proteins. Albumin is of crucial in the maintenance of oncotic pressure in the blood (http://adam.about.com/encyclopedia/003480.htm?terms=albumin). That is to say, it keeps the fluid from leaking out into the tissues.

Decreased serum albumin may result from liver disease or kidney disease (http://www.labtestsonline.org/understanding/analytes/albumin/test.html). Decreased albumin may also be explained by malnutrition or a low protein diet. Low albumin levels can also be related to inflammation, shock, and malnutrition. High albumin levels usually reflect dehydration (http://www.labtestsonline.org/understanding/analytes/albumin/test.html).

Drugs that can increase albumin measurements include anabolic steroids, androgens, growth hormone, and insulin (http://www.labtestsonline.org/understanding/analytes/albumin/test.html).

Significance of Measurement
Low levels of albumin have been related to heart attack, stroke, functioning loss, and death among older persons (Cohen et al., 1997; Kannel et al., 1987; Kuller et al., 1991, 1996; Mendall et al., 1996; Reuben et al., 2002; Ridker et al., 1997; Tracy et al., 1995, 1997). Data from the MacArthur study have related low levels of albumin to functional decline, death (Reuben et al., 2002; Weaver et al., 2002) and cognitive impairment (Cattin et al., 1997).

Concomitant low serum cholesterol and albumin levels may identify high functioning older persons who are at increased risk of subsequent mortality and functional decline (Reuben et al., 1999).

Method of Measurement
The test requires blood serum. In the MacArthur Study of Successful Aging analysis of allostatic load, low albumin has been included as a risk factor with a cutoff of 3.9 mg/dl or lower considered as high risk (Seeman et al., 2004).

References
· About. (n.d.). Albumin-Serum. Retrieved March 28, 2005, from http://adam.about.com/encyclopedia/003480.htm?terms=albumin
· Cattin, L., Bordin, P., Fonda, M., Adamo, C., Barbone, F., Bovenzi, M., et al. (1997). Factors associated with cognitive impairment among older Italian inpatients. Journal of the American Geriatrics Society, 45, 1124-1130.
· Cohen, H., Pieper, C., Harris, T., Rao, K.M., & Currie, M. (1997). Plasma IL-6: An indicator of functional disability in community dwelling elderly. Journal of Gerontology: Medical Sciences, 52A, M201-M208.
· Kannel, W., Wolf, P., Castelli, W., & D’Agostino, R. (1987). Fibrinogen and risk of cardiovascular disease: The Framingham Study. Journal of American Medical Association, 258, 1183-1186.
· Kuller, L., Eichner, J., Orchard, T., Grandits, G., McCallum, L., & Tracy, R. (1991). The relation between serum albumin levels and risk of coronary heart disease in the Multiple Risk Factor Intervention Trial. American Journal of Epidemiology, 134, 1266-1277.
· Kuller, L., Tracy, R., Shaten, J., & Meilahn, E. (1996). Relation of C-reactive protein and coronary heart disease in the MRFIT nested case-control study. American Journal of Epidemiology, 144, 537-547.
· Lab Tests Online. (2001). Albumin. Retrieved March 28, 2005, from http://www.labtestsonline.org/understanding/analytes/albumin/test.html
· Mendall, M., Patel, P., Ballam, L., Strachan, D., & Northfield, T. (1996). C-reactive protein and its relation to cardiovascular risk factors: A population based cross sectional study. British Medical Journal, 312, 1049-1050.
· Seeman, T.E., Crimmins, E.M., Huang, M.H., Singer, B., Bucur, A., Gruenewald, T., et al. (2004). Cumulative biological risk and socioeconomic differences in mortality: MacArthur Studies of Successful Aging. Social Science and Medicine, 58(10), 1985-1997.
· Reuben, D.B., Chen, A.I., Harris, T., Ferrucci, L., Rowe, J., Tracy, R., & Seeman, T. (2002). Peripheral blood markers of inflammation predict mortality and functional decline in high-functioning community-dwelling older persons. Journal of the American Geriatrics Society, 50, 638-644.
· Reuben, D.B., Ix, J.H., Greendale, G.A., & Seeman, T.E. (1999). The predictive value of combined hypoalbuminemia and hypocholesterolemia in high functioning community-dwelling older persons: MacArthur Studies of Successful Aging. Journal of the American Geriatrics Society, 47(11), 1386-1387.
· Ridker, P.M., Cushman, M., Stampfer, M.J. Tracy, R.P., & Hennekens, C.H. (1997). Inflammation, aspirin, and the risk of cardiovascular disease in apparently healthy men. New England Journal of Medicine, 336, 973-979.
· Tracy, R., Bovill, E., Yanez, D., Psaty, B., Fried, L., Heiss, G., et al. (1995). Fibrinogen and factor VIII, but not fact VII, are associated with measures of subclinical cardiovascular disease in the elderly: Results from the Cardiovascular Health Study. Arteriosclerosis, Thrombosis and Vascular Biology, 15, 1269-1279.
· Tracy, R., Lemaitre, R., Psaty, B., Ives, D., Evans, R., Cushman, M., et al. (1997). Relationship of C-reactive protein to risk of cardiovascular disease in the elderly: Results from the Cardiovascular Health Study and the Rural Health Promotion Project. Arteriosclerosis, Thrombosis and Vascular Biology, 17, 1121-1127.

