The creatinine-ARM index as alternative for the creatinine-height index in the elderly

P.27

INFLUENCE OF BODY MASS INDEX (BMI)IN ANTHROPOMETRIC FINDINGS CORRELATED WITH CT-SCANS IN SUBJECTS OVER SIXTY YEARSOF AGE. G. Gaggiotti, P. Orlandoni, R. Lanza *, R. Piazzai, G. Boccoli. Department of Surgery and *Department of Radiology, I.N.R.C.A.,Ancona, Italy. The aim of this work is to evaluate the correlation between the values of muscular and adipose areas in the upper limb, which were obtained using classical and computerized findings, in a non-hospitalized population over-sixty and with BMI 430.

A total of 37 subjects, 17 men with a mean age of 69 (range 61-78) and with a mean BMI of 25.7 (range 19.29 - 29.2), and 20 women with a mean age of 69 (range 61-83) and with EM1 of 26.1 (range 20.32 - 29.68) , with no pathology and stable from a nutritional point of view, underwent CT-scans of the non-dominating upper limb, at the same topographical level as the anthropometric findings (Tricipital skinfold and circumference of the arm). The values of the Fatty Areas (FA) and the Muscle Areas (MA) obtained using the anthropometric method (Heymsfield's equations) were compared to those obtained with a computerized calculation of the areas outlined with a lightpen on the CT-scans images; the differences between the two methods were then correlated in percentage with the subject's BMI. The FA values obtained by anthropometry were lower than those obtained by CT-scans'&erage by 32.8% in women and by 28.5% in men; the differences showed a correlation coefficient with BMI of 0.63 in women (p
P.28

THE CREATININE-ARM IN THE ELDERLY.

INDEX

AS ALTERNATIVE

FOR

THE

CREATININE-HEIGHT

INDEX

R.Van HOEYWEGHEN, M.Vandewoude, G.Van Vlasselaer, T.Hartoko, I.De Leeuw, Dept.Geriatrics, Dept.Endocrinology/Nutrition, University of Antwerp, Belgium. Creatinine height index (CHI) is a routine parameter to estimate muscle mass for nutritional assessment. In the elderly patient, however, body length and lean body mass (LBM) are known to be reduced, even in the absence of malnutrition. This makes the calculated CHI less appropriate in the geriatric setting. To evaluate the usefulness of an adapted creatinine arm index (CAI) a complete nutritional profile was determined in a group of healthy, well nourished elderly patients with normal renal function (N = 20, mean age : 78.9 + 7.8yr). There was no statistical difference in wrist circumference TWC) and total arm length (TAL). A very high correlation was observed in the younger adults between TAL and body length (0 : r = 0.94, p < 0.001; r : 0.82; p < 0.001 ). From the regression line and the ideal body weight (IBW) formula, it is p ssible to determine IBW from parameters that are not age-dependent : B = IBW = 2 WC (cm) + 0.88 TAL (cm) - 17.5 = IBW = 2 WC (cm) + 0.98 TAL (cm) - 24.1 % ince LMB is reduced in the healthy elderly the reference value of expected creatinine excretion (23 mg/kg IBW/d for men and 18 mg/kg IBW/d for women) is no longer valid. From the 24-hr urinary creatinine excretion (821 + 344 mg/d) and IBW values a mathematical development shows that the numerical value used to multiply IBW for obtaining the expected daily creatinine excretion is 14 mg/kg IBW/d for men and 9 mg/kg IBW/d for women. We conclude that in the geriatric patient CHI is of limited value and should be replaced by CAI which is much more appropriate to quantify malnutrition independent of age-related changes in length and LBM. 68