Arm anthropometry in a large reference population and in surgical patients.

Triceps skinfold (TSF) and midarm circumference (MAC) were measured and the arm muscle circumference (AMC) calculated in 1860 healthy persons aged between 20 and 101 years and because the distribution of our findings was not Gaussian we have used the 5th and 10th percentiles instead of standard deviation to define limits between severe and moderate malnutrition and between moderate malnutrition and normal. One-way variance analysis showed significant increases in TSF in women from the 3rd (mean 18.3 mm) to the 6th (mean 23.6 mm) decades (p<0.05 - 0.001). No variation was seen in the 6th and 7th decades but thereafter decreases occurred to the 10th (mean 14.4 mm) decade (p<0.05 - 0.001). In men, TSF showed no variation from the 3rd (mean 10.8 mm) to the 9th (mean 10.6 mm) decades but in the 10th (mean 9.4 mm) decade it decreased significantly (p<0.05). In women, AMC increased from the 3rd (mean 21.1 cm) to the 6th (mean 22.1 cm) decades (p<0.05 - 0.001). No variation was seen from the 6th to 8th decades, but thereafter decreases occurred to the 10th (mean 20.2 cm) decade (p<0.05 - 0.001). In men no variation was seen in AMC from the 3rd (mean 26.2 cm) to the 7th (mean 25.9 cm) decades, but decreases were shown to the 10th (mean 23.0 cm) decade (p<0.001). Using these values in 112 surgical patients, 26 per cent showed signs of malnutrition in their fat stores and 6 per cent in muscle. The wide variation in anthropometric measurements between different age groups precludes the use of a mean reference value covering all ages in the assessment of malnutrition.