J. Fastbom et al., LEVELS OF SERUM CREATININE AND ESTIMATED CREATININE CLEARANCE OVER THE AGE OF 75 - A STUDY OF AN ELDERLY SWEDISH POPULATION, Archives of gerontology and geriatrics, 23(2), 1996, pp. 179-188
Serum creatinine was measured and creatinine clearance estimated using
the Cockcroft-Gault (C-G) formula, in elderly people participating in
a population study of the elderly, the Kungsholmen Project. This is a
n ongoing longitudinal study which was begun in 1987 and comprised all
people in a district of Stockholm, born in 1912 or earlier. Out of 23
68 people 1810 participated. In 1362 cases, serum creatinine and an es
timation of the creatinine clearance could be obtained. The mean age o
f these elderly people was 81 years, and 92% were living in their own
homes. A linear regression model showed that the weight of the elderly
decreased by age, indicating a decrease in muscle mass. However, this
was not accompanied by a decrease in serum creatinine levels. When cr
eatinine clearance was estimated using the C-G formula, a significant
decline with age was seen at an average rate of 1.2 ml/min per year. I
t declined from 52 ml/min at age 75 to 27 ml/min at age 95. The mean f
or the whole study group was 44.6 ml/min. Our data suggest that the gl
omerular filtration rate may be very low in the oldest old and that th
ere is a continuing decline with increasing age, even in a population
where a high number of the elderly are still living in their own homes
. Furthermore, the lack of major changes in serum creatinine levels wi
th age supports the idea that this parameter is not a reliable measure
of renal function in the elderly.