The influences of height and age on waist circumference as an index of adiposity in adults

OBJECTIVES: To assess the influences of height and age on the differences in waist circumference between individuals of different stature. SUBJECTS: 3319 males and 4358 females from four studies in the UK and the Netherlands. MEASUREMENTS: Waist circumference, body weight, height, and age. RESULTS: Linear regression analysis of log(10) height as the independent variable on log(10) waist as the dependent variable was used to determine the optimal index powers (OIP) ((P)) to minimize the influence of height in the relationships of waist/height(P). Six out of eight samples of men and women had OIP of height not significantly different from zero, with the remaining two groups had OIP between 0.15-0.58, indicating that height had very limited influence on the differences in waist circumference measurement between individuals. Age adjustment increased the relationship between waist and height, with OIP of 0.19-0.89 in men and 0.02-0.58 in women. Without age adjustment, height explained 0.3-3.5% and 0.1-2.5% variance in waist in men and in women respectively, and the corresponding variances were 0.4-7.5% in men and 0.0-2.6% in women with age adjustment. A similar analysis of weight and height showed the OIP of height in weight/height ratio ranged from 1.32-2.25 in men, and 0.87-1.74 in women without age adjustment, and from 1.47-2.24 in men and 1.25-1.96 in women with age adjustment. CONCLUSION: Height and age had limited influences on the differences in waist between Caucasian subjects of different stature. Waist alone may be used to indicate adiposity or to reflect metabolic risk factors. In contrast, the influence of height on body weight is important.