Iron

Homocysteine

1

Description
Homocysteine is an amino acid measured in plasma that is related to a higher risk of coronary heart disease, stroke and peripheral vascular disease (http://www.americanheart.org/presenter.jhtml?identifier=535). Homocysteine may have an effect on atherosclerosis by damaging the inner lining of arteries and promoting blood clots.

Approximately one third of those older than 65 years have elevated homocysteine levels (>14 mol/L) (Selhub et al., 1993). Although the prevalence may have declined since dietary fortification with folate began in 1996 (Jacques et al, 1999; Crimmins et al., forthcoming). Homocysteine levels are related to vitamin intake particularly B6 and B12 (Mudd et al., 1985; Jacques et al., 1999). Because of this evidence, several randomized trials are under way to test whether vitamin supplementation decreases cardiovascular events (Hankey and Eikelboom, 1999).

Significance of Measurement
Homocysteine has garnered recent attention because of its importance in predicting many of the major health outcomes common in aging populations such as cardiovascular disease, peripheral vascular disease, and poorer cognitive function (Arnesen et al., 1995; Jacques and Riggs, 1995; Riggs et al., 1996; Verhoef et al., 1996).

Experimental evidence suggests that elevated plasma homocysteine levels may cause toxicity by a variety of mechanisms, including oxidative damage, which has been linked to an increased rate of aging (Loscalzo, 1996; Hensley and. Floyd, 2002).

Methods of Measurement
The method used by the laboratory at Quest Diagnostics requires 1 mL (0.2 mL minimum) room temperature serum, heparin plasma, or EDTA plasma. A >8-hour fast prior to sample collection is recommended.

Homocysteine levels increase ~10% for every hour the serum/plasma is not separated from the red blood cells using a centrifuge at room temperature. Once separated, serum/plasma is stable for: 4-7 days at room temperature; 2 weeks at 2-8C; and several years at -20C (http://www.questdiagnostics.com/hcp/intguide/jsp/showintguidepage.jsp?fn=TS_Homocysteine.htm)

References
· American Heart Association. (2005). What is homocysteine? Retrieved March 28, 2005, from http://www.americanheart.org/presenter.jhtml?identifier=535
· Arnesen, E., Refsum, H., Bonaa, K.H., Ueland, P.M., Forde, O.H., & Bnordrehaug, J.E. (1995). Serum total homocysteine and coronary heart disease. International Journal of Epidemiology, 24(4), 704-409.
· Crimmins, E., Alley, D., Reynolds, S., Johnston, M., Karlamangla, A., & Seeman, T. Changes in biological markers of health: Older Americans in the 1990s. Journal of Gerontology: Medical Sciences, forthcoming.
· Hankey, G.J., & Eikelboom, J.W. (1999). Homocysteine and vascular disease. Lancet, 354, 407–413.
· Hensley, K., & Floyd, R.A. (2002). Reactive oxygen species and protein oxidation in aging: A look back, a look ahead. Archives of Biochemistry and Biophysics, 397, 377–383.
· Jacques, P., & Riggs, K. (1995). Vitamins as risk factors for age-related diseases. In I.H. Rosenberg (Ed.), Nutritional Assessment of Elderly Population: Measure and Function. New York: Raven Press.
· Jacques, P.F., Selhub, J., Bostom, A.G., Wilson, P.W.F., & Rosenberg, I.H. (1999). The effect of folic acid fortification on plasma folate and total homocysteine concentrations. The New England Journal of Medicine, 340, 1449–1454.
· Loscalzo, J. (1996). The oxidant stress of hyperhomocysteinemia. Journal of Clinical Investigation, 98, 5–7.
· Mudd, S.H., Mudd, F., Skovby, H.L., Pettigrew, K.D., Wilcken, B., Pyeritz, R.E., et al. (1985). The natural history of homocystinuria due to cystathionine beta-synthase deficiency. American Journal of Human Genetics, 37, 1–31.
· Questdiagnostics. (2002). Homocysteine: Test summary. Retrieved March 28, 2005, from http://www.questdiagnostics.com/hcp/intguide/jsp/showintguidepage.jsp?fn=TS_Homocysteine.htm
· Riggs, K.M., Spiro, A., Tucker, K., & Rush, D. (1996). Relations of vitamin B-12, vitamin B-6, folate and homocysteine to cognitive performance in the Normative Aging Study. American Journal of Clinical Nutrition, 63, 306-314.
· Selhub, J., Jacques, P.F., Wilson, P.W., Rush, D., & Rosenberg, I.H. (1993). Vitamin status and intake as primary determinants of homocysteinemia in an elderly population. Journal of the American Medical Association, 270, 2693–2698.
· Verhoef, P., Stampfer, M., Buring, J., Gaziano, J., Allen, R., Stabler, S., et al. (1996). Homocysteine metabolism and risk of myocardial infarction: Relation with vitamins B6, B12, and folate. American Journal of Epidemiology, 143, 845-859.

Sodium

Potassium

Vitamins / Antioxidants

Oxidative Stress

IGF-1