Total Exchangeable Potassium and Chloride and Total Body Water in Healthy Men of Varying Fat Content

During the past few years various attempts have been made to develop an improved standard of reference for comparison of those parameters of body composition which refer largely to lean body mass. Weir measured carcass chloride in dogs and found poor correlation between carcass chlo- ride and body weight (1). He found, however, better correlation between carcass chloride and fat- free carcass weight (2). Corsa and co-workers (3) pointed out the theoretical desirability of re- lating total exchangeable potassium (Ke) to lean body mass or to a parameter closely related to lean body mass. Cheek and West (4) found that Ke, carcass potassium, Cle, and carcass chloride in rats were closely related to both fat-free carcass weight and to total body water (TBW). Mul- downey, Crooks, and Bluhm (5, 6) measured Ke, Cle, antipyrine space, plasma volume, and red cell mass in adult human beings and compared all these except antipyrine space with lean body mass, derived from antipyrine space, and with creatinine excretion. They found that the correlation of each parameter with the derived lean body mass was significantly better than its correlation with body weight. McMurrey and co-workers (7) meas- ured total exchangeable chloride, potassium, and sodium (Cle, Ke, and Nae), red cell mass, plasma volume, and TBW in a group of ten healthy men and ten healthy women. Their data show much better correlation of these parameters with TBW than with body weight.