Aging in women—the four-compartment model of body composition

• Published in: Metabolism, clinical and experimental Vol. 45; no. 1; pp. 43 - 48
• Main Authors: Aloia, John F., Vaswani, Ashok, Ma, Ruimei, Flaster, Edith
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 1996; Elsevier
• Subjects: Absorptiometry, Photon; Adult; Aged; Aged, 80 and over; Aging; Aging - physiology; analysis; Biological and medical sciences; Body Composition; Body Composition - physiology; Body Mass Index; Body Water; calcium; Calcium - analysis; carbon; Carbon - analysis; Cross-Sectional Studies; Female; Fundamental and applied biological sciences. Psychology; General aspects. Body compartment; Humans; Linear Models; Metabolisms and neurohumoral controls; Middle Aged; Models, Biological; Multivariate Analysis; nitrogen; Nitrogen - analysis; physiology; Sex Characteristics; Vertebrates: anatomy and physiology, studies on body, several organs or systems; women; Water; Human; Measurement; Radiodiagnosis; Inorganic element; Statistical study; Body composition; Proteins; Absorption spectrometry; Female; Body compartment; Fat body; Densitometry; Age
• ISSN: 0026-0495; 1532-8600
• DOI: 10.1016/S0026-0495(96)90198-5

The four-compartment model of body composition was examined in 155 white women through measurement of total body carbon (TBC), nitrogen (TBN), calcium (TBCa), and water levels. The age (mean ± SD) of the population was 51.4 ± 13.5 years, and values for the four compartments were as follows (in kilograms): protein 8.9 ± 1.0, water 30.9 ± 3.5, mineral 2.6 ± 0.4, and fat 22.6 ± 7.3. There was a linear change with age for protein and water, whereas mineral and fat were curvilinear. These latter two compartments also showed differences in premenopausal and postmenopausal rates of change. Various models were fit to the data to adjust for body size and age. Each of the four compartments (mineral, water, fat, and protein) changed with age, with fat increasing and the other compartments declining. The equation, y = age + age 2 + height + weight, fit the data as well as the other models. Equations are provided to assess body composition in populations with disorders of nutrition, as well as other illnesses, using height, weight, and age as covariates. Since this was a cross-sectional study, longitudinal studies will have to be performed to confirm the accuracy of rates of change with age predicted with each compartment.