De Lorenzo A, Andreoli A, Battisti P, Candeloro N, Volpe S L, Di Daniele N
Human Nutrition Unit, Via Montpellier 1, University of Rome Tor Vergata, 00173 Rome, Italy.
Ann Hum Biol. 2004 Jul-Aug;31(4):381-8. doi: 10.1080/03014460410001703718.
Whole-body (40)K counting is a valuable tool for assessing cellular changes in body composition with ageing.
The objectives of this study were to assess total body potassium (TBK) and body cell mass (BCM) differences with age, and to compare TBK and BCM between individuals with a body mass index (BMI) < 25 kg m(-2) versus > 25 kg m(-2).
Body composition of 840 healthy Italian men, 18-70 years of age, was measured by whole-body counting of (40)K. BCM (kg) was calculated as 0.00833 x TBK (mmol).
Body weight did not differ among groups. TBK, TBK/height, TBK/body weight, and BCM were significantly lower for the 51-70-year-old group compared with all other groups. The 51-70-year-old group with a BMI < 25 kg m(-2) had significantly lower TBK, TBK/height, and BCM than all other decades with a BMI < 25 kg m(-2); whereas TBK/body weight was significantly lower than the 18-30 and 31-40-year-old groups. The 51-70-year-old group with a BMI > 25 kg m(-2) had significantly lower TBK, TBK/height, TBK/body weight, and BCM than all other decades with a BMI > 25 kg m(-2).
TBK and BCM decrease significantly with ageing, which could result in decreased functional capacity in older adults.
全身（40）K计数是评估随着年龄增长身体成分细胞变化的一项重要工具。
本研究的目的是评估不同年龄组的全身钾（TBK）和身体细胞质量（BCM）差异，并比较体重指数（BMI）<25 kg m(-2)与>25 kg m(-2)的个体之间的TBK和BCM。
采用全身（40）K计数法测量了840名年龄在18 - 70岁的健康意大利男性的身体成分。BCM（kg）的计算方法为0.00833×TBK（mmol）。
各年龄组间体重无差异。与所有其他组相比，51 - 70岁组的TBK、TBK/身高、TBK/体重和BCM显著降低。BMI<25 kg m(-2)的51 - 70岁组的TBK、TBK/身高和BCM显著低于BMI<25 kg m(-2)的所有其他年龄段组；而TBK/体重显著低于18 - 30岁和31 - 40岁组。BMI>25 kg m(-2)的51 - 70岁组的TBK、TBK/身高、TBK/体重和BCM显著低于BMI>25 kg m(-2)的所有其他年龄段组。
TBK和BCM随年龄增长显著下降，这可能导致老年人功能能力下降。
