Abdominal fat depots measured with computed tomography: effects of degree of obesity, sex, and age

Computed tomography scans at the level of L4/L5 were analysed in 66 men and 34 women who presented for routine tomography, stratified into different age categories. Areas of intra-abdominal fat and subcutaneous abdominal fat were calculated from the scans. In men and in women the proportion of the body surface as intra-abdominal fat increased with age (in men from 12.4 per cent in the age group less than 40 years to 18.0 per cent in the age group greater than 65 years; in women from 10.5 per cent to 14.7 per cent in the respective age categories). Only in men this increase with age was independent of the degree of obesity. In women younger than 40 years the proportion of intra-abdominal fat did not increase with increasing BMI while it did in older women and men. The proportion of intra-abdominal fat in 7 adolescents appeared to be 5.4 per cent, considerably lower compared to adult men and women. Subcutaneous fat areas increased with the degree of obesity but not with age. From simple anthropometric measurements, the intra-abdominal fat area was best correlated with the waist circumference in all ages (except for women younger than 40 years) while it showed weaker associations with abdominal skinfolds and circumference ratios. Age and BMI explained 68 and 74 per cent of the variance in intra-abdominal fat area in men and women respectively. Waist added 8 per cent to the explained variance in men but nothing in women. BMI and waist circumference showed similar correlations to total, intra-abdominal and subcutaneous fat areas in all age categories whereas correlations of skinfolds with intra-abdominal fat areas decreased with age.     

Changes in fat-free mass during weight loss measured by bioelectrical impedance and by densitometry

A group of 13 apparently healthy, premenopausal obese women (134-196% ideal weight) volunteered in a weight reduction study for 8 wk on a 4200 kJ (1000 kcal) diet. Before and after the weight reduction period body composition was measured by densitometry and by the bioelectrical impedance method. Changes in fat mass and fat-free mass were calculated. Mean weight loss was 10.0 +/- 2.8 kg and loss of fat-free mass was measured to be 2.3 +/- 1.7 kg (23%) by densitometry and 0.6 +/- 1.9 kg (6%) by impedance measurements. The underestimation of the change in fat-free mass measured by the impedance method could be due to losses of water bound to glycogen after the weight-reduction period. For this reason the impedance method may be not applicable in studies in which changes in glycogen stores can be expected.     

Amyloidosis of heart and liver: comparison of Tc-99m pyrophosphate and Tc-99m methylene diphosphonate for detection

A prospective, comparative study was made of the efficacy of technetium-99m pyrophosphate (Tc PYP) and technetium-99m methylene diphosphonate (Tc MDP) in detecting soft-tissue amyloidosis. Tc PYP and Tc MDP scans were obtained within ten-day intervals in seven patients with histologically proven amyloidosis. Tc PYP was a better scanning agent for soft-tissue amyloidosis in all patients. Cardiac and hepatic involvement were proved by autopsy in one patient. Involvement of the heart was confirmed by echocardiography in five patients. The potential use of Tc PYP scanning as a screening test for soft-tissue amyloidosis is discussed.     

The relation between overweight and subjective health according to age, social class, slimming behavior and smoking habits in Dutch adults

Subjective health status was assessed in relation to overweight by administering a list of 51 health complaints to adult men and women who were either chronically overweight as defined by Body Mass Index (BMI) or not overweight, in a continuous morbidity registration in four general practices during the period 1967-83. Responses were received from 455 men (182 overweight) and 790 women (386 overweight), ages 26-66 years. Response rate (71 per cent) and age distribution (mean age 48) were similar in overweight and non-overweight groups of both sexes. BMI was correlated with the total number of complaints in women (r = 0.15) but not in men (r = 0.07). Multiple regression analysis revealed, however, that age was an effect modifier in this relation, there being a negative association between BMI and subjective health in younger men and a positive association in older men, whereas in women the association between BMI and subjective health was much more pronounced at younger ages than at older ages. In addition, current smoking habits and social class (in men and women) and reported slimming behavior (in women) had an independent relation to the total number of health complaints. BMI was also related to specific complaints and groups of complaints, particularly in women